science teacher 2011 Featuring: Future focus Science education like wrestling with octopus Innovative pedagogies Microfluids have huge potential Data deluge and polymath Can maths glimpse future? Food and obesity Advancing evolution by convergence Towards $1000 genome Bio-nano interface Origin of Polynesians Primary science And more...
Number 126
ISSN 0110-7801
THE SCIENCE LEARNING HUB
www.sciencelearn.org.nz Explore the Science Learning Hub to find a wealth of resources for year 5–10 teachers including contemporary science stories, feature articles, people profiles, images, animations and video clips that showcase New Zealand’s world class science sector.
w w w . b i o t e c h l e a r n . o r g . n z Discover the processes, people, organisations and stories of our biotechnology sector through the Biotechnology Learning Hub - developed especially for New Zealand’s teachers.
NZ
science teacher
contents
126
Editorial Advisory Group: Rosemary Hipkins, Chris Joyce, Suzanne Boniface, Beverley Cooper, Miles Barker and Anne Hume Editorial Address: lyn.nikoloff@xtra.co.nz
Editorial 2 From the President’s desk 3
contents
NZST PublicationTeam: Editor: Lyn Nikoloff, Bijoux Publishing Ltd, Palmerston North Sub editor: Teresa Connor Typesetting and Cover Design: Pip’s Pre-Press Services, Palmerston North Printing: K&M Print, Palmerston North Distribution: NZ Association of Science Educators
Feature: Future Focus Data deluge needs a modern polymath 4 Can maths help us glimpse the future? 6 The disruptively changing face of ICT 8
NZASE National Executive: President: Lindsey Conner Senior Vice-President: Jenny Pollock Treasurer/Web Manager: Robert Shaw Primary Science: Chris Astall Auckland Science Teachers: Carolyn Haslam Publications: Matt Balm
Nanoparticles, health and bio-nano interface 10 A conversation about nanotechnology 12 Future foods: sustainability and obesity 13
Mailing Address and Subscription Inquiries: NZASE PO Box 30069 Lower Hutt 5040 Tel: 03 546 6022, Fax: 03 546 6020 email: janh2@attglobal.net NZASE Subscriptions (2011) School description Secondary school
Roll numbers Subscription > 500 $240.00 < 500 $185.00 Area School - to be determined TBA Intermediate, middle and > 600 $240.00 composite schools 150-599 $90.00 < 150 $65.00 Primary/contributing schools > 150 $90.00 < 150 $70.00 Tertiary Education Organisations $240.00 Libraries $110.00 Individuals $50.00 Student teachers $45.00 Special Interest Group (includes access to secure sites): BEANZ, NZIC, STANZ, SCIPED $10 per group Note: SIG fees are included all subscriptions except for individual members. Additional copies of the NZ Science Teacher Journal $32.06 per year for three issues Subscription includes membership and one copy of NZST per issue (i.e. three copies a year). All prices are inclusive of GST. Advertising: Advertising rates are available on request from nzst@nzase.org.nz Deadlines for articles and advertising: Issue 127 - Model IT April 20 (publication date: 1 June) Issue 128 - (Bio) Diversity August 20 (publication date: 1 October) NZST welcomes contributions for each journal but the Editor reserves the right to publish articles it receives. Please contact the Editor before submitting unsolicited articles: nzst@nzase.org.nz Disclaimer: The New Zealand Science Teacher is the journal of the NZASE and aims to promote the teaching of science, and foster communication between teachers, scientists, consultants and other science educators. Opinions expressed in this publication are those of the various authors, and do not necessarily represent those of the Editor, Editorial Advisory Group or the NZASE. Websites referred to in this publication are not necessarily endorsed.
Future food 15 Advancing evolution by convergence 17 Towards the $1000 genome 19 Taiwan and the origin of Polynesians 21 HPS: future trends 24 Microfluids have huge potential 26 Education research School science is like wrestling with an octopus 29 Innovative pedagogies 31 Nature of science and the NZC 33 Supporting science education 38 Primary science Mr Science – part 1 40 Harry Potter: science and spells 41 The nature of science in action 43 Subject associations Biology 44 Chemistry 45 Physics 46 ESSE 47 Technicians 48 Resources Book Review 46
Front cover: Microfluidics (see page 26). Photograph courtesy of Mathieu Sellier and Volker Nock, cover design by Antony Radley.
New Zealand Association of Science Educators
1
NZ
science teacher
editorial
126
2
and now to the future! In the early 1990s I cut my IT teeth grappling with the vagaries of WordPerfect; but for all the technological capability of the program I was still dependent on a cardboard strip attached to my ‘F’ keys to remind me of their functions. So I was very excited to upgrade my Operating System in 1995 to Windows and I also added a laser printer to the suite. I thought I had made it to IT heaven! About the same time cell phones became readily available (and affordable), I couldn’t imagine why I needed one and most certainly never envisioned that within fifteen years my PC, printer and cell phone would be an integrated system. Not so many years ago I was busy confiscating cell phones from students who were using them in the classroom. Now schools and teachers are using text messaging to routinely contact students and caregivers. A local state secondary school here in Palmerston North has mooted the idea that all students must have a laptop by 2012. They are after all, only following a nationwide trend. Yet it wasn’t so many years ago that schools had computer labs where students learnt the rudiments of keyboarding. Today, in less than five years, these skill-based courses and computer rooms are redundant thanks to the affordability of laptops. And ICT is also transforming the way we think about and do science (p.8). So as technology changes the way we engage our students, educators must also consider some innovative pedagogies (p.30), and with recent changes to the NZC, science educators must better understand the 14 underpinning ideas of the Nature of Science strand (p.32). As this issue has a future focus theme it seems appropriate that we feature an article that looks at the future of science education, a must read for all science educators (p.29). Also read about a great new science assessment resource from the NZCER (p. 38). And to assist primary educators develop contexts for their science programmes, in this issue we have articles about using the Harry Potter films, Mr Science (p.40), and the Nature of Science in action (p.43). Practical work is necessary in all science programmes, but can be time-consuming and costly to set up, and this is exacerbated by the move towards enquiry learning in achievement standards (p.48). So teachers and technicians are ever on the lookout for practical tips. In this issue we have a cheap toy for kinetic theory (p.46), ideas for using rhubarb for rates of reaction (p.45), how to use the ocean as a context (p.47), also information about Biolive 2011 (p.44). Yet how do we prepare science students for tomorrow with today’s technology and paradigms? To begin with, we must better understand how current scientific researchers foresee the future. In this issue we have brought together a series of essays written by some key science and education thinkers and whose ideas impact on your students’ future. While the pace of technological change is creating a data deluge requiring modern polymaths (p.4), it is also enabling
New Zealand Association of Science Educators
the modelling of ecosystems to better predict which species will become extinct (p.6), and getting scientists ever closer to the Holy Grail of evolution – watching it happen (p.17). And did you know that the $1000 genome is almost within reach (p.19)? And that DNA analysis is re-evaluating Polynesian migration in Oceania (p.21)? Did you know that currently there are 1000 projects involving nanotechnology? John Watt predicts that its use will begin to raise issues at the bio-nano interface (p.10). So with this in mind, we invited Rose Hipkins to have a conversation with John about how teachers can use nanotechnology as a context (p.12). The future of food is one area that is of great concern to us all in terms of sustainability and obesity (p.13), so what are some future foods? Broccoli (p.15). Microfluidics is at the leading edge of science and engineering (p.25) – think ink-jet printers – and it is certainly an area where many of today’s students will find future work at both application and research levels. While we may be unable to see clearly tomorrow’s science from today’s cliff tops, we must nonetheless never lose a clear understanding of what science is (p.23). So what do our science students need to know for the future? And if the future is yet to be created, how do we prepare them using today’s paradigms and technologies? The answer could be to simply encourage them, and yourself, to be adaptable, creative and use critical thinking and be open to possibility. And I think this has huge implications for science teachers and students, and curriculum writers. I recall 20 years ago sitting in a PD session with Bill McIntyre who dared to suggest that in the future science teachers would be facilitators – how right he was! For me there is one clear thesis emerging from this issue of the NZST: scientists of tomorrow must have a fundamental grounding in mathematics and have a vast general knowledge to analyse the data deluge. And that is your challenge as science educators. I conclude by proffering my prediction for 2011: by December 2011 you will be using and integrating currently unknown (to you) technological applications into your daily life and work. And you might like to consider as the year unfolds how these changes impact on the future focus of science. I would like to thank all the contributors who gave generously of their expertise and time to ensure that our readers could gain an insight into the future of science and education. Your support is much appreciated. Thank you! To our readers, I commend to you this issue of the NZST and encourage you to share its content with your colleagues. I wish you all a year ahead that is technologically innovative. Kind regards
Lyn Nikoloff
NZ
science teacher
Looking ahead to 2011 with the Primary Science Week (2-7 May) this year, where you’ll have the opportunity to participate in various venues around the country. Secondary teachers may also like to take these events up as opportunities to connect with and support their primary colleagues. In secondary schools, there is still a need for teachers to find the balance between designing a teaching and learning programme to best suit the students’ needs and the demands of NCEA assessments. In 2011 the new Level 1 standards will be implemented. Some of these are familiar but some, especially the new internally assessed standards that incorporate aspects of the Nature of Science are not. It is of concern that, at the end of 2010, the support material for the internally assessed standards is variable. Designing an assessment programme for less able students in the senior school is a big issue with the loss of the 189xx series of Unit Standards as assessment tools. A team of NZASE members is writing tasks for the new Level 1 standards that will be available from the beginning of 2011 to NZASE members through our website. These tasks will pass moderation and can be used by all students. We have secured a new contract with the Ministry of Education for administering the animal ethics procedures for student projects. This service is available to students in schools which are members of NZASE. As an organisation we are continually reviewing the way we operate within our budget, and have moved to posting news’ items regularly on the website rather than sending paper newsletters. There have been many other enhancements to our website, particularly in the way members of standing committees (STANZ, NZAPSE, BEANZ, Chemistry Group, Earth and Space Science Group) can edit and add items to their own pages. We are hoping that more regional associations will make use of the NZASE website to share and advertise their activities. We have also trimmed our administration and would like to thank Conferences and Events for all their support over the last three years or so. We have also appointed a new administrator and delegated other tasks to new members of the executive team, who have taken on enormous tasks, all on a voluntary basis. They work very hard on your behalf and I would like to thank them publically for their efforts to maintain our Association. Noho ora mai Lindsey Conner President NZASE
fromthepresident
Welcome to the first issue of NZST for 2011. The focus of this issue on science for the future is timely, given the changes occurring at all levels of schooling in terms of the New Zealand Curriculum implementation, and the outcomes of the recent TIMSS study (Trends in International Mathematics and Science Study). Science and technology education seem to be taking a higher priority at ministerial levels with the realisation that we need to build capability and capacity in the sciences to support the long-term economic growth of New Zealand. For many of you, revamping units of work and inserting new ‘thinking’ or literacy and numeracy-based activities may be your focus for implementing the new curriculum. The Nature of Science strand is becoming more obvious in school schemes as we all grapple with the possibilities for how we can make the various aspects of the Nature of Science clearer and upfront for students. There will be many initiatives coming to fruition this year to support teachers in implementing the new curriculum. For example, the Teaching and Learning Guide for science curriculum Levels 6-8 will be released soon. We have just posted a notice on our website about how you can provide feedback on the draft document. It promises to indicate key concepts, indicators and contexts for the different Achievement Objectives. There also seems to be a resurgence of resources to support science, especially in the digital cloud. It would be great if members could design activities that use these, try them out with students and then tell us about how it went either as a future article in our teaching and learning pages in this magazine or through our revamped website: www.nzase. org.nz. We would like to encourage you to submit articles to NZST on new teaching and learning activities so that other teachers can take advantage of your creative talents. Our long-term goal for the magazine is for it to be sought after internationally. NZASE is promoting and actively contributing to initiatives related to the implementation of the new curriculum through liaising with the Ministry of Education, professional development providers and developers of teacher refresher courses and resources. We are also proud to support initiatives such as the Royal Society’s Advancing Primary Science and those of our own primary science standing committee, which has recently become the New Zealand Association of Primary Science Educators. Watch out for notices and events associated
126
Read the latest NZASE news online today! The NZASE website now has regular postings of the latest news, information and happenings. Members are encouraged to regularly visit the website. Also check out your subject association.
Visit www.nzase.org.nz today!
New Zealand Association of Science Educators
3
NZ
science teacher
futurefocus–datadeluge
126
data deluge needs a modern polymath Ever wondered where your science students will be working in the future and what skills they will need? They will be a modern polymath, as Vic Arcus, from the University of Waikato, explains: This article has been adapted from a talk given at The Runninghot! Conference held at Te Papa in November 2010 (http://www.runninghot.org.nz/). The by-line for the Conference was “Wonder and Widgets: realising the value of research for New Zealand”. The talk was given in the final session whose theme was “The future of research”. Here are three separate ideas that, when considered together, I find both scary and exciting. It’s a circus trick with three plates spinning on poles. Normally the circus juggler would place a dozen spinning plates up on poles and frantically race around each one to keep them all continuously spinning and upright. And the suspense of the trick is that at any moment, they may all come crashing down. I will stick with just three plates and hopefully they remain aloft throughout.
The data deluge The first spinning plate to go up on a pole is the notion of ‘the data deluge’. This phrase appeared on the cover of The Economist at the beginning of 2010. Inside the magazine, they talked about the economic potential of the vast amounts of data that are openly available and just waiting to be tapped and exploited by clever people with innovative ideas. The volume and breadth of these data that are freely available are enormous. For an example of the array of different things that you can do with these data, try visiting WolframAlpha at: http://www.wolframalpha.com/
Role for the modern polymath The second spinning plate to go up on a pole is ‘a role for the modern polymath’. When I was discussing this with my wife, my 12-year-old son asked if a polymath was a bit like a polygon. This is true − a polymath is someone with many sides. A square is a polygon and it used to be said that it was “hip to be square”, but I’m thinking more in the realms of dodecahedrons when it comes to different facets of knowledge. Thus, for the purposes of this article, a polymath is someone who knows a lot about a lot of different things. This is in contrast to the specialist, who is someone who knows almost everything about one particular thing. The ultimate polymath is someone who knows everything! There is some disagreement about the last person to know everything. Was it Thomas Young or Francis Bacon? What is not in contention is that these scholars lived in the 17th and 18th centuries. So the last person to know everything lived over 250 years ago, and the idea that one person can have a detailed knowledge of most domains of modern thought today is patently ridiculous. Thus, we have the data deluge…I’ll give that plate a spin… and the idea of a polymath…spin that plate as well. Now, for the third plate…the power of exponential growth.
Power of exponential growth Here is an old example to illustrate the difference between exponential growth and incremental growth − this is my get-rich-quick scheme. First, find an unsuspecting capitalist from whom you don’t mind taking money. Capitalists aspire to incremental growth. They don’t really understand exponential growth. They understand compound interest, which has an 4
New Zealand Association of Science Educators
exponential component, but the exponents are very small and so don’t amount to much. Second, appeal to your capitalist’s aversion to collective bargaining and say that you are prepared to work for substantially less than the minimum wage. And then say that you will work hard for him for thirty days (we’ll assume that your strident capitalist is male). Propose that on the first day, he need only pay you one cent. On the second day he needs to pay you 2 cents. On the third, 4 cents and so on. He will quickly do the sums in his head for the first week (1c + 2c + 4c + 8c + 16c = 31c for the first week) and more than likely say, “Yep, you have a deal.” But the power of exponential growth will mean that on the thirtieth day, he will have to pay you $5.37 million dollars! Compare this to incremental growth. If you said that you wanted to be paid the minimum wage ($12.50 per hour) and you wanted to add $1.25 to your hourly rate every day (10%, non-compounding), your capitalist friend will say, “No way, that’s a ludicrous demand.” But this is a much better deal compared to the one above because on the thirtieth day you’re going to be paid $48.75 per hour, which is just $390 for the day − 1200 times less than the exponential scheme! The divergence between exponential growth and incremental growth gets bigger and bigger as well. Imagine that you worked for a further two days to finish the job. Under the exponential scheme, the first extra day would net you $10.74 million, and the second extra day would give you $21.47 million. Compare that to $410 for the second day under the other scheme − now you’re earning 52,000 times more after just two days. Now I have my three ideas − my three spinning plates: the data deluge, the modern polymath, and exponential growth − and I want to tell the stories of three of my PhD students to bring these ideas together in a scientific context.
Research examples The first PhD student is an experimental biochemist, Jo M. She has spent four years studying three proteins from two different organisms. The reason that we are interested in these proteins is that we think they are important in the biology of a bacterium called Mycobacterium tuberculosis. This causes tuberculosis (TB) in humans and is responsible for more deaths globally than any other infectious disease (including HIV). TB kills approximately 3 million people per year. The proteins that we study each have their own inhibitors. Four years, three proteins, two inhibitors (one inhibitor we couldn’t purify) and two different organisms. This is incremental scientific investigation. Jo and I have spent four years trying to understand the biological roles of three tuberculosis proteins. The second PhD student is a protein crystallographer, Marisa. Recently, Marisa took her protein crystals to the Australian synchrotron to collect diffraction data. Before she left, she and I went down to Dick Smith’s and bought a 1 terabyte hard drive for $118! That’s 1,000 gigabytes at a cost of just 12 cents a gigabyte! In the course of her two-day trip to the synchrotron, Marisa collected just over 600 gigabytes of data. The third PhD student is interested in the genomes of different strains of Mycobacterium tuberculosis from people with TB. She is going to sequence the genomes of six strains of tuberculosis. That will be 24,000,000 base pairs of DNA.
NZ
science teacher 126
futurefocus–datadeluge
Figure 1: Vic Arcus (back row: third from left) and his research group including Jo (front row: third from right) and Marissa (front row: at right). And she will collect these data in one sequencing run on a new DNA sequencing machine in New York in about 80 minutes. In fact, the latest sequencing machines will be able to produce 3 billion bases every hour. It now costs just $5,000 to sequence the entire genome of a human. These last two examples are examples of the exponential growth of data collection. Thus, in our lab, we have arrived hard up against the ever-widening gap between our ability to collect data (increasing roughly exponentially) and our ability to understand these data (increasing roughly incrementally). How is it possible that we can sequence the entire genomes of several strains of tuberculosis in an afternoon (these genomes encode ~24,000 proteins) and yet it takes over 4 years of intensive research to understand the role of just three of these proteins?
Where to from here? The Economist estimates that humans created 150 exabytes of data in 2005 and in 2010, 1,200 exabytes of data will be produced. What is an exabyte? The prefixes go: kilo, mega, giga, tera, peta, exa. Hence, an exabyte is a billion gigabytes. It just gets easier to think of the number of zeros after the 1. An exabyte has a 1 with 18 zeros after it. Moore’s law has uncannily predicted that computer speed approximately doubles every two years. There was one transistor in a computer in 1965. Now there are the equivalent of 2,000 million transistors in a laptop computer. There is a similar exponential function for data storage. But the analysis of the data and finding the underlying meaning in the data is a much slower process. I can’t find any empirical evidence about how fast this might grow. But at least from my own personal experience and that of my research group, it’s going at about the same pace or slightly faster each year. If we assume that the exponential growth of our ability to collect data continues and our laboratory experiments can only progress at an incrementally increasing pace, then consider the situation in 20 years time. There will be
a mammoth divergence between the amount of data that we can collect and store and our ability to understand it. I think that this will mean that science and research will be a fundamentally different pursuit in 20 years. There will be a revolution in the way we approach the scientific method. In 20 years’ time, the global population will be approximately 8 billion people. It is quite within the realms of possibility that I might sequence the genomes of a significant proportion of these people. Let’s say 10% of the population, 800 million people. This will give me 2.4 exabytes of genomic data. What are we going to do with these data? What scientific approach will we use to extract meaning from this vast array of data? What will governments do with these data? What will insurance companies do with these data?! Firstly, we’re going to need lots of hyper-specialists to deal with the data and analyse different aspects. But possibly more importantly, we’re going to need many polymaths to see into the implications of these data. People who understand migration, genetics, epidemiology, politics, Marxism, capitalism, history, psychology, economics and statistics. It will be the polymaths who can see the important implications hidden in these data and the potential consequences of our newfound knowledge. John Maynard Smith − the famous evolutionary biologist − wrote an influential book called “The Major Transitions in Evolution” for life on Earth over the last 3.5 billion years. He predicted that the next major transition in evolution will be the integration of digital data, computational data, with humans. I was sceptical when I heard him say this 10 years ago. But now I’m inclined to believe him. Is it possible that the next revolution in research will also be a major transition in evolution? That is quite scary, but also amazing. Are my three plates still spinning? For further information contact: varcus@waikato.ac.nz
New Zealand Association of Science Educators
5
NZ
science teacher
futurefocus–predictingthefuture
126
can maths help us glimpse the future? Why is prediction of some natural phenomena easy and others hard? Professor Mike Steel, Director of the Biomathematics Research Centre at the University of Canterbury, explains: Consult a tide chart or astronomy website, and it seems that predicting far into the future can be simple. It is easy to tell if it will be high tide at my local beach in two years from today, or whether or not there will be a solar eclipse on 8 April in 2024. So why can’t someone tell us if it will rain for a picnic in two weeks from now? Or whether there would be a magnitude 6.0+ aftershock in the week following the Canterbury earthquake? In other words, why is it that we can predict very accurately far into the future for some phenomena, yet the best computers in the world struggle to tell us about other events only a few days ahead? There are several reasons. Firstly, describing, say, the orbit of planets requires specifying only a few variables (speed, position etc.), while describing the weather or predicting an earthquake requires specifying a huge number – there are still only a few basic quantities, but we need to measure them at a huge number of locations (e.g. for weather, the air pressure, humidity etc. at all places on the surface of the Earth). Secondly, some dynamical systems are highly sensitive to errors in measurements of variables – any variation can balloon rapidly with time. This has more to do with the mathematic form of the equations than the number of equations and variables (Lorenz’s famous ‘chaotic’ system has just three of each). Thus, with complex processes, we face a ‘double hit’: not only do we need to measure an infinite number of variables, but we need to measure them all with great accuracy. Since we can’t measure an infinity of variables, we make do with a finite number of them – but even measured with infinite precision this ‘discretization’ of the process usually behaves differently, in the long-term, to the original continuous one. Other obstacles to predicting the future of complex systems include that they are often not truly closed systems but influenced by external events. Computational limitations are also a factor. One way forward is to use random models to estimate the probabilities of coarse events (e.g. an earthquake of magnitude 7.5 or higher in NZ in the next 100 years) without specifying the fine details (i.e. exactly where or when the earthquake will occur). For some processes, like weather, we have a good measure of predictive accuracy – each week provides a test. But more unique and far-off predictions, such as the impact of human activity in causing climate change, or the timing and magnitude of the next ‘flu pandemic are much harder to test due to statistical fluctuations and model uncertainty – more about this shortly.
Mathematical aspects of prediction A fundamental tenant of science is that the past influences the future only via the present. That is, if X(t) is a complete description of the state of a closed physical system at time t, and t1 < t2 < t3 then X(t1) tells us nothing more about X(t3) than X(t2) does. This principle of ‘no action at a temporal distance’ underlies both classical science (where X(t) is completely determined by X(t’) for t’ < t) and quantum theory. However, even in classical science it is usually impossible or impractical to deal with a complete description of a 6
New Zealand Association of Science Educators
closed physical system, so we resort to a coarse ‘lumping’ of micro-states into macro-states. In other words, we deal with a derived process Y(t) = f(X(t)) here f is a many-to-one function from micro-states to macro-states. In genetics, for instance, the micro-states might correspond to the alleles at a genetic locus (or several loci), while the macro-states might correspond to the less informative phenotype (blue eyes or brown etc.). Now in contrast to X(t) the lumped process Y(t) can exhibit ‘temporal action at a distance’, for example, the phenotype of grandparents can provide additional clues to the likely phenotype of a child than what the parents’ phenotypes tell us. Moreover, even though X(t) is totally determined by any earlier value of the process, as in classical physics, the lumped process Y(t) need not, since it depends on which micro-state we were in at the earlier value. It is usual to model this by regarding Y(t) is a random process, and the assumption of no ‘action at a temporal distance’ is often accurate (though one can always find exceptions, as we indicated above). Mathematically, we can express this assumption by saying that the probability that Y takes a certain value y at any time s in the future from now (time t), conditional on all of the past history up to time t is the same as if we just condition on the state we are in at time t. Or, more succinctly: Pr(Y(t + s) = y | Y(t’) : t’< t) = Pr(Y(t + s) = y | Y(t)) Such processes are called ‘Markovian’ and they pervade almost every corner of science. What can we say about such processes? Plenty, but here is one general result: suppose a Markov process with a finite number of states satisfies the following two properties: if one is in state x, at time t, then the probability of being in state y at time t+s is: (i) strictly positive for some s (i.e. by a sequence of steps) (ii) independent of t. As a simple example of such a process, consider the order of 1,000 genes along a chromosome. After a random (exponential) waiting time we pick up a random block of genes of random length and invert them (this is a ‘step’) leading to a new order. After a very long time there will have been a lot of ‘steps’ and the genes will have been thoroughly shuffled (like cards in a deck). A universal property of this, and any other Markov process on finite states that satisfies properties (i) and (ii), and with t continuous, is that they converge to some equilibrium distribution – it may not be uniform (like the above shuffling example) but it is the same distribution regardless of our present starting position, so the ‘trace’ of where we started gets lost the further we look into the future. There is even a theorem that guarantees that the ‘information’ that the present state provides about the future state goes to zero exponentially fast the further we look into the future. Prediction into the far future is thus provably hard for any such Markov process! Without properties (i) or (ii) we can sometimes predict far out indefinitely into the future. For example, imagine an extremely rare but neutral mutation that arose in one individual, was subsequently passed on to many descendants to the point where it is now present in 5% of a population. Eventually, after many generations, the gene will either get fixed (everyone will have it) or lost, and the probability is exactly 95% of being lost under simple population-genetic models. In this case the distant future
can be easier to predict than the not-so-distant future. This process fails property (i) since once a gene is fixed (or lost) the population is assumed to stay in that state.
matching g-FOB model means we have much less precise estimates of N under the more ‘realistic’ model.
126
Figure 1: A food web showing some marine species’ interactions in the Chesapeake Bay estuary of North America. An arrow from x to y indicates that species y feeds on x. Our ‘eco-FOB’ model introduces far higher uncertainty into the estimates. If we consider two set-ups that lead to the same expected (average) value of the number N of extinction, and we consider the variance in N (species ‘richness’), then Figure 2 shows how this is much higher under the eco-FOB model than a ‘generalised field of bullets’ (g-FOB) model that allows each species to have a matching extinction rate (but with extinctions treated independently). This ‘variance inflation’ in the eco-FOB model over the
Figure 2: The ‘inflated’ statistical variance (top curve) in the number of species that survive under an eco-FOB model over a matching model that ignores the food-web dependences (bottom curve).
futurefocus–predictingthefuture
The paradox of‘more is less’: Model mis-specification It is a generally assumed axiom that the more realistic a model we use, the more accurately we should be able to predict the future. However, this is not always the case. Simple models can allow ‘precise’ estimates into the future, while models that build in more ‘reality’ can make the estimates far less reliable. Usually all it means is that the original ‘precise’ estimates are likely to be completely wrong, because the model used to predict them was overly simple. Below we describe an example from our work in biodiversity conservation, in which the more ‘realistic’ model leads to greater uncertainty about the future. Example: predicting the loss of biodiversity In studying the loss of biodiversity, a simple model of extinction is the so-called Field of Bullets (FOB) model, in which each species x has a certain probability p(x) of going extinct in the next 100 years, and extinction of each species occurs independently of other species. Suppose there are 100,000 species in an ecosystem today, each with a 99% chance of surviving the next 100 years, and so p(x) = 0.01 for all x. What can we say about the number N of species who will be extinct in 100 years? By the independence assumption we know that N has a binomial distribution with n = 100,000 and p = 0.01. Thus, as any Year 13 statistics student knows, N is normally distributed with a mean of 1000 and a standard deviation of around 31. So we can be more than 99% sure that the number of extinctions will be between 900 and 1100. The model won’t provide any clues as to which species will go extinct, but it seems to give an impressively accurate estimate: 1% plus or minus (±) 0.1% of species will go extinct. However, the assumption that extinctions proceed independently is not very realistic. The demise of some species on which another depends is likely to increase the chance of extinction of that second species. Thus, we can build into simple FOB model ecosystem interactions, for example, a food web, and ask how this affects the estimates. This is something we mathematically modelled recently, using a Chesapeake Bay marine food web, shown below in Figure 1.
NZ
science teacher
Why do we see this variance inflation? The reason is that, large numbers of independent variables are highly predictable, by the Central Limit Theorem (as we saw above), but dependent variables can be subject to ‘cascade’ effects. In the ecosystem setting this means, roughly speaking, that the some extinctions can tend to set off of a chain of other extinctions (if they occur) while others will not, and it is difficult to predict which cascade scenarios will occur (if any), and how severe they will be.
Science and technology ten years from now Anyone old enough to remember the Moon landing knows that predicting the future is a risky business. Back then, our expectation of manned space exploration over the coming decades was captured by Stanley Kubrick’s 2001: A Space Odyssey. Yet the reality was quite different, and this year the U.S. is to suspend manned space flights altogether. More recently, the sequencing of the human genome, just over a decade ago, promised an ‘open book’ revealing which gene causes which disease, ushering in a revolution in ‘genetic medicine’. Again the reality fell far short; perhaps the biggest surprise was the relatively small numbers of genes humans have – similar to some other ‘primitive’ species, such as the puffer fish – and the emerging picture of genes working in concert with each other, and the environment. Yet sometimes the future exceeds our expectations. One has been the unexpected pace of DNA sequencing technology. While computer power has chugged along as expected, increasing by a respectable factor of around 30 per decade according to ‘Moore’s law’, the speed and cost of DNA sequencing technology has been far more dramatic – the cost is reportedly 100,000th of what it was a decade ago, and the quantity of data being generated is now outpacing the ability to process it. This all goes to reinforce the words of former Danish physicist, Niels Bohr: “Prediction is very difficult, especially about the future.” For further information contact: Mike.Steel@canterbury.ac.nz
Further reading Ingram, T., & Steel, M. (2010). Modelling the unpredictability of future biodiversity in ecological networks. Journal of Theoretical Biology, 264, 1047-1056 Sober, S., & Steel, M. (2011). Entropy increase and information loss in Markov models of evolution. Biology and Philosophy, in press.
New Zealand Association of Science Educators
7
NZ
science teacher
futurefocus–ICT
126
the disruptively changing face of ICT In the past 15 years Skype, iPod, Facebook and the USB flash drive, to name a few, have changed our lives and the only certainty is that there is more to come in the future as Professor John Hosking, Director Centre for Software Innovation and Professor of Computer Science, Department of Computer Science, at The University of Auckland explains in this thought provoking, must-read article: Predicting the future in Information and Communication Technology (ICT) is difficult. Ken Olsen, President of Digital Equipment, said in 1977, “There is no reason for any individual to have a computer in his home.” How wrong can one be! The difficulty arises from the well-known Moore’s law, which states, “The number of transistors that can be placed inexpensively on an integrated circuit has doubled approximately every two years.” This exponential growth in chip complexity leads to all manner of derived “laws” relating to growth of computation, memory, network capacity, stored information content, etc. These provide many motivating examples for students to understand the need for exponentials and logarithms. Humans are pretty good at predictions in linear situations, but far less so when things are exponential: exponential change implies disruptive change, when existing ways of thinking are rapidly superseded and new approaches, and business models based on them, arise. Table 1, for example, lists familiar ICT organisations and products that have become iconic in approximately the last 15 years. Many started with what appeared ludicrous ideas that ICT advances made practicable: “Why use bookshops to sell books?”; “Let’s charge users nothing for our services”; “An encyclopedia anyone can edit”; or “Let’s make international phone calls free”. So it is with some trepidation that I join the group of future speculators.
Connectedness and convergence There is exponential growth in the number and range of Internet-connected devices. This is why the means of uniquely addressing devices, IPV4, is running out of “numbers”, making a shift to the newer IPV6 urgent.
Nowhere is growth more evident than in mobile devices, with the advent of laptops, netbooks, smartphones, tablets, etc. There is also a convergence of capabilities: voice, video, and web content are increasingly being bound together, both in the devices used to send and access them, and applications using them (think YouTube, Skype, OnDemand TV). This is causing a revolution in everyday use of ICT. Morgan Stanley call this the 5th cycle of ICT evolution. Table 2 shows the five cycles. In each cycle, new dominant companies have emerged based on new application and device types, and the number of units (computers or devices) has increased tenfold. Table 2: Cycles of ICT evolution/revolution, after Morgan Stanley, 2009 Cycle
Date
No of units
Iconic companies
Mainframe
1960s
1M
IBM
Mini
1970s
10M
Digital
Personal
1980s
100M
Microsoft
Desktop Internet
Late 1990s
1000M
Google, Amazon
Mobile Internet
Late 2000s
10000M
Apple? Google? Facebook?
The 5th cycle, mobile Internet, is underway and the competition for dominance is fierce. Dominance requires not just an interesting and useful application, but a platform and ecosystem: the iPhone is not just a smartphone, it is part of a platform comprising apps, iTunes, the AppStore, iPads, iPods, iPhones etc., and an ecosystem including third party app and service providers. Facebook provides a similar platform for social networks. Who will be dominant in the 5th cycle? That is not clear to me yet as mobile Internet platforms are rapidly evolving. I do predict video will be a much more significant platform feature than it has been to date. Not surprisingly, privacy issues become significant in such a highly connected, platform environment. Identity theft
Table 1: New organisations and products Organisations
8
Products
Amazon
1995
Toyota Prius hybrid
1997
1998
Commercial HDTV
1998
Salesforce.com
1999
Retail broadband in NZ
1999
TradeMe
1999
USB flash drive
2000
PayPal
2000
iPod
2001
Wikipedia
2001
F&P Dishdrawers
2002
Skype
2003
Nintendo Wii
2006
2004
iPhone
2007
2006
iPad
2010
New Zealand Association of Science Educators
The cloud A typical Web application involves your local computer, network routers, Web server computers, connected to business logic computers and database servers. So computer systems are no longer just a single ‘thing’ sitting in a box, they are massively connected systems comprising many computers running diverse software elements. Building and maintaining such systems is complex and costly. To simplify this, virtualisation software was developed. This makes it very simple to set up and run (deploy) complex computer systems on sets of ‘standard’ computers. Systems can then be quickly scaled in size as demand increases and easily moved to new computers. It then makes sense to develop ‘server farms’ centralising computers to lower overall costs of air-conditioning, security, etc. Similar arguments relate to storage. Increasing network bandwidth means the location of these server and storage farms becomes irrelevant. This leads to the concept of the cloud, where service providers, such as Amazon and Google, provide cheap and efficient access to large server and storage farms where many different computer systems can be deployed. Many businesses now run their entire IT services from the cloud. They swap the cost of owning and maintaining their own servers for leasing time and space on cloud servers. Expect this trend to accelerate as companies overcome security fears associated with their data being held elsewhere. Most Internet-based applications you use in the future will be cloud hosted.
The data and computational deluge All the extra devices and uses of ICT mean we are swamped with information. The Economist claims mankind created 150 exabytes (billion GB) of data in 2005 and 1,200 exabytes in 2009 (exponential growth again). Much growth is in video content, but there are many other factors. To deal with this corresponding growth in computational power is needed, another driver for the growth of cloud services. Consider some science examples. Third generation genome sequencing machines will significantly drop the time and cost to do sequencing, to around $1500 for a bacterial genome. However, the bottleneck moves to storing and processing the vast amounts of genomic data generated. Most genomic computation involves n2 algorithms, i.e. if you have n data values, the computation time needed is proportional to n2. Increasing data then implies a need for a massive increase in computational capacity. Biologists are, unsurprisingly, at the forefront of demand for computing resource in our universities. CERN’s Large Hadron Collider produces 15 petabytes (million GB) of data a year, requiring massive international
resources to store and analyse. The proposed Square Kilometer Array, a 3000km baseline radio telescope array with a total collecting area of 1km2, will dwarf this producing 1TB (1000 GB) of data per minute requiring 1015 operations per second (1 petaflop) to analyse. This scientific data deluge has prompted commentators, such as Chris Anderson, to question the viability of the scientific method itself, suggesting that “Correlation is enough”. Even corporate, public and private data growth is problematic. Companies often claim of “not knowing what we know” as prior learnings are unable to be discovered easily for reuse. To deal with this deluge, so called ‘artificial intelligence’ techniques such as filtering, inference, reasoning, and semantic analysis are becoming essential elements of computer applications. These use computational logic methods, to extract meaning from raw data in ways understandable to humans. This gives rise to the term ‘the semantic Web’ where such reasoning techniques are incorporated into ‘smart’ Web applications. Expect to see many more such applications and much more configurable to your own personal needs. Some you are already familiar with include spam filters and recommender systems.
NZ
science teacher 126
futurefocus–ICT
and unintended consequences, e.g. being fired due to a Facebook comment, are significant issues. I predict reaction to these may well define the next generation of social platforms shaping the next dominant player. What will be the 6th cycle? I speculate it will be based on sensor-networks, comprising large numbers of small cheap sensors, producing the so-called Internet of Things. Applications include environmental monitoring (regional, local, home), surveillance, and medical monitoring. Current science-oriented examples include: New Zealand’s seismic GeoNet; large oceanographic systems, e.g. in Monterey Bay; and the Large Hadron Collider at CERN. Medical systems will use body area networks, connecting multiple sensors (blood pressure, heart rate, motion – even direct brain interfaces!) wirelessly to an Internet device, such as a smartphone. Encourage your students to think about sensor network applications – they may well pay for your retirement.
Power Even with efficiencies such as cloud server farms, the amount of power needed to run the world’s ICT needs is becoming of concern. It only takes 1kJ, what a human body uses in 10s, to run a Google search. However, there are approx 3 B of them per day, implying power needs of 900GWh per day. Spam alone is projected to require 90GWh per day. An interesting class exercise is to evaluate the carbon footprint of world ICT use. Such issues are driving organisations to seek more efficient ‘green computing’ approaches to minimise power wastage. These include recycling heat generated by computer cooling plants and even moving server farms adjacent to renewable energy sources (loss from power cables is much greater than cost of optical data pipes to remote locations). Expect these issues to be more prominent, with businesses making more of their green computing credentials.
And finally, social implications I have chosen to focus on the technicalities of the ICT future in this article. For information on social impacts, I urge you to look at sources such as TEDtalks and Google TechTalks. These provide a wealth of, sometimes oddball but always thought-provoking, views on how the future will unfold. However, I will say that the social implications of the disruptive changes I have postulated are enormous. The organisations and technologies in Table 1 have changed our lives significantly. Expect even greater changes in the future. For further information contact: j.hosking@auckland.ac.nz
References Anderson, C., The End of Theory: The Data Deluge Makes the Scientific Method Obsolete, Wired Magazine: 16.07, 2008, http://www.wired.com/science/ discoveries/magazine/16-07/pb_theory, accessed 20th Feb 2011. Armbrust, M., Fox, A., Griffith, R., Joseph, A.D., Katz, R., Konwinski, A., Lee, G., Patterson. D., Rabkin, A., Stoica, I., and Zaharia, M. 2010. A view of cloud computing. Commun. ACM, 53, 4 (April 2010), 50-58. The Economist, The data deluge: Businesses, governments and society are only starting to tap its vast potential, The Economist, Feb 25th 2010, http://www. economist.com/node/15579717, accessed 20th Feb 2011. Jovanov, E., Milenkovic, A., Otto, C., and de Groen, P.C., A wireless body area network of intelligent motion sensors for computer assisted physical rehabilitation. Journal of NeuroEngineering and Rehabilitation, 2005, 2:6 Mayer, M., Innovation at Google: The Physics of Data, PARC Forum, 2009, http:// www.parc.com/event/936/innovation-at-google.html, accessed 20th Feb 2011. Morgan Stanley, The Mobile Internet Report Setup, Dec 15 2009, http://www. morganstanley.com/institutional/techresearch/pdfs/2SETUP_12142009_ RI.pdf, accessed 20th Feb 2011.
New Zealand Association of Science Educators
9
NZ
science teacher
futurefocus–bio-nanointerface
126
nanoparticles, health and the bio-nano interface There are currently over 1000 nanotechnology projects raising concern about the health effects of nanotechnology as, Dr John Watt, School of Chemical and Physical Sciences, Victoria University of Wellington, explains: Introduction In the near future nanotechnology will be commonplace in consumer products. Pushing this along has been an explosion in research into nanotechnology over the last two decades. A number of technologies have already found their way into the marketplace with applications including new solar technologies, smart fabrics, industrial catalysts, electronics and a huge range of others. The global market for goods incorporating nanotechnology is expected to exceed $1.5 trillion by 2013, with the greatest growth being in the Asia-Pacific region (RNCOS 2009). Therefore, it is almost certain that the reader will come into contact with nanotechnology in the future. It is difficult to confirm exactly how many products already on the market contain nanotechnology as the prefix ‘nano’ is often used incorrectly. However, some initiatives such as The Project on Emerging Nanotechnologies put the number of products at well over 1000, leading to a call for systematic investigation into the health effects of nanotechnology or ‘nanotoxicology’ (http://www.nanotechproject.org/). In what is perhaps a cautionary move precipitated from previous mistakes (e.g. asbestos) governments, industry and research institutions are putting considerable effort into minimising the risks from nanotechnology while hoping to maintain their significant technological impact (Maynard 2006). In research terms significant resources have recently been devoted to biomedical applications of nanotechnology, including MRI contrast agents and cell tracking and tagging technologies. This research is making important contributions to fields such as the early detection and destruction of cancers. With this increase in biological applications comes a desire to fully understand the nanobio interface. Looking to the future this fundamental description of the nano-bio interface will give us as scientists a better understanding of the health effects of nanotechnology. This will lead to increased public awareness and allow the public better choice in their interactions with nanotechnology.
Nanotechnology The idea for nanotechnology was put forward by the eminent physicist and Noble Laureate Richard P. Feynman in his 1959 lecture ‘There’s Plenty of Room at the Bottom’. In this lecture he ushered in a new era of science and technology by asking ‘Why cannot we write the entire 24 volumes of the Encyclopædia Britannica on the head of a pin?’ From then on, a number of researchers began to think small. Nanotechnology is the study of the very, very, very small. A nanoparticle is typically defined as a material that has one or more of its three dimensions between 1 and 100 nanometres (nm) in size. 10
New Zealand Association of Science Educators
To put this in perspective the diameter of a human hair averages at around 100 µm. Therefore, the materials being developed are 1000 to 100 000 times smaller than the width of a human hair. When we reduce to this length scale the nanoparticle behaves in a very different manner than when compared to its bulk counterpart. This is due to an exponential increase in surface area. When we reduce to the nanoscale a large percentage of the material is located on the surface which interacts directly with the environment leading to complex and unique behaviour. This behaviour is largely dependant on the nature of the surface, so by changing the morphology of a nanoparticle or by changing what is attached to the surface we can change its chemical and physical properties. For instance, just by changing the size of a semiconductor silicon nanoparticle you can change the colour from bright blue to yellow. It is the understanding, manipulation and application of these unexpected behaviours that forms the basis of nanotechnology research. Just as the chemical and physical properties are influenced strongly by the nature of the nanoparticle’s surface so too are interactions with biological systems.
The bio-nano interface The main factors influencing the way that a nanoparticle interacts with any type of system, biological or inorganic, are: size, shape and surface area; the nature of the surface i.e. charge, roughness and energy; the chemical species attached to the surface; material type and crystal defects. When applied to a biological system a significant number of new interactions become important leading to complexity in the system. The first thing to consider is that a nanoparticle is rigid whereas a cell is not. The cell possesses a compliant membrane which can deform leading to a complex set of interactions (Nel 2009). These include stretching of the cell membrane and thermal fluctuations at the surface. Secondly, there is often a large size disparity between nanoparticles and cells. Cells are typically 10 µm large whereas a nanoparticle can be as small as 1 nm. Due to the presence of biological proteins and other species on the surface, cells can have secondary surface structure or a certain ‘roughness’ which may be on the length scale of between 10 – 50 nm. Therefore, a small nanoparticle would perceive the cell as rough and experience a different set of interactions than a larger nanoparticle which would perceive the cell as smooth. However, the largest complexity arises because cells are active, living entities, unlike the inorganic nanoparticles. The surface of a cell changes as transporting ions, proteins and other biological molecules are secreted. This leads to a ‘time-dependant dynamic interface’ as the nanoparticles constantly absorb and desorb biological species, affecting the nanoparticle-cell interaction (Clift 2010). An important example of this is the formation of a ‘protein corona’ around the nanoparticle. When a nanoparticle
enters a biological fluid it can become coated in proteins which strongly influence its biocompatibility and distribution. This protein binding can be irreversible, permanently changing the surface and hence the properties of the nanoparticle (Lynch 2009). Depending on the type of proteins absorbed, the nanoparticles can stimulate or suppress immune responses and affect nanotoxicology. For instance, making nanoparticles more invisible to the immune system by the binding of a certain protein type may increase their cell penetration rates and hence their toxicity. Studies show that surface area is a major factor influencing the nano-bio interface and that smaller, finer particles with a large surface area experience much greater interactions with cells (Sager 2007). Shape is also a major factor. Small, spherical nanoparticles are easily engulfed and removed by the body’s immune system, whereas long elongated nanoparticles can become partially engulfed. This causes the cell to release harmful oxygen radicals and enzymes in an effort to break the intruder down, leading to chronic inflammation (Poland 2008).
NZ
science teacher
Conclusion The field of nanotoxicology is young and debate has just begun about how to most effectively investigate and understand the health effects of nanotechnology. The sheer number of different nanoparticles makes it very difficult to assess nanotoxicology using established techniques, and therefore new methods must be discovered. This will be a long-term challenge that requires a multidisciplinary approach. Medical researchers will need to work very closely with materials’ scientists and industry to identify new nanoparticles as they are formed. Using a series of simple, standardised tests, these new nanoparticles can have their nanotoxicology quickly evaluated. Any new nanoparticles that offer concern can then be subjected to more rigorous and targeted testing. With this we can be confident that our interactions with nanotechnology will be safe in the future, and that we reap the many exciting benefits that this technology has to offer. For further information contact: john.watt@vuw.ac.nz
Nanoparticles and health
References
The first interest into the health effects of nanoparticles was based on the known effects of airborne pollutants (Clift 2010), it is well understood that a component of environmental air pollution, airborne particulates less than 10 µm in size, can lead to the onset of pulmonary disease. This led to a focus on in-vivo experiments into nanoparticle exposure (Ballou 2004). However, the enormous diversity of nanoparticles with different characteristics (they are thought to exceed that of conventional chemicals) soon led to researchers adopting in-vitro techniques which are much simpler and enable the researcher to elucidate models for the bio-nano interface (Maynard 2006, Gil 2010). Consequently, research has been dedicated to in-vitro analysis techniques including high throughput screening (HTS) and cell cultures; however, each has its problems. High
Ballou, B., et al (2004). Noninvasive Imaging of Quantum Dots in Mice. Bioconjugate Chemistry, 15, 79-86. Clift, M.J.D., et al (2010). Nanotoxicology: a perspective and discussion of whether or not in vitro testing is a valid alternative. Archives of Toxicology, advance online. Feliu, N., & Fadeel, B. (2010). Nanotoxicology: no small matter. Nanoscale, 2, 2514-2520. Gil, P.R., et al (2010). Correlating Physico-Chemical with Toxicological Properties of Nanoparticles: The Present and the Future. ACS Nano, 4, 5527-5531. Lynch, I., et al (2009). Protein-nanoparticle interactions: What does the cell see? Nature Nanotechnology, 9, 546-547. Maynard, A.D. (2006). Safe handling of nanotechnology. Nature, 444, 267-269. Nel, A.E., et al (2009). Understanding biophysicochemical interactions at the nanobio interface. Nature Materials, 8, 543-557. Poland, C.A., et al (2008). Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenecity in a pilot study. Nature Nanotechnology, 3, 423-428. RNCOS (2009). ‘Nanotechnology Market Forecast to 2013’. Sager, T.M., et al (2007). Improved method to disperse nanoparticles for in vitro and in vivo investigation of toxicity. Nanotoxicology, 1, 118-129.
126
futurefocus–bio-nanointerface
Figure 1: Transmission Electron Microscope (TEM) image of lead sulphide (PbS) nanoparticles for use in infrared (IR) active solar cell technology. The scale bar is 50 nm. The nanoparticles were synthesised using solution phase chemistry and imaged at Victoria University of Wellington.
throughput screening is used extensively in drug discovery and involves the automated screening of large chemical libraries for activity against biological targets (Feliu 2010). However, this technique requires a large number of welldefined, stable nanoparticle species, which can be lengthy and costly to make, so to prepare a large number for concurrent screening would be difficult. Also, the stability of a nanoparticle can degrade with time and is strongly dependant on the suspending media. Any degradation of the nanoparticle, or difference in the nature of suspending media, would inject unwanted variables into the screening process. In-vitro cell cultures can be better controlled and yield reproducible data; however, they require a high level of standardisation (Clift 2010). Also, cultures made up of one type of cell are a long way from accurately representing the in-vivo situation and cultures utilising more than one cell type are needed. Ideally, these cultures will aim to mimic a certain organ i.e. the lungs, heart or liver. Furthermore, in order for cell cultures to be an effective technique for investigating nanotoxicology, the culture type must constantly evolve alongside new research.
continued from page 40 Crooks, T., Smith, J., & Flockton, L. (2008). National Education Monitoring Project: Science Assessment Results 2007. Dunedin, New Zealand: Educational Assessment Research Unit, University of Otago. Darling-Hammond, L. (2000). Teacher quality and student achievement: A review of state policy evidence. Education Policy Analysis Archives, 8 (1). Retrieved from http://epaa.asu.edu/ojs/article/viewFile/392/515 . Goodnough, K. (2008). Moving science off the “back burner”: Meaning making within an action research community of practice. Journal of Science Teacher Education, 19, 15-39.
Johnson, C.C., Kahle, J.B., & Fargo, J.D. (2007). Effective teaching results in increased science achievement for all students. Science Education, doi:10.1002/sce.20195. Keogh, B., Naylor, S., Downing, B., Maloney, J., & Simon, S. (N.D.). Puppets bringing stories to life in science. Retrieved from http://www.puppetsproject.com/ documents/psr-2006-puppets.pdf . Rivkin, S.G., Hanushek, E.A., & Kain, J.F. (2005). Teachers, schools, and academic achievement. Econometrica, 73, 417-458. Shen, J., Gerard, L., & Bowyer, J. (2010). Getting from here to there: The roles of policy makers and principals in increasing science teacher quality. Journal of Science Teacher Education, 21, 283-307.
New Zealand Association of Science Educators
11
NZ
science teacher
futurefocus–science/scienceeducationinterface
126
A conversation about nanotechnology at the science/ science education interface The following article investigates the science/science education interface and is based on John Watt’s article entitled “Nanoparticles, health and the bionano interface” (published in this issue), as Rosemary Hipkins, NZCER explains: Maintaining a dual focus on science and science education poses interesting challenges for journals such as the New Zealand Science Teacher. One way to manage these potentially competing priorities for busy teachers’ attention is to bring them together and explore what emerges in the “space between”. Recently there have been calls for dialogue between scientists and science teachers to help move our curriculum forward (Bull, Gilbert, Barwick, Hipkins, and Baker, 2010; Hipkins, 2010). But what would such a dialogue involve, and what might we find out that could be helpful for teachers in their day-to-day work, and for thinking longer term about how the curriculum might evolve? This short article captures a first attempt at this type of conversation, with Dr John Watt bravely agreeing to be our “guinea pig”. When John had completed a draft of his article on nanotechnology he sent it to me. Having read it, I then went to meet John armed with several questions as conversation starters. My purpose was not to critique the article, but rather to see where it could take us in a wider conversation in the space between science and science education. What could we learn there that neither party knew on our own?
Science teachers need to know about nanotechnology I asked John why science teachers should pay attention to nanotechnology when so many other areas of research compete for their attention. He looked ahead ten years and predicted a ubiquity for nanotechnology in daily life. Fine, I thought, but computers are ubiquitous now and most of us don’t really know much about how they work. John countered this by saying that a lot of fears could be raised by opponents of the technology, and that while some of these may be areas where we should be concerned, most of the arguments will be groundless. In the latter category, he gave the example of the idea of ‘nanobots’ that could replicate and run amuck. I recognised this idea at once, as would anyone who has read science fiction novels such as The Diamond Age (1995), but John explained that nanoparticles are essentially passive technologies. This idea of passivity interested me because although I can see it is implied in the article I’m not sure I would have focused on it if the question hadn’t arisen.
Nanotechnology: a surface area context I next asked what John thought were the most important concepts a senior secondary science student should know if they were thinking of studying and perhaps working in this area. He struggled to pick out just one or two ideas because for him all the necessary concepts are bound up with each other in a systems’ view of how nanotechnology works. 12
New Zealand Association of Science Educators
We talked about the important challenge of developing systems’ understandings in a range of areas. I then suggested that maybe surface area was a really key concept and John readily agreed. He noted that the action of nanoparticles can be explained in various ways, but ultimately other explanations such as quantum confinement all come back to effects that take place because of the very large surface areas of these particles. One aspect of the conversation that interested John was the different ways that the two of us perceived the size of a cell compared to a nanoparticle. I wasn’t sure quite how to size them comparatively, whereas for John a cell is gigantic in comparison! Cells are usually considered miniscule things, and John said this was a perspective he’d overlooked. He took note of this to strengthen the idea in the article.
Nanotechnology research has specific methodologies We then talked about the focus in the later part of John’s article on methods of research in this area, and the need to create special cell lines as research tools. I had in mind the ‘investigating’ sub-strand of NOS and how seldom we teachers see accessible discussions of methods for a specific area of research. I wonder if scientists neglect to share important contextual information when they take their inquiry procedures and technologies as a “given” when communicating with their peers (unless of course a change or adaptation of method is the point of a paper). We talked about the idea of in-vivo and in-vitro methods. I wondered aloud if teachers would think to highlight these as important NOS information for their students. John said he had wondered if he should define them, but decided not to because, “They are simple ideas that everyone can easily research on their own.” Do your students know them? How might not knowing them impede access to the points he was making?
In summary... Summing up then, this was a very interesting conversation that drew out some ideas that were there all along but perhaps lurking in John’s mind and experience as background to the text. My education-focused experience prompted me to pay attention to some different (perhaps unexpected for John?) aspects of the article. We can’t pay attention to everything at once and some interesting challenges about what is in the foreground and what is in the background were raised by this conversation. For further information contact: rosemary.hipkins@nzcer.org.nz
References Bull, A., Gilbert, J., Barwick, H., Hipkins, R., & Baker, R. (2010). Inspired by Science: A paper commissioned by the Royal Society and the Prime Minister’s science advisor. Wellington: New Zealand Council for Educational Research. Hipkins, R. (2010). Public attitudes to science: rethinking outreach initiatives. New Zealand Science Review, 67 (4), 107-114. Stephenson, N. (1995). The Diamond Age. New York: Bantam Dell.
future foods: sustainability and obesity NZ
science teacher 126
It’s not easy predicting the future, even with science on your side. Witness the contention associated with the climate change debate – Is it natural? Man-made? Or even occurring at all? Even scientists can’t agree, and under these circumstances it becomes difficult to formulate the most appropriate means of tackling the problem. Predicting the future focus of food is no less challenging, if less contentious than observed for climate change. In thinking about the future of foods we need to consider exactly how far into the future we need to look. Can we realistically anticipate what our diets will look like in 100 years time, let alone 1000? Certainly it might be considered that, based on little or no change to our biological makeup, our future nutritional requirements will be little different from that of today, just as our dietary needs don’t appear to have changed much over the past few centuries. We will still need a certain proportion of basic macronutrients – protein, carbohydrate and fat – as well as micronutrients – vitamins, minerals etc. – as part of our daily intake for maintaining good health.
Fighting obesity For developed and affluent societies food supply is not currently a problem. Most of us continue to have access to low cost, readily available and safe food products. Indeed, one recognised problem is the over-availability and overconsumption of food. Based on an increasingly sedentary way of life our energy requirements are actually less than they would have been 100 or 200 years ago, and yet we have more choice, more spending power and far easier access to food than we did then. The statistics showing rapidly elevating populations of overweight and obese individuals is, at its simplest, a consequence that for many people energy intake is regularly being allowed to exceed energy expenditure.
Organisation for Economic Co-operation and Development (OECD) show that, at least in the short-term future, the incidence of obese and overweight individuals will continue to be a steeply upward trend for many countries (Figure 1), with projections showing no indication of plateau by 2020. These are genuinely worrying statistics, with over 1 billion people in the world now being classified as overweight. Whilst obesity might at first glance seem a relatively trivial and cosmetic issue, there are profound social and economic consequences associated with the problem. For example, a report issued by Diabetes Australia indicated the financial costs associated with obesity to be in excess of AU$3.7 billion for the year 2005. Looking at the projections highlighted in Figure 1, it would be considered a fair assumption that developing new approaches to better regulate energy intake will be one of the priority areas for food manufacturers in the near future. What needs to be done to make this approach successful? Well, at its simplest this approach requires a tangible reduction in energy content across a substantial range of food products, such that the net calorie intake can be lowered on a daily basis.
Challenges reducing fat and sugar in food
futurefocus–food,sustainabilityandobesity
Future food scientists focus on addressing the twin issues of obesity and sustainability, as Matt Golding, Massey University explains:
One could argue that this is already the case for many fat or sugar reduced foods, and indeed the market sector for reduced energy food was estimated to be in excess of US$70 billio for 2010. However, an established low energy market seems to be having little impact on the observed trends shown in Figure 1, so why is this approach not more successful and how can innovation be used to improve this approach going into the future? Part of the problem is palatability. Both fat and sugar contribute to the pleasurable eating experience of many foods, and their removal is invariably associated with a loss of quality. A considerable amount of innovation has been developed and implemented by food companies in recent years, as part of trying and compensate more effectively for the removal of fat and sugar from food products. By better understanding the roles of these ingredients in the microstructure of a product, it is becoming increasingly possible to manipulate product structure to achieve improvements in the sensory performance of that product. Some nice recent examples included the use of encapsulated water to reduce the fat and sugar content in chocolate, and the use of small stable air bubbles to mimic the sensation of fat in emulsion type products such as creams, ice creams and mayonnaises. Future developments in the ability to manipulate product microstructure will continue to allow for improved sensory performance, allowing for not only high quality low energy products, but enabling other enhancements, such as salt reduction and potentially reducing raw material costs.
Controlling energy intake Figure 1: OECD data for incidence and projection of overweight populations. In many respects this is a remarkably recent phenomenon – indeed the word obesity did not really enter the public consciousness until after 2000. However, projections by the
Solving quality is only half the issue with improving the effectiveness of reduced energy foods. The second aspect is in relation to the eating behaviour of such products, to ensure that energy intake remains at or below acceptable limits. In this respect there are additional problems to be overcome, such as misdirected consumption (e.g.
New Zealand Association of Science Educators
13
NZ
science teacher
futurefocus–food,sustainabilityandobesity
126
14
consuming more reduced energy products on the basis that they are lower in calories), reduced guilt, and the issue of satiety. This latter aspect is a particularly intriguing problem in that reduced calorie foods will invariably lead to a poorer satiating response than energy dense ones. In such cases, total energy intake can actually increase due to hunger and subsequent grazing/snacking type behaviours. There is already considerable research interest in addressing this problem (particularly if we’re used to eating calorie rich foods), and future food focus is expected to continue to progress our understanding of the variable mechanisms of satiety and how they can potentially be manipulated. Already we are beginning to be able to control the rate of digestion by influencing the material properties of digesta during transport through the gut, with recent research focusing on how complex, poorly digestible sugars such as polysaccharides can be used to slow down the digestive process. For example, recent research activities at Massey University have shown that a gum extract from the native mamaku fern is able to slow down the rate of meal emptying from the stomach, enhancing the feeling of fullness. Likewise, we are now beginning to develop new approaches to control the way in which fat can be structured during digestion, again with the result that we can control the rate at which lipids are absorbed into the body. There is also some fascinating research being undertaken to identify whether the perception of tastes within the mouth can influence meal intake, with high intensity tastes leading to a reduced consumption of those foods. This concept of sensory specific satiety has resulted in the identification of fats and oils as tastants in their own right, and the accompanying observation that individuals displaying effective taste perception of fat tend to consume less fatty foods, and have a lower relative body mass index compared to poor fat tasters. Findings such as this provide insights as to why we crave particular foods, and how suppression of our ability to taste (taste fatigue) due to excessive consumption of high taste foods may actually promote overeating. There have been some genuine advances in recent years as to the relationship between the molecular, material and sensory properties of foods and their relationship to digestion. This continues to be a highly researched area and is expected to generate new findings and new opportunities and new formulations for the regulation of weight management in the near future. However, it should be pointed out the majority of current research on aspects such as satiety control work on model systems under controlled conditions. The success of these technologies relies on their incorporation into a broad range of food products, whilst maintaining their functional benefits. This is not a trivial exercise, and the research challenges of the next 10 – 20 years will be the extension of these technologies into mainstream foods, and the verification of their benefits and ensuring that food products with proven effects maintain consumer appeal. These approaches demonstrate one means by which the food industry is seeking innovative solutions to the obesity epidemic. However, it is realised that there is no magic bullet for this problem, and that even proven technologies for the control of energy intake can only work as part of an holistic approach to weight management. If food manufacturers can universally begin to lower the energy content of foods, then this approach may work (providing that consumers do not try to compensate for the benefits of eating lower energy foods). This approach is already
New Zealand Association of Science Educators
being successfully adopted by many companies for the reduction of salt in food products, and appears to work best when consumers are not even aware that the products they’re eating have been modified to a healthier profile. It may be that the development of the next generation of reduced energy foods would best served by taking a similar approach.
Sustainability of food impacts diet Given the projections shown in Figure 1, we can anticipate that one particular focus of the food industry in the near future will be the provision of a broader range of foods aimed at specifically addressing the obesity crisis. Can we expect this trend to continue beyond 2020? Perhaps, if we assume that food supply continues to remain plentiful, low cost and pleasurable to eat. However, looking towards 2050 it may well be that other issues such as sustainability and rising food costs will lead to an inevitable transition in our eating behaviours. Already sustainability is being recognised by many food manufacturing companies as the single biggest issue facing the food industry going forward. By 2050 our global population will be approaching 9 billion, and the food requirements for that population are estimated to be double that of current global population. It is difficult to say with certainty how we will manage to ensure that food supply can be managed to accommodate this number of people, and whether we will see further polarisation of populations with or without access to sufficient nutrition. It may become more of the case that much of the food that we currently take for granted, such as meat and dairy products, will become increasingly more expensive and will begin to feature less in our diets. The cost of grains and sugars may also increase due to aspects such as crop production for biofuels. It may simply be that in the future it may be simply too expensive to maintain a consistently indulgent diet when it comes to food consumption, and that the incidence of obesity will eventually plateau and begin to decrease purely as a consequence of limitations of global food supply. In this respect, technology will continue to play an important role in ensuring food production. Given the crucial aspect of water in the production of raw and processed food materials, it would seem likely that water management and irrigation will be a particular concern in the next few decades. The provision of protein will become more of a concern, and alternative sources, such as algal and seed crops may need to be considered, with less focus on animal proteins. Adaptation of crops to allow for growth in more extreme conditions may eventually lead to the acceptance and widespread implementation of genetic modification. These possibilities suggest that the future of food production is likely to be focused on ensuring that nutritional needs can be maintained. This of course is but one scenario as to future developments in food innovation and manufacture, and there will continue to be many other challenges and opportunities that will need to be addressed by the food industry as we move forward. Yet, within this scenario, it is clear that to simply maintain the status quo for issues such as obesity and sustainability is not acceptable, and that addressing these will by necessity require solutions from science. For future food scientists and technologists, there are undoubtedly challenging times ahead. For further information contact M.Golding@massey.ac.nz
NZ
science teacher
future food One could take the extreme long-term view and ask the question, as Sir Douglas Adams (1980) did, that if there was a restaurant at the end of the Universe what would it serve? Alternatively one could take the more immediate scenario of imagining what foods we will be eating in the next 10 to 20 years. In many cases future food will be barely discernible from existing foods. As humans have done for thousands of years the interaction of environment and consumer demand has influenced farmers’ decisions as to what plants to grow and what animals to raise. Traditionally consumer pressure has come from quality attributes such as taste, visual appearance coupled with a simplistic “is it good for me?” (which translates as wanting to know if the food could possibly be construed as a vegetable, contain vitamin C or at least is not too fatty and salty). The same pressures still exist and will do so in the future; however, what has changed and will continue to do so is the metric of ‘quality’.
Food quality and broccoli Increasingly science is enabling us to determine exactly what food does when we consume it and is answering such questions as: How does food break down during digestion? How do the breakdown products interact with gut bacteria or the intestinal wall? How do the absorbed components interact with physiological processes? Thus we are reaching a position where choices about what vegetables/animals to grow/raise can include the impact on health. Take, for example, the humble broccoli… it has been extolled as a healthy vegetable for many years and is known to contain high levels of calcium, folate, iron, protein and vitamins A and C. Recently, however, we have discovered that beyond these commonly known nutrients broccoli is a storehouse of glucosinolates which, when they come in contact with the enzyme myrosinase (also found in broccoli) under the right conditions, are converted into sulforaphane. Sulforaphane in turn has been demonstrated in vitro to interfere with a range of cancer processes including the inhibition of cancer cell proliferation, induction of apoptosis and angiogenesis. Research conducted by the Vital Vegetables® consortium of Australian and New Zealand scientists has isolated broccoli cultivars with high concentrations of glucosinolates that are to be released commercially in the coming year. Will this future broccoli be significantly different to look at and eat? Well apart from apparently being slightly sweeter, probably not – it will just be better for you. On the manufacturing side of the food production equation there is increasing pressure to convert raw materials into an edible product with the greatest efficiency. Efficiency is a term that is used in almost all human endeavours where we are concerned about waste, but to make a process efficient one has to know, as with the term ‘quality’, what the measure of efficiency is. Traditionally the main concern has been centred on conversion of a mass of raw material into a mass of food product while minimising loss of quality. With a growing change in the view of food quality to encompass the deeper impact of food on health, current research is focusing on minimal processing or rather optimal
processing conditions for a given food. Returning to the broccoli research, we mentioned that conversion of glucosinolates to sulforaphane happens under the right conditions – there is a myrosinase co-factor found in broccoli, epithiospecifier protein (ESP), that if active, results in myrosinase converting glucosinolates to sulforaphane-nitrile, which does not have beneficial physiological consequences. Luckily the ESP is more heat labile than myrosinase which means that a processing window exists wherein a food technologist can design a heat treatment that inactivates ESP while retaining myrosinase activity – the result is a ‘cooking’ process that maximises the yield of the bioactive sulforaphane. Interestingly, it appears that the way in which heat is applied is also important with Vital Vegetables® scientists having discovered that cooking via steaming results in broccoli with higher concentrations of sulforaphane than either microwaving or boiling. Similar research is taking place with many of our existing foods, and with this knowledge the food technologist of the not too distant future will be able to optimise food manufacture based not only on sensory, economic and gross nutrient (protein, vitamins, minerals) compositional data, but will additionally take the impact of processing on bioactives (glucosinolates in the case of broccoli) into account.
futurefocus–food
What will the future of foods look like? Probably the same, yet different from the foods we currently consume, as Dr Alistair Carr, Massey University explains:
126
Future food drivers Future foods are unlikely to come from a vacuum spontaneously appearing on dinner plates and supermarket shelves. Their development will typically be driven by governmental, economic, environmental, and consumer pressures. A recent research project by Allan Hardacre and Jeremy Smith within the Massey Food Technology Department illustrates how these pressures can combine to produce new foods. In New Zealand during the farming of small grain crops, tick beans are used to provide both a disease break and fix nitrogen as part of crop rotation. The tick beans themselves are harvested and used in the manufacture of animal feeds due to their high protein content; however, in this format they yield a relatively low financial return to the farmer. In the wider social environment consumers are increasingly becoming more health conscious and the market segment of healthy foods is increasing yearly. Additionally government regulations worldwide are mirroring the same trend and actively enforce healthy eating such as Arnold Schwarzenegger’s 2005 Californian Senate Bill 12 which regulates foods served in schools. When these factors are coupled with the environmental need for growing tick beans (nitrogen fixing and as a disease break— reducing the need for chemical fertilizers and sprays), and the low economic return when sold as animal feed, a potential was seen in developing a process to incorporate tick beans into extruded snack foods to make them healthier. After optimising the process conditions in the extruder, particle size of tick bean, and the ratio of hull to endosperm, a product was able to be produced with over three times the protein and four times the fibre content of existing extruded corn products. At last we truly can have our cake and eat it without having to worry about that other adage “seconds on the lips, years on the hips”. New Zealand Association of Science Educators
15
NZ
science teacher
futurefocus–food
126
Restaurant at the end of the Universe After looking at the more immediate future of foods we will now envisage the restaurant at the end of the universe scenario and not a bad place to start is from the words of Sir Douglas Adams himself. On board the improbability drive spaceship was a vending machine called a Nutri-Matic Drinks Synthesizer, which, “…claimed to produce the widest possible range of drinks personally matched to the tastes and metabolism of whoever cared to use it. When put to the test, however, it invariably produced a plastic cup filled with a liquid that was almost, but not quite, entirely unlike tea.” Douglas Adams was not the first to envisage such a machine. On board the USS Enterprise, not the US naval variety but the Star Trekkian sort, the crew obtain their meals from a similar type of vending machine which in addition to beverages also serves customised food. Oddly enough these types of imaginings are real possibilities, and there is much research being conducted to enable consumers to have individualised food. Of course individualised food has always been possible on a smallscale, if you have a friendly chef, or access to a kitchen, one can make a mint and marmite flavoured mallowpuff if that is what one desires. What is envisaged here though is individualised food manufactured on a large scale – mass customisation.
Nutrigenomics However, beyond customisation of food based on mere hedonistic reasons, individualisation of food could also take into account the health of the individual and tailor a food based on an individual’s current health status and even their genetics. The input of genetic data into the design of foods for an individual is termed ‘nutrigenomics’. Essentially nutrigenomics comes from an increasing understanding that the health of a person is an interplay between their genotype and the environment – and given that the largest surface area humans have for interaction with the environment is the gut, the importance of food which contacts that permeable surface is significant. This may sound a bit farfetched but such research is taking place. A project based on this concept, POSIFoods™, has been developed in New Zealand by Fonterra and is described in an article by Boland (2006). According to the patent protecting the technology (US7762181) POSIFoodsTM (point-of-sale individualised foods) is a novel system designed to cater for individual health needs and sensory preferences, while at the same time providing the convenience of fast food. The way in which POSIFoodsTM might be implemented is illustrated in Figure 1.
In this scenario a customer will tell the machine what kind of drink they wish to purchase.The machine will use background health data housed in the customer database to design the nutritional composition of the drink within the constraints of the drink choice (the expectation that the consumer has of what the drink should look and taste like) and the interaction of the chemicals in the formulation (consumers prefer the word ingredients) with desired bioactives and fortificants. For example, the consumer might have requested a hot coffee – in this case even though probiotics might be beneficial for the client their addition would be pointless as the probiotic bacteria would be killed by the heat. The client has an expectation that the coffee will not be served lukewarm! The machine may on the other hand add a blood pressure lowering protein hydrolysate (known for their bitter taste) as the algorithm ‘knows’ that the bitterness will be masked in coffee as the client has an expectation that the coffee will be slightly bitter. Within the algorithms there has to be of course safeguards to ensure the dietary intake of fortificants is within a safe range. The technology to bring this invention into reality is not a trivial exercise – it is not a case of a machine adding a teaspoon of this and that as is the case in a modern coffee vending machine. Many of the added nutrients will require addition in milligram quantities, nanoscale delivery mechanisms of fortificants and process optimisation to minimise ingredient interactions or degradation. For instance some ingredients may require dissolving at temperatures that would inactivate other bioactives. Other bioactives may need to be encapsulated to protect them from components in the drink/food, or the environment of the stomach itself. Cleaning mechanisms will need to be provided to avoid contamination of food/drinks. While it is always tempting to look at the future and imagine all the exciting and positive possibilities, it is important to think about foods that we might not have in the future: extinct cuisine. With globalisation and a morphing into a homogenous society, the so-called McDonaldization of society (Ritzer, 2000), foods from cultures on the margins are being lost. The reasons for this loss of knowledge are varied and include active denigration of a culture by governments to passive processes such as urbanization which disrupt the passing of traditional food processing knowledge from one generation to the next, particularly in cultures dependent on oral tradition.
In summary To summarise: future foods are likely to taste and appear largely the same as they do today but they are likely to be healthier, more sustainable, environmentally friendly and hopefully kinder on the wallet than foods of today. Though the differences may be hard to discern, the technology that brings about these changes is not going to be simple. To quote Sir Douglas Adams (1979) ““It is a mistake to think you can solve any major problems just with potatoes.” For further information contact: A.J.Carr@massey. ac.nz ; and for information on how to acquire the skill set necessary to take a lead in making future foods visit: http:// food.massey.ac.nz/.
References
Figure 1: Possible schematic of a POSIFoodsTM vending machine. Redrawn from Boland (2006). 16
New Zealand Association of Science Educators
Adams, D. (1980). The Restaurant at the End of the Universe. Pan Books. Adams, D. (1979). The Hitchhiker’s Guide to the Galaxy. Pan Books. Boland, M.J., Munro, P.A., Haylock, S.J., James, A.D.L., Thompson, A.K., & Archer, R. (2010), Customised Nutritional Food and Beverage Dispensing System. US7762181. Boland, M. (2006). Perspective: Mass customisation of food. Journal of the Science of Food and Agriculture, 86, 7-9. Ritzer, G. (2000). The McDonaldization of Society, New Century Edition, Thousand Oaks, Ca: Pine Forge Press.
Future for evolutionary biology lies in marrying the deepest of questions with new intellectual frameworks and technological advances, as Paul Rainey from the New Zealand Institute for Advanced Study and Allan Wilson Centre for Molecular Ecology and Evolution, Massey University at Albany explains: Creative minds construct questions; minds grounded in reality assess the quality of the questions and, critically, the feasibility of obtaining answers. Banal questions are simply not worth addressing. Great questions are worth thinking about, and indeed may reveal new horizons. But not all great questions are answerable and in the absence of answers, science does not progress. The future for evolutionary biology lies in marrying the deepest of questions with new intellectual frameworks and technological advances.
Darwin and the reason to question With publication of The Origin of Species in 1859, Charles Darwin shattered the idea of Divine Creation and thus gave biologists reason to question. Since this time, the field of evolution has been home to some of the deepest and most profound problems: the origin of life, the origin of heredity, the origin of cells, the origin of multicellularity, the origin of development, the origin of species, the origin of sex, and the origin of societies (to name but a few). Despite theoretical refinement to key ideas and new technologies, tackling these questions is tough, even daunting. With few exceptions, biologists are only just beginning to formulate experimental programmes that might permit theoretical ideas to be empirically tested. Because so much of evolution has taken place in the past, the study of key events has traditionally relied on inferences based on historical and comparative studies. For example, the fossil record in conjunction with isotopic analysis has done much to reveal past species, their time of origin and extinction. When combined with morphological comparisons we have learned about the likely relationship among species, the timing of speciation events, their magnitude and so forth.
Fuel from molecular biology In recent times, spectacular advances in molecular biology have given comparative and historical studies an altogether new lease of life. Capacity to obtain direct knowledge of the order of nucleotides that comprise genes on chromosomes – knowledge of the genetic bases of heredity – has been revolutionary. Where, as we once looked to ancient rocks for insight into past evolutionary events, we can now do so via the historical record that exists within the genome of extant – and more recently, even extinct – organisms. The fact that the most recent of technological advances in DNA sequencing allows entire genomes to be sequenced at relatively little cost opens the door to exciting times. Not only can we expect more accurate phylogenies, but detail insight into differences among species and even individuals within species. With this comes knowledge of how the past has shaped extant organisms, and, perhaps
NZ
even understanding of why some species became extinct. Applied at the level of human populations we are promised great advances in medicine and public health, but equally we will contend with increasingly thorny ethical issues. Comparative genomics is already revolutionizing understanding of the evolutionary emergence of disease. The recent outbreak of Pseudomonas syringae pv. actinidiae (PSA) on kiwifruit vines provides a case in point. Critical questions concern the origins of the NZ disease (import vs. home grown), the length of time in NZ, the rate of evolution in NZ, the relationship of NZ isolates to known foreign isolates and the causes of virulence. As recently as two or three years ago the possibility of obtaining direct (as opposed to indirect and inference-based) insight into these questions was almost non-existent. Today, the capacity to sequence entire bacteria genomes for as little as ~$1,000, means that unequivocal answers to all but the last of the above questions can be got cheaply and rapidly. In essence, evolutionists get to watch and record events happening in real time…in the wild. With newly emerging diseases being a fact of life, the field of comparative genomics will prove increasingly important, and not just for understanding the past. With sufficient knowledge of evolutionary process, opportunities for predicting the future – based on knowledge of the past – becomes truly possible.
126
futurefocus–advancingevolution
advancing evolution by convergence
science teacher
Observing evolutionary process What then of evolutionary process? While much evolutionary biology is devoted to understanding and interpreting patterns of diversity, there is equal interest in underlying mechanism: the evolutionary processes including natural selection, genetic drift, mutation, recombination and migration that, according to the Modern Evolutionary Synthesis, together generate and shape patterns of diversity. Inferences on the operation of these processes have stemmed from both historical and comparative studies, including those that are genomeenabled; indeed, the field of population genetics is devoted to this subject. But to many, the reliance on inference for evidence of process is not only unsatisfactory, but will ultimately fall short of delivering the kind of mechanistic insight that is increasingly demanded. For example, it may be that genome-based studies reveal that the most primitive multicellular organisms differ from unicellular ancestors by certain key genes; analysis of patterns of nucleotide substitution might lead us to infer, let us say, the operation of selection. But such information – as interesting as it would be – would not amount to an explanation for the evolution of multicellularity. Lacking would be knowledge of the all-important selective conditions, the seminal mutations and their phenotypic effects, and the ecological circumstances. Real progress requires that we obtain direct insight into evolutionary process. Of course this poses massive challenges given that we lack an operational TARDIS that might transport us back in time, but possibilities for evolutionary experiments conducted in the laboratory – in real time – that tackle some of the deepest problems are not without substance.
New Zealand Association of Science Educators
17
NZ
science teacher
futurefocus–advancingevolution
126
Experimental evolution and the Holy Grail Studies that directly observe evolution process have a long, but overlooked, history. The good Reverend Dallinger recounted, in his 1887 presidential address to the Royal Microscopical Society, experiments with laboratory populations of microbes that showed the operation of natural selection. Unfortunately Darwin, with whom Dallinger corresponded, missed the significance of the discovery, but then so too did Dallinger. Nonetheless, such approaches have not been forgotten, and indeed over the last two decades, have resurfaced with a vengeance. At the present moment many of these studies are confined to the use of bacterial or viral populations for the purpose of exploring the mechanistic bases of adaptive evolution. However, already with new technologies, such experiments are shifting not only to eukaryotes, but also to the wild. The advances brought by the so-called discipline of experimental evolution have come largely through the provision of experimental tests of longstanding evolutionary theory, but I am certain that as the field matures and experimenters become more confident and ever bolder, the possibility of observing directly, in real time, some of the seminal evolutionary events that lie at the heart of the deep questions stated above, will be realised. Indeed, I will not be surprised if in the next decade or so, I learn that someone, somewhere, has succeeded in observing the evolution of a simple self-replicating chemistry of the sort that may have marked the start of life on Earth. In fact, I would go as far as to predict that studies that progress understanding of mechanism and process will have far-reaching consequences for our understanding of evolution – and even for that holy of Holy Grails – the Modern Synthesis. The Modern Evolutionary Synthesis – to give it its full name – is the cornerstone of biology. Its formulation took place during a time when understanding of the connection between genotype and phenotype (development) was not only in its infancy, but was difficult to reconcile with the Darwinian view of gradual evolution. Accordingly, development was left out of the Modern Synthesis. One outcome of experimental studies in evolution has been mechanistic evidence for development as a causal process. As a consequence, a number of evolutionists have begun to argue the need for an Extended Synthesis – one that incorporates development. Any such extension requires understanding of the factors that affect the translation of mutation into phenotypic
variation – the raw material for natural selection. Central to the translation process is a complex network of functional and regulatory connectivities that define the genotypeto-phenotype map. Theory predicts that this network of genetic interactions – the totality of development – constrains and channels evolution; restricts the pathways it takes and – by imposing limits to phenotype space – defines the rules by which it works. The discovery of numerous examples of molecular parallelism (the evolution of similar or identical features in two or more lineages) in both natural and laboratory populations provides the first evidence suggestive for the existence of evolutionary rules. A striking case comes from the study of flowering time variation in wild populations of Arabidopsis thaliana where null mutations in a single gene account for early flowering in 20 independent populations. A similar example comes from Drosophila where, of the numerous genes that underpin the pattern of epidermal projections known as trichomes, mutations affecting trichome patterning occur solely within the gene shavenbaby. The fact that flowering time variation is regulated by more than 80 genes and shavenbaby by many hundreds of genes, and yet evolutionarily relevant mutations occur at just a single locus, provides justifiable reason to consider seriously the possibility that genetic evolution follows particular rules. Our own work on the genetic bases of phenotypic evolution in experimental bacterial populations has gone even further showing quite clearly that genetic architecture biases the molecular variation presented to selection; that this restricts the pathways taken by evolution, and importantly provides molecular explanations for why.
Future of evolution is not dull The future for evolution is anything but dull. The possibilities emerging through genome and systems-driven research – particularly when combined with genetics, physiology and development – are spectacularly exciting. That these might even converge with laboratory and field-based studies of real-time evolution to bring about an extension of the Modern Synthesis has me itching with anticipation. Of course there are challenges too, but the extent to which we progress will be less dependent upon technology and more on the existence of future students with creative, inquiring minds, and with the capacity for courageous thinking. For further information contact: p.b.rainey@massey.ac.nz
continued from page 20 Into the future... So, the prospect of the $1000 personal genome thought impossible less than 10 years ago is not far away if the Ion Torrent lives up to its promise! Imagine a time when your GP sends a small sample of your blood off to the local pathology lab to have your genome done! Does this prospect excite or worry you? Certainly, knowing what drugs you respond to or should avoid, or what disease susceptibilities you might be carrying that could be passed on to your children is important
18
New Zealand Association of Science Educators
information that many people will find invaluable. It will certainly alleviate the need for genetic testing, should the need arise, and will give people the ultimate choice. Your genetic profile will be all that’s needed and will last a lifetime. The great danger of course is if others get hold of this information and make judgements or decisions that affect you based on their perceived risk. That of course, is an entirely different topic for this brief article. The personal genome is not too far off! For further information contact: jd.fraser@auckland.ac.nz
Thought impossible ten years ago, the prospect of the $1000 genome is now within grasp, as Professor John Fraser, Head of School of Medical Sciences, Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland explains: Ten years ago, the first draft of a human genome was completed at an estimated cost of over 3 billion dollars. Since then, the goal has been to sequence a human genome for the magical target of $1000. New developments look set to make this a reality far sooner than we had ever thought possible. The first draft of a human genome, heralded by a presidential announcement in 2001 was a major scientific achievement. On one side of President Clinton was J. Craig Venter, CEO of Celera Inc., a private company that had sequenced the human genome in a little over a year. On the other side of Clinton was Francis Collins who represented the 15 year long public project. The public project used a method called chromosome walking that begins with large bits of chromosomes cloned into bacterial cosmids (BAC), special plasmids that can hold large inserts of foreign DNA. The BAC library was distributed around the world with each centre agreeing to work on a different set of clones then reporting back their maps and sequences to a central repository. The BAC inserts were mapped to locate known genetic markers and methodically sequenced from end to end. The Celera shotgun method was far simpler. The DNA was broken into millions of random fragments, cloned into a simple plasmid library and sequenced en masse with no consideration of a master map to worry about. All the sequences were pieced together by massive computers using an algorithm that finds and matches overlapping fragments, progressively building larger and larger contigs. Some of the more interesting facts revealed from this first genome include: only 20,500 genes are required to make a complete human being; only 1.3% of the genome contains protein coding genes; only 7% of the genes are unique to vertebrates, suggesting that we humans are only about 7% more complex than flies!; and there are 3.5 billion base pairs in the human genome, which, at a final project cost of over $3 billion, that’s about $1/base!
Next generation sequencing In the past five years developments have improved sequencing capacity by a phenomenal seven orders of magnitude and reduced the cost to 0.0001 cent/base. The new technology is referred to as Next Generation (NextGen) or Deep Sequencing and some argue that its impact rivals the original genome project. NextGen sequencing allows the rapid comparison of multiple genomes or transcriptomes with great accuracy. It has been instrumental in identifying new genetic biomarkers for early detection of cancer and another much publicised project headed by Craig Venter that seeks to map the billions of organisms that make up the ocean’s biodiversity.
The old chain termination method Old DNA sequencing relied on the Sanger chain termination method – named after Cambridge University’s two times Nobel Laureate Dr Fred Sanger. A single stranded DNA
NZ
template is read by DNA polymerase and as it builds the complementary strand, it randomly incorporates either a deoxynucleotide or a chain terminating dideoxy nucleotide (ddNTP). This produces a mix of random sized fragments that are separated through a thin capillary gel. Each fragment that elutes from the capillary is one base shorter than the next and because the four ddNTPs are labelled with fluorescent dyes, the colour of an eluting fragment reveals the terminal nucleotide. High-end Sanger sequencers ran large bundles of capillaries, but the read-lengths were never that good (about 300bp) so the total amount of sequencing achieved in 24 hours from a single sequencer was at best, about ten thousand base pairs.
The new method – parallelized sequencing
126
futurefocus–$1000genome
towards the $1000 genome
science teacher
The first NextGen sequencer was marketed in 2004 by a company called 454 Life Sciences founded by Jonathan Rothberg. Rothberg developed the idea of separating, amplifying and sequencing millions of individual DNA fragments using the surface of a microchip. Several companies have since developed different flavours of this basic concept, but all NextGen sequencers employ the shotgun approach and sequence millions of DNA fragments simultaneously in massively parallel arrays. The trick to this revolution was figuring out how to capture, amplify and deposit individual DNA fragments in a dense array. The technique of PCR remains fundamental to this process because without amplification there’s just not enough of the original DNA to generate a detectable signal. This method consists of three stages as described below (Figures 1A, B, and C). Step 1: Library generation A common method (but not the only one) is to attach synthetic universal primers called adaptors to the ends of random DNA fragments produced by enzymatic cleavage or physical shearing. The adaptors act as primers for all subsequent polymerase reactions in steps 2 and 3. The fragments with adaptors are captured onto tiny beads densely pre-coated with a complimentary synthetic primer. Dilution ensures that on average each bead only captures a single DNA strand. Step 2: Fragment separation and amplification. The beads are separated from each other by nebulising in a water/oil emulsion droplets that also contains the ingredients for PCR. Amplification contained within the oil/water droplet coats the bead with thousands of clonal copies of the original fragment. The beads are then deposited onto the surface of a chip coated with millions of wells just big enough to hold a single bead. Step 3: Sequencing There are three main sequencing methods used. Pyrosequencing developed by 454 Life Sciences passes a cocktail of enzymes and chemicals across the surface of the chip. Individual beads emit a flash of luminescent light when a phosphodiester bond is made signalling the addition of a nucleotide. The drawback with this method is that a separate cycle is needed for each of the four dNTP additions, slowing the process. The company Illumina has developed another method shown in Figure 1D. Here the cocktail contains DNA polymerase and four terminating dNTPs each with a different fluorescent dye. The fluorescent chemical prevents the addition of any more than a single base. An image is New Zealand Association of Science Educators
19
NZ
science teacher
a)
b)
c)
d)
futurefocus–$1000genome
126
Figure 1: A – First DNA is fragmented and capped with synthetic oligonucleotide adaptors; B – An individual fragment is captured by a tiny bead densely coated with a complimentary synthetic primer; C – PCR amplification results in a bead coated with clonal copies of the fragment. This is performed in a nebulised oil/water droplet to keep each bead isolated; D – Once the beads are deposited on the chip surface, the sequencing cocktail is passed across the surface. The Illumina approach uses 4 fluorescent dye tagged nucleotides. An image is taken and deconvoluted to give the growing nucleotide sequence for each spot. The fluorescent dyes must be removed after each cycle. taken of the array at the end of each cycle to record the colour of each spot before the dye is cleaved off, freeing up the 3’ hydroxyl of the growing sequence ready for the next cycle. Because all four bases are added, every bead sequence is extended although an additional cleavage cycle is required. If the cleavage is not efficient, the signal from following cycles progressively diminishes. A third process developed by the company Applied Biosystems uses ligation based sequencing. The cocktail that passes the chip surface contains DNA ligase and a large pool of 8bp fluorescent primers that anneal and ligate to the DNA template with the first 2 bases at the 5’ end determining specificity. The colour of each bead reveals first 2 bases. The last 3 bases of the primer containing the fluorescent dye are then cleaved off to allow the next cycle to proceed. The sequence is therefore built up 2 bases at a time with a 3bp gap in between. Once the first cycle set is complete, the entire strand is removed by melting and the process repeated but using a starting primer that is one base shorter than the previous. This means the sequence starts at n-1. This primer reset is repeated 4 times so that every base is interrogated twice leading to much greater accuracy. The ABI SOLID currently boasts the highest capacity at 30 Giga bases/run and the highest base calling accuracy at 99.99% (1 base in every 10,000 is possibly wrong).
than one base is added – such as in homopolymer stretches – the voltage is proportional up to 6X that of a single base addition. The voltage change is converted immediately to a remarkably simple single digital value. This requires no more than a laptop to record and store. The Ion Torrent also eliminates the need for expensive reagents such as fluorescently labelled terminating nucleotides. Instead, as Rothberg proudly announced: Ion Torrent decided not to fight one billion years of evolution and went with unmodified bases and DNA polymerase! These are dirt cheap so the reduction on cost is just enormous. While currently the throughput of the Ion Torrent (0.5Gb) does not match that of an Illumina HiSeq (10Gb) or the ABI SOLID (30Gb), time will inevitably see the density of the semiconductor wells on the Ion Torrent chip increase (perhaps to the level of today’s microprocessors) and the read lengths extend to the point where this technology rivals or surpasses the current NextGen sequencers – at a fraction of the cost!
The next step in NextGen sequencing In a recent development, the company Ion Torrent headed again by Jonathan Rothberg of 454 Life Sciences fame, has developed a microfabricated semiconductor chip (currently 1.4 million wells are on a single chip) that detect a pH change from the release of a proton during nucleotide addition. The Ion Torrent does away with expensive light, optics’ and lasers’ systems and so is a much cheaper and faster method. Notably it does not require the high resolution images that generate multi-megabyte files after each cycle. Rather, it simply samples each of the 1.4 million wells 50 times a second for any change in voltage that signals that a base has been added and a proton released – a reaction that is completed in 5 seconds. When more 20
New Zealand Association of Science Educators
Figure 2: A typical image of an Illumina chip surface.
continued on page 18
Polynesia is probably the best region in the world to understand the origin and dispersal of human groups and its impact on naïve environments, as Professor David Penny, Institute of Molecular BioSciences, Massey University, explains: When Captain Cook and his naturalists first sailed around the South Pacific they wondered how the distant and remote islands of Polynesia were settled. Where had the people come from? How had they got to these islands? The Europeans considered themselves great sailors and navigators (and they were), but they recognised it would have taken another people with great sailing and navigation skills to have discovered and settled Polynesia (Figure 1). In their talking with Polynesian navigators they were quickly convinced from the knowledge of the Polynesians that they knew a lot about navigation at sea – the stars and constellations, waves, and how the behavior of sea birds could be used to indicate the direction of land. So really, there were two great sets of sailors and navigators in the Pacific: the Polynesians and the Western Europeans. What does modern science tell us about where the Polynesians came from? What extra will it tell us in the future? We do need to be careful – we will get different answers at different times, for example, where were the Polynesian ancestors 2000 years ago, 3000 years ago, 4000 years ago, etc. Because it occurred so recently, Polynesia is probably the best region in the world to understand the origin and dispersal of human groups, their domesticated plants and animals, cultural and linguistic evolution, and human impacts on a pristine environment.
A brief background to the region 14
C dating indicates that modern humans entered Australia and New Guinea by ~50 000 BP (before present) – soon after the DNA evidence shows modern humans spreading out from Africa. Although Australia and New Guinea were connected during periods of lowered sea levels, the first settlers must still have crossed the open ocean from Southeast Asia. By 29 000 BP, people had colonized the Bismarck and Solomon Islands, which together with New Guinea, form ‘Near Oceania’. But nobody was in Polynesia. Then, around 3300–3500 BP, a new culture – Lapita – appears in the archaeological record of Near Oceania, and in a previously unoccupied coastal niche (their stilt houses were often built over beach reefs or shallow lagoons). Lapita is characteristically defined by a decorated pottery style, and is named after an excavation site in New Caledonia. Lapita culture introduced new features, including permanent villages, a range of horticultural crops, domesticated animals (pigs, dogs, chickens and rats), fishhooks for inshore and open ocean fishing, fishing nets, seagoing canoes, stone adzes, anvils and shell bracelets. Although this expansion is thought to have started in China following the domestication of rice, it may have been in Taiwan (5000–4500 BP) that the basic canoe building expanded, and we can trace the expansion back that far. From Taiwan the expansion continued to the Philippines (4500–4000 BP), to Wallacea (the biogeographical area
NZ
between Borneo and New Guinea, Figure 1) and to Near Oceania. Within another 200–300 years the Lapita culture is found in some parts of previously uninhabited ‘Remote Oceania’ (Eastern Melanesia, Micronesia, and Polynesia – including sites in Vanuatu, New Caledonia, Fiji, Tonga and Samoa). Then there appears to be a pause of at least 1000 years before permanent settlement of the easternmost islands of Polynesia; greater skills in sailing and navigation were required. So Taiwan is the start of our answer.
What does molecular genetics tell us? The two main markers used so far are the mitochondrial DNA (mtDNA, which is inherited maternally by both sons and daughters) and the Y-chromosome (inherited paternally, but in males only). An important ‘signature’ in most Polynesian mtDNA is the loss of one copy of the sequence CCCCCTCTA of some individuals. In other words, most humans have two copies repeated one after the other (CCCCCTCTACCCCCTCTA), but because it is in a ’spacer’ region between two genes it doesn’t seem to matter whether one, or two, copies are present. Thus the mutation is thought to be ‘neutral’; ‘neither beneficial nor injurious’ in Charles Darwin’s words. We summarise this as a 9-bp (base pair) deletion, and the loss seems to have happened occasionally and independently in different parts of the world. Together with three other mutations the 9-bp deletion forms a ‘Polynesian Motif,’ and its distribution is very informative. The full motif has its highest frequencies in Polynesia (where it predominates), and is largely confined to speakers of the Central/Eastern Malayo-Polynesian subgroup of Austronesian languages in Wallacea and the Pacific (Figure 1). Stepping backwards, the ancestral lineage with two out of the three mutations (plus the 9-bp deletion) is found across the range of Austronesian speakers from Madagascar to Easter Island. However, the earlier lineage (with only one of the three mutations) is confined to the central part of this range, and among the indigenous Formosans. Thus, this pattern of a directional series of mutations shows the dispersal of the 9-bp deletion from Taiwan. Earlier still it must have come from somewhere in East Asia, but there have been too many population changes there to follow it yet. Basically, the mtDNA and the archeology agree about Taiwan.
126
futurefocus–DNAandpolynesianmigration
Taiwan and the origin of Polynesians
science teacher
What can we learn from languages? Before moving to the Y-chromosome, let’s consider languages. It may seem surprising, but we can use similar methods for analyzing the evolution of languages as for the evolution of DNA seqeunces. Austronesian (including Polynesian) is the world’s largest and the most widely distributed family of languages. Its ~1200 languages are classified into ten subfamilies, nine of which are spoken only by indigenous Taiwanese (the Formosans). By contrast, languages of the tenth subfamily, Malayo-Polynesian, are spoken from Madagascar (47° east) to Easter Island (109° west), and their relative similarity suggest that they share a recent common origin. Examine the words in the different languages in Figure 2. The world waka, vaka, va’a and wa’a is considered the same word; the ‘v’ ‘w’ change is quite common between related New Zealand Association of Science Educators
21
NZ
science teacher
a)
futurefocus–DNAandpolynesianmigration
126
b)
Figure 1: Map of Near and Remote Oceania, with ice age sea levels, language families, Polynesian paternal and maternal lineages, and archaeological dates. (a) The distribution of Austronesian subfamilies, and their phylogenetic relationships. The Malayo-Polynesian (MP) languages include Western (WMP), Central and Eastern (CEMP), Central (CMP), Eastern (EMP) Malayo-Polynesian, as well as South Halmahera/Western New Guinea (SHWNG) and Oceanic. Shading indicates the approximate coastline during the last glacial maximum. (b) Age of the earliest evidence for permanent settlement for Neolithic (black) and post-Neolithic (blue) archaeological sites throughout the region. Particularly on islands, exploration and discovery would be earlier. (Ref: M. E. Hurles, E. Matisoo-Smith, R. D. Gray and D. Penny (2003). Untangling Pacific settlement: the edge of the knowable, Trends in Ecology and Evolution 18: 531-538)
languages; as is the ‘k’ becoming unsounded and being a ‘break’ in the word. So we conclude that all the eleven languages share the same word, and so we record it as the ‘same character state’ – just as we would for the same nucleotide or amino acid in a sequence. But when we come to ‘rainbow’ the languages of Tonga and Niue have a different word than the others, so we code nine languages as sharing the same word, and the other two as different. We then use methods designed for DNA seqeunces and find the tree of languages that have the minimum number of changes. The top panel in Figure 1 shows the results of such a tree. The oldest languages are the 9 subfamilies of Austronesian from the Formosan peoples in Taiwan; then there are many languages in Western Malaysian/Polynesian; then the Central group; then the division into the South Halmahera/ Western New Guinea and the Oceania groups (that includes the Polynesian languages). So archeology, mtDNA, and languages agree.
The Y-chromosome DNA Y chromosome studies enrich the picture across Polynesia and island Melanesia. Several recent studies report two groups of Y-chromosome lineages predominating in Polynesia, one of which is absent from the current population of indigenous Taiwanese. The best interpretation we have is that, throughout prehistory, some males kept migrating eastwards, and were accepted into local groups, including Polynesians. 22
New Zealand Association of Science Educators
Biologists accept some interbreeding as helpful in increasing genetic diversity (the royal houses of Europe show some of the problems of close interbreeding). This result reinforces that the Polynesian ancestors kept changing and adapting as they moved from Taiwan, to the Philippines, Near Oceania, Remote Oceania, into Western Polynesia and finally into Eastern Polynesia.
Did the Polynesians get to the Americas, and back? Yes, is currently the best supported scientific answer. The first evidence came from the kumara (sweet potato), all the wild (non-domesticated) species are in South and Central America. Yet on Captain Cook’s voyage, herbarium samples of kumara were collected from plants being cultivated in New Zealand! So on this evidence it looked as if the Polynesians might have brought it back (most of the Polynesian crop plants were from the west – from SouthEast Asia – so the kumara was an exception). In addition, in the Quechua language of Peru the term for sweet potato is strikingly similar – kumar – compare kumara. DNA studies on Eastern Polynesian kumara (including from New Zealand) show that they relate to kumara varieties in Peru – they are different from the current main commercial varies that come more from Central Americas. The plot thickens. There were early reports that chickens were present in South America before the arrival of the Spanish. Then some old chicken bones were unearthed from Chile that have been 14C dated to before Spanish
Tonga vaka ua nima fefine
Niue vaka ua lima fifine
Samoa va’a lua lima fafine
rainbow
‘umata tangaloa nuanua
E.Uvea vaka lua nima fafine
E.Futuna vaka lua lima fafine
Mangareva vaka rua rima ahine
Marquesas vaka ‘ua ‘ima vehine
Hawaii wa’a lua lima wahine
Tahiti va’a rua rima vahine
Tuamotu vaka rua rima vahiine
Rarotonga vaka rua rima va’ine
nuanua
nuanua
anuanua
aanuanua
aanuenue
aanuanua
anuanua
aanuanua
NZ
science teacher
Figure 2: A sample of cognate (homologous) words for eleven Polynesian languages. Noncognate terms are in an italic bold font. arrival. And ancient DNA techniques from these bones make it probable that these are ancient Polynesian chickens. The evidence is still partly disputed, so it would be good to have more ancient bones, and more DNA from ancient bones of both South American and Polynesian chickens. The work continues. There is now evidence of a Polynesian settlement just off the coast of Chile, evidence from sailing technologies in parts of South America, and even evidence from archeology from islands off the coast of southern California (possibly a more northern contact from Hawaii?). Thus the genetic, archeological and radiocarbon dating supports the contact. So the best evidence we have at present is that such as the Polynesians left the chickens in South America, and brought back the kumara; we call this the “chicken ‘n chips” model. But – and it is an important ‘but’ – as good scientists, we always look for a more thorough testing of our models and our ideas.
Conclusions and future directions Increasingly we will see whole human genomes being sequenced, and this will give even more detailed
information of the history of the Polynesians. If there was ongoing acceptance of males into the local groups, we may find a gradient across the Pacific, with less introgression the further eastward we go? Molecular genetics offers many opportunities for increased precision, and we find the subject attracts mathematicians and physical and computer scientists. A new opportunity comes from the detection of haplotype blocks – relatively long stretches of nuclear DNA where recombination has not occurred for many generations. Increased genetic study of commensal and domesticated species, such as chickens, pigs, taro, breadfruit and kumara are necessary. Models of long-distance voyaging make getting to South America and back realistic for early Polynesians. Nowhere else in the world offers the same opportunity to unravel the dramatic and complex effects of humans on the environment and on indigenous plants and animals. Everything we have learned confirms that Remote Oceania is the best location to test our understanding of human migration and impacts on a naïve environment. For further information contact: D.Penny@massey.ac.nz
126
futurefocus–DNAandpolynesianmigration
Meaning canoe two five woman
continued from page 25
New HPS questions internationally Within healthy science there is a critical dynamic, but for there to be such a dynamic requires at the same time a complementary dynamic of (considered, rationally defensible) trust. The social negotiation of this relationship is researched (e.g. by Helen Longino, a leader in this field) with the critical purpose of understanding when science is sick, not only when it is well. A particular case concerns professional determination that complex scientific experimentation has come to an end; that equipment (often constructed and maintained by whole teams of people, typically diverse in their expertise, and even at odds with one another in the general view they have of the natural world) has produced results that truly tell the characteristics of arcane phenomena of nature. Peter Galison and Ian Hacking are among the leaders of this sociological, but at the same time epistemic, work on experimental science. A wonderful new set of questions arise because of
heightened recognition of the sociological richness and independent epistemic significance of the experimental side of science. What relation cognitively is there between the refinement of practical skills, and our possession of clear or contentful concepts? The question reaches beyond the naïvety of empiricist operationalism into contemporary reaches of cognitive science, as well as the depths of Heideggerian philosophy. Work like Galison’s and Hacking’s on experimental science also models on the sociological microscale the formation of trust surrounding pronouncements by science. On the sociological macroscale such understanding is pertinent to key social issues of the present day, such as evaluating the trust owed by the polis to scientific concerns about geohazards, greenhouse gas emissions and climate change, water geological issues surrounding agriculture or health, vaccination avoidance, antibiotics overuse, and so on.
futurefocus–HPS
meaning, mentation, and who is who in the history of philosophy, including in recent and contemporary philosophy. They have all marked philosophy of science from these parts in ways that the rest of the world truly recognises and truly cares to know about. Meanwhile, historians of science in the two countries broaden understanding among other things of Australian and New Zealand contributions to science, and of the science-society relationship down under. With regards to the New Zealand connection, look out for works by Rebecca Priestley for example. One aspect of science-society relationships is the relation of down under indigenous and down under later arriving peoples. I am myself exploring this in the New Zealand connection.
Concluding concern One could have expected that universities worthy of the name would ever secure a place for academics who pursue these general, reflective concerns, and thus for their mode of reflection. But that expectation is challenged by most contemporary universities, perhaps especially those in Australia and New Zealand. Individualised by recent re-design to an egregious extent, universities also fail to advance liberal education. Students breathe the same air as their teachers. They focus and follow a single path. The number of, say, science or engineering students, who branch out and study HPS, falls away. I am not as confident as I would wish to be that NZ will even hold onto this significant and important mode of reflection on science. For further information contact: philip.catton@canterbury.ac.nz New Zealand Association of Science Educators
23
NZ
science teacher
futurefocus–HPS
126
HPS: future trends The idea itself of science originated in human historical terms remarkably recently. To elucidate this idea, explain its origins and adequately evaluate its significance are the defining work of HPS. Dr Philip Catton, co-ordinator of the University of Canterbury programme in History and Philosophy of Science, provides the following outlook on future trends in this endeavour. Future of HPS in the NZ science curriculum Curriculum agenda reflect an ideal: that not only students of science, but also their educators should be knowledgeable about the history of science. Moreover, they should be able to reflect (or philosophise) upon what makes science valuable. Their claim to know what science even is seems legitimate only to the extent that they have reflected both carefully and well about how science is possible. Yet, wherever in the rush of professional life would time exist for these demands to be fulfilled? Postmodern life pastes into paper documents supposed imperatives such as “examine science in the making”,“promote understanding of personalities that have helped make science possible”, “study the risks to science – why the culture and tradition of scientific excellence is fragile”,“recognise science to be too young to have yet asked, let alone answered, all its potentially important questions”,“discuss the interrelationship of theoretical and experimental science, and between science and technology”, and “coach students to greater sophistication about the methodology of science, and about the richness of the question what the methods are of science”. Yet postmodern life also is not conducive to sustained and searching reflections. Of all the richness that HPS (history and philosophy of science) could bring to fulfilling these imperatives, little is known to most educators, who are by no means supported to read and discuss and reflect on it, and still less is ever brought to students of science either at secondary or tertiary levels. It is a truism that because there is science our society is far different from how it might have been. I dearly wish that HPS were part of everyday intelligence, as a means for thinking about our society. How does science work and what are its effects? Given that science is implicated in most of the greatest challenges and many of the greatest triumphs of our age, what values quite generally would we – who live in this scientific era – most coherently possess? In what ways are social trends (for example, towards ever heightened individualisation of people, and magnification of professional focus) liable to help science advance and what threats inhere in them to the integrity even of science? Is science an enhancement of or is it more significantly a threat to the human prospect? I believe not only that HPS has evolved worthy relevant research concerns, but I also believe that to pause over and support and participate in HPS reflections has never been more important in society than it is now. Because curriculum agenda reflect an ideal, I am confident that official calls will continue that science educators should know about HPS and should take inspiration from HPS into their teaching of science at school. The present article briefly examines future trends, not only within HPS but also affecting it.
24
New Zealand Association of Science Educators
HPS’s interdisciplinarity Parents of three who produce a fourth child soon discover that four seems a whole lot more than one more than three: once the fourth child grows a little, possibilities for two-way sibling squabbles will have doubled from three to six, possibilities for three-way squabbles will have quadrupled from one to four, and there will now obtain the unique new possibility of four-way squabbles among the children; thus, with the addition of simply one more child to a former brood of three, eleven kinds of potential tension among the kids will have replaced four kinds formerly. Also, opportunities for mutuality will have increased in the same non-linear way. There is not one-third-again, but rather almost-triple the noise; and there is not one-third-again, but rather almosttriple the potential joy. The jump from three to four is merely illustrative. The point is that both richness and complexity of relationships increase non-linearly with the number of things related. Three is in this respect a lot more than one more than two; five a lot more than one more than four, and so on. HPS wears threefold interdisciplinarity in its official rubric but in fact combines far more disciplines than three. It bridges the ‘two cultures’ of humanities and natural science quite by making relevant for reflective purposes skills and knowledge from almost all the various disciplines in either culture. HPS is amply noisy and joyful, academically speaking. I will illustrate this below, citing current trends. While it is thus in its way a happening field, some similar forces threaten HPS today, as today turn people away from having large broods. Let me address for a minute this surprising connection and then remark my hopes (even so) for significant further progress of HPS. The world needs human procreation rates to fall. But that need is not why birth rates fall. People today experience life as fast and demanding. The capitalist system of production and consumption works hard to individualise people. Every public institution is affected by its imperatives, including schools and universities. These factors shift people’s aspirations and planning. Few elect to manage the demands of career together with care for numerous progeny. In an individualised society, progeny are in any case no substitute for personal retirement saving, nor are they any longer quite as they once were hallmarks of the social definition either of success or even of personal joy. The ultimate reason why birth rates fall is the individualising demand for job focus, as well as the related heightening of aspirations for maximisation of individual material consumption. To pause over and take interest in the richness of interdisciplinary studies is against the spirit of our times. Just as professionals experience the demand for job focus the most keenly and so their birth rates are lowest, university studies are these days especially liable to concern narrowly the demands of a major subject. Some aspects of our times are welcome: a lowered birth rate for one. (This is complex to think through, in part because each child, in her- or himself, is precious. We need children to arrive in abated numbers, but we also need those who do arrive to flourish. Yet many instead lose out. Adults’ need for job focus can be a factor in a child’s losing out, as absence of siblings also can
Frontiers of science interdisciplinary An irony is that science innovation itself much requires the skills and knowledge of multiple disciplines to be combined together. Conspicuous in ‘big’ science – such as experimental particle physics, or experimental biotechnology – is deployment together of expertise of multiple kinds. Participants who make one single project of ‘big’ science happen often run to the thousands, and generally neither all have the same skills nor think the same way. It is even often necessary in order for the ‘big’ science project to flourish that those involved do not think altogether compatibly. One marvel of the present day is the social design of ‘big’ science. Quite without mitigating the narrowness of focus of individual researchers, things are accomplished socially that combine skills and knowledge from diverse fields. The very understanding what disciplines there are (and what their point is) can shift thus for sociological reasons. Fifty years ago, life science and engineering could scarcely have seemed more disparate, yet today it’s fuzzy to distinguish between them. Likewise, fifty years ago meteorology seemed a relatively mature field, whereas computing was merely nascent. No one anticipated that connection would happen that would be enormously fertile for both. Within agglomerative ‘big’ science movements that are significantly interdisciplinary at the level of the collective, amazing job focus is nonetheless possible at the level of the individual. Yet, is anyone wise about what is going on? This is an HPS concern if ever there was one.
Current struggles for HPS and past glory HPS is diminished the more that the academy is individualised. In its interdisciplinarity HPS emblematises academic need for discussion. The greatest of its practitioners are polymaths, but not by dint of secluded silent reading. Rather, they are passionate public people with pronounced concerns about science, its health, its worth, and the health and worth of society’s direction in relation to it. The learning behind them, while vast, is similarly publicly oriented and publicly acquired. Greek-oriented sweeping history of science like William Whewell’s or George Sarton’s aimed to expand the classical self-understanding of the West, so that natural science – not only political philosophy – expressed itself duly in that understanding. As philosopher, Karl Popper far furthered this redefining re-evaluation. Popper essentially prioritised philosophy of science to political philosophy in his own championing of the ideal of the Open Society. In doing so, he quite non-standardly chose his heroes among the Greeks: for example, he chose to revile Plato – and to a lesser extent Aristotle – rather than admire them, and to champion some “Presocratic” philosophers that most had viewed as curiosities. Complementary to this, yet at the same time correcting of it, historian Otto Neugebauer helped direct ‘history of science’ attention beyond the West. Neugebauer cultivated rich discussion of cultures of inquiry in the ancient world and of transmission of ideas around about ancient societies and down to medieval and even modern times. Neugebauer thereby enhances the understanding potentially available
to contemporary society of where it comes from. Among the HPS experts, convictions change steadily even now concerning the causes and character of the modern ignition of science. The new studies address the rich question whether in any good sense of the word a scientific ‘revolution’ truly occurred. Key to this debate is the question of the relation of natural philosophy to science, with historians of science recognising within the intellectual culture of eighteenth, nineteenth, and even twentieth century society a diversity of currents that in their diversity but interconnection blur and otherwise complicate the very understanding of science. Re-evaluation of contemporary intellectual culture even as regards our self-conception as a scientific society is strongly invited by this work, which again is amply important politically. What is it for public decision making to go well, on matters that require to be informed by science? Crucial pertinent work towards resolving this is helped along by contemporary HPS.
NZ
science teacher 126
futurefocus–HPS
be.) However, there are many effects of individualisation that are not so good. Not all professions are enhanced by job monasticism. The exigencies of individualisation are doubtless damaging to pursuits that demand interdisciplinarity. They even hurt the prospects for people to be wise about themselves and their projects; for maniacally focused people cannot be wise. In order to be wise a person must take pause for searching, rational reflection.
HPS trends in Australasia Australasia has sported many distinguished philosophers who ruminate about science in an appreciative way. A lot of their work broadly metaphysical, a lot broadly epistemological, Australasian work typically is sharply distinct from positivist-influenced philosophy of science of the Americas. It is also typically sharply ill-disposed to the German Frankfurt School on one hand, and to all varieties of post-modernism on the other. And it is often touched by particular Australasian penchants (for example, for vigorous realisms, and for an ontology-semanticsepistemology direction of investigation), yet always with break away developments that defy these generalisations and sometimes establish new trends. The early greats of the Australasian HPS scene were Popper (in Christchurch) and Gerd Buchdahl (in Melbourne). Those were heady days when scholars ruminated chiefly about what they took to be the whole defining nature of science. As philosophy of science has developed, its practitioners have generated ever more reason to be suspicious against the conception that there is one single self-consistent thing that science is, or indeed that similarly reductive accounts are possible of theory, commitment, evidence, explanation, cause, law, meaning, reduction itself, and so on, which were all key questions within the heady days of mid-twentieth century philosophy of science. A significant trend is away from thinking realism (the conviction that theory is about more than organising empirical facts economically, and concerns the reality behind those appearances) a hot and central concern of all philosophy of science. The more so in recent decades, much Australasian philosophy looks into abstruse reaches of specific theoretical sciences. While classical physics and relativistic space-time theory (about which realism seems possible) eclipses quantum theory (about which realism seems impossible) as an Australasian preoccupation in philosophy of physics, there are exceptional Australasian philosophers who do both. Biology has come on strongly as science of choice in the Australasian philosophical arena (philosophy of biology now a vibrant down under subdiscipline very high in its international standing) and is a science which in its nuances pushes back in its way against philosophicalbanner-carrying either for realism or for anti-realism. And so, too, have distinctive Australasian forms of philosophical thinking about materiality, complex systems, mathematics, logic, universals, ontology, causality, time, possibility,
continued on page 23 New Zealand Association of Science Educators
25
NZ
science teacher
futurefocus–microfluidics
126
microfluidics have huge potential Microfluidics is a new fast-growing area for research and development, and has already given us the ink-jet printer and improved medical technologies. Currently, there are two exciting projects being undertaken at the University of Canterbury, as Mathieu Sellier and Volker Nock explain: Introduction Microfluidics, literally micro-scale fluid dynamics, is a new, fast-growing area of research and development. The growth of this field has been driven by its technological potential, and the range of fascinating scientific and engineering challenges arising at the micron or sub-micron scale. This article draws on two recent projects from the University of Canterbury illustrating how this field is pushing the boundaries of technology and science. The historic origins of microfluidics are found in the micro-analytical methods, where in the 1990s the use of micro-capillaries revolutionised chromatography. IBM then realised that controlling small-scale flow phenomena could benefit the printing industry: ink-jet printers were born. Nowadays, medical technologies provide the major driving force with microfluidics promising to enable personalised point of care diagnostics such as immunoassays, blood analysis and drug delivery, as well as DNA sequencing. Traditionally, the development of microfluidics parallels that of microchips in a computer. A microchip, like a microfluidic device, includes a multitude of small-scale electronic components performing basic functions. The resulting chip is able to perform highly complex tasks as a result of integrating these basic components. The equivalent concept to the microchip in the context of microfluidics is the ‘Lab-on-a-chip’ which aims to emulate the functions of a macro-scale analytical laboratory on a pocket-sized device. Similar to the strip conductors in integrated circuits, microfluidic devices have microchannels through which fluid samples are transported. These microchannels typically have dimensions ranging from 1 to 100 microns (100µm is the average diameter of a human hair). This small scale means that only minuscule amounts of sample fluids are required. The latter constitutes a key advantage of microfluidics as for example, smaller sample size means less blood is needed for analysis thus reducing patient stress in particular in long-term treatments such as for diabetes. Furthermore, the reduction in size combined with the integration of the various processing functions on a single chip allows a much higher throughput resulting in cheaper and faster diagnostics. Many reagents in personalised medicine, such as for targeted cancer treatment, are very expensive and only microfluidics make their use feasible. A third major advantage of microfluidics is that it relies on small-scale flow phenomena, normally absent at the macro-scale, which can be exploited to achieve novel applications. The next section describes in more detail the fundamentals and related physical phenomena of the field of microfluidics.
Microfluidic fundamentals All microfluidic devices involve one or more of the following basic functions: fluid transport, mixing or separation of 26
New Zealand Association of Science Educators
reagents (inputs) and detection of reactants (outputs). The typical building blocks of a microfluidic device are the pumping system, the interconnecting microchannels, the reacting chambers, and an output in the form of a detection mechanism or a sample interface. Many of the manufacturing technologies used to engineer microfluidic devices originate from the semiconductor industry and traditionally use the same materials such silicon and glass. More recently, the use of polymers has become prevalent because of its ease of use and potential low cost for mass manufacturing. Polymer-based fabrication commonly relies on photolithography, a process capable of the highthroughput reproduction of micrometer-sized features using light. At the University of Canterbury this usually first involves the creation of a photomask of the fluidic circuit using Computer-Aided Design software and a laser mask writer. UV-light is then shone through this mask to transfer the pattern onto a photoactive polymer generally referred to as photoresist. The non-exposed areas of the resist can then be washed away leaving a three-dimensional relief. This relief constitutes an inverse replica (master) of the microfluidic channels and can be repeatedly replicated into a polymer (mold) by casting, a technique similar to injection molding. The fluid flow inside microfluidic devices is described by the Navier-Stokes equations, a set of complex differential equations derived more than two centuries ago expressing the conservation of mass and momentum. Because of the highly confined nature of the flow in microfluidic devices, fluid friction prevails over fluid inertia. Since inertial effects are responsible for the appearance of instability and ultimately turbulence, the flow in microfluidic devices is generally turbulence free, i.e. laminar. Laminar flows are characterised by near parallel streamlines with very little cross-flow mixing. This reduction to diffusive mixing sometimes limits reaction kinetics at the expense of device throughput. Another important consideration in microfluidics is that the pressure difference required to drive the flow for a given flow rate is inversely proportional to the fourth power of the channel size, i.e. if the size of the channel is halved, the pressure requirement is increased by a factor 16 imposing a great demand on the pumping mechanism and the device seals. In contrast, the sharp increase in surface area-to-volume ratio compared to macro-scale devices results in an improved heat and mass transfer from the channel walls to the bulk of the fluid. Surface tension effects, also known as capillary effects, thus dominate when more than one fluid phase co-exist.
NZ
science teacher 126
futurefocus–microfluidics
Figure 1: Photographs of microfluidic devices used for the generation and measurement of oxygen gradients. (a) A three-stream laminar flow device with attached gasexchangers. Inlet flows from three exchangers combine in the central microchamber. (b) With a subjacent oxygen sensor film. White arrows indicate the flow direction. Blue dye-coloured water was used for visualisation. (c) Fluorescence microscopy image showing the different oxygen concentrations (high brightness ~ low O2) of the three streams inside the chamber at different locations. As can be observed from the image, due to laminar flow and despite being in direct physical contact, the individual fluid streams do not mix. The slight broadening of the cross-chamber plot at the outlet is a direct result of interstream oxygen diffusion. Source: Nock et al. (2010).
Surface tension effects – responsible for the curved meniscus in capillaries or the spherical shape of small droplets for example – are often overseen at larger scales because they are dominated by gravity. However, this is not the case at small scales, thus giving rise to a new paradigm coined ‘digital microfluidics’. Here fluid droplets are used as solute carriers instead of fluid streams in microchannels. A more complete review of the fascinating physics involved in microfluidics can be found in References 1-3. This brief exposition highlights some of the peculiarities of microfluidics and the following section will illustrate via two examples drawn from research projects undertaken at the University of Canterbury how these features can be exploited.
Figure 2: Microfluidics with droplets. (a) Microfluidic platform to generate droplets in a controlled manner and induce propulsion. The dyed fluid is pushed through small microchannels embedded in the substrate and escapes through micron-size ports to generate droplets. (b) Droplet propulsion induced by the coalescence of a pre-deposited dyed water droplet (labeled DI) and an ethanol droplet deposited in the top right-hand corner of the picture. The sequence reading from top left to bottom right shows the droplet system moving and taking the corner. See Ref 5 for more details.
Microfluidic applications 1. Multistream microfluidic devices As mentioned previously, flow in microchannels is predominantly laminar. This for example, makes it possible to combine several different streams in one chamber without convective mixing. Upon contact, the individual streams will form a stable inter-stream boundary and continue to flow parallel to each other. Due to the absence of cross-stream flow reagents, such as dissolved oxygen (DO), in the different streams only exchange via lateral diffusion. As this process is slow compared to the time in which the combined body of fluid traverses the chamber length stable concentration gradients can be formed across the chamber width. At the University of Canterbury we use these so-called controlled micro-environments to study the reaction of human cancer cells to variations of DO. Not only an important parameter with significant effect on cellular development and function, oxygen or rather the lack of, is also a direct indicator of cancer growth with tumors typically characterised by hypoxia. To investigate this and other cell biological processes, we New Zealand Association of Science Educators
27
NZ
science teacher
futurefocus–schoolscience
futurefocus–microfluidics
126
28
have developed integrated microfluidic gas exchangers capable of precisely controlling the oxygen concentration of a fluid. Combined in a single chamber on-chip the flow of several of these can be used to produce custom oxygen gradients, as illustrated in Figure 1. By integrating a novel optical sensor film inside the chamber fluorescence microscopy can be used to exactly determine the local oxygen concentration of the fluid. A fascinating side effect of this capability is that via the gradual broadening of the initially sharp concentration profile along the chamber length, one is able to directly observe and measure oxygen diffusion in the carrier fluid. Further building on the peculiarities of laminar flow the same device can be extended using hydrodynamic flow focusing to expose single cells or even targeted areas on the cell membrane to a specific oxygen concentration, while keeping the remainder of the chamber as nonstimulated control. This and the fact that reagents are not limited to oxygen, make these devices, and microfluidics in general, ideal tools to provide novel insights into cell biology. 2. Droplet propulsion The previous section emphasised the stringent demand on pumping and seals in closed microfluidics devices relying on fluid streams in microchannels and the emerging concept that droplets could be used to transport and mix reagents. This has lead the authors to envisage a new droplet propulsion mechanism to perform one of the key functions of microfluidic devices: fluid transport. The ‘fuel’ used to displace the droplets is the surface tension gradient which arises when two droplets of different fluids mix. The fluid, having a tendency to flow towards regions of higher surface tension and the breaking of the symmetry of the droplet pair result in net motion of the system which is sustained until both fluids have fully mixed.
This concept is illustrated in Figure 2(b), where a droplet of dyed distilled water (DI), is pushed around a corner by a droplet of ethanol (not visible in the picture) deposited in the top right-hand corner (see also the proof of concept video at http://www.scivee.tv/node/26233). The motion of the droplet can be steered by creating “hydrophilic pathways” patterned on an otherwise hydrophobic surface using plasma treatment. The fluid droplets, having a tendency to preferentially wet hydrophilic surfaces, are constrained to move along these pathways. This simple propulsion mechanism, while still in its conceptual stage, could offer an attractive alternative to other mechanisms typically requiring complex multistage microfabrication techniques.
Conclusion A lot of the basic science underpinning microfluidics has been known for some time. The novelty, and thus the large potential of the technology, arises from the integration of such a wide range of different scientific principles. A conference on microfluidics often involves physicists, engineers, biologists, and material scientists, to name but a few. The multidisciplinary nature of this field is precisely what makes it a fascinating area of research with great potential for technological leaps. For further information contact: mathieu.sellier@canterbury.ac.nz
References 1
2
3
4
5
Whitesides, G.M. (2006). The origins and the future of microfluidics. Nature, Vol. 442, pp. 368-373. Purcell, E.M. (1977). Life at low Reynolds number. American Journal of Physics, Vol. 45, pp. 3-11. Squires, T.M., & Quake, S.R. (2005).Microfluidics: Fluid physics at the nanoliter scale. Reviews of Modern Physics, Vo. 77, pp. 977-1026. Nock, V., & Blaikie, R.J. (2010. Spatially Resolved Measurement of Dissolved Oxygen in Multistream Microfluidic Devices. IEEE Sensors Journal, Vol. 10, pp. 1813-1819. Sellier, M., Nock, V., & Verdier, C. (In press). Self-propelling coalescing droplets. International Journal of Multiphase Flow.
continued from page 30 The model is intended to stimulate debate about what really matters in science education, and what is the best way forward in the short term. However, it seems likely that something much more radical will be needed in the longer term.
Where to from here? The aim of this article has been not to talk about the future of science education, but instead to show how past thinking has led to the science programmes we have now. It also aimed to lay down the foundations for discussion and exploration of the bigger issues facing twenty-first century science educators. There is already strong pressure for change in science education from four broad areas: • changes in society, the nature of work, and young people • changing ideas about what schools are for • new theories of learning (influenced by recent developments in neuroscience) • changes in science itself (the increasing speed of knowledge change, changes in the way science works, changes in science’s relationship with the wider society, and the new kinds of skills needed by its workforce).
New Zealand Association of Science Educators
To meet these challenges in the future many of the traditional purposes of science education will have to be rethought and re-packaged (not necessarily thrown out). Yet if we as science educators are to do this, we need a shared understanding of the ground we stand on now, and of how that ground is likely to shift in the future. I hope this article gives you useful background information to encourage you to engage in this discussion. For further information contact: Jane.Gilbert@nzcer.org.nz
References Bull, A., Gilbert, J., Barwick, H., Hipkins, R. and Baker, R. (2010). Inspired by science: A paper commissioned by the Royal Society and the Prime Minister’s Science Advisor. Available at http://www.nzcer.org.nz/pdfs/inspired-by-science.pdf. DeBoer, G. (1991). A history of ideas in science education: Implications for practice. New York: Teachers College Press. Deng, Z. (2007). Transforming the subject matter: Examining the roots of pedagogical content knowledge. Curriculum Inquiry, 37(3), 279-295. McKenzie, D. (1992). The technical curriculum: second class knowledge? In G. McCulloch (ed.) The school curriculum in New Zealand: History, theory, policy practice. Palmerston North: Dunmore Press (pp.29-39). Osborne, J. and Hennessy, S. (2003) Literature review in science education and the role of ICT: Promise, problems and future directions. Futurelab Series, Report 6. http://archive.futurelab.org.uk/resources/publications-reports-articles/ literature-reviews/Literature-Review380
The Prime Minister’s Chief Science Advisor, Sir Peter Gluckman, recently commissioned a report looking at how we can engage more young people in science. This question is now seen as being of key strategic importance to this country’s future. The report, entitled Inspired by Science, was written by the New Zealand Council for Educational Research (NZCER) and focuses, in particular, on the role of schools. 1 This article highlights the tension between the four purposes of school science and the challenges to twentyfirst century science educators.
Then, when we add to this the tendency to confuse science (and its purposes) with science education (and its quite different purposes) as though they were the same thing, we start to get a sense of why it is so hard to think clearly about how best to engage more young people in science. We concluded our report by arguing that it needs to be much clearer what school science education is supposed to achieve if school science is to play a role in engaging more young people in science. However, because the report will only be read by a small number of people, and having done this thinking, we thought it should be summarised for a wider audience. And given that the theme for this issue of the NZST is ‘future focus’, and given that teachers are increasingly being asked to debate the future direction of their subject area(s), some of this history could be useful.
Introduction
Why is science in the school curriculum?
To begin with, the NZCER team explored the assumption that there is a problem engaging young people in science in New Zealand, and considered: who is saying this, and why are they saying it? They reviewed research that had focused on what young New Zealanders think of science, and how well they achieve in it. The results of their research review raised some challenging questions: what do young people who are ‘engaged’ in science look like, and how would you measure this? should it be through measures of their interest and commitment, or through measures of their participation and/or achievement? what sorts of interest, commitment, participation or achievement predict long-term engagement in science? do the commonlyused measures capture what matters here? (e.g. are high achievers necessarily ‘engaged’ in science?); and how, if at all, are ‘science’ and ‘school science’ linked? Thinking about these questions led us to consider the historical underpinnings of science in the school curriculum. So…why was science put into the school curriculum? What was it supposed to achieve? Why was this thought to be important? Do these goals still apply today? How might school science need to be offered differently in the future? Is its purpose the same at all levels of schooling? If not, why not? The short answer to these questions is that school science education has traditionally been asked to serve many different purposes, and that these are often confused. In addition, new purposes have been added over time without necessarily removing any of the ‘old’ ones, many of which underpin most people’s ideas of what should be in the curriculum. The result is that the task of the school science curriculum (and school science teachers) is actually very difficult.
So: why, then, is science a core part of the school curriculum?2 Most people would say that it gives young people useful knowledge, or that knowing some science is part of being an ‘educated’ person – that is, its purpose is to provide certain kinds of knowledge. Interestingly, this isn’t what would be emphasised by education theorists. They would say that the educational purpose of including science in the school curriculum is as a vehicle (one among many) for developing students’ intellectual capacities – that is, for teaching students to think, to organise their thinking, and to think in increasingly complex ways as they become more educated. The other ‘learning areas’ – English, mathematics, history, other languages, the arts and so on – are included for the same reason: for their ability to ‘expand students’ minds’, to help them learn to think in different contexts. Thus the ‘layperson’s’ view of education as the process of acquiring knowledge and skills – usually for some ‘useful’ purpose – differs from educational theorists’ view of the purpose of education. For the theorists, acquiring knowledge is not an end in itself. Rather, because knowledge is the result of thinking, it is a way into thinking about thinking (and about different kinds of thinking). This model of education’s purpose is very old (it can be traced back 3000 years or so to the thinking of the Ancient Greeks, Plato in particular), but it is still the foundation of today’s curriculum. However, once mass education was introduced (a century or so ago), the ‘pure’ form of this idea had to sit alongside other ideas that were added into curriculum thinking. Education systems are provided by the state for everyone and are supposed to meet individual learning needs, whilst at the same time providing society with the kinds of citizens it wants, and meeting the ‘human resource’ needs of the economy.
1
2
When considering the role of science in the school curriculum – past, present, and future – it’s like wrestling with an octopus, as Jane Gilbert, New Zealand Council for Educational Research, explains: Background
The NZCER report can be downloaded at: www.nzcer.org.nz/pdfs/inspiredby-science.pdf. The author of this paper was a member of the team, and has drawn on the contributions of that team in writing this paper.
NZ
126
futurefocus −schoolscience
School science is like wrestling with an octopus
science teacher
The term ‘curriculum’ is used here to refer collectively to the different sets of official guidelines for what should be taught in schools that have been developed over time, not the current New Zealand Curriculum document.
New Zealand Association of Science Educators
29
NZ
science teacher
futurefocus −schoolscience
126
The modern school curriculum has to do much more than develop students’ ability to think: it must socialise them – that is, make sure they have the skills and ‘dispositions’ they need for their likely future role in society/the economy/the public sphere. This includes a whole variety of things, some explicitly acknowledged and some not (working with others/behaving in certain ways in groups; being punctual, organised and neat; respecting authority, and so on). Another function it serves, particularly at secondary level, is as a de facto ‘sorting’ device, a tool for channelling students into ‘pathways’ that are appropriate for their likely post-school destination. To summarise: the ‘learning areas’ are made up of knowledge taken from the disciplines to serve purposes other than those it serves in the disciplines. The curriculum is not supposed to foster knowledge acquisition as an end in itself, and the knowledge that underpins the ‘learning areas’ is not the same as the knowledge of the disciplines (e.g. science) it is derived from.
The past informs the present Past developments have structured today’s school science in key ways. Understanding this makes it easier to see why it is really quite difficult to engage a wide range of young people in science via school science programmes. For example: the egalitarian aim of mass education produced ‘general science’ – programmes emphasising ‘useful’, ‘practical’ and ‘relevant’ science knowledge (basic mechanics and electricity, human biology and so on).3 Attempts were made to teach this kind of knowledge in separate school systems (Technical, Secondary, Agricultural etc.): however, this proved to be socially unacceptable.4 By the mid-twentieth century, there was a strong commitment to the ‘general science’ idea, but it didn’t ever replace traditional ‘academic’ science education. Both were retained, sitting alongside each other. This is a key – and longstanding – tension in science education. Education theorists have attempted to resolve it by developing curriculum approaches that foreground the needs of the learner (that is, not the ‘needs’ – or structure – of the subject matter), so that the subject matter of a ‘learner-centred’ curriculum is selected to meet the educational needs of particular individual students, not to model the conceptual structures/progressions of the primary discipline.5 Today’s school science has, therefore, developed in a crucible of different, often conflicting, ideas, and, as a result, it has a range of quite different, often conflicting, purposes. These purposes can be summarised as follows: 6 1. the ‘pre-professional training’ purpose (preparing students for a career in science) 2. the ‘utilitarian’ purpose (equipping students with practical knowledge of how things work, so that they can use them more effectively and/or fix them) 3. the ‘democratic/citizenship’ purpose (building students’ ‘literacy’ in science to allow informed participation in science-related debates and issues) 4. the ‘cognitive/intellectual’ purpose (developing students’ knowledge of science and scientific thinking to ‘expand’ their minds). 3
4
5
6
30
The term ‘general science’, along with the concept of a ‘core’ curriculum for all, appeared in the 1940s in New Zealand – before that the sciences were taught as separate subjects (physics, chemistry and biology). See McKenzie (1992) for an account of the rise and fall of the ‘technical’ high school in New Zealand This distinction – between ‘learner-centred’ and ‘knowledge-centred’ teaching approaches – has a long and contentious history in education theory; see DeBoer (1991) for a science education-based account, or, for a more general review of this debate, see Deng (2007)). While most school curriculum documents officially emphasise learner-centred approaches, they are, for all sorts of reasons that are beyond the scope of this paper, more common in primary classrooms than in secondary. This framework follows one used in Osborne and Hennessy (2003).
New Zealand Association of Science Educators
1. Pre-professional training purposes Preparing students for a career in science usually means emphasising key science concepts organised into conceptual progressions that would be recognised by scientists. While this is not supposed to be the primary purpose of school science education, research study after research study has shown that it is, particularly at secondary level. 7 Programmes designed to achieve this purpose are knowledge-centred, and effectively ration access to university science study to students who can orient themselves to this approach. This is a problem, however, if our goal is to engage more young people in science. 2. The utilitarian purpose Programmes designed to achieve the ‘utilitarian’ purpose are quite explicitly not designed to prepare people for university science study, or to engage them in science for its own sake. Their aim is to give students everyday life skills and information that will allow them to make better choices. While on the surface this seems a worthwhile goal, research doesn’t support the idea that having knowledge – about, for example, nutrition, physical exercise, the effects of alcohol, or high speed collisions – changes behaviour, and many of our everyday electronic devices include technology that make them difficult for non-specialists to repair. 3. Education for citizenship Education for citizenship means building students’ ability to participate in public debates on the major issues of the time, many of which are science-related (climate change, sustainable energy use, and genetic modification being some obvious examples). Participating in debates on these issues requires knowledge of the science concepts involved, knowledge of how these concepts were developed and tested, and some appreciation of the complexity and contentiousness of work in these areas. It also requires critical and ethical thinking skills, and the ability to work with science ideas in non-science contexts (debates in the wider society). These are complex skills. They are often collectively referred to as ‘science literacy’ because they are needed to ‘read’/work with science ideas and scientific ways of thinking in a society in which science plays a major role. While there have been many attempts in recent decades to include such skills in the core science curriculum, this area remains underdeveloped. 4. Expanding and strengthening mental capacities As outlined earlier, the fourth purpose of science education – expanding and strengthening students’ mental capacities (much as one might strengthen one’s muscles by working out in a gym) – is a cornerstone of general education. However, it isn’t as explicit in science education as it could be, particularly as we consider future pressures.8
The report: Inspired by Science The above four purposes are each very different, and a programme designed to meet one would be very different from one designed to meet another. Yet today’s school science education programmes are asked to attempt them all. What should we do about this? Focus on one and not the others? Which one, and why? The Inspired by Science report suggested a model that attempts to meet all of these purposes by emphasising them differently at different stages of the school system.9 7 8
9
For a list of a few such studies, see the Inspired by Science report (pp.12-13). It is possible that some recent curriculum developments – for example, the foregrounding of ‘the nature of science’ strand in the current curriculum document, the ‘thinking’ key competency, and the focus on ‘thinking with evidence’ – may be having an influence, but the jury remains out on this. See p.35-38 of Inspired by Science for a full account of this.
continued on page 28
NZ
Written by Miles Barker At 7.30 a.m. on the frangipani-lined and rambling rose-festooned pathways, the staff members at CEMASTEA (Centre for Mathematics, Science and Technology Education in Africa) are emerging out of the still lingering mist. One reason for their early arrival is to avoid the inevitable traffic jams on the road from central Nairobi to the Centre, in the leafy outer suburb of Karen. They make their way to the Centre’s various departments, housed in a cluster of converted domestic dwellings scattered amongst the trees and shrubs around an historic but disused colonial homestead, whose presence resonates with the reason why the suburb is so named: Karen Blixen, of ‘Out of Africa’ fame, lived nearby in a homestead of similar vintage. The other reason for the long working day is the enormity of the task. The Centre not only provides teacher development for Kenya’s 40 million people; its mission is to all Africa. Last week the cheery but spartan nearby hostel was buzzing with ‘Francophone’ educators from western and sub-Saharan Africa; this week the catchment might range from Lesotho to Zaire. For Kiwis, this geography may be boggling, but CEMASTEA’s framing of the task – seeking a meaningful science education for the future – Is startlingly similar to our own. My work at the Centre in June 2010 focused on a national workshop for trainers: ‘Qualitative Research and Innovative Pedagogies in Science Education’. What I would like to share with NZST readers now is something that has flowed from the Workshop: part of a draft set of notes, provisionally called ’Innovative Pedagogies and Teacher Development: A position statement’ that Centre staff and I are currently working on. The Centre invited me to provide a small sample of accompanying readings with an international flavour and also, gratifyingly, works from the New Zealand tradition …
PREAMBLE – What are innovative pedagogies? ‘Pedagogy’ is increasingly used instead of ‘teaching’ but ‘pedagogy’ has a wider meaning than ‘teaching’. It includes reference to the values, aims and philosophy of education. In other words, a pedagogy is “a method of teaching interpreted in its widest sense”; a pedagogy links to ideas about the curriculum, about power, and about socio-cultural practice. A desirable pedagogy may therefore be anything from a wonderfully inspired teacher’s unique ability to enthuse and motivate children in their own classroom, across to a very deeply thought out approach to the whole area of teaching and learning. ‘Innovative’ simply means ‘new’, and we know that what is new in teaching may not necessarily be any better; it may be merely idiosyncratic, gimmicky, shallow and ultimately time-wasting. A desirable innovative pedagogy – one which merits exploring, sharing and developing with our teachers
– must therefore, have some worthwhile underlying purpose which can be clearly stated. (References: Bell (2005), pp.113-115, Goodyear 2005).
WHY – Purposes cited for exploring innovative pedagogies in science education Here are ten purposes (there are surely many others) which various sources have cited as being foundational for science education of the future. They have either been advanced to justify existing pedagogies, or have caused the pedagogies to be developed in the first place: 1) Promoting better learning The pedagogy might encourage better conditions for learning (increased enjoyment, social co-operation, ownership, student confidence and student motivation) and also better learning outcomes (learning skills, conceptual development and improved results on tests and examinations). References: Bell and Pearson (1992), Claxton (2008) 2) Apprehending the everyday world more meaningfully As the whole constructivist approach to science education continues to show, there is an ongoing gulf that needs to be bridged between the commonsense everyday worlds of students (the kitchen, garden, pasturelands, marketplace, etc.) and the often counter-intuitive world of the science lesson (with its formulae, definitions and abstractions). Pedagogies that enrich students’ lives by meaningfully drawing these two worlds together continue to be needed. Reference: Driver, Asoko, Leach, Mortimer, & Scott (2004). 3) Learning both the content and the nature of science These pedagogies aim to promote both learning in science (the traditional content of biology, physics, etc.) and also (and this is usually the innovative part), learning about science (how science knowledge is special, what scientists do, and how science and society interact). Learning both in and about science often occur simultaneously, but each needs to be made very explicit. Reflecting on the similarities and contrasts between school science and professional science is an important way of learning about science, i.e. revealing the nature of science. References: Lederman (2007), Hodson (2008). 4) Achieving better on assessments of student learning This purpose is sometimes thwarted and innovative pedagogies sometimes appear to fail because the traditional means of assessment (for example, essay writing) has been retained and the new learning arising from the innovative pedagogy is not actually assessed. What is needed to achieve higher grades is not only more appropriate modes of assessment (oral presentations, research, role play, student journals, conferencing, etc.) but a whole teacher shift in thinking about the teaching/ learning/assessment nexus. Reference: Anderson (1998). New Zealand Association of Science Educators
126
futurefocus–innovativepedagogies
Innovative pedagogies, teacher development and the future of science education: an African connection
science teacher
31
NZ
science teacher
futurefocus–innovativepedagogies
126
32
5) Advancing futures’ focused science education Pedagogies that successfully prepare science students to confront social issues (for example, sustainability, citizenship, enterprise, globalization) that they may be expected to face during their adult lives are much to be valued. These pedagogies, which are often shared with those in environmental education, and in which creativity and problem solving usually feature strongly, view schooling as a platform for initiating lifelong learning. References: Buntting (2010), Saunders (2010), Hart (2007). 6) Promoting scientific literacy There is some general consensus that a scientifically literate person is one who appreciates the impact of science and technology on everyday life; takes informed personal decisions about science-related matters (health, diet, etc.); understands and reflects critically on media reports involving science; and engages in public issues that involve science. Pedagogies designed to achieve this are promoting scientific literacy. References: Telford (2008), Hodson (2008). 7) Developing more culturally sensitive teaching and learning Pedagogies serving this purpose project the view that to learn science is to acquire the culture of science and that this process is more likely to be successful if teaching takes account of the existing culture of the learner. This style of pedagogy resonates with socio-cultural views of learning and it casts the teacher in the role of culture broker. Reference: Jegede and Aikenhead (2004). 8) Preparing students to be science specialists and/or citizens In contrast with school science programmes devoted only to ‘science for some’ (i.e. the 20% or so of students heading for careers in science), many innovative pedagogies consciously cater for ‘science for all’ students. This aligns with notions of ‘scientific literacy’ (see above) and ‘science for citizenship’. The motivational aspects of ‘science for all’ pedagogies are clearly crucial: students need to enjoy science and find it meaningful if they are all to become engaged in school science. References: Sjorberg (2000), Hipkins (2010). 9) Enacting national curriculum frameworks Many countries, including African nations, have a national educational framework that is intended to subsume all the learning areas, including science education. These frameworks typically comprise overarching Vision Statements, Aims, Principles, Values, Competences, etc. Unfortunately, science teachers sometimes bypass these worthy ‘big picture’ statements and work only from the science curriculum. Innovative science pedagogies may be needed to prevent this, e.g. pedagogies which consciously develop broad core competences (such as thinking; using language, symbols and texts; managing self; problem solving; relating to others, and so on) at the same time as more specific science learning is occurring. This could be restated by saying that innovative pedagogies are needed to promote curriculum integration. References: Barker (2009), Czerniak (2007). 10) Providing a greater contribution to national wealth While education is often proclaimed to be the road to enhanced national wealth (frequently interpreted, it turns out, to mean national economic growth), even a cursory analysis shows that the links between any particular pedagogy and economic growth at large are tenuous and complex because issues of power, gender, politics and values always intervene. Pedagogies involving information communication technology (ICT) and notions of “the knowledge wave” are probably those most often suggested as ways of linking education and economic growth.
New Zealand Association of Science Educators
Reference: Gilbert (2005).
WHAT – The basis for exploring innovative pedagogies in teacher development New pedagogies continue to arise on the educational scene: interactive teaching; narrative-aware teaching; mastery-based teaching; teaching which promotes experiential learning; teaching for instructional congruence … The list is endless. However, for a new pedagogy to be viable, it should have two characteristics: 1) It must be accompanied by a wealth of rich, practicable, enticing classroom activities that enthuse and attract teachers. 2) It must clearly be seen to contribute towards achieving some accepted educational purpose (like the ten listed above). Successful teacher development workshops conducted by presenters therefore typically comprise two modes: A) Presenter-initiated, hands-on modeling of classroom activities by teachers. B) Reflective discussion by presenters and teachers about the broad purposes of the activities. Both modes are essential: Discussing broad purposes without modeling classroom activities is sterile. Modeling classroom activities without discussing broad purposes is directionless. For further information contact: mbarker@waikato.ac.nz
Acknowledgements I acknowledge with huge affection my two principal co-workers in this project, Mr Tom Mboya Okaya and Mr John Odhiambo. Also, I salute the indispensable support of Director Madame Cecelia Ng’etich, the initiative of Mr Sammy Mutisya, the friendship of Mrs Irene Yaa-Mwaniki, and the inspiration afforded by people like Ms Abida Barak.
References Anderson, R.S. (1998). Why talk about different ways to grade? The shift from traditional assessment to alternative assessment. New Directions for Teaching and Learning, 74, 5-16. Barker, M. (2009). Science teaching and the New Zealand curriculum. New Zealand Science Teacher, 120, 29-31. Bell, B. (2005). Learning in science: The Waikato research. London: RoutledgeFalmer. Bell, B. & Pearson, J. (1992). ‘Better learning’. International Journal of Science Education, 14(3): 349-361. Buntting, C. (2010). Introducing and expanding a futures focus in science classrooms. New Zealand Science Teacher, 125, 34-37. Claxton, G. (2008). What’s the point of school? Rediscovering the heart of education. Oxford: Oneworld. Czerniak, C. (2007). Interdisciplinary science teaching.In S.K. Abell & N.G. Lederman, Handbook of research on science education. Mahwah, NJ: Lawrence Erlbaum, pp.537-559. Driver, R., Asoko, H., Leach, J., Mortimer, E., & Scott, P. (2004). Constructing scientific knowledge in the classroom. In E. Scanlon, P. Murphy, J. Thomas & E. Whitelegg, Reconsidering science learning (pp.58-73). London: RoutledgeFalmer. Gilbert, J. (2005). Catching the knowledge wave: The knowledge society and the future of education. Wellington: NZCER Press. Goodyear, P. (2005). Educational design and networked learning: Patterns, pattern languages and design practice. Australasian Journal of Educational Technology, 21(1), 82-101. Hart, P. (2007). Environmental education. In S.K. Abell & N.G. Lederman, Handbook of research on science education (pp.689-726). Mahwah, NJ: Lawrence Erlbaum. Hipkins, R. (2010). Engaging students in science. New Zealand Science Teacher, 123, 37-40. Hodson, D. (2008). Towards scientific literacy: A teachers’ guide to the history, philosophy and sociology of science. Rotterdam: Sense Publishers. Jegede, O. & Aikenhead, G. (2004). Transcending cultural borders: Implications for science teaching. In E. Scanlon, P. Murphy, J. Thomas & E. Whitelegg, Reconsidering science learning (pp.153-175). London: RoutledgeFalmer. Lederman, N. (2007). Nature of science: past, present and future. In S.K. Abell & N.G. Lederman (Eds.) Handbook of research on science education (pp.831879). Mahwah, NJ: Lawrence Erlbaum. Saunders, K. (2010). Teaching and learning about controversial science issues, New Zealand Science Teacher, 125, 30-33. Sjorberg, S. (2000). Interesting all children in ‘science for all’. In R. Millar, J. Leach, & J. Osborne, Improving science education: The contribution of research (pp. 165186). Buckingham: Open University Press. Telford, M. (2008). Scientific literacy in the Programme for International Student Assessment 2006 (PISA). New Zealand Science Teacher, 118, 4-8.
NZ
Written by Miles Barker, University ofWaikato Introduction Sometimes the future presses in on us with great insistence. The New Zealand Curriculum1 presents teachers of school science with two major, inescapable new challenges that we must face in the immediate future. Firstly, we must ensure that the generic “front end” of the curriculum – the vision, principles, values, and key competencies – influences everything that we do in science education.2 Secondly, and the concern of this article, we need to accept that the Nature of Science (NoS), for the foreseeable future, must be both the entry point and the driver for all teaching and learning in school science in New Zealand. A major issue with the Nature of Science has always been that while many educators concede its importance, it has seemed too diffuse and vague to teach effectively. Indeed, teachers often ask: what do students actually have to know about the Nature of Science? This article, building on lessons learned in New Zealand and overseas during the last twenty years, and based on an analysis of our new curriculum, proposes fourteen classroom-accessible ideas about the Nature of Science that could be thought of as underpinning our national science curriculum.
Ideas about science − a new formulation Internationally, not just in New Zealand, teaching and learning about NoS has advanced very slowly. Advocated in the United States as early as the 1960s,3 it was generally considered to be too complex and conjectural to be pursued in schools. If philosophers, historians and educators Propositions about the Nature of Science (Rutherford & Ahlgren, 1990)
couldn’t agree about what the Nature of Science actually is,4 how could there possibly be any consensus about what school students should be expected to know about NoS? However, a breakthrough came in 1990 when two American science educators, James Rutherford and Andrew Ahlgren proposed a catalogue of thirteen curriculum-appropriate ‘propositions’ about NoS, grouped under three generic headings5 (Table 1). In New Zealand, although the writers of the 1993 science curriculum included a Nature of Science strand,6 the fact that there was little accompanying material spelling out what NoS actually comprised was one of the factors7 resulting in the strand being largely ignored in science lessons over the next fifteen years.8 A brave development, advanced in 2005, was the ‘Science IS’ website9 which listed nineteen ‘science themes’, grouped under four headings. It skilfully shows how teachers can integrate these themes with the content of the 1993 science curriculum. As suggested already, however, the flagship status of NoS in our current curriculum demands a renewed and urgent attention to the question: What do students actually have to know about the Nature of Science? A group of thirteen experienced science teachers10 has now provided a response. Using the Rutherford and Ahlgren format as an initial template, they set themselves the task of reformulating the original package of propositions into a format appropriate for the implementation of our new science curriculum. The outcome, ‘fourteen ideas about
126
futurefocus–natureofscienceandcurriculum
nature of science andThe New Zealand Curriculum: fourteen underpinning ideas
science teacher
Fourteen Suggested Contemporary New Zealand-Relevant Ideas About Science (2009)
The Scientific World View 1. The world is understandable. 2. Science ideas are subject to change. 3. Science knowledge is durable. 4. Science cannot provide complete answers to all questions.
Science Knowledge 1. The world is understandable. 2. Science ideas are evolving. 3. Science cannot provide complete answers to all questions. 4. Many science explanations require specialist language and symbols and are in the form of ‘models’.
Scientific Enquiry 5. Science demands evidence. 6. Science is a blend of logic and imagination. 7. Science explains and predicts. 8. Scientists try to identify and avoid bias. 9. Science is not authoritarian.
Scientific Enquiry 5. Science demands evidence. 6. Science is a blend of curiosity, imagination, creativity, logic and serendipity. 7. Science aims to explain and predict. 8. Scientists try to identify and avoid bias. 9. Scientists work together. 10. Scientists’ observations are influenced by their existing ideas. 11. Scientists often study complex interrelated systems.
The Scientific Enterprise 10. Science is a complex social activity. 11. Science is organised into content. Disciplines and is conducted in various institutions. 12. There are generally accepted ethical principles in the conduct of science. 13. Scientists participate in public affairs both as specialists and as citizens.
Science and Society 12. Issues of ethics, values, economics and politics operate between science and the rest of society. 13. Informed citizenship entails applying rational argument and scepticism to science text. 14. Participating in informed decision making about socio-scientific issues is a civic responsibility .
Table 1: A suggested rewriting and updating of the classic Rutherford and Ahlgren (1990) propositions about the nature of science, relevant to the contemporary New Zealand situation. New Zealand Association of Science Educators
33
NZ
science teacher
futurefocus–natureofscienceandcurriculum
126
science’11 is shown in Table 1. One thing that needs to be noticed is that these ‘fourteen ideas about science’ are written in terms of scientists, i.e. adult professionals who are usually paid for ‘doing science’. We shall return to this point below. Comparing the two catalogues in Table 1 is interesting. While some elements are seen to be enduring (for example, “science demands evidence”), the differences cut much more deeply than an exercise in merely updating (“contemporary”) and localising (“New Zealand-relevant”) the language. The relationship between science and society is the biggest mover. This reflects the huge number of initiatives since 1990 from educators, the public and scientists themselves that have sought to explore, enrich and promote cross-cultural understandings between professional science and the rest of society. A few of these initiatives, each with their distinctive acronym are: The Public Understanding of Science (PUS); Science, Technology and Society (STS); the Sociology of Scientific Knowledge (SSK), and Community Research Networks (CRNs). In the words of authors Ziauddin Sardar and Borin Van Loon, “science has become just too important to be left to the scientists and those who manage their work and control their products. Citizen participation at almost every level of the scientific enterprise has become essential”.12 But such an exploration of ideas about science is of little use to teachers if it floats free of the science curriculum. Just as Rutherford and Ahlgren’s work was in the context of the American ‘Project 2061’, so do we need to ask how far our ideas about science resonate with The New Zealand Curriculum, in particular with the science essence statement (p.28) and with the Nature of Science achievement objectives for levels 1/2, 3/4, 5/6 and 7/8.13
Analysing the Nature of Science in our science curriculum Table 2 shows how a reading through of the essence statement can reveal explicit links to each of the fourteen ideas about science. There is, however, a significant difference between the orientation of the statement and of the fourteen ideas. The difference relates to the two populations we are thinking of when we talk about people ‘doing science’: on the one hand, as mentioned above,
there are scientists (and both columns in Table 1 are clearly couched in terms of scientists) and on the other hand, there are teachers and students in schools. The essence statement, by contrast, deliberately expresses ‘doing science’ in terms which are population non-specific; it is (laudably, I think) non-committal about WHO (scientists or teachers and students) is ‘doing science’. The Nature of Science strand in levels 1/2, 3/4, 5/6 and 7/8 of our science curriculum is the reverse − it is population-specific: whilst the subset ‘Understanding about science’ is always couched in terms scientists, the other three subsets (‘Investigating in science’, ‘Communicating in science’ and ‘Participating and contributing’) are clearly intended to apply to teachers and students in schools. This situation has given rise to both a constraint, and to a liberating possibility. The constraint is the fact that the essence statement, in being generic, has had to omit many things that are crucial to ‘doing science’ but which apply EITHER to scientists OR to teachers and students in schools, but not to both. These differences are things like prior life experiences, tools, knowledge structure, knowledge generation, and product evaluation. For professional scientists, doing science is centrally about the quality of one’s prior tertiary training; about accessing costly specialised equipment; about a fluid and flexible approach to knowledge structures; about the creation of what has not been previously known; and about rigorous peer review. By contrast, for teachers and students in schools, doing science is about the significance of everyday concepts brought to science lessons from the wider world; about standard-issue materials in school labs; about traditional categories of knowledge (physics, biology, and so on); it is mainly about apprehending what is already known by other people; and it is about NCEA results. In a word, the essence statement is culture-free and, as a consequence of this constraint, it has little to say about what I have suggested above has been the growth area in science education internationally over the past twenty years: the perception of science as a culture and the relationship between science and society. But there is also a liberating possibility here. True, writers
The Science Essence Statement What is science about? Science is a way (3) of investigating, understanding (1) and explaining (7) our natural physical world and the wider Universe (11). It involves generating and testing ideas, gathering evidence – including by making observations (10), carrying out investigations and modelling (4), and communicating (13) and debating (8) with others (9, 14) – in order to develop scientific knowledge, understanding and explanations. Scientific progress comes from logical, systematic work and from creative insight (6), built on a foundation of respect for evidence (5). Different cultures (12) and periods of history (2) have contributed to the development of science. Key: The Fourteen Ideas About Science 3. Science cannot provide complete answers to all questions. 1. The world is understandable. 7. Science aims to explain and predict. 11. Scientists often study complex interrelated systems. 10. Scientists’ observations are influenced by their existing ideas. 4. Many science explanations require specialist language and symbols and are in the form of ‘models’. 13. Informed citizenship entails applying rational argument and scepticism to science text. 8. Scientists try to identify and avoid bias. 9. Scientists work together. 14. Participating in informed decision making about socio-scientific issues is a civic responsibility. 6. Science is a blend of curiosity, imagination, creativity, logic and serendipity. 5. Science demands evidence. 12. Issues of ethics, values, economics and politics operate between science and the rest of society. 2. Science ideas are evolving.
Table 2: An analysis of the wording of the science essence statement (see page 28, The New Zealand Curriculum), identifying explicit linkages to the fourteen ideas about science. 34
New Zealand Association of Science Educators
science are implicated in the achievement objectives, either at two, three or all four of the combined levels, i.e. levels 1/2, 3/4, 5/6 and 7/8. 2. They are strongly represented at each combined level, i.e. eleven of the fourteen at level 1/2; thirteen at level 3/4; ten at level 5/6; and eleven at level 7/8. 3. The three-way grouping of the fourteen ideas about science (four as ‘knowledge’, seven as ‘inquiry’, and three as ‘society’) mirrors the distribution of ideas in the achievement objectives. Overall, therefore, it is possible to conclude that these fourteen ideas about science substantially underpin both the science essence statement and the achievement objectives for the Nature of Science in The New Zealand Curriculum. In that sense, they could be proposed as a response to the question: what do students actually have to know about the Nature of Science?
NZ
science teacher
The fourteen underpinning ideas about science – two wider considerations There are two crucial points that I think we need to consider. Firstly, attention should be drawn to the provisional nature
Levels One and Two: Understanding about science
Investigating in science
Communicating in science
Participating and contributing
• Appreciate that scientists ask questions about our world (1) that lead to investigations (5) and that open-mindedness (8) is important because there may be more than one explanation (7).
• Extend their experiences and personal explanations (7) of the natural world through exploration, play, asking questions (6) and discussing (9) simple models (4).
• Build their language (4) and develop their understandings (7) of the many ways (13) the natural world can be represented.
• Explore and act (14) on issues (12) and questions that link their science learning to their daily living (11).
126
futurefocus–natureofscienceandcurriculum
have for a long time pointed out that the cultures of scientists’ science and school science are very different,14 and it has even been suggested that two cultures have actually significantly diverged during the twentieth century.15 Nevertheless, the generic nature of the science essence statement helps us to keep faith with the notion that what we do in schools actually does illuminate, in significant ways, how professional science operates. For that reason, I believe it is certainly legitimate to seek resonances between the achievement objectives for the teacher-and-student orientated ‘Investigating in science’, ‘Communicating in science’ and ‘Participating and contributing’ subsets (as well, of course, with ‘Understanding about science’) and the fourteen scientist-orientated ideas about science. Tables 3 and 4 identify to what extent the fourteen ideas about the nature of science underpin the wording of levels 1/2 and 3/4, and 5/6 and 7/8 respectively, and Table 5 summarises these two tables. Table 5 suggests three conclusions concerning the fourteen ideas about science: 1. They resonate strongly with the wording of the achievement objectives. All fourteen of the ideas about
Underpinning ideas about science 1. The world is understandable. 5. Science demands evidence. 8. Scientists try to identify and avoid bias. 7. Science aims to explain and predict.
7. Science aims to explain and predict. 6. Science is a blend of curiosity, imagination, creativity, logic and serendipity. 9. Scientists work together. 4. Many science explanations require specialist language and symbols and are often in the form of ‘models’.
4.
Many science explanations require specialist language and symbols and are often in the form of ‘models’. 7. Science aims to explain and predict 13. Informed citizenship entails applying rational argument and scepticism to science text.
14. Participating in informed decision-making about socio-scientific issues is a civic responsibility. 12. Issues of ethics, values, economics and politics operate between science and the rest of society. 11. Scientists often study complex interrelated systems.
Understanding about science
Investigating in science
Communicating in science
Participating and contributing
•
•
•
•
Levels Three and Four:
•
Appreciate that science is a way (3) of explaining the world (1) and that science knowledge changes over time (2). Identify ways in which scientists work together (9) and provide evidence (5) to support their ideas.
•
Build on prior experiences (10), working together (9) to share and examine their own and others’ knowledge (8). Ask questions, find evidence (5), explore simple models (4) and carry out appropriate investigations to develop simple explanations (7).
•
Begin to use a range of scientific symbols, conventions and vocabulary 4). Engage with a range of science texts and begin to question the purposes for which these texts are constructed (13).
•
Use their growing science knowledge when considering issues (12) of concern to them. Explain various aspects (11) of an issue and make decisions about possible actions (14).
Underpinning ideas about science 3. Science cannot provide complete answers to all questions. 1. The world is understandable. 2. Science ideas are evolving. 9. Scientists work together. 5. Science demands evidence.
10. Scientists’ observations are influenced by their existing ideas. 9. Scientists work together. 8. Scientists try to identify and avoid bias. 5. Science demands evidence. 4. Many science explanations require specialist language and symbols and are often in the form of ‘models’. 7. Science aims to explain and predict.
4.
Many science explanations require specialist language and symbols and are often in the form of ‘models’. 13. Informed citizenship entails applying rational argument and scepticism to science text.
12. Issues of ethics, values, economics and politics operate between science and the rest of society. 11. Scientists often study complex interrelated systems 14. Participating in informed decision making about socio-scientific issues is a civic responsibility.
Table 3: Identifying where fourteen ideas about the nature of science underpin the wording of the Level 1/2 and Level 3/4 science statements in The New Zealand Curriculum. New Zealand Association of Science Educators
35
NZ
science teacher
futurefocus–natureofscienceandcurriculum
126
1990 as a way of approaching stories from the history of science.17 Secondly, there is the question of progression of achievement objectives. The very first item in Table 5, an achievement objective for level 1/2, provides a good talking point: “Appreciate that scientists ask questions about our world …”. That seems to me to be an absolutely appropriate objective − young children’s questions have long been recognised as a powerful entry point to science18; but actually, there is probably a lifetime’s worth of ongoing understanding to be mined from that level 1/2 achievement objective. There is good evidence to suggest that sixteenyear-olds have considerable difficulty deciding what are, and what are not, scientific questions (“how was the Earth made?”,“do ghosts haunt old houses at night?”19). And underpinning this is the whole matter of whether or not, in
of ideas about science. I am not for a moment suggesting here that this formulation of ideas about science is, or should be, enduring. Just as science itself is subject to change, so is our perception of it. What is important, however, is to continue to seek a set of ideas about science that addresses science at large, that resonates with our current science curriculum, and which is meaningful for our teachers and learners. Also, it is proper (desirable, even) that we each have a unique set of personal experiences that we bring to this task. For my part, I have great fondness for many other ways of describing science that do not appear among these fourteen ideas about science (for example, the notion that “many scientific explanations are in the form of ‘models’ of what we think may be happening, on a level which is not directly observable”16) and I actually continue to make use of Rutherford and Ahlgren’s fourteen propositions from
Levels Five and Six: Understanding about science
Investigating in science
Communicating in science
Participating and contributing
• Understand that scientists’ investigations are informed by current scientific theories (10) and aim to collect evidence (5) that will be interpreted through processes of logical argument (6).
• Develop and carry out more complex investigations (11). • Show an increasing awareness of the complexity of working scientifically, including recognition of multiple variables (11). • Begin to evaluate the suitability of the investigative methods chosen (8).
• Use a wider range of science vocabulary, symbols and conventions (4). • Apply their understandings of science to evaluate both popular and scientific texts (including visual and numerical literacy) (13).
• Develop an understanding of socio-scientific issues (12) by gathering relevant (3) scientific information in order to draw evidence-based conclusions (5) and to take action where appropriate (14).
Propositions about the nature of science 10. Scientists’ observations are 11. Scientists often study 4. influenced by their existing complex interrelated systems. ideas. 8. Scientists try to identify and 5. Science demands evidence. avoid bias. 6. Science is a blend of curiosity, 13. imagination, creativity, logic and serendipity.
Many science explanations require specialist language and symbols and are often in the form of ‘models’. Informed citizenship entails applying rational argument and scepticism to science text.
12. Issues of ethics, values, economics and politics operate between science and the rest of society. 3. Science cannot provide complete answers to all questions. 5. Science demands evidence. 14. Participating in informed decision making about socio-scientific issues is a civic responsibility.
Levels Seven and Eight: Understanding about science
Investigating in science
Communicating in science
Participating and contributing
•
•
•
Use accepted science knowledge, vocabulary, symbols and conventions when evaluating accounts (7) of the natural world (4) and consider the wider implications of the methods of communication and/or representation employed (13).
•
Science aims to explain and predict. Many science explanations require specialist language and symbols and are often in the form of ‘models’. Informed citizenship entails applying rational argument and scepticism to science text.
3.
Understand that scientists have obligations to connect their new ideas to current (10) and historical (2) scientific knowledge and to present their findings (7) for peer review (9) and debate (8).
Develop and carry investigations that extend their science knowledge (11), including developing their understanding of the relationship between investigations and scientific theories and models (4).
Use relevant (3) information to develop a coherent understanding (7) of socioscientific issues (12) that concern them (11), to identify possible responses at both personal and societal levels (14).
Propositions about the nature of science 10. Scientists’ observations are influenced by their existing ideas. 2. Science ideas are evolving. 7. Science aims to explain and predict. 9. Scientists work together. 8. Scientists try to identify and avoid bias.
11. Scientists often study 7. complex interrelated systems. 4. Many science explanations 4. require specialist language and symbols and are often in the form of ‘models’. 13.
Science cannot provide complete answers to all questions. 7. Science aims to explain and predict 12. Issues of ethics, values, economics and politics operate between science and the rest of society. 11. Scientists often study complex interrelated systems. 14. Participating in informed decision making about socio-scientific issues is a civic responsibility.
Table 4: Identifying where the fourteen ideas about the nature of science underpin the wording of the Level 5/6 and Level 7/8 science statements in The New Zealand Curriculum. 36
New Zealand Association of Science Educators
Underpinning Ideas About Science
Levels 1/2
1. … understandable … 2. …evolving … 3. … complete answers … 4. … explanations … models.
I
C
X X
X
I
C
PC
I
C
X X
X
X
X
X
I
C
Levels /4 PC
X X
X X X X
X X
6/7
6/7
X
X
X
X
X X
4 4 4
X
X
X
3/3
3/3
3 2 3 4 3 3 4
5/7
X X
3/3
X
5/7
X X
2 2 3 4
NZ
science teacher
3/4
X X
X
X
2/4 X X
X X X X
X X
Total ‘Society’ UIASs
U
X 4/4
X
PC
X X
2/4
X X
U
Levels 7/8
X X
X
Total ‘Inquiry’ UIASs 12. …issues of values … 13. … argument … text … 14. participating …
U X X X
Total ‘Knowledge’ UIASs 5. …demands evidence. 6. …a blend of … 7. … explain/predict … 8. …avoid bias … 9. …work together … 10. …observations/ideas 11. … complex/interrelated
PC
Levels 5/6
X 3/3
Table 5: A summary of Tables 3 and 4, showing instances (X) where the wording of the fourteen underpinning ideas about science (UIASs) and the wording of the achievement objectives in the science learning area of The New Zealand Curriculum coincide. The analysis is by combined curriculum levels (1/2, 3/4, 5/6 , 7/8) and shows the four divisions of the Nature of Science strand at each level (U = Understanding, I = Investigating in science, C = Communicating in science, PC = Participating and contributing). fact, “the world is understandable”, namely, the assumption in science that the world is not capricious and inscrutable but rather that there actually are regularities that can be interrogated. As scientist and author Jacob Bronowski movingly claimed, this possibility of knowing is part of the wonder of science: “Every judgement in science stands on the edge of error, and is personal. Science is a tribute to what we can know although we are fallible”.20 In short, we do not relinquish this achievement objective when we pass on to level three. Just as the fourteen underpinning ideas about science are not level-specific, so it is with the NoS achievement objectives; they are best made sense of if they are thought of as being cumulative rather than sequential. A teacher’s knowing how and when to introduce them, and when to return to them, is crucial. Clearly, this demands teaching which has a deep understanding of the scope of NoS and access to a wealth of rich, motivating, learnerappropriate activities and experiences.
Footnotes
Ideas about science – a final thought
9
Whatever ideas about science we teach in the future, I would hope that, in sum, they adequately convey the cultural dimension: the notion that science is a human process. There is a lovely quote from science educator Derek Hodson21 that conveys this way forward exactly: “I want the curriculum to show students that these people (scientists) can be warm, sensitive, humorous and passionate. More importantly, I want them to realise that people who are warm, sensitive and passionate can still become scientists, though they are required to conduct their work in accordance with the codes of practice established, scrutinised and maintained by the community of scientists.”
Acknowledgements I am grateful of the indispensable input of the following thirteen colleagues: Michelle Ballard, Suzanne Boniface, Faye Booker, Terry Burrell, Steve Chrystall, Matthew Easterbrook, Eluned Fitzjohn, Karen Mitchell, Colin North, Jenny Pollock, Kate Rice, Craig Steed and John Whakamoe. Nigel Evans, Ministry of Education, also provided valued guidance and encouragement throughout the development of this article.
1 2 3
4
5 6
7
8
10 11 12 13 14 15
16
17 18
19 20
21
Ministry of Education (2007). The New Zealand Curriculum. Wellington: Learning Media. Barker, M. (2010). Lifelong science learning. New Zealand Science Teacher, 123, 32-36. Pella, O’Hearn and Gale (1966). See: Barker, M. (2004). Key aims for science education in New Zealand schools in the 21st century: messages from the international literature. A commissioned research report for the Ministry of Education, Wellington, New Zealand. Abd-El-Khalick, F., Bell, R. & Lederman, N. (1998). The nature of science and instructional practice: making the unnatural natural. Science Education, 82 (4), p.417-436. Rutherford, J., & Ahlgren, A. (1990). Science for all Americans. New York: Oxford University Press. Ministry of Education (1993). Science in the New Zealand Curriculum. Wellington: Learning Media. The full title of the strand was ‘Making sense of the nature of science and its relationship to technology’. Hipkins, R., Barker, M., & Bolstad, R. (2005). Teaching the ‘nature of science’: modest adaptations or radical reconceptions? International Journal of Science Education, 27(2), 243-254. Baker, R. (1999). Teachers’ views: ‘Science in the New Zealand Curriculum’ and related matters. New Zealand Science Teacher, 91, 3-16. Loveless, M. & Barker, M. (2000). “Those pages we just turn over ...”: The ‘Nature of Science’ in Science in the New Zealand Curriculum. New Zealand Science Teacher, 93, 28-32. http://www.tki.org.nz/r/science/science_is/ dated 30th June 2005. The four headings are: ‘Exploring science ideas’, ‘Forming science explanations’, ‘Science knowledge’, and ‘The culture of science’. The group met in Wellington in September 2009 under auspices of NZASE and the Ministry of Education. These, of course, are ideas about science; they are not ideas in science, i.e. the content knowledge of science. Sardar, Z. & Van Loon, B. (2002). Introducing science. Cambridge, UK: Icon Books, p.172. The analysis that follows was carried out by me alone; I am responsible for any flaws or errors. Claxton, G. (1991). Educating the inquiring mind: The challenge for school science. Hemel Hempstead: Harvester Wheatshaft. Aikenhead, G. (2000). Renegotiating the culture of school science. In R. Millar, J. Leach & J. Osborne (Eds.), Improving science education: the contribution of research. Buckingham: Open University Press, pp. 245-264. Millar, R. & Osborne, J. (1998). Beyond 2000: science education for the future. London: Kings College, p.22. This ‘Idea-About-Science’ was proposed for Key Stages 1 & 2 in the British science curriculum. Barker, M. (2010). Ripping yarns: science stories in Asia. New Zealand Science Teacher (in press). Biddulph, F. (1990). Pupil questioning as a teaching/learning strategy in primary science education. In A. Begg et.al. (Eds.), SAME papers 1990. Hamilton: Centre for Science and Mathematics Education Research, pp. 60-73. Driver, R., Leach, J., Millar, R. & Scott, P. (1996). Young people’s images of science. Buckingham: Open University Press, p.73. Bronowski, J. (1973). The ascent of man. London: British Broadcasting Corporation. The quotation, p.187, from the TV series of the same name, was made as Bronowski paced through the marshes at Auschwitz. Hodson, D. (1998). Science fiction: the continuing misrepresentation of science in the school curriculum. Curriculum Studies, 6 (2), 191-216. The quotation is from page 208.
New Zealand Association of Science Educators
126
futurefocus–natureofscienceandcurriculum
U
Levels 3/4
37
NZ
science teacher
futurefocus −supportingscienceeducation
126
supporting science education
Science: Thinking with evidence consists of four standardised tests developed specifically for use in Years 7-10. These tests are designed to assess how well students use evidence to think about scientific contexts and issues. Each test consists of stimulus material with multiple-choice questions. The tests identify specific aspects of thinking in science rather than attempting to measure overall achievement in science. Each of the items in the tests is aligned with one of the substrands of the Nature of Science strand of NZC (although in reality this classification is somewhat arbitrary as there is considerable crossover between the sub-strands). Items require students to do one or more of the following: • identify the available evidence and its limitations (understanding about science) • understand the strengths and weaknesses of scientific investigations (investigating in science) • read a wide range of texts (communicating in science) • apply scientific concepts to real-life contexts. (participating and contributing). The tests are not intended to provide definitive illustrations of the full scope of each sub-strand, but rather provide a starting point for teachers to think about what could be involved in the Nature of Science strand.
Knowledge is still important, but students also need to be able to use this knowledge. This change in the intended curriculum, however, seems unlikely to lead to change in the enacted curriculum unless it is accompanied with resources that support teachers to think in new ways about what they teach in science classes (and why they teach it), and how they assess what students know and can do. As yet, there has been little concrete support for teachers as they wrestle with the demands of this new curriculum. In developing Science: Thinking with evidence we hoped to go some way toward filling this gap. Designing an assessment resource rather than a teaching resource may seem like putting the horse before the cart. After all, why would you want to assess a type of science learning that is probably not common practice in many classrooms yet? This is an issue we debated at length. We eventually decided that while there is pressure on teachers to ensure the decisions they make are data-driven, there is also the potential for the available assessments to drive what is taught. This makes it important to find ways to assess what we say we value, rather than just the things we already know how to assess. Science: Thinking with evidence is an attempt to assess something new, but we are hoping teachers will also be able to use it for ideas about how they might usefully adapt their teaching. Having settled on developing an assessment (rather than a teaching) resource our next challenge was narrowing down exactly what we wanted to assess. We eventually decided to design a test that focused on just one element of science literacy: “thinking with evidence”. As thinking is one of the Key Competencies we felt by becoming clearer about both what thinking in science involves and what progress in thinking might look like, we could shed some light on how science as a learning area could contribute to the development of Key Competencies as well as foregrounding the Nature of Science strand of the curriculum. By designing this assessment resource we hoped to: • find out something about progress – how do you tell if a student is getting better at thinking? • provide teachers with a tool to see which aspects of thinking their students were already good at, and where they might need to build more opportunities into their programmes for developing thinking • provide teachers with some practical ideas for adapting their classroom practice.
Why this resource?
What does progress look like?
The NZC signals a change in focus for science education and places an emphasis on scientific literacy for everyone. It aims to develop students who “can participate as critical, informed, and responsible citizens in a society where science plays a significant role,” (Ministry of Education, 2007, p17). There is an increased emphasis on students knowing about how science works. The traditional disciplines of biology, physics, chemistry and Earth sciences are now seen as the contexts within which knowledge about science is developed and the ‘Nature of Science’ strand has become the key, overarching strand of the science curriculum.
When the resource was being developed items were written and piloted with small groups of students. Psychometric information from the pilot tests was then used to select about 160 items suitable for including in the second phase. These items were grouped into four separate tests and trialled with a larger sample of students. All the items were then calibrated on a single scale allowing students’ progress to be qualitatively described over the four Year levels. The final stage involved trialling the items with around 2000 students at each Year level.
NZCER’s science assessment resource Science: Thinking with evidence provides support for teachers, as Ally Bull and the NZCER science education team, explain: Many educationists argue that schooling needs a major change in emphasis if it is to prepare students for life and work in the 21st century. The New Zealand Curriculum (NZC) (Ministry of Education, 2007) is a forward-looking document that gives teachers permission to make such changes, but it provides little guidance as to what these changes might look like in practice. In 2010, NZCER published a new science assessment resource called Science: Thinking with evidence in an attempt to provide some support for teachers. In this article we briefly describe what the resource is and why we decided to develop it. We make some suggestions as to how teachers might use the resource to think about their classroom programmes as well as students’ progress. We also briefly discuss how some of the challenges we experienced in developing this resource are adding to our own thinking about what science teaching for the 21st century might look like.
The resource
38
New Zealand Association of Science Educators
Using the test results to support student learning The tests can be used to identify both individual and class strengths and weaknesses. A class-wide pattern of incorrect answers in a particular Nature of Science sub-strand might indicate the need for further opportunities for students to develop particular skills/dispositions/competencies. Response patterns might shed light on questions such as: • Do the students understand the importance of evidence, and what counts as evidence? • Do students need practice in reading or interpreting data? • Do students carefully consider alternative explanations? If a teacher really wants to find out more about their students’ thinking it could be useful to use incorrect responses as a basis for discussion. Are there some items where many students chose the same incorrect distracter? Perhaps there were questions where responses were fairly evenly spread across the distracters. In either case, challenge students to think about why students might have chosen particular answers. Perhaps students could work out what knowledge was needed to be able to think successfully. The teachers’ manual that accompanies the tests gives some suggestions of activities and approaches that teachers may find useful as they think about adapting their teaching practices. For example, if many students are having difficulty with identifying evidence and its limitations, teachers could simply focus students’ attention on this by encouraging them in class discussions to ask the question, “How do you know that? What’s the evidence?” Alternatively, students could be given data sets and then asked to brainstorm as many possible explanations as they can for any patterns they see in the data. As a group discuss which explanations are the most plausible. How do you know? What additional data would you need to decide which is the best explanation?
The test items themselves could also provide teachers with ideas for adapting their own teacher-generated assessments. Many of the test items could be adapted to whichever context the class is studying. Used in these ways we think Science: Thinking with evidence has the potential to provide useful support for teachers as they work out what curriculum policy changes might look like in their classrooms. We see it as a thinking tool for both students and teachers and we hope that is the way it will be used. Developing this test has certainly challenged our thinking.
NZ
science teacher
Challenges in assessing thinking One of the challenges in designing this resource was that we wanted to measure how well students could use knowledge, but we had no way of knowing what knowledge students had and obviously students can’t use knowledge they don’t have. Our solution to this dilemma was to provide most of the information a student needed to be able to think about the problem. This solution has limitations though. According to cognitive science, “Successful thinking relies on four factors: information from the environment, facts in the long-term memory, procedures in the long-term memory, and the amount of space in the working memory. If any of these factors is inadequate, thinking will fail,” (Willingham, 2009, p14). This means that even though the necessary information is given in the test question (information from the environment) a student’s capacity to think with that information will still be affected by the other factors. We would expect students to be able to think better when the content and context is familiar. We saw an example of this in a small research project we carried out with some Year 9 classes in five different schools. Generally, the students in the higher decile schools did better on the items in Science: Thinking with evidence than the students in the low decile school. The one question where this was not the case was one about shadows. The low decile school’s students had just completed a unit of work on shadows and they scored better than the other schools’ students on this item. This poses an interesting question as to whether or not you can assess thinking as a general skill, or whether it is always context specific. If a student can think through problems that involve complex relationships and multiple thinking steps in one context in science but can only work with simple direct relationships in another science context, how do we decide how well they can think in science? Another question to ponder is how is the thinking students do in science the same or different from the thinking they do in other learning areas? What is the specific contribution thinking in science makes to the development of the key competency, thinking? These are some of the questions the science education team at NZCER is currently thinking about as we continue to grapple with what future-focused science education might look like. For further information contact: Ally.Bull@nzcer.org.nz
126
futurefocus −supportingscienceeducation
Close analysis of the test items showed that a number of factors combine to make an item either more or less difficult than others. Low-demand items usually require students to: read only one text type; work within a familiar context; work with familiar or provided science knowledge; think in ways that require them to make simple or direct links. The most demanding tasks require students to: read multiple text types; synthesise factors from different pieces of evidence; work in unfamiliar contexts; use challenging/ complex science knowledge; and think through complex relationships that might involve orientating information in space or time, or involve multiple thinking steps. Items of moderate difficulty make higher demands on students in some of these areas and lower demands in others. We found no pattern identifying that any one of these areas on its own necessarily makes an item any more or less difficult. For example, presenting evidence with very little written text does not by itself necessarily make a question easy if there are other high-demand aspects. To progress (i.e. answer harder questions) students need to master a range of competencies, such as the ability to read a range of text types, or to transfer ideas from one context to another. The metaphor of ‘progress in pieces’ (Carr, 2008) where progress looks more like putting together the pieces of a jigsaw puzzle than a series of linear steps, seems useful here.
References Bull, A., Ferral, H., Hipkins, R., Joyce, C., & Spiller, L. (2010). Science: Thinking with evidence. Wellington: NZCER. Carr, M. (2008). Zooming in and zooming out: challenges and choices in discussions about making progress. Presented at ‘Making progress – measuring progress’, NZCER Conference, Wellington. Ministry of Education (2007). The New Zealand Curriculum. Wellington: Learning Media. Willingham, D. (2009). Why don’t students like school? San Francisco: Jossey-Bass.
New Zealand Association of Science Educators
39
NZ
science teacher
primaryscience
126
Mr Science – Part 1 Mr Science promotes thinking and problemsolving in primary schools, as Steve Sexton explains: Over the past decade, research has suggested that students’ success in science is strongly dependent upon the quality of their teacher (Darling-Hammond, 2000; Johnson, Kahle, & Fargo, 2007; Rivkin, Hanushek, & Kain, 2005; Shen, Gerard, & Bowyer, 2010). However, much of this same research goes on to report that many teachers are unprepared in science subject knowledge. Cowie, Jones and Harlow (2003) reported that many primary teachers in New Zealand lack the confidence to teach science due to their own lack of content knowledge. This is reflected in the National Education Monitoring Project (Crooks, Smith, & Flockton, 2008) and TIMSS 2006/07 (Cargill, 2008) data which suggest that although many primary students are interested in science they are not happy with the science they are getting. For most New Zealand primary school teachers, their teacher education programmes are what Cooper, Cowie and Jones (2010) referred to as, “generalist programmes that prepare teachers across all curriculum learning areas” (p.95). Therefore, it is of little surprise that some New Zealand teachers are not comfortable with teaching science content and, similar to their overseas counterparts, they may adopt teacher-centred approaches when teaching science (Goodnough, 2008). Sterling Cathman as ‘Mr Science’ is how some primary schools in Nelson have been able to bring inquiry based science teaching into their classrooms. He describes his role as not only presenting science to students as exciting and engaging, but also instilling confidence in the teachers by supporting them with energizing ideas that they are then able to follow up themselves. While he was trained as a secondary science teacher he is now a specialist primary science teacher. In Sterling’s own words, “I am out there most days blowing the socks off the wee kiddies with the magic of science.” It is for these reasons that in 2008 Rob Wemyss, Principal of Clifton Terrace School, “leapt at the chance to have him (Mr Science) in the school.” Mr Science offered students at Clifton Terrace School the chance of hands-on science as its teachers had become, “reluctant to take on science experiments and have all the gear required.” Science is now something these students look forward to. Every class is rotated through Mr Science along with a weekly extension group. In these sessions Mr Science incorporates specific science concepts, as requested by the teachers, through contexts such as ‘Natural Disasters’ and ‘Planet Earth and Beyond’. He is able to bring to these classes a greater depth of content knowledge, built around the Nature of Science, than the teachers have. At Hampden Street School, Mr Science spends a day in each class per term. Principal Don McLean had seen the benefits to his school by bringing in specialist teachers. He stated, “We piloted the specialist science teacher following on from the arts’ teacher success, and instantly we could see that added knowledge and skills enhanced our school science programme greatly.” This affected not only the students but also the teachers, and as well both the students and the classroom teachers were being exposed to specialist skills
and knowledge resulting in what Mr McLean referred to as, “an extremely high level of student engagement.” This level of student engagement was echoed by Victory Primary School, where Sterling Cathman is both senior teacher release and Mr Science for the whole school. Wendy Taylor, Deputy Principal of Victory Primary School, described how students are now able to transfer the knowledge from science into their everyday world. One student took her glowstick bracelet that had stopped glowing and put it into warm water so it would last longer. This student explained she knew it was worth a try as they had experimented with this in class several weeks before. Wendy went on to say that for the first time students reported wanting to be scientists. But just as important, the teachers are also inspired by the possibilities of science and motivated to re-visit the ideas Mr Science has investigated with their class. This has created a feeling within the school that not only is science fun, but also a valued part of the curriculum. Wendy has also noticed how teachers have grown in their own confidence and ability to teach science when they have access to an inspirational scientist. Sterling sees his role as encouraging children, “I teach science as a way of thinking and problem solving.” Students think and figure out what, how and why something is happening. In a typical session of 90 minutes, 80% or more of the time is spent in active student activity. The remaining time involves Mr Science and Einstein the puppet (see Keogh, Naylor, Downing, Maloney, & Simon, N.D. for more information on teaching science through puppets). Einstein is a lot of fun but not very bright, so the students have to keep explaining to him, “What is science?”,“Why do we do science?”,“What does science mean to our lives?” and any other questions that may arise. This means Sterling is not the focus of attention. Einstein’s lack of content knowledge emboldens the students and provides them the opportunity to develop their own confidence. Einstein helps to foster an environment that has fewer inhibitions and more freedom of thought, as it is the students who are the ones doing the wondering, predicting, noticing, asking questions and trying to figure things out. Mr Science was created by Stirling as a way to bring fun and exciting science to primary students, and to incite a lifelong interest in science with them. Just as importantly, it has encouraged and motivated classroom teachers to work alongside Stirling and see science teaching modelled in the classroom. This has increased both teacher confidence and teacher understanding, especially of the Nature of Science strand of the curriculum. In Nelson, not only are some students now waiting with anticipation for their next science encounter, but also so are their teachers. Clifton Terrace, Hampden Street and Victory Primary schools agree that Mr Science’s enthusiasm and excitement for science has become infectious resulting in positive feedback from students, parents and teachers. For further information contact:steven.sexton@otago.ac.nz
References Caygill, R. (2008). Science – Trends in Year 5 science achievement 1994 to 2006. Wellington, New Zealand: Ministry of Education. Cooper, B., Cowie, B., & Jones, A. (2010). Connecting teachers and students with science and scientists: The science learning hub. Science Education International, 21(2), 92-101. Cowie, B., Jones, A., & Harlow, A. (2003). Primary and secondary teachers experiences of science in the New Zealand curriculum. New Zealand Science Teacher, 104, 29-34.
continued on page 11
40
New Zealand Association of Science Educators
Children of all ages engage with stories as Chris Astall, NZAPSE National Co-ordinator, University of Canterbury, and Lee Astall, Educational Consultant, Brivezac, France, explain: Literacy can provide an authentic context for science learning. Literature, when used as a springboard for science, can fuse the children’s imagination from the texts with the reality of science activities offering learning opportunities that are real, engaging and exciting. Haylie Eilken and the 25 children in her class at Rolleston School had invited Chris Astall to their Harry Potter day. Haylie wanted to use her Year 5 children’s enthusiasm for the fantasy novels as an opportunity to teach some ‘handson science that was fun’. The challenge for Chris was to work with Haylie to develop a series of activities that would not only engage the children but also give her an opportunity to develop her own understanding of the ‘Nature of Science’ component of the science curriculum, as well as giving Hailey some experience in teaching aspects of the Material and Physical World. Haylie wanted to focus on developing the children’s questioning, activities that allowed children to engage in practical science and to see how Chris would manage and organise the children and equipment. Chris suggested that they also explore the ‘Communicating in Science’ theme of Nature of Science with a particular focus on using scientific vocabulary.
NZ
have another child light the top of the tea bag with a match. Have the child wait a few seconds until the tea bag is burnt about halfway down. Then say the spell and swish the wand, the tea bag will rise into the air! Further details of the experiment, the science concepts behind the activity, and key safety advice are given in Burchill’s (2004) article ‘The flight of the humble tea bag’1 . For this activity the children were given the starter stem ‘What would happen if?’ and were encouraged to develop a range of questions. It was important that both Haylie and Chris modelled questioning during the activity. Many questions stemmed from the children trying to develop an understanding of what they had witnessed. Questions included those around the ‘magic’ as well. For example, “What would happen if we used different magic words?” “What would happen if we did not swish the wand?” All the questions were collected and recorded on the white board. We discussed the questions and the children chose, as a class, the two they would like to explore further. Chris advises teachers to always try the activity yourself first. Have the children working in pairs and one pair at a time do the experiment. Carefully outline the rules regarding the use of matches and what happens if the tea bag falls over (leave it to burn, do not waft it about) and have a damp tea towel handy.
126
primaryscience
Harry Potter: science and spells
science teacher
Activity 2: Aunt Marge’s Big Mistake, from Harry Potter and the Prisoner of Askaban. (Scene 2) “Shut up! SHUT UP!” said Harry Potter. In this scene, Harry’s anger towards Aunt Marge causes her to inflate. For this activity Chris poured water into a 300mL plastic water bottle until it was a quarter full. Chris drew a mark on the outside of the bottle and labelled it water. He then added the same volume of white vinegar, and again drew another mark on the bottle and labelled it vinegar. Chris then copied these marks to another 14 plastic bottles. Each group was provided with a tote tray containing one empty plastic bottle, a round balloon, a container of vinegar, another of water, a teaspoon and a container of bicarbonate of soda (NOT baking powder). Have a variety of 1
In Physics Education, 39(1). http://tinyurl.com/4pnur2h
Figure 1: Casting the ‘Wingardium Leviosa’ spell. Photograph reproduced with permission and courtesy of Chris Astall.
The day’s activities, with reference to appropriate scenes in the Harry Potter DVDs, are described below.
Activity 1: Wingardium Leviosa, from Harry Potter and the Philosopher’s Stone. (Scene 17) “Stop, stop, stop. You are going to take someone’s eye out. Besides you’re saying it wrong,” said Hermione Granger. In this scene, the young magicians from Hogwarts attempt to levitate a feather. You will need a standard tea bag made of a tube of gauze which is folded in half and stapled at the top. Tea bags that are sealed in the middle of the tube do not work very well. Open the tea bag and remove the contents. Straighten the bag out and stand it upright on a 6cm square of silver foil placed upon a non flammable surface (e.g. a desk or table). Have one child practise with their ‘magic wand’ – the swish and flick wrist action whilst saying the spell ‘wingardium leviosa’. When you are ready,
Figure 2: ‘Hogwarts students’ explore the properties of their ‘slugs’ on different surfaces. Photograph reproduced with permission and courtesy of Chris Astall.
New Zealand Association of Science Educators
41
NZ
science teacher
primaryscience
126
brands/types of vinegar, different sized plastic bottles, and a selection of balloons available. The children drew Aunt Marge’s face on the balloon. They added the water, then the vinegar to the respective marks on the bottle. One teaspoon of bicarbonate of soda was placed into the balloon. The balloon was attached over the mouth of the bottle so that when the balloon was lifted up, the powder fell into the diluted vinegar. It is important to test this activity first as different brands of vinegar may not be as effective. Once the children have completed the activity, encourage them to write down at least five questions that come to mind. You may want to introduce a variety of question starter stems to help guide their questioning. Now the children can complete an exploration type activity as they try to answer one of their questions more fully. The science concepts, associated vocabulary and other activities to do with fizzing and foaming are outlined in the Ministry of Education publication2 ‘Making Better Sense of the Material World’ under ‘Fizzing and Foaming’.
Activity 3: Ron’s Slugs from Harry Potter and the Chamber of Secrets. (Scene 12) “You’ll pay for that one Malfoy. Eat slugs,’” said Ron Weasley. In this scene, Ron defends Hermione by casting a spell but it backfires. For this activity the class worked in larger groups of six. Each group was given a tote tray containing gelatine powder, food colouring, hot water and ice cube moulds. 50mL of hot water was added to a container along with two teaspoons of gelatine powder and half a teaspoon of glycerine (that had some green food colouring mixed into it). The mixture was stirred thoroughly and poured into ice cube moulds and allowed to set for at least 30min. The ‘slugs’ were then removed from the moulds. Again it is important to test out the mixtures and the setting times prior to doing the activity. We found that the mixtures took a lot longer to set and that some did not set at all well. When the children have made their mixtures, if they did not work we challenged them as to why and what they could change to improve the ‘slugs’. The children observed the properties of the slug. They squashed it, shaped it and completed a group brainstorm of words to describe how it felt.The children explored a range of different surfaces including a window (watch out for those who test the ceiling as it can take a few minutes before the slug falls back again!) including a window. Finally the children placed their slug into a cup of hand-hot water. The children also tested the now ‘slimy slugs’ again on the different surfaces. The children were asked to give feedback to the class and share their findings. They were encouraged to share specific observations and to use language that accurately described their observations. The children were then able to make some deductions about the changes that were happening to the slugs. The children were challenged to rewrite Ron’s slug spell. With a focus on using alliteration and descriptive vocabulary, we worked on writing and
continued from page 43 4
5
6
42
time. Identify ways in which scientists work together and provide evidence to support their ideas. Achievement aims and objectives can be found at: http:// tinyurl.com/2utnn6t. This list is taken from Bull, A., Joyce, C., Spiller, L. & Hipkins, R. (2010). Kick Starts; Kick-starting the Nature of Science. Wellington: NZCER Press. Akerson, V., & Donnelly, L (2010). Teaching Nature of Science to K-2 Students: What understandings can they attain? International Journal of Science Education, 32(1), 97-124. Lederman, G.N., & Lederman, S.J. (2004). Revising instruction to teach nature of science. The Science Teacher, 71(9), 36-39.
New Zealand Association of Science Educators
editing a class spell that the children then dramatically cast on one another… Eat… squishy, slimy, sloppy, slippery revolting, slithering, puke yellow gagging, acidic, body convulsing regurgitate, sickly green SLUGS. The science concepts, vocabulary and other activities to do with slime are outlined in the Ministry of Education publication3, ‘Making Better Sense of the Material World’ under ‘Slime and Ooze’.
Final thoughts... For each of the three activities described above, the Harry Potter novels were used as a way of engaging the children. The science activities were developed from the ideas and themes within the books and we had a specific focus on teaching, and giving the children experience of, aspects of the Nature of Science. As Haylie explained “The focus of the Harry Potter day was to take the children’s enthusiasm for the novels and incorporate some hands-on science, which the class loved. You could literally see the awe and wonder on their faces and hear the questioning going on as the children wondered how everything worked.” It was important for Haylie that the children really engage with the science. “I also wanted the children to see that science can be really hands-on and FUN! I wanted them to be enthusiastic about the subject and want to know more and learn more. I appreciated observing [and helping] someone implement a FUN and engaging science day.” Teaching alongside Haylie also gave Chris an opportunity to model how science lessons could be taught and managed. As Haylie commented, “I sometimes think that the organisation of equipment for science puts teachers off, so it was good to see the use of some everyday objects and gear. Science is something I love to teach, but that sometimes is put on the back burner at school due to demands on teachers.” The focus of this article was to show how one teacher engaged the children in her class through the use of literacy. Of course, these activities can also be used to allow the teacher to focus on developing conceptual understanding. We will leave the last words to Haylie from Rolleston School, “I remember the children absolutely loving the day! So much so, that they wrote about it in their end of year reflections as one of the best days in the classroom.” For further information contact: chris.astall@canterbury.ac.nz
2 3
7
http://tinyurl.com/4g8khuy http://tinyurl.com/4g8khuy
Using children’s’ fiction texts provides a framework and context for the science activity, allowing the teacher to engage the children. See www. sciencepostcards.com. 8 http://www.tki.org.nz/r/science/science_is/. 9 The articles are intended to stimulate discussion and to provide starting points for further investigations by individuals, groups, or a whole class. http://www. tki.org.nz/r/technology/connected/index_e.php. 10 Links to the NZC Nature of Science are made explicitly throughout the contexts. The resource includes activities and videos of scientists. http://www. sciencelearn.org.nz/. 11 ‘Kick Starts; Kick-starting the Nature of Science’ and the recent publication ‘Science: Thinking with Evidence’ tests which can be used to identify some specific aspects of thinking in science. See http://www.nzcer.org.nz
NZ
science teacher
the nature of science in action
126
The importance of developing children’s scientific attitudes; that is their understanding of ideas about science, what science is and how scientists work is central to the New Zealand Curriculum (NZC)1. The Nature of Science is the core strand and ‘required learning for all students up to Year 10’. The contexts for developing ideas about the Nature of Science are provided in the other four strands. Developing ideas and attitudes about science is important if we are to guide children towards becoming scientifically literate – thinking and working scientifically2.
A Focus on ‘Understanding about Science’3. Take a glass tumbler and half fill it with cold water. Add three tablespoons of white vinegar. Add one teaspoon of bicarbonate of soda (not baking powder) and drop in about 6 raisins. Ask the children to observe the raisins and get them to explain what they think is happening. This simple activity can be used as an example of how the Nature of Science can be taught in the classroom. The raisins move up and down through the tumbler. One product of the reaction between the bicarbonate of soda and the water/vinegar mixture (a dilute acid) is the formation of carbon dioxide bubbles. These bubbles attach to the raisins. Children can share their ideas back to the class in a number of ways, i.e. through drawing, annotations, mapping ideas, class discussion, pair sharing or writing. At this initial stage it is important that all the children’s ideas are valued and that all their explanations are accepted. Some of the children’s ideas may be wildly incorrect, however, the important part of this exercise is to then ask the children to provide some evidence to support their explanation of what is happening, i.e. observations or gathered data. So you may get an explanation such as this: “The raisins make the bubbles and the bubbles join up and get bigger. The air in the bubbles makes the raisins rise up to the top, then the bubbles of air pop and the raisins fall down again.” The child developed an idea based on their observations. Their idea makes sense to them and helps explain their observations. Teachers need to create an environment that allows for their ideas to be safely challenged and for students to understand that science ‘lets me change my answer’. When considering ‘Understanding about science’ what do we want children to understand about the features of scientific knowledge, how it is generated and how scientists work? Consider… 4 • science knowledge is developed by people, and changes over time • scientists provide evidence to support their explanations • Science explanations must withstand peer review before being accepted as knowledge • scientists design investigations to test their explanations • open-mindedness is important to science. We might also add… • being prepared to re-evaluate your science ideas • using creative insight to aid explanation
•
having your ideas challenged by other people • being curious • being willing to challenge others’ ideas. So how can we use the raisins activity to help students develop an understanding of the Nature of Science? Revisit the students’ explanations and ask them if they have enough evidence to support their ideas. Older children’s ideas can be challenged, or maybe the children can challenge each others’ ideas. Having children try to explain their thinking helps them realise that they may not have enough evidence to support their ideas. Children can start to devise experiments that will allow them to test their explanations. Another child suggested that the bubbles formed when the baking soda was added and that the raisin was not making the bubbles. In this example, the child’s idea that the raisins made the bubbles was questioned. To test this idea the children designed a similar experiment where raisins were added at different stages: after the water was added; after the water and vinegar were added; and after the water, vinegar and bicarbonate of soda were added. In light of alternative evidence, do the children revise their ideas? Do the children use new evidence to support their ideas? Some children may not want to change their ideas, they may be stubborn or refuse to believe they are wrong – but being prepared to re-evaluate the evidence, having an open-mind, and forming ideas based on experiences are some key aspects of ‘Understanding about Science’. Sometimes we are just not able to explain the reason, and not knowing the answer is also a valid conclusion. Just by doing the raisins activity will not ensure that children develop a better understanding of what science is about. Children need to be explicitly taught about the aspects of the Nature of Science that you want to develop5, and this means thinking about what elements of the Nature of Science need to be planned for and integrated into the science lesson6. There are a number of NZ resources that have been developed to support teachers. The Science Postcard resource7, developed by teachers, provides science activities that have a specific Nature of Science focus. A number of key Nature of Science themes are explored on the Science IS website8 on TKI. The Connected Series9 have a range of articles designed to engage students in mathematics, science, and technology in the context of students’ everyday lives. The Science Learning Hub10 uses the latest New Zealand research as a context for providing resources for teachers for Years 5-10. NZCER have also produced a number of publications to aid teachers1 1. For further information contact: chris.astall@canterbury.ac.nz 1
2
3
primaryscience
Written by Chris Astall, University of Canterbury
Ministry of Education, The New Zealand Curriculum, Learning Media, Wellington, 2007, pp.28-29. In the article ‘What is Scientific Literacy’ Ian Milne from the University of Auckland explores the question in relation to the aims and goals of science education. http://tinyurl.com/4bl3uo3. At Levels 1/2: Appreciate that scientists ask questions about our world that lead to investigations, and that open-mindedness is important because there may be more than one explanation. At Levels 3/4: Appreciate that science is a way of explaining the world and that science knowledge changes over
continued on page 42 New Zealand Association of Science Educators
43
NZ
science teacher
biology
126
biology education: a connected journey
Written by Jacquie Bay, President Biology Educators’ Association of New Zealand Te Ro¯pu¯Whakaako Koiora o Aotearoa The New Zealand Curriculum describes a vision of lifelong learning established through the school years. This vision points to school students “developing the values, knowledge, and competencies that will enable them to live full and satisfying lives” and indicates that this should lead to young people who will be “confident, connected, actively involved, and lifelong learners” (Ministry of Education, 2007 p.8). The rapid pace of development of biological knowledge, combined with the connection of biological knowledge (old and new) to daily life and the social and economic wellbeing of our communities, provides a strong impetus for the development of understanding and appreciation of biology throughout the education journey. BEANZ believes that connection and co-operation between the different stages in the education continuum is essential if we are to encourage lifelong learning. During the past two years, BEANZ has been exploring opportunities to enable primary, secondary and tertiary educators to learn more about what each sector is doing to encourage students to become lifelong learners engaged in understanding and the appreciation of biology. The appointment of Victoria Rosin in 2009 to the BEANZ executive, representing primary education has given a voice to primary teachers, complementing the long established contribution of Alison Campbell, the tertiary education representative. In 2009, BEANZ co-ordinated the provision of scholarships provided by three of New Zealand’s Centres of Research Excellence (CoRE) to enable secondary teachers to attend BioEd 09, encouraging interaction between secondary and tertiary sectors. This has also provided a continuing line of communication and interaction between BEANZ and the three CoREs. The BEANZ forum at Biolive 09, led by Bill MacIntyre, explored a vision for biology education, engaging participants in a panel discussion. Managing transitions between primary, secondary and tertiary education arose as a theme within this discussion. Feedback indicated
44
New Zealand Association of Science Educators
that the opportunity to hear from and understand issues in biology education from differing perspectives was appreciated by participants, a number of whom suggested we should engage together in discussion more frequently. While BEANZ was undertaking work on the contract for the Ministry of Education Teaching and Learning Guidelines (Biology) in 2010, we created an opportunity to engage with senior biologists representing five major universities and the Office of the Prime Minister’s Science Advisory Committee. A great deal of learning and increased awareness occurred for all parties involved in the discussions. Tertiary representatives gained clarity and insight into the structure and purpose of biology education in the secondary sector. All participants gained from robust discussion around teaching of core biological concepts which contributed positively to the development of the teaching and learning guidelines. While acknowledging that each educational phase has particular goals and requirements, increased understanding of where students have come from, or are going to, has the potential to improve transitions and encourage the fulfilment of the vision for lifelong learning stated in the New Zealand Curriculum. The Biolive 2011 Conference is designed to allow groups from all phases of the education continuum to meet together, as well as meet within their specific groupings. We hope that this participation from all sectors in discussion around curriculum, pedagogy and assessment will encourage connectedness. Acknowledging that connectedness between sectors may have been somewhat limited in the past, reduced conference fees for new graduates will be offered to encourage a new generation of teachers from all sectors to connect and work together. We hope that Biolive 2011 will celebrate the mutual interdependence of all biology educators, and create a forum where teachers from all the different sectors can come together and share insights. We look forward to your contribution.
Written by Suzanne Boniface
Stories about NZ Scientists The MacDiarmid Institute has just launched the first two stories in a series, about New Zealand scientists. Aimed at Year 10 and above, these articles are intended to illustrate aspects of the Nature of Science in the New Zealand Curriculum. The stories include information about the science, the scientist and their inspiration. The first story is about Alan MacDiarmid, who received a Nobel Prize in 2001 for his discovery of conducting polymers. The second story is about Professor Sir Paul Callaghan, a recipient of this year’s Prime Minister’s Science Award for his work with nuclear magnetic resonance. The stories are available in PDF format at: http:// www.macdiarmid.ac.nz/opportunities/nature.php.
Useful chemistry experiments The following experiments have been developed by the Royal Society of Chemistry to help inspire and engage students. They are reproduced here by permission of The Royal Society of Chemistry. These and others can be found at: www.practicalchemistry.org. Rates and Rhubarb This is great for a novel introduction to rates of reaction. There is sufficient oxalic acid in rhubarb stalks (leaves contain higher levels and are poisonous and not to be used) to decolourise a dilute solution of potassium permanganate. And it’s great to use as students might be more familiar with rhubarb than some laboratory reagents (such as magnesium ribbon) and it is possible to measure the surface area of the rhubarb – thus quantifying the change in surface area. This experiment works well on a simple level, although the reaction itself is quite complex; the Mn2+ ions produced actually catalyse the reaction so it is difficult to relate the rate back to the reaction. 1. Surface area: The reaction is carried out using 30mL of potassium permanganate solution in a 100mL beaker. Students will need 5cm lengths of rhubarb. One piece should be left whole and other pieces sliced into similar sized strips to give varying surface areas. For example, one piece halved and one quartered etc. The total combined surface area of each piece could be measured using squared/graph paper. The potassium permanganate solution should be pale pink and can be made by dissolving 4 or 5 crystals into 500mL of distilled water and then adding 500mL of 2 mol L-1 sulfuric acid. Since the oxalic acid concentration of the rhubarb varies, the reaction should be checked beforehand to ensure that a colour change will occur in an appropriate time with the rhubarb that is being used. 2. Effect of concentration: The rhubarb should be boiled for about 5 minutes (5cm rhubarb to 250mL water) until it falls to pieces. Cool and strain the mixture and keep the filtrate. Measure 30mL of potassium permanganate into a 100mL beaker and the same amount of water into a second 100mL beaker. Add 5 drops of the rhubarb filtrate to the potassium permanganate and start the timer. Stop the timer when the colour disappears. Repeat for varying numbers of drops of rhubarb filtrate. Use results to discuss with students ways for improving the experiment to make it a fair test.
NZ
Neutralisation Circles. The following experiment gives a permanent record of the colours of Universal indicator in acidic and basic solutions. Use a 12.5cm diameter piece of filter paper (Whatman no. 1 works well). On the paper, draw two circles in pencil about 1cm in diameter and about 2–3cm apart. Label one ‘acid’ and the other ‘base’. Place the paper on a white tile and add a few drops of the acid and base supplied to the appropriate circle (0.1 mol L-1 NaOH and 0.1 mol L-1 HCl). Wait for a few minutes for the solutions to soak through the filter paper and meet. Place drops of universal indicator on the area of the filter paper where the acid and base have met and reacted. A ‘rainbow’ will be produced showing the range of colours produced by universal indicator. The filter paper can be dried and will retain the colour. Flame tests without Nichrome wire. Cheaper more convenient flame tests can be carried out using wooden splints soaked in salt solutions. The splints should initially be soaked in water at least 24 hours before they are needed for the experiment. The water soaked splints should be then be placed into boiling tubes half filled with the salt solutions at least 4 hours before the lesson. Students to place a soaked splint in a blue Bunsen flame and record the flame colour. Note: It is important not to let the splint burn too vigorously. A beaker half filled with water can be used for the disposal of the used splints.
126
chemistry
chemistry news
science teacher
International Year of Chemistry 2011 - tense issues Plans are still coming together for IYC 2011 in New Zealand and was launched in Wellington on 9th February. The following Friday secondary school students were invited to a Chemistry Variety Show which included an address by a visiting Nobel Prize winner. Each branch of the NZ Institute of Chemistry will be running their own local programme and a number of national and international events are being planned. 1. Global Chemistry Experiment. Schools are invited to take part in an international study of water quality and water purification in their local environment. Data collected will be logged on a website to build up a picture of global water quality. The project can be tailored to different levels, from Years 7/8 to Years 12/13. Information about this project can be obtained from: www.chemistry2011.org. 2. Senior secondary school quiz. Regional branches of the NZIC will be running local competitions to select a team of four students to represent the region in the final of the national quiz, which is being held on 5th July at Victoria University in Wellington. 3. Other activities. During the year there will be other competitions and activities including patchwork and knitted Periodic Tables. For further information check out: www.yearofchemistry.org.nz. For further information contact: Suzanne.Boniface@vuw.ac.nz New Zealand Association of Science Educators
45
NZ
science teacher
physics
126
a useful cheap toy for kinetic theory Designed and written by Paul King
When asked for the single sentence that any survivors could use to rebuild science after a nuclear holocaust, Richard Feynman proposed the following: “All things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.” The following cheerful and fun demonstration illuminates Feynman’s comment and also fulfils requirements of the ‘Nature of Science’ strand. At Physikos 2009, Denis Burchill demonstrated his new favourite toy: the “Pee Pee Boy”. It is a hollow pottery statue with a single strategically-placed hole. When partly filled with water (or any appropriate fluid) and doused with hot water a satisfying jet is projected a surprising distance. This is a delightful demonstration of kinetic theory which students can be asked to explain with some hope that they might show understanding. However, the statue has two drawbacks (aside from its vulgarity): it is currently only available in South East Asia and it takes forever to reload with water. How about a Kiwi-made alternative?
bookreview
Making a kinetic theory demonstration toy
46
1. Half fill an empty plastic drink bottle with water. Screw on the cap tightly. 2. Use a sewing needle to make a small hole below the waterline. (Fine sewing needles are very sharp. They slide through the thin plastic walls with almost no resistance.) 3. Place the bottle on the edge of a bowl or sink and pour hot water over the top. (I thought nothing was happening until the nearly invisible jet caught my hand over a metre away from the hole.)
Investigations of kinetic theory And now a happy world of competitive experimentation opens up with these cheap and easy to make and use toys. Begin by investigating factors that affect the water range such as: • the temperature of the hot water • the amount of hot water • the speed of pouring of the hot water • the temperature of the water in the bottle • the height of the hole above the point of impact • the proportion of air space in the bottle • the size of the needle hole • the distance between the water level and the hole. Different groups can investigate each variable and their combined results yield the conditions required to achieve the maximum range. Note: The range can be measured by having the jet splash down onto newspaper which both clearly marks the spot and mops up at the same time. Further fun challenges: • What is the lowest water temperature to project the jet one metre? • Which group can project 10mL of water into a target cup the fastest? For further information contact: dhousden@xtra.co.nz
The Uncertainty Of It All: Understanding the Nature of Science by Jane Young Book and CD: RRP $79.95. (Additional copies of the text: $34.95). Copies from: triplehelix@slingshot.co.nz Reviewed by: Robert Shaw, Open Polytechnic This resource consists of six PowerPoint presentations and a book which elaborates on each of the slides. The presentations are organised around three themes: What Science Is, How Science Works, and People and Science. Teachers will empathise with the author’s description of the sceptic and superstitious students that we meet all too frequently in schools. The book is an attempt to portray science in a positive light, and to open up some of the discussions which we need to hold now that the national curriculum requires that we address the nature of science. Although the book has a distinctly New Zealand flavour – for example it mentions Campbell Live (p.49), SAFE (p.209), New Zealand Association of Science Educators
and a survey of New Zealand scientists’ opinions (p.97) – I struggled to find much on Ma¯ori science or Pasifika science. Nor is there any sophistication about the philosophy of science, which is a problem that dogs the international “nature of science” movement as much as our own curriculum developers. There are slides on Greek, Arab, and Chinese science, and these build to material on the rise of modern science. The wealth of material on experimentation, data, measurement and logic is worthwhile. The author enters some of the controversies that occur when science rubs against society, for example the section on Darwin and Christianity (p.195) is useful, as is the section on Morals (p.201), homeopathy and the paranormal are included (p.83). I saw this book as an attempt to legitimise the broad initiatives of those science teachers who try to relate their discipline to society and human beings. Pity the poor science teachers of today – apart from their knowledge of their own disciplines they must be competent historians, philosophers and social commentators.
NZ
science teacher
ESSE news
126
1. The name of the NZASE standing committee supporting teaching of the Planet Earth and Beyond (PEB) strand and the new Earth and Space Science (ESS) subject has had a name change. It is now called Earth and Space Science Educators or ESSE for short. This replaces the rather clunky name of SCIPEB. It also clearly shows which area of the science curriculum the standing committee is supporting. 2. ESS is gaining a lot of tertiary support. This bodes well for having ESS as a scholarship subject and for ongoing support. 3. There will be PD on ESS in Auckland, Hamilton, New Plymouth, Palmerston North, Napier, Wellington, Nelson, Christchurch, Dunedin and Invercargill in terms 2 and 3 this year. The dates and venues will be posted onto the website at the beginning of the school year. 4. ESSE are hoping to run a field trip instead of a conference in 2011. A few organisations have offered to host this. Keep an eye on our website for details. 5. The ESSE part of the NZASE website can be found at: http:// www.nzase.org.nz/esse/. This website will be updated regularly with news on resources, standard updates, news of courses and dates for conferences or field trips. 6. Part One of the Teaching and Learning guidelines is now online and can be found at http://seniorsecondary. tki.org.nz/Science. This Web document is important for gaining an understanding of the five strands of NZC. The sections that tease out the Achievement Objectives can be useful for classroom ideas. Work on Part Two is about to start. This part will contain learning programme design ideas for Years 11-13 and cross curricular programmes. 7. Secondary school teachers now have a single Web portal to use when looking for information about senior subject teaching and assessment. It is at: http://secondary.tki. org.nz/. From there you link to NZQA’s and TKI’s NCEA pages, Teaching and Learning Guides, the resource for secondary middle leaders, and other materials. There is a News section, and an RSS feed that teachers can subscribe to. If you have any ideas about how this portal can be improved send them to Nigel Evans at: nigel.evans@minedu.govt.nz
The Ocean as a Classroom Context It is becoming more and more apparent that students must not only know about the processes of the land but also the ocean. The ocean provides some wonderful contexts for classroom study. Some fundamental concepts and principles of Ocean Sciences are listed below. For a comprehensive list, as compiled in the Ocean Literacy Initiative document 2004–2005, visit: http://tinyurl.com/ycxk233. 1. The Earth has one big ocean with many features. The ocean covers 70% of the planet’s surface. There is one ocean with many ocean basins, such as the North Pacific, South Pacific, North Atlantic, South Atlantic, Indian, Southern and Arctic. An ocean basin’s size, shape and features (such as islands, trenches, mid-ocean ridges, rift valleys) vary due to tectonic plate movement. The highest peaks, deepest valleys and flattest vast plains are
all in the ocean. The ocean has one interconnected circulation system powered by wind, tides, the force of the Earth’s rotation (Coriolis effect), the Sun, and water density differences. The shape of ocean basins and adjacent land masses influence the path of circulation. 2. The ocean and life in the ocean shape the features of the Earth. Many Earth materials and geochemical cycles originate in the ocean. Ocean life has lain down most siliceous and carbonate rocks. Sea level changes over time have shaped the surface of land. Tectonic activity, sea level changes, and force of waves influence the physical structure and landforms of the coast. 3. The ocean is a major influence on weather and climate. The ocean controls weather and climate by having a significant influence on climate change by absorbing, storing, and moving heat, carbon and water. The ocean absorbs much of the solar radiationreaching Earth and loses heat by evaporation. This heat loss drives atmospheric circulation. Condensation of water evaporated from warm seas provides the energy for hurricanes and cyclones. The El Niño/La Niña Southern Oscillation causes important changes in global weather patterns because it changes the way heat is released to the atmosphere in the Pacific. 4. The ocean makes Earth habitable. The earliest evidence of life is found in the ocean. Most of the oxygen in the atmosphere originally came from the activities of photosynthetic organisms in the ocean. 5. The ocean supports a great diversity of life and ecosystems. Most life in the ocean exists as microbes. Microbes are the most important primary producers in the ocean. Not only are they the most abundant life form in the ocean, they have extremely fast growth rates and life cycles. Ocean habitats are defined by environmental factors. Due to interactions of abiotic factors such as salinity, temperature, oxygen, pH, light, nutrients, pressure, substrate and circulation, ocean life is not evenly distributed. Some regions of the ocean support more diverse and abundant life than anywhere on Earth, while much of the ocean is considered a desert. 6. The ocean and humans are inextricably interconnected. The ocean supplies freshwater (most rain comes from the ocean) and nearly all Earth’s oxygen. It moderates the Earth’s climate, influences our weather, and affects human health. From the ocean we get foods, medicines, and mineral and energy resources. In addition, it provides jobs, supports the economy and serves as a transport highway. Much of the world’s population lives in coastal areas. 7. The ocean is largely unexplored. Less than 5% of the ocean has been explored. Exploration, inquiry and study are required to better understand ocean systems and processes. Over the last 40 years, use of ocean resources has increased significantly, therefore the future sustainability of ocean resources depends on our understanding of those resources and their potential and limitations. For further information contact: jenny.pollock@xtra.co.nz New Zealand Association of Science Educators
earthspacescienceeducators
Written by Jenny Pollock
47
NZ
science teacher
technicians
126
changes to senior standards and enquiry learning It is lucky that the human brain is plastic; otherwise we would not be able to deal with the pace of change in the New Zealand High School environment. Get ready for science department adaptation and rapid evolution! Writes Marlis Peden. Over the next three years, the number of senior science external standards is going to be reduced to three, and the number of internal standards increased to balance the adjustment. Next year we begin to adapt Level 1 classes, in 2012 Levels 1 and 2, and in 2013 all senior classes. Alongside these assessment changes, we are also moving towards significantly more enquiry learning − otherwise known as discovery type learning − that involves students working in small groups at their own pace and competency level and doing their own computer-based research, and scientific experiments. It seems that the move towards enquiry learning in NZ schools is already well underway and for the science technician this has its consequences. It could be generally agreed that dull moments are rare for a technician as the demands in this role are many and varied. It could also be said that it is always busy and that school holidays are necessary for physical and sometimes emotional recovery; the latter being a measure of how stressed the department is. Nevertheless, any extra work without more time allocated is probably going to be met with a certain lack of enthusiasm. Enquiry learning and experimentally-based internals undeniably mean extra work for the technician. The students are our future leaders in society, and their understanding of life on this planet is necessary for our society to be balanced, peaceful, rational and based on scientific sense. So any improvement in teaching science is surely welcomed. It is delightful to live in a predominantly educated and advanced society. Many believe that enquiry learning works very well in the classroom and that is an improvement on old teaching styles as it accommodates advances in technology and information access. However, time is time and it only passes more quickly at altitude. We all work at sea level, so we are making the best of it, but we only have eight hours. It is important that the science technician is not overwhelmed daily with the demands of small groups involved in a variety of experiments with all the equipment that this requires. Students at junior level arriving at the technician’s door with their orders is very time-consuming as it is almost necessary to do an investigation oneself to elicit what is the best equipment for them. Also, complicated orders for small groups of students that have different needs can also prove to be very time-consuming for the technician and will quickly be ruled out as an option. It is much more time efficient to provide equipment for a large group in standard class sets, and the students to pick from that.
48
New Zealand Association of Science Educators
Whether or not increasing the number of internal standards will improve the competency of the students is questionable. I would like to assume that this is being put in place in order to give a fairer assessment, but it may just be a cheaper option on the face of things as recession bites and budget strings are tightened. The hidden costs will no doubt become obvious as the system is tested on the ground. If the internals are enquiry based and demand student Internet access, then the costs may skyrocket very quickly. Some schools may have computer access already at total capacity, and this move may require another computer suite and improved Internet services for downloading information at speed as volumes increase. Schools may need to hire more IT staff to cope. If the internals are experimental and laboratory based then the hidden costs may appear in student materials and equipment costs. Add to this technician time. Technician hours will probably need to increase to cope with these changes, and so middle managements may need to consider this in light of the future budget. Next year should be reasonably straight forward as changes in the Level 1 standards will have a manageable impact on the technician and the department in general. However, it will be next year that we will need to prepare for Level 2 courses in the following year and this will probably result in the need for more technician hours and more equipment and consumables. This may be particularly so for Level 2 chemistry as it will probably involve another experimentally based assessment, and this can be a huge load on the technician’s time. If equipment and chemicals’ purchases are necessary, it may be advisable to be prepared to commit a significant amount of the 2012 budget for this. A very important aspect of this new arrangement is going to be stress on the teaching staff and this will filter down to the technician. Internal chemistry experimentally based assessments are notorious for raining down stress just by the nature of the running of them. Marking demands are going to be significantly greater and so this may equate to more tension, maybe even more sick days, and so maybe another hidden cost to the school, although this is hard to predict. In terms of budgeting technician hours, I would think it a valuable exercise to sit down after deciding on the content of the new internals and try to work out how many extra hours the technician may need to fulfil the requirements of the extra workload. This, to a certain extent, may only become calculable once work is in progress. If this is the case, my only advice is this…middle management be prepared! If your technician is running down the science department hallways in 2012 tearing out his/her hair in clumps, do not say that you were not forewarned. For further information contact: bemckinnell@papatoetoehigh.school.nz
EARTH AND SPACE SCIENCE BIENNIAL FIELD TRIP 2011 From Mt John Observatory in Tekapo to Kaikoura If you are interested contact jenny.pollock@xtra.co.nz
NZASE National Primary Science Week 2nd – 7th May, 2011 The NZASE National Primary Science Week is a new initiative that has been developed to replace the very successful biennial Primary Science conferences. The two main aims of the NZASE National Primary Science Week are: • to continue to support teachers of primary science and so enhance teaching and learning of science in the primary school through professional development and • to celebrate science throughout New Zealand Primary Schools by involving students, teachers, parents, communities and science providers in a variety of fun, engaging science activities. The NZASE National Primary Science Week will be coordinated by the Primary Science Standing Committee of NZASE. The event will happen simultaneously in 7 regional centres across NZ; Auckland, Bay of Plenty, Wellington, Nelson, Christchurch, Dunedin and the West Coast. For further information please contact: Chris Astall (National Coordinator) at chris.astall@canterbury.ac.nz or Jessie McKenzie at jessie.mckenzie@royalsociety.org.nz
Craig Steed - Convenor, Email: SteedC@freyberg.ac.nz
National NZIP Conference
CONSTANZ ‘11
The 15th National NZ Institute of Physics Conference
The Science Technicians’ Association of NZ Conference 2011
17-19 October 2011
10 to 12 October 2011
Victoria University, Wellington Energise your physics teaching with three days of ideas, stimulation and interactions! For further details visit: www.nzip.org.nz
John McGlashan College, Dunedin This Conference will appeal to all school science technicians, and also some technicians from tertiary institutions (such as Polytechnics) For further information contact: Margaret Woodford - Conference Convenor, Margaret.Woodford@kvc.school.nz or Anne-Marie Pulham - Secretary, ampulham@kavanagh.school.nz
CONSTANZ ‘11