SCIENCE SCIENCE FOR FOR SOUTH SOUTH AFRICA AFRICA
C harle s Dar win:
ISSN 1729-830X ISSN 1729-830X
VOLUME 5 • NUMBER 3 • 2009 VOLUME 3 • NUMBER 2 • 2007 R29.95 R20
t he ma n who ma de biolog y a sc ie nce
Da r win in t he C a p e: how t he gr eat ma n s aw u s The ma n b e hind t he O rigin o f Sp e c ie s: a r e luc t a nt he ro Da r win's love o f sc ie nce: mor e t ha n The O rigin of Sp ec ie s
A C AACDAEDMEYM YO FO FS C I EI ENNCCEE OOFF SS O U TT HH AAFFRRI C I CA A SC OU
Charles Darwin at the Cape Wilmot James On his voyage around the world in the Beagle Darwin singled out the Cape in his notebooks. 7
Charles Darwin: Reluctant hero of science? Mike Bruton Charles Darwin was a modest, self-taught biologist living at home with his family.
Darwin at home: His love of science Randal Keynes Darwin’s great-great-grandson looks at how Darwin pursued his love of science with his family.
Contents VOLUME 5 • NUMBER 3 • 2009
A year-long celebration of life and survival Lacea Loader
Darwin as a geologist
How the University of the Free State is celebrating Darwin’s life.
John Rogers Few people realise that Darwin’s first love was geology. 36 18
Gateways to the West: Understanding the ocean circulation at the Mascarene Plateau Isabelle Ansorge and Claire Attwood
The many colours of Galaxies
Research in a remote part of the Indian Ocean gives us important information about the biological and oceanographic effects of the currents in the area.
Benne Howerda Astronomers use light to see galaxies, providing an array of astonishing effects. 42
Viewpoint Teaching and learning about evolution: Part 2
You, me and UV – Under the sun
Dealing with the controversies.
Just how harmful are the rays that make us ‘sunny South Africa’?
Managed Cape honeybee colonies and conservation
The Voyage of the Beagle
There is more to the production of honey than we realise.
The Hubble Telescope
Meet the scientist Meet Lucinda Backwell: The woman who found the oldest human hair
How might drought affect biodiversity in South Africa? Will climate fluctuations affect the biodiversity of the succulent Karoo?
Diary of events
Back page science • Mathematical puzzle
Young concerns How one small clinic is responding to the challenge of increasing HIV prevalence among young people.
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SCIENCE SCIENCE FOR FOR SOUTH SOUTH AFRICA AFRICA
C harle s Dar win:
ISSN 1729-830X ISSN 1729-830X
VOLUME 5 • NUMBER 3 • 2009 VOLUME 3 • NUMBER 2 • 2007 R29.95 R20
t he ma n who ma de b iolog y a sc ie nce
Da r win in t he C a p e: how t he gr eat ma n s aw u s The ma n b e hind t he O rigin o f Sp e c ie s: a r e luc t a nt he ro Da r win's love o f sc ie nce: mor e t ha n The O rigin of Sp ec ie s
A C AACDAEDMEYM YO FO FS C I EI ENNCCEE OOFF SS O U TT HH AAFFRRI C I CA A SC OU
Darwin's life. Images: Wikimedia commmons SCIENCE FOR SOUTH AFRICA
Editor Dr. Bridget Farham Editorial Board Roseanne Diab (University of KwaZulu-Natal) (Chair) Michael Cherry (South African Journal of Science) Phil Charles (SAAO) Anusuya Chinsamy-Turan (University of Cape Town) George Ellis (University of Cape Town) Jonathan Jansen (University of Free State) Penny Vinjevold (Department of Education) Correspondence and The Editor enquiries PO Box 663, Noordhoek 7979 Tel.: (021) 789 2331 Fax: (021) 789 2233 e-mail: email@example.com (For more information visit www.questsciencemagazine.co.za) Advertising enquiries Barbara Spence Avenue Advertising PO Box 71308 Bryanston 2021 Tel.: (011) 463 7940 Fax: (011) 463 7939 Cell: 082 881 3454 e-mail: firstname.lastname@example.org Subscription enquiries Andrea Meyer and back issues Tel.: (012) 843 6484/81 e-mail: email@example.com Copyright © 2009 Academy of Science of South Africa
No stranger to controversy
harles Darwin was born on 12 February 1809 – 200 years ago. He was, by all accounts, an unassuming man. Born into a wealthy family he was able to pursue a life as a ‘gentleman naturalist’ – his greatest love being geology. In Darwin’s time, geology was a controversial science because of the literal interpretation of the bible, which proposed a young Earth. However, always an analytical man, Darwin chose to follow the ideas of the great geologist Charles Lyell, who, by looking at the evidence around him, deduced that the Earth was indeed very old and, what is more, had changed over the centuries and is still changing. It was with this analytical and evidence-based approach to science that Darwin joined the five-year long voyage of the Beagle, as geologist and companion to the captian, Robert Fitzroy. The outcome of that voyage was to change Darwin’s life – and to plunge the society in which he lived into a turmoil of emotions, as Darwin proposed that we were not created as we are, but evolved, as did all life, from a common ancestor. Darwin was somewhat reluctant to release his findings, knowing the controversy that they would cause. However, the imminent publication of a paper by Alfred Wallace, setting out similar theories, spurred him into print. At the time, he avoided the term ‘evolution’ talking instead of ‘common descent’ because of the controversy surrounding the idea that humankind had ‘evolved’. Darwin himself was apparently a freethinker and had attended a Unitarian chapel with his mother when still living at home. So it was likely that he was inherently open to ideas that went against the literal interpretation of the bible. Whatever the case, biology, and indeed many aspects of society, have never been the same since the publication of On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, to give the book its full title. The book was published on 24 November 1859 and the entire print run of 1 250 copies was sold out within days. And so started what has turned out to be 200 years of controversy among some religious people and the start of the science of biology by those who live and evidence-based life. Liberal clergymen of the day, and indeed of the present day, saw the mechanism of natural selection as God’s approach to creation. Others simply dismissed the theory as laughable. We now know that evolution is a fact and that Darwin’s ability to analyse and interpret the information he found all around him was the start of our understanding of that fact. It was this ability that was the seat of his genius. Looking at his life and how he lived it can help to provide us with the inspiration and motivation to continue our own pursuit of knowledge, unfettered by prejudice and preconceptions.
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Right: A watercolour by HMS Beagle’s draughtsman, Conrad Martens. Painted during the survey of Tierra del Fuego, it depicts the Beagle being hailed by native Fuegians. Image: Wikimedia commons
On his voyage around the world in the HMS Beagle, Charles Darwin singled out the Cape in his notebooks. Wilmot James describes Darwin’s impressions of this diverse part of our continent.
Charles Darwin at the Cape C harles Darwin’s great greatgrandson, Randal Keynes, points out that an early chalk drawing (now hanging at Down House) of Darwin and his sister Catherine shows him holding a pot plant containing what Keynes thought was the flowering fynbos plant the Cape cowslip or Lachenalia. The plant was identified by the South African National Biodiversity Institute and confirmed as Lachenalia by Graham Duncan, the bulb specialist horticulturist at Kirstenbosch National Botanical Gardens, who thinks it is a Lachenalia aloides hybrid. Darwin’s father, Robert Waring Darwin, was a physician, businessman and amateur horticulturalist. The Cape cowslip was a favourite in his garden and this explains why it is part of Sharples’ picture.
Charles and his sister as young children, drawn by the contemporary artist Ellen Sharples. Image: Wikimedia Commons
what others had already done. Although he was interested in a wide range of subjects, he would not revisit previously covered subjects. It is important to recall that, from the Galapagos onwards, all of the specimens collected by Darwin had to be kept on board the HMS Beagle. Limitations on space forced Darwin to be selective about what he collected. Though he was interested in everything, his passion at the time was geology.
Lachenalia plants are commonly called Cape cowslips because of their external resemblance to certain members of the genus Primula. Bulb enthusiasts have prized Lachenalia for centuries. Descriptions date back to the earliest plant collecting exploits of the Dutch East India Company, which started in about 1650. Initially called Hyacinthus, the bulbs were classified as a unique genus in 1784 when they were named after the Swiss botanist Werner de la Chenal. Lachenalia is a species found in part of one of the world’s richest plant regions of the world, the Cape Floral Kingdom. As we know, the diversity of botanical life in this small part of the world rivals that of the Amazon for numbers of endemic species per square kilometre. It is well documented that 5 800 of the 8 600 known species in this kingdom are found nowhere else in the world and 2 256 species are found on Table Mountain alone.
An example of the genus, Lachenalia carnosa found in Namaqualand, Northern Cape. Image: Wikimedia commons
Preparing for his voyage Darwin had already encountered the Cape through his habit of reading voraciously. Before he arrived at the Cape on his voyage on the HMS Beagle, he had read Andrew Smith’s Illustrations of the Zoology of South Africa. Later, while in the Cape, Darwin records that he received a personal copy from the author, who accompanied him on two Cape excursions, including the memorable Sea Point Contact that took place in present-day Bantry Bay. Darwin’s intellectual preparation for the visit to the Cape – as for anywhere else – was thorough and meticulous. He had a well worked out collection strategy. He voraciously read everything there was to read on a subject. As time was precious, he would not repeat
The difference between Spanish and Dutch etiquette is the ‘former never asking his guest a single question beyond the strictest rules of politeness, whilst the honest Dutchman demands where he has been, where he is going, what is his business, and even how many brothers, sisters, or children he may happen to have.’ Charles Darwin, The Voyage of the Beagle, p.58
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Above (from top): Catherine Cloete’s pencil drawing of Wynberg in 1853. Image: SANL INIL 7096 A map showing Cape Town as Darwin would have seen it. Image: Brenthurst Library Paarl rock. Image: University of Cape Town Press
Darwin at the Cape Charles Darwin visited the Cape between 31 May and 18 June 1836. He was 27 years old at the time. The HMS Beagle was on its way home after five long years circumnavigating the globe. The HMS Beagle had visited the Cape Verde Islands, Brazil, Argentina, the Falkland Islands, Tierra del Fuego, the Straights of Magellan, Chile, Peru, the Galapagos Archipelago, Tahiti, New Zealand and Australia. From Mauritius the Beagle sailed past the southern part of Madagascar and along the Natal coastline straight into a storm near Cape Agulhas. This
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early June storm was typical of the season, with low temperatures and high winds. Ships frequently berthed in Simon’s Town, in False Bay, in the winter because the harbour offered protection from the northwesterly winds and swells associated with the winter weather. It was a miserable time of the year to visit the Cape. The crew was exhausted. ‘The little town of Simon’s Bay offers but a cheerless aspect to the stranger’ Darwin recorded stepping into present-day Simon’s Town. He immediately set off for Cape Town, travelling along the base of the western part of Table Mountain. The first fourteen miles were ‘desert’, by which he meant unpopulated by human beings, punctuated he added by the ‘pleasure’ that the sight of fynbos brought. Darwin admired Wynberg because ‘a grand wall of mountains that gives the scene a degree of uncommon beauty’ overwhelmed it. Later that evening he arrived in Cape Town and struggled to find quarters. He stayed at the only good hotel in Cape Town, which he referred to as ‘this great inn on the great highway of nations’. The next morning he ‘walked to a neighbouring hill to look at the town. It is laid out with the rectangular precision of a Spanish town’ Darwin observed. The Cape was becoming English and this was a good thing as far as Darwin was concerned. This, despite the fact that the Dutch ‘thoroughly dislike our whole nation.’ Nevertheless some few of the Dutchmen have lately sent their sons to England to learn a proper system of agriculture.’ Darwin as a scientist Most of Darwin’s publications were in the area of geology. The only time he referred to himself as a scientist was as a geologist. It is in geology that he thought he would make a lasting contribution to science. Darwin’s visit to the Cape illustrated his self-concept and habits of science. He collected plant, insect, reptile and other specimens – often for others – and although the non-geological specimen lines later became important for his theory of evolution, he spent most of his time at the Cape, as elsewhere, ‘geologising’ as he put it. The Beagle arrived from Mauritius on the evening of Tuesday 31 May
and left the Cape on 18 June 1836. Of the 18 days in the Cape eight were spent geologising with Andrew Smith and four were spent pursuing general interests with an eye for issues of geological interest in the circular ride he took to Paarl, Franschoek and Houw Hoek. Smith took Darwin to the Sea Point granite-slate contacts. Darwin mentions in his geological notes that he visited Green Point and Lions Head and gives a detailed description of the area’s geology. He was struck by what he described as the ‘very splendid wall of the well-known Table Mountain’. Darwin collected geological specimens from Simon’s Town, the road to Cape Town, the road to Paarl, the sand flats between the Peninsula and Cape Town, Paarl, ‘French Hoeck’ Pass, the ‘Lion’s Rump’ as well as a specimen taken from the junction of granite and clay slate on ‘Lion’s Back’. The specimens are now held at the Sedgwick Museum, Cambridge. The ‘junction of granite and clay slate’ fascinated Darwin. The manner in which the granite and clay-slate combined posed a ‘great difficulty’ for ‘ordinary theory’ he wrote, ‘of granite having been injected whilst liquefied’ into the clay. Instead, he concludes,‘it has been here formed by the metamorphic action, a circumstance doubted, under nearly similar circumstances, by some authors’. The fusion of rock types by metamorphosis is one of those general laws of nature that Charles Lyell always encouraged Darwin to formulate. Indeed, it confirmed Lyell’s new theory of geological change. Charles Lyell (1797-1875) was the foremost British geologist of his day and had a profound influence on the young Charles Darwin. He published a threevolume book, The Principles of Geology, between 1830 and 1833.
Darwin collected a few entomological and zoological specimens, and later, when back in England, corresponded with South African plant specialists. These specimens are to be found in different collections, including the botanical ones at Kew Botanical Gardens, the zoological ones being at London’s Natural History Museum and the University of Cambridge.
On slavery and the question of ‘race’ Randal Keynes wrote that during the voyage of the Beagle ‘two experiences which had nothing to do with his work as a naturalist shook Charles deeply. Both were encounters with people – black slaves in Brazil and ‘savages’ in Tierra del Fuego. Darwin had first learnt about the tropics from a freed black slave called John Edmonston in Edinburgh. Edmonston earned his living as a ‘birdstuffer’, now called a taxidermist. Darwin took lessons from him and enjoyed their conversations; he commented later how Edmonston’s mind was like those of Europeans. It was at that time an exceptional view to hold among people in Darwin’s social position. So too was his objection to slavery. His grandfather Josiah Wedgewood I had been a leading member of the Committee for the Abolition of the Slave Trade in the 1780s, and produced at his pottery the well-known cameo of the chained slave with the question ‘Am I not a man and a brother?’ Keynes goes to talk about how Darwin argued furiously with the Beagle captain Fitzroy about the morality of slavery. Fitzroy saw little wrong with it. Darwin rejected the argument that it was a ‘tolerable evil’ to separate children from their parents. For him it was cruel: ‘Picture to yourself’ he wrote ‘the chance, ever hanging over you, of your wife and your little children being torn from you and sold like beasts to the first bidder.’ Keynes talks about how Darwin recognised the reality of people deemed ‘savages’ acquiring the mental sophistication of the ‘civilised’; the man from whom he learnt his bird-stuffing, John Edmonston, demonstrated that much to him. They had three individuals from Tierra del Fuego on board the Beagle (Fitzroy adopted them during his first expedition); ‘quiet and well-mannered young people’ who could follow the etiquette of an audience with the King and Queen of England. But their fellow tribesmen, yelling and waving on the rocks of their South American habitat, ‘looked scarcely like earthly inhabitants’, Darwin observed. The gulf between savagery and civilisation was enormous and yet the three Fuegians had stepped across it. The issues stayed with him throughout the voyage and challenged Darwin at the Cape. He remarked on how ‘ill-treated’ the aboriginals were, by which he meant the Khoi people. He was at the Cape two years after the initial and first phase of the gradual abolition of slavery. He noted that European people of the Cape did not take well to abolition. He went on his travels into the Cape hinterland accompanied by an English-speaking Khoi groom. Nowhere in his publications or notes does Darwin mention the groom’s name. The nameless groom ‘wore a long coat, beaver hat, and white gloves!’ Darwin continued in the observational anthropology of the time to say that ‘to my eye’ the Khoi ‘look like partially bleached Negroes; they are of small stature. They have most singularly formed heads and faces.’ Darwin observed that the groom had a ‘temple and cheek bones’ that ‘project so much, that the whole face is hidden from a person standing in the same side position’. Darwin referred to ‘Hottentots’ as
‘Hodmadods’, an unfortunate expression coined by the 17-18th century English buccaneer and navigator, William Dampier. I wonder what Darwin and the Khoi groom spoke about. They spent a special time together, in each other’s company for four days. They shared a language – English A Khoi soldier drawn – so communication was by Lady Anne Barnard. possible. Image: Cape Archives ‘A very short stay at the Cape of Good Hope is sufficient to convince even a passing stranger’ Fitzroy and Darwin wrote in an essay titled as a letter penned ‘at sea’ 28 June 1836 ‘that a strong feeling against the Missionaries in South Africa is there very prevalent.’ They go on to say that ‘from what cause a feeling so much to be lamented has arisen is probably well known to residents at the Cape. We can only notice the fact: and feel sorrow.’ Why sorrow? The missionaries had done well to turn human beings living in a state of savagery to become social beings capable of civilisation, that is why Fitzroy and Darwin felt the Cape Europeans’ antipathy to missionaries was sorrowful. The origin of the feeling was of course the missionaries’ support for the abolition of slavery – a cause with which Darwin more than Fitzroy agreed. The Cape Europeans had not experienced what Fitzroy and Darwin had, which was the cannibalism of Tiera del Fuego and Tahiti, which the missionaries so bravely countered. These wretched ‘savages’ they wrote, ‘went naked, destitute of any covering. Except a small piece of seal skin worn only upon their shoulders; that they … devoured their enemies slain in battle; or that they had smothered and afterwards eaten, the oldest women of their own tribe, when hard pressed by hunger during a severe winter!’ By placing their lives at risk, the missionaries had shown it possible to ‘transform them into well behaved civilised people’ and that therefore ‘there is some cause for thinking that a savage is not irreclaimable, until advanced in life; however repugnant to our ideas have been his early habits.’ The idea that the moral nature of people was not unalterably fixed was a forward-looking one at the time. Neither was the proposition racially defined, for Fitzroy and Darwin applied the notion of the ‘alterable savage’ to their own Saxon ancestors, whom they referred to as ‘barbarians’. Quoting approvingly from Sir James Mackintosh, who said that ‘Our scanty information relating to the earliest period of Saxon rule leaves it as dark as it is horrible’. Even the most ‘faithless and ruthless barbarian’ Saxons could, like the Fuegian and Tahitian cannibals, be elevated into a better moral state by the missionaries who ‘exposed themselves to a cruel death for the sake of teaching truth.’
Early thoughts on evolution In his autobiography Darwin writes that ‘during my last year at Cambridge I read with care and profound interest Humboldt’s Personal Narrative. This work and Sir John Herschel’s Introduction to the Study of Natural Philosophy stirred up in me a burning zeal to add even the most humble contribution to the noble structure of Natural Science.’ Herschel was resident in Cape Town at the time of Darwin’s visit and Darwin and Fitzroy met with the Herschels a number of times. During a dinner held at the Feldhausen Estate, Herschel and Darwin both referred to their discussions as being about the ‘mystery of the mysteries’, probably about speciation. Four months before the arrival of the Beagle at the Cape, Herschel had been considering the evolution of species. In a long letter to Charles Lyell (who had himself speculated on the origin of species in his 1832 Principles of Geology) Herschel cautiously began to worry about ‘that mystery of mysteries – the replacement of extinct species by others. Many will doubtless think your speculations too bold but it is as well to face the difficulty at once’ he wrote. Herschel went on to observe that South Africa was ‘a beautiful country for studying the graduation of botanical species – the families are so rich in species. I am little or nothing of a Botanist – but with one feature it is impossible not to be struck – viz. that when you find a species which fills up as you fancy a wanting link between two others – it does not merely fill it, but does so with the superaddition of some new characters.’ Darwin set off on Saturday, 4 June, 1836 on his circular journey around the Cape. In a letter dated 3 June, 1836 he wrote to his sister Catherine: ‘I hope to set out on a short ride of three or four days, to get a few glimpses of African landscape, or rather I should say, African deserts’. ‘Having seen so much of that sort of country in Patagonia, Chile and Peru, I feel myself to a certain degree a connoisseur in a desert and am very anxious to see these. Every country has its peculiar character; and every country is well worth seeing.’ He hoped to see some large animals. He later made a number of observations in the Origin of Species about the curious relationships between the large animals he saw in Argentina and the
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Left: The Feldhausen estate. Left below: The early Cape landscape.
Andrew Smith told Darwin that, in an hour’s march around latitude 24 degrees there were ‘between 100 and 150 rhinoceros’ and ‘several herds of giraffes amounting together to nearly 100’. Then there were the crocodiles, herds of antelope, flocks of migratory birds, birds of prey, lions, hyenas, other large cats and an abundance of what is known as the smaller ‘quadrupeds’. ‘I confess it is truly surprising how such a number of animals’ Darwin wrote, ‘can find support in a country producing so little food’. The rapid regeneration of edible vegetation was one answer to the puzzle as was what must have been horrific daily carnage and slaughter in the world of animals.’ Darwin went to say that we must remember the fact of the camel, of great bulk but in need of little sustenance, being an extreme example suggestive of a more general conclusion that ‘against anterior probability, among the mammalia there exists no close relationship between the bulk of the species, and the quantity of the vegetation, in the countries which they inhabit.’ ■ Dr Wilmot James is a DA MP and an Honorary Professor in The Division of Genetics at the University of Cape Town.
barren stretches and poorly vegetated ecologies in which they lived. It puzzled Darwin that, in South Africa, as in Argentina such a ‘sterile’ and arid place could support such large animals - and in such abundance.
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There was the elephant, several species of rhinoceros, the hippopotamus, the giraffe, what he called the ‘bos caffer’, the eland and some smaller varieties in the zebras, the now extinct quaccha, gnus and several antelopes.
Barlow N. ed. The Autobiography of Charles Darwin. New York: WW.Norton, 1958 Darwin C. Geological observations on the volcanic islands visited during the voyage of H.M.S. Beagle, together with some brief notices of the geology of Australia and the Cape of Good Hope. 1844. Keynes R. Darwin, His Daughter and Human Evolution. New York: Riverhead Books, 2001.
reluctant hero of science? Mike Bruton gives us some insight into Charles Darwin as a person.
natural instinct for recognising known and unknown species or forms. During his excursions on land during the Beagle cruise, he also showed that he was brave and tough. On several occasions he survived close encounters with wild animals and armed bandits. During the cruise he had to endure sea sickness, tropical diseases, injuries and many frustrating months at sea. Charles was also a practical man, who happily busied himself with chores around the house and garden, and was an excellent experimenter. He was also an avid reader and a superb correspondent – over 29 000 of his letters have survived. How he would have loved the World Wide Web and email! Charles had other qualities that helped him to become a great scientist. Even when he was young, he befriended and worked with the best scientists. He was a keen and observant gardener and plant and pigeon breeder, and showed a keen interest in the breeding of farm animals. He gained many insights into the process of natural selection through these hobbies, and was equally at home in the company of pig farmers and top scientists! Childhood Charles was born in 1809 in the village of Shrewsbury in England. His father, Robert, a member of the Lunar Society, which met once a month to discuss issues in science and technology - was a prosperous country doctor, and had ambitions for Charles to become a doctor or clergyman. Robert was a friend of the famous potter, Josiah Wedgwood, and married his daughter, Susannah. Charles’ grandfather, Erasmus, was also a medical doctor as well as a respected scientist and poet. He wrote his scientific views down in verse, including his ‘Theory of Biological Transformation’, which commented on the views of the French palaeontologist, Jean Baptiste Lamarck, on evolution. Erasmus was also a staunch anti-slavery campaigner, and it is likely that Charles inherited his antislavery stance from him. During his school years in Shrewsbury, Darwin was an inquisitive
Charles Darwin at the age of 51. Image: Wikimedia commons
and energetic boy who collected shells, coins and rocks and, later, beetles and bird’s eggs. When he was older, he also enjoyed hiking, fishing, horse riding, shooting and hunting, but he disliked social sports, such as cricket. He later said that his time at school was wasted learning the Greek and Latin classics, and that he learned more carrying out chemistry experiments at home with his brother, Erasmus. They investigated the chemical composition of various domestic substances by mixing, boiling, separating and crystallising them, and, as a result, he picked up the nickname of ‘Gas’. The early years His father sent Charles off to Edinburgh University at the age of 16 to study medicine. He took advantage of the opportunity to read widely and to explore marine biology and geology. He also learned the skill of skinning and drying bird specimens from a freed slave and the first black man he ever knew, John Edmonstone. But his kind heart and gentle feelings were outraged by amputations and surgery without anaesthetics, and he never qualified as a doctor. ▲ ▲
harles Darwin’s impact on biology was as great as that of Isaac Newton on physics. Yet Newton was a formidable man, a genius who changed the direction of science, an aggressive and argumentative man who had several lifelong feuds with other scientists. He was also a highly influential man who became the President of the Royal Society of London and Chief of the Royal Mint in England. Charles Darwin, whose theories forever changed the way we think about plants and animals, was, by comparison, a modest, self-taught biologist living with his family in his country home. He was neither argumentative nor authoritarian, and he never held a senior position in science. Although he received many honours later in life, he remained humble and self-effacing. Darwin had few of the character traits of a hero of science. He was shy, and did not enjoy public speaking. He was timid and retiring, disliked publicity, and, above all, was comfortable and happy in his rural home with his wife and children. He was also self-employed as he inherited money from his father, and never worked for a university, research institute or government department. During his later years he was also sickly, and for long periods he was unable to work because of his ailments. How could this be? How could such a simple man make such an important contribution to science? Darwin had other qualities that made him special – he was intelligent and very determined, as well as extremely patient and observant. During the voyage of the HMS Beagle, he gained unique experience of the diversity of plant and animal life in a variety of natural habitats, and of the massive forces that change the surface of our planet (earthquakes, volcanoes, storms, erosion, reef building). He was also extremely sharply focused, and retained the intense curiosity and inquisitiveness of a child throughout his life. He was an avid and highly organised collector and classifier of plants and animals, as well as rocks and minerals, with a
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In 1827, his father sent him to Cambridge University to study theology and become a clergyman. Charles made new friends, took part in many plant, animal and rock collecting trips, and achieved his BA, but was never ordained as a Minister of the Church. By this time, he had a thorough understanding of the scientific method, and a good basic understanding of zoology, botany and geology, but how would he apply this valuable expertise?
Top: The path at Down House where Darwin did most of his thinking. Image: Wikimedia commons Above: Captain Robert Fitzroy.
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Voyage of the HMS Beagle The chance of a lifetime was offered to Charles when he was recommended as the naturalist on the voyage of a Royal Navy ship, the HMS Beagle, during a round-the-world surveying trip. His first encounter with the skipper of the Beagle, Captain Robert Fitzroy, did not go well. Fitzroy was a very formal and judgmental person who believed in physiognomy, a fashionable pseudoscience that proposed that you could tell the character of a person from the shape of his nose and other features. Fitzroy did not like Darwinâ€™s nose! To him, it indicated that Darwin was lazy and lacked confidence. How wrong he was!
Darwin and Fitzroy could not have been more different from one another. Fitzroy was a traditional Navy man whose life revolved around strong discipline and obedience; he also believed in slavery and in creationism â€“ that organisms were instantaneously created by God. Charles was in the flush of youth, full of new ideas, excited about the changing world around him, and disliked rigid ideas and discipline. Despite these differences, and their regular arguments about slavery, punishment and racism, they nevertheless formed a good team that achieved a great deal during their nearly five-year voyage together. On board the Beagle, Charles was released from his nagging and ambitious father, and from the stuffy manners of Victorian England. He was free to pursue his passion as a collector of natural history specimens. He spent nearly three years on land during the voyage, and mounted energetic collecting trips in the Cape Verde Islands, along the east and west coasts of South America, Galapagos Islands, New Zealand, Australia and at the Cape of Good Hope.
The collections and observations that Charles made during the voyage helped him to put his thoughts in order and to start to make sense of the amazing natural world around him. He began to see trends that no-one else had seen before, and to gather evidence for revolutionary new ideas about the mechanism for evolution. He became convinced that the Earth is not static but constantly changing, and that plants and animals would need to change as well if they are to survive. But how do they change? Throughout the trip he sent specimens of rocks, plants, insects, reptiles, birds, mammals and fossils back to England to be identified by leading experts. By the time he returned to England in 1836, his collections had made him famous, but he never made a long voyage again in his life! He settled in London and methodically set about writing books about the vast collections that he had made. He also wrote about his observations on earthquakes, coral reef formation and plant, animal and human diversity. Marriage and family life Charles married Emma Wedgwood, his first cousin, at the age of 30 in 1839, three years after the Beagle voyage. Emma was very supportive of Darwin’s work, although her strong religious views worried him as he put together the theory that would go against religious thinking at the time. Emma was also an excellent mother and ran a stable and happy home for the hard-working Darwin. Soon after their marriage, they settled into a lovely country house, Down House, in the village of Downe in the English countryside. They lived there for the rest of their lives.
of orchids, which shoot pollen onto a pollinating insect when it lands on the flower. He took a bit of springy whalebone (baleen) from his wife’s corset to make a model of the orchid’s trigger mechanism (plastics had not been invented then). He also borrowed some artificial flowers from his wife’s bonnet to do experiments on the colours that attract pollinating insects. In his wife’s kitchen, he boiled the bodies of small mammals and birds on the stove to extract their skeletons. He used a lawnmower pulled by a donkey to mow his lawn at different rates, and then lay on his stomach (with his children) counting the numbers of insects in the short and long grass. He was keen to know whether earthworms have a sense of hearing, so he asked his wife to play the piano while he watched the behaviour of earthworms in a jar. The worms did nothing! When he placed the jar on top of the piano (while it was being played), they all burrowed quickly downwards. He concluded that earthworms can’t hear sound but that they are very sensitive to vibrations, which would have helped them to escape from walking predatory birds. He once gave his children a bucket full of flour and a feather duster and asked them to flick flour onto passing bumblebees. He then chased these ‘tagged’ bumblebees around the garden to work out their home ranges! The big idea Ever since the voyage of the Beagle, Darwin had been mulling over his ideas on how species change. He wrote a short essay on the subject in about 1833,
which he hid away in a drawer; it would be 18 years before he published it. The reasons for the delay tell you more about his character: ■ He was afraid of controversy. An essay published a number of years earlier about evolution (written anonymously by a Scottish publisher) caused a huge outcry, and Charles was afraid that his conclusions would have the same impact. ■ Fear of persecution. Charles was afraid that he and his family would be persecuted by the Church for what some may consider to be antireligious views. ■ His wife’s religious beliefs. Charles was also afraid of offending his wife, who was staunchly religious. ■ Scientific caution. Charles was, by nature, a cautious scientist who did not rush into publication until he was absolutely sure of his facts. ■ Non-confrontational personality. Charles was a timid, non-aggressive person who did not want to create controversy. ■ There was no hurry. Until he received a letter from a specimen collector in Borneo, Alfred Russell Wallace, Darwin had no reason to believe that anyone else had the same ideas as he had. He therefore felt no urgency to publish his conclusions. When Darwin received Wallace’s letter in 1858, he was shocked. It was clear that someone else had come to the same conclusions as he had about the mechanism for evolution. He now faced an ethical dilemma: should he ignore Wallace’s letter, or pretend that he had never received it, and publish
Experiments at home Charles loved to do experiments, some of them complicated, others amusingly simple. His mischievous and playful attitude is obvious in these little adventures. He was fascinated by the way in which plants, which appear to be so static, are able to move. He studied the way in which creepers grow towards the light by arranging potted plants in different positions in his attic, which had a skylight. He even placed a clothes peg over the growing root of a pea plant to measure the force exerted by the root as it grew. He studied the trigger mechanisms
Charles Darwin, Charles Lyell and Joseph Hooker in the study in Down House. Image: Down House, Kent/The Bridgeman Art Library
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shattering theory was first presented to the scientific community! He was ill, and unwilling to attend the event.
Darwin as an old man. Image: Natural History Museum, London What would have surprised Darwin today? If Charles Darwin arrived unexpectedly back on Earth today, what would have surprised him the most? This is a little ‘thought experiment’ that is interesting to carry out. I think that he would have been most surprised by the following: ■ That so many people are still studying evolution. ■ That we have discovered so many fossils, and have such a good understanding of extinct life forms. ■ The amazing insights that have been gained by studying genetics and DNA, as well as biotechnology and nanotechnology. ■ The tremendous advances in medical science, but also the fact that many millions of people still live in ill health and poverty. ■ That science and religion have still not reconciled their differences, and that there is a growing belief in creationism. ■ That there are still unresolved conflicts between different human societies. ■ That we have not as yet discovered all the species of plants and animals on Earth (yet we spend billions exploring outer space). ■ That humans have caused massive damage to the natural environment, and seem to be incapable of reversing this damage. ■ That we have created huge electronic databases of information outside our own brains. ■ The amazing inventions that people have made, ranging from the motorcar and aeroplane to radio, television, the internet and email.
his own work first? Or should he submit Wallace’s letter for publication, knowing that Wallace would then get all the credit? Charles consulted two of his friends, the botanist, Joseph Hooker, and the geologist, Charles Lyell, for advice. They told him to publish his conclusions at the same time as those of Wallace. Darwin agreed, but did not even attend the meeting of the Royal Institution at which his world-
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What did Darwin say? Darwin’s theory of natural selection made the following important points, which had never been presented as a single idea before: ■ There is a constant struggle to survive among plants and animals as they compete for limited resources of food, water and space. ■ The Earth is not static – it is constantly changing due to earthquakes, volcanic action, floods, erosion, weathering and other shortand long-term events. ■ Because the Earth is changing, plants and animals must also change if they are to survive and produce offspring. ■ Because most plants and animals reproduce sexually, i.e. the male and female gametes come from different individuals, ‘novelties’ are produced that show random variation within each generation, i.e. the young are not all identical. ■ The differences between the young equip some to survive better than others; the survivors pass on their characteristics to the next generation. ■ This process of ‘descent with modification’ is permanent and irreversible. ■ Natural selection, which is relatively random and blind, is different from artificial selection, as in domesticated animals, which is more directed and deliberate. On the Origin of Species Soon afterwards, Charles assembled all his notes and essays into his famous book, ‘On the Origin of Species’. It differs from Newton’s great book, Principia, in that it is essentially an expanded essay. He planned to write a comprehensive book on the subject, but never got round to it. But he wrote several other books that provided even more support for his theory. Probably less than 0.1% of the human population has ever read and understood Newton’s book (which was written in Latin), but millions have read and understood Darwin’s ‘Origins’, and gained inspiration from it. Why was Darwin’s theory so controversial? There were several reasons why Darwin’s theory of natural selection was controversial. These included: ■ Creationism: There was still a strong belief in the literal interpretation of the Bible and in creationism at
the time, i.e. that all living things, including humans, and been created instantaneously by God, and that nothing had changed since that initial act of creation. ■ Youth of the Earth: Many people also believed that, according to the Bible, the Earth was relatively young, and that enough time had not elapsed for Darwin’s evolution to have taken place. ■ Permanence of the Earth: Likewise, many people believed that the Earth was static and unchanging. ■ Permanence of living things: Because the Earth is unchanging, most people thought that there was therefore no need for species to change. ■ Progressionism: Most people thought that God had deliberately created creatures at different levels, but that they stayed at those levels through time without the one descending from the other. ■ Uniformitarianism: Many scientists, including Charles Lyell, concluded that the physical world changes but that plants and animals remain the same. In his books Charles gathered a vast body of evidence that gradually dispelled these myths. Middle and later years During his middle and later years Charles continued doing research on a variety of plants and animals, including orchids, barnacles and earthworms, and on animal variation, the evolution of man and human emotions. Despite his many accomplishments, Darwin remained modest until the end. He concluded his autobiography with the words, ‘With such moderate abilities as I possess, it is truly surprising that thus I should have influenced to a considerable extent the beliefs of scientific men on some important points.’ He intended to be buried in St Mary’s churchyard in Downe village; he was buried with pomp and ceremony at Westminster Abbey in London, among kings and queens. The Daily Telegraph described him as ‘The greatest naturalist of our time, and, perhaps, all time.’ He was, perhaps, a reluctant hero, but he was certainly deserving of all the recognition that he received. ■ Mike Bruton is a scientist-turned-science educator who works for an international museum and science centre design company, MTE Studios, as Director of Imagineering. He is currently based in Saudi Arabia. Boulter, M. Darwin’s Garden: Down House and The Origin of Species. London: Constable, 2008.
Right: Down House, Charles Darwin’s home. Image: Wikimedia commmons
Darwin at home:
his love of science Randal Keynes, Darwin’s great-great-grandson, looks at how Darwin pursued his love of science, not just on his epic voyage, but in his home with his family.
Darwin’s great-great-grandson, Randal Keynes.
A young orang utan. Image: Wikimedia commons An orang utan ‘laughing’. Image: Wikimedia commons
closely with his garden plants and the wild plants of the neighbourhood, and was always happiest to be able to show a feature of natural life in a species that would be familiar to most readers rather than a botanical rarity. Emma, his wife, is the unsung heroine of Darwin’s achievement in science. She had doubts and worries about his theory but understood how important his work was to him and loving him as she did, she supported him loyally. A few examples show her patience with what she had to put up with in their daily life. One summer Darwin wanted to see what attracts insects to flowers and persuaded her to give up some of the brightly coloured artificial flowers she had for pinning to her bonnet so that he could drop a blob of honey in the centre of each, put some fresh leaves around them and stick them in the soil to watch what insects came to them. William, then two and a half, was playing in the garden and spotted the experimental flowers from some way away. He called out that they weren’t ▲ ▲
hen Darwin first realised that man and other animals might be closely linked it gave him a fresh view of life. As soon as he saw the possibility, he thought about how to test it. He went to London Zoo and met Jenny, a young orang utan who had recently been brought from Sumatra and was drawing crowds. People were then reluctant to look for similarities between man and ape. But Darwin specifically sought these. He returned to Jenny’s enclosure later with a hand mirror and a sprig of verbena, some sweets and a harmonica to see whether she liked ‘smells, peppermint and music’. She played with them all eagerly, and in such childlike ways that he saw his next step at once. He wrote in his private notebook, ‘Natural history of babies’, and jotted down a string of games to play with a human infant, each a simple experiment for a comparison with a baby animal. As soon as his son, William, was born, Darwin was able to start on his ‘natural history’ of the infant’s development, watching every stage and repeating the game Jenny had played with the hand mirror. These simple, bold experiments at home with his own child clearly confirmed the link he had spotted, the deeply rooted connection with our animal cousins which is so important for our understanding of our common origin and nature. Darwin is now regarded as one of the greatest scientists of all time. But after the voyage of the Beagle he did almost all of his scientific work at his home, around his garden and in the surrounding countryside. He worked
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Darwin’s study at Down House. Image: Wikimedia commmons
A bumble bee, attracted to a bright flower. Image: Wikimedia commmons
A carpenter bee carrying pollen.
The insect-eating plant, Heliamphora chimantensis.
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real but had been made by his father, and coming closer, exclaimed that they were from ‘Mamma’s cap’! Some years later when Darwin was investigating how clover depends on visiting bumblebees to cross-pollinate its flowers, he used pieces of the light muslin Emma had for her summer dresses to cover up some of the flowers in a clump in their meadow, and showed that no seeds set on those flowers the bumblebees couldn’t reach. On another occasion he wanted an object that was as light as possible to test the extreme sensitivity of an insect-eating plant he was studying. He took a strand of Emma’s hair, which was so slender that it only just outweighed the very lightest weight on the most sensitive chemists’ scales available at the time. He then made an item just one six hundredth of that very lightest detectable weight by cutting off a six hundredth of the length of the hair, and was pleased to find that the plant’s tendril curled at its touch. Lastly, around the same time, when he wanted to test his idea for how a remarkable orchid managed to catapult its pollen at passing insects
in order to ensure cross-pollination, he built a working model of the mechanism using a whippy piece of a whalebone stay taken, we can only guess, from Emma’s corset! Darwin wrote his most important books for scientists, of course, but also quite as importantly and with great care, for the general reader. He wanted everyone to understand the extraordinary new insights he had gained into natural life. A month after The Origin of Species appeared, he was delighted to hear from a friend that she’d overheard someone asking for it at a station bookstore; the storekeeper had sold out but understood ‘it was a very remarkable book’ and was restocking. To help all his non-expert readers, Darwin used his own kitchen garden plants and farmyard creatures for many of his most telling experiments in The Origin of Species. He explained his findings about varieties of peas, beans and gooseberries, a fat white Aylesbury Duck, Emma’s choice poultry, and tame rabbits and pigeons which the children helped look after. He showed the web of life by
tracing the ties of dependence and destruction between the clover, bumblebees, field-mice and cats in his meadow. He grew seedlings out of small birds’ droppings he’d picked up in the garden to show how organisms can be transported from one place to another. He gave science’s first view of the range of biodiversity in a single area by counting the different plant species he could identify in a three foot by four foot section of his back lawn which the gardeners had left unmown so that the plants could be recognised when they grew to flower and seed. He counted twenty different species, an extraordinary number for a small patch where most of us would have recognised only one kind, undifferentiated grass. Darwin had spotted all these points through careful observation around his country home and garden, but he realised that in many cases, the key features for understanding are missed by most people because they are hidden from view in our remoteness from natural life. He wrote about the struggle for existence, the driving force for evolution: ‘We behold the face of nature bright with gladness, we often see superabundance of food; we do not see, or we forget, that the birds which are idly singing around us, mostly live on insects or seeds, and are thus constantly destroying life; or we forget how largely these songsters, or their eggs, or their nestlings, are destroyed by birds and beasts of prey …’ This suggestion that ‘we do not see, or we forget …’ was critical for him because he was convinced that unless the universal struggle for existence ‘be thoroughly ingrained in the mind … the whole economy of nature with every fact on distribution, rarity, abundance, extinction, and variation, will be only dimly seen or quite misunderstood.’ Again, to help to emphasise the universal struggle for existence – a huge task for a writer in Darwin’s position, he highlighted this key process through a single small experiment he’d carried out in an abandoned strawberry bed in his orchard – an almost wilfully trivial example to give in relation to the global significance of the point he was trying to show. But the experiment’s simplicity and the ease with which it could be understood from everday experience were its strength, not a weakness. Clearing the soil in March 1857, marking with a stick each shoot that emerged from then on, checking the sticks regularly and removing any whose seedling had been eaten or destroyed, he found that 357 seedlings appeared but only 63 survived, so six out of every seven plants had been killed in the first stage of their life above ground. Such was the force of destruction, and hence the pressure of natural selection, that Darwin was able to show were playing on the plant seedlings in his quiet orchard that one season. In the present crisis of climate change and loss of natural habitats, we all need to have that sure grasp of ‘the whole economy of nature’ that Darwin wrote about, if we are to succeed in what needs to be done to preserve what still survives. One way is to follow in Darwin’s footsteps on the Beagle voyage and learn what he showed us can be learnt from Paarl Rock, the Cape fynbos and so much more along his whole journey around the world. Another way is to follow Darwin at Down House in our own daily lives and experience, focusing in the ways he did on what we can understand about natural life and its history from what we can observe around us. Fit the two views together, and we have a resource for the global understanding we need. Develop that understanding, and we can save the wealth of natural life Darwin has helped us to come to value. This article is an adaptation of one written by Randal Keynes for the Darwin 200 year commemorations in Cape Town recently. ■
Research Centre of Excellence for Nutrition
The Centre of Excellence at the North-West University does cutting edge research in Nutrition, looking for solutions to local and global nutrition problems. The approach to research in the Centre is a holistic, trans-disciplinary and integrated one, in which molecular, clinical and epidemiological aspects of these nutrition problems are examined in depth. The molecular research includes a genetic programme in which the genetic influences on responses to the effects of dietary changes are investigated. In this part of the research, the focus on the influences of dietary factors on blood coagulation and breakdown of blood clots is unique and Potchefstroom is known as a leader in this field. The clinical research is done in a well-equipped metabolic unit. The contribution of nutrient and dietary interventions on health outcomes, and the mechanisms of these effects are researched. In the epidemiological work, the focus is on how and why populations change their dietary patterns and nutrient intakes when they urbanize, modernize or acculturize. The findings of this research inform policy on a global level to prevent the negative consequences of the nutrition transition in developing countries. The approach to post-graduate training is to develop nutrition scientists in Africa, for Africa, with knowledge and skills to tackle the nutrition-related public health problems in Africa. Moreover, these students are trained in well equipped laboratories and funded research projects, which optimize the training period. In addition to its Honours, Masters and Doctoral programmes, the Centre is also responsible for the African Nutrition Leadership Programme, in which young scientists from all over Africa are helped to develop their leadership skills. Although the staff in the Centre focus on relevant local problems, the results of their research is known, quoted and used on an international level.
Prof Esté Vorster Director: Research Centre of Excellence for Nutrition Tel +27 18 299 4237
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Randal Hume Keynes (born 29 July 1948) is a British conservationist and author and a great-great-grandson of Charles Darwin. He is the author of the intimate exploration of his famous ancestry, Annie’s Box, subtitled Darwin, His Daughter, and Human Evolution a book about the relationship between Darwin and his daughter Annie whose early death deeply affected him and his views on religion.
Innovation through diversity
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Right: A beach on one of the volcanic Cape Verde Islands. Image: Wikimedia commons Below: A map showing the route the Beagle took around the world. Image: Wikimedia commons
The voyage of HMS Beagle D
Above left: His encounter with the natives of Tierra del Fuego on his Beagle voyage made Darwin believe that civilisation had evolved over time from a more primitive state. Image: Wikimedia commons Above right: Illustration of Darwin’s Rhea, published in 1841 in John Gould’s decription of birds collected on the Beagle voyage. Image: Wikimedia commons
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arwin’s famous voyage on the HMS Beagle took place on the second voyage of the ship. This circumnavigation of the world took place between 27 December 1831 and 2 October 1836. The captain of the ship was Robert Fitzroy, who took command on its first voyage after the previous captain had committed suicide. Fitzroy wanted a geologist on board and was looking for a ‘gentleman naturalist’ as a companion during the long voyage. Charles Darwin, who wanted to travel before settling down, took the opportunity. Geology was Darwin’s ‘principal pursuit’ and his notes on that subject were almost four times longer than his zoology notes. During the voyage, he wrote to his sister that ‘there is nothing like geology; the pleasure of the first day’s partridge shooting or first day’s hunting cannot be compared to finding a fine group of fossil bones, which tell their story of former times with almost a living tongue’. In the nearly five years of the voyage, Darwin spent only 18 months at sea. Although Darwin took advantage of the voyage to collect geological specimens and fossils, the main aim of the voyage was a hydrographic survey of the coasts of the southern parts of South America – continuing the work of previous survey voyages. These surveys allowed the production of charts that were used by vessels during periods of war and also for commerce. The Beagle’s first landfall was on the volcanic Cape Verde Islands. It was here that Darwin started his journal. The ship took readings to accurately determine longitude, so important for navigation. Darwin was drawn to the tropical vegetation, which he had never seen before, and to the island’s geology. He carefully studied its stratigraphy and worked out how the strata had formed. He followed the ideas of the foremost geologist of his time, Charles Lyell, who believed that landforms were the result of processes that took place over huge periods of time. Darwin used these theories to form his own ideas about the geological
Q Fact File
Left: A mounted skeleton of a fossil mastadon. Image: Wikimedia commons Below: The various Galápagos Mockingbirds Darwin caught resembled the Chilean Mockingbird Mimus thenka, but differed from island to island. Image: Wikimedia commons
history of the islands. Darwin had a special position as guest and social equal of the captain, so junior officers called him ‘sir’ until the captain dubbed Darwin Philos for ‘ship’s philosopher’, and this became his suitably respectful nickname. The Beagle now carried out its survey work along the coasts of South America, going to and fro to allow careful measurement and rechecking. Darwin spent much of the time away from the ship, returning by prearrangement when the Beagle returned to ports where mail could be received and Darwin’s notes, journals and collections sent back to England. Tierra del Fuego was particularly important in Darwin’s mind. It was here that he encountered native Fuegians, from the islands south of Tierra del Fuego, a people called the Yaghan. He constrasted their behaviour with that of three native Fuegians who were returning to the area as missionaries, after education in England, who had been given the names of York Minster, Fuegia Basket and Jemmy Button. He described his first meeting with the native Fuegians as being ‘without exception the most curious and interesting spectacle I ever beheld: I could not have believed how wide was the difference between savage and civilised man: it is greater than between a wild and domesticated animal, inasmuch as in man there is a greater power of improvement.’ In contrast, he said of Jemmy that ‘It seems yet wonderful to me, when I think over all his many good qualities, that he should have been of the same race, and doubtless partaken of the same character, with the miserable, degraded savages whom we first met here.’ Four decades later, in his book The Descent of Man, Darwin used his impressions from this period as the basis of his idea that civilisation had ‘evolved’ from a more primitive state. When the ship reached Rio Negra in Argentina, Darwin left the ship and journeyed inland with gauchos, inhabitants of the area of European origin. On this journey he was told of a rare smaller species of Rhea – a flightless bird native to the area.
He also found the fossil tooth of a mastadon. The ship spent some time in the area around Tierra del Fuego and then sailed to the Falkland Islands, where Darwin noted the large number of different organisms that were dependent on the kelp beds around the islands. After surveying the west coast of South America, the Beagle reached the Galapagos Islands – where Darwin probably started to formulate his ideas about speciation and natural selection from his observations of the finches or mockingbirds native to the islands. The Beagle then made the long crossing of the Pacific Ocean, sailing from Tahiti to Australia, where Darwin saw his first marsupial, the potoroo. Reflecting on the strange animals of the country, he thought that an unbeliever ‘might exclaim “Surely two distinct Creators must have been [at] work; their object however has been the same and certainly the end in each case is complete”,’ yet an antlion he was watching was very similar to its European counterpart. The platypus was another strange animal and few Europeans at that time believed aboriginal claims that the animal laid eggs.
Darwin observed coral reefs in the Keeling Islands in the Indian Ocean and then reached the Cape of Good Hope on 31 May, from where the Beagle set out for home, stopping at Ascension Island on the way. On his return, Darwin was quick to take the coach home, arriving late at night on 4 October 1836 at The Mount House, the family home in Shrewsbury, Shropshire. Darwin reportedly headed straight to bed and greeted his family at breakfast. After ten days of catching up with family he went on to Cambridge and sought Henslow’s advice on organising the description and cataloguing of his collections. Darwin’s father gave him an allowance that allowed him to put aside other careers, and as a scientific celebrity with a reputation established by his fossils and Henslow’s publication of his letters on South American geology, he toured London’s society institutions. His work on the voyage of the Beagle meant that he became firmly established as a scientist, collaborating with other naturalists to describe his specimens and to discuss the ideas formulated on the trip. ■
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Right: The Sea Point contact was visited by Charles Darwin in 1836. It is essentially a frozen image in time, showing the contact between the older dark siltstones of the Malmesbury Group and the original hot magma that intruded over 500 million years ago, 10 km below the surface of the Earth. Image: Mike Golby
There was a lot more to Darwin than the theory of evolution. John Rogers writes about a less well-known but important side to Darwin’s genius.
Darwin as a geologist W
hen one thinks of the ‘naturalist’ Charles Darwin, it is his contribution to our understanding of how living creatures evolved that casts anything else he might have done into the shadows. But Darwin’s skills were certainly not limited to theorising on the survival of the fittest nor were his eyes fixed only on living creatures as he embarked on his epic voyage on the HMS Beagle in 1831. He was, in fact, a A clinometer or inclinometer is an instrument for measuring angles of elevation of slopes, for example, of a bed of sandstone. Clinomteres measure both inclines, which are positive slopes and declines, which are negative slopes.
A compass with a clinometer attached. Image: Wikimedia Commons
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skilled and influential geologist whose work continues to resonate in the field. He was, for example, the first to make a geological cross-section of the Andes mountains in South America. He also made important observations on both the development of volcanoes and was able to add to the explanations around the occurrence of coral atolls. Darwin was born just over 200 years ago on 12 February 1809 and lived as a child in Shrewsbury on the eastern border of North Wales. He went to Edinburgh University at the age of 16, to train as a medical doctor like his father and grandfather before him. While there, he attended lectures in geology, palaeontology, crystallography and mineralogy. Unfortunately, one geology professor, Robert Jameson, was so tedious and dull that Darwin vowed never again to read a book on the subject. Not enjoying his medical studies, he dropped out of Edinburgh University in 1827, at the age of 18. He then went to Cambridge University to study for a BA. His mentor was Professor John Henslow, a mineralogist and botanist, who often invited Darwin to his home to meet famous scientists and often went on long walks with him, so much so that
other professors called Darwin, ‘the man who walks with Henslow’. Henslow persuaded Darwin that he simply had to have a foundation in geology and offered to train him privately. Darwin then bought a clinometer and practised using it by tipping the tables in his room, back home in Shrewsbury, to many different angles, so that he could write to Henslow, ‘I will venture to say I have measured them as accurately as any Geologist could do’. During the summer of 1831, Henslow asked Adam Sedgwick, then in his heyday as a professor of geology at Cambridge, to take Darwin with him to North Wales, despite Darwin never having attended Sedgwick’s lectures. In early August of that year, Sedgwick and Darwin rode on horseback into the Welsh hills, where Sedgwick trained Darwin to become a field geologist. He later wrote to Henslow from Rio de Janeiro in Brazil in May 1832 ‘…(Sedgwick) does not know how much I am indebted to him for the Welch (sic) expedition, – it has given me an interest in geology, which I would not give up for any consideration…Tell him that I have never ceased being thankful for that short tour in Wales’. At about the same time, the first
volume of the first edition of Charles Lyell’s famous book Principles of Geology was published. This became Darwin’s geological Bible. On returning home, Darwin received a very important letter from the Admiralty, via Henslow, inviting him to participate in a two-year circumnavigation of the world, at his own expense, aboard the HMS Beagle, as a gentleman companion to the hydrographer, Captain Robert Fitzroy. The invitation was from Francis Beaufort, the Hydrographer of the Admiralty. Darwin accepted • Geological, Geochemical, Metallogenic Marine mapping theGeotechnical, invitation and the voyageandbegan • Minerals Development on 7 December 1831 in Plymouth • Construction Materials and Agricultural Minerals • Water-Resource Assessment Protection and lasted, inand the end, for nearly five • Environmental Geoscience years. The journey, which came to an • Engineering Geology and Physical Geohazards • Palaeontology end on 2 October 1836, included an • Laboratory Services 18-day stopover in Simon’s Town. • Geophysics • Seismology The epic journey on the HMS Beagle • Geographic Information Systems (GIS) had some extraordinary geological • Information Databases • Nationalhighlights Geoscience Library for Darwin including the discovery of a giant extinct sloth in soft rock off the coast of Chile and personal experiences of both a massive earthquake and an erupting volcano. He was not only the first scientist to make a geological crosssection of the Andes, he also found a forest of silicified trees, since dated by South American geologists as Triassic, still known as the Darwin Forest. The forest is still marked with an appropriate plaque, erected in 1909, honouring Carlos Darwin, 100 years after his birth. Darwin had longed to see a coral reef and, around the Polynesian island of Moorea, he saw surf breaking on a fringing reef and a lagoon with
transparent water surrounding a volcanic island. Darwin had studied Lyell’s views on corals, the living polyps of which can only live in the warm, transparent, illuminated surface waters of the ocean. In Lyell’s view their circular shape meant that they grew around the rims of submerged volcanic craters. In contrast, Darwin modified his mentor’s ideas and concluded that the atolls originally were fringing reefs around a since-sunken volcanic island. After leaving the Cocos Islands, off Indonesia, the Beagle crossed the • Geoscience Museum Indian Ocean to reach Mauritius off National Core Library the • east coast of Madagascar on 24 April 1836. Being on the homeward COUNCIL FOR GEOSCIENCE MISSION:To provide expert and services improve the management of leg information of the voyage, Darwintowas starting naturalof resources and the environment to think his post-Beagle future. for the benefit of the society. He wrote from Mauritius to his sister, Silverton, PRETORIA Caroline: ‘I am280 in Pretoria high Street, spirits about • Private Bag X112, PRETORIA, 0001 my geology,Tel:–+27 and even aspire to (0)12 841-1911 • Fax: +27 (0)12 841-1221 www.geoscience.org.za the hope that my observations will be considered of some utility by real geologists’. Two centuries later, real geologists consider Darwin’s contribution to their field to have been very significant indeed. ■
LEADING EARTH-SCIENCE SOLUTIONS
Dr John Rogers is based at the Department of Geological Sciences at the University of Cape Town. This article is based on a recent address commemorating the 200th anniversary of Darwin’s birth. Above right: A coral reef, showing the huge biodiversity in these environments. Image: Wikimedia Commons Right: Geological specimens collected by Darwin at the Sea Point Contact. Image:Sedgewick Museum, Cambridge
LEADING EARTH-SCIENCE SOLUTIONS • Geological, Geotechnical, Geochemical, Metallogenic and Marine mapping • Minerals Development • Construction Materials and Agricultural Minerals • Water-Resource Assessment and Protection • Environmental Geoscience • Engineering Geology and Physical Geohazards • Palaeontology • Laboratory Services • Geophysics • Seismology • Geographic Information Systems (GIS) • Information Databases • National Geoscience Library • Geoscience Museum • National Core Library
COUNCIL FOR GEOSCIENCE MISSION: To provide expert information and services to improve the management of natural resources and the environment for the benefit of the society.
280 Pretoria Street, Silverton, PRETORIA • Private Bag X112, PRETORIA, 0001 Tel: +27 (0)12 841-1911 • Fax: +27 (0)12 841-1221 www.geoscience.org.za
The many colours of galaxies Benne Holwerda tells us how astronomers use light to see colours in galaxies.
stronomy is the study of anything that is not on the Earth but that we can still see: moons, stars, planets, galaxies and so on. But, because we cannot travel to most of these places, we can only study the light from the stars. In 1969 people travelled to the Moon and many robot probes have gone to the other planets in our solar system; any place beyond that is out of our reach for now. Figure 1: The spectrum of light. Light comes in many types, each at a different typical size of the wave. The typical size of each type of wave is below each icon. On the far left is gamma radiation (nuclear reactors). Then come X-rays. The X-ray machine in the hospital that takes a picture of your bones uses these: Xrays go through everything in your body except the bones. Then comes ultraviolet. This is the light in a tanning bed. In the middle is the light we can see, starting at purple, going through the rainbow of colours until red. Next is infrared, the warm feelings coming off a glowing heater. Beyond that are the many waves we call radio waves. Cell phones, walkie-talkies, the radio, TV signals and many more are all in this part of the spectrum. Humans have learned how to ‘see’ at each wavelength with specialised cameras: we can take pictures at each wavelength.
Figure 2: The colour of stars and their temperature. This diagram shows the temperature of the stars in degrees against their size. Big stars are at the top, small stars at the bottom. Cool stars are on the right, hot stars are on the left. Stars are born on the diagonal (the ‘main sequence’). AB Doradus C is a very small red star. Our Sun is a yellow middlesized star. Stars that are dying are red (super) giants. Stars eventually end up as white dwarfs towards the end of their lives. Image: http://www.eso.org/gallery/v/ESOPIA/illustrations/phot-28c-07.jpg.html
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This means that essentially astronomy is the study of the light from distant stars, galaxies (thousands of millions of stars) and clusters (thousands of galaxies). How can we use the technology we have to find out how a galaxy is made, what galaxies are made of and whether or not galaxies are all the same age? We can only study the part of any galaxy that is facing us. As much as we would like to, we cannot peek
under or around the side of any star we are looking at. Think of it this way – you are studying cars by only looking at one picture of the front of one car, another picture of the side of a different car and a third picture of the underside of yet another car or possibly a truck. This makes the whole of astronomy one giant puzzle of perspective. Fortunately we have two tricks we can use: first there are a great number of stars and galaxies in the sky so we have many picture; the other trick is that there are many different types of light and we have learnt how to picture all of them. What is light? Light is very much like a wave, like a ripple in water, but travelling very fast. The important thing is that light behaves like a wave. There are big waves and very small quick ripples. The light that we can see is only a very small part of the spectrum, which is the word we use to describe all the possible sizes of light waves (see Figure 1). Blue is the shortest
Figure 3: M51: The Whirlpool Galaxy. The Hubble Space Telescope took this image of the Whirlpool Galaxy. The sweeping spiral arms are visible in blue. These have many new young stars in them. In the centre, the bulge is yellow, and contains mainly older stars. The yellow shape at the top is a companion galaxy swooping around the Whirlpool Galaxy. It is composed of mainly old, yellow stars. The dark brown swirls are dust blanketing out the light from stars behind it. Image: http://heritage.stsci.edu/2005/12a/index.html
wavelength that we can see, red is the longest. The rest of the colours fall in between. The rainbow of colours that we see are a few of the lengths of lightwaves; there are many, many others. Bluer than blue for instance is ultraviolet, and redder than red is called infrared, which literally means ‘under red’. The colour of stars The colour and brightness of a star says a lot about it, the star’s age, temperature and size (Figure 2). Hot stars are blue, cool stars are red. Our Sun, with its yellow colour, is pretty average for a star. Think of fire on Earth for a moment: the yellow flame of a campfire is hot, but cooking on it takes time. The blue flame of a gas hob cooks much faster. So blue stars are hotter than yellow or red ones. The bigger stars are also brighter. They are like a bigger fire. Blue and bright stars are both hot and massive. These huge stars (many times the size of our own Sun), live only for a short time compared with most other stars (still several million years). Older and smaller stars stars are much redder, dimmer and smaller. They also live much longer (thousands of millions of years). So if we see blue stars, we see shortlived stars; red and yellow stars live much longer. The colours of galaxies A galaxy is an enormous collection of stars, dust and gas, swirling together. In Figure 3, there are many blue and red stars visible as well as dark brown swirls of clouds. The blue, bright stars are those that have just switched on. Where you see these, stars have just been made out of a cloud of gas and dust collapsing into a ball. The yellow stars have been around much longer. So from the colours we can work out what kind of stars are in each galaxy. But there are
more than just stars in galaxies and many more types of light. So what do the other types of lightwaves tell us? Figure 4 shows one galaxy in every type we can detect. The gas of the galaxy emits in radio waves (far right) and the dust emits in the infrared. Both these things are the stuff between stars. If there is a clump of gas and dust, this might collapse into itself and form new stars. Stars emit mostly in the light we can see. Old, cool stars emit red and yellow light, young stars emit blue light and ultraviolet. Truly exotic astronomical bodies shine in X-rays. This light comes from pairs of stars where one star sucks the surface off the other, or black holes that swallow gas and stars forever. So the different types of light tell us what a galaxy is made of: the raw material for stars (gas and dust), the most recently added stars (blue and ultraviolet) and the older stars are red. We cannot look at the galaxy sideways, but we can pull it apart by taking a picture in every different type of light.
Figure 4: The Whirlpool Galaxy in every colour we can see.This is the same galaxy seen in a series of types of light. On the left are X-rays, the remains of stars after they die; black holes, neutron stars and white dwarfs leeching off another nearby star. Ultraviolet are the youngest and brightest stars. In the visible part of the spectrum the blue stars are young and the yellow ones are old. In the infrared the red shows where dust (this is like smog between stars) is emitting its typical light. On the far right is radio, marked in blue. Images: x-ray: http://chandra. harvard.edu/photo/2002/0158/index.html. ultraviolet: http://coolcosmos.ipac. caltech.edu//cosmic_classroom/multiwavelength_astronomy/multiwavelength_ museum/m51.html. Visible: http://heritage.stsci.edu/2005/12a/index.html. Infrared: http://www.spitzer.caltech.edu/Media/releases/ssc2004-19/index.shtml Radio: http://www.mpia-hd.mpg.de/THINGS/Spiral_Galaxies.html
How to make a colour image when we cannot see a particular light Astronomers use a trick to make a colour picture when we humans cannot see the type of light the original picture was taken in. We take three pictures, each at a different wavelength. The longest wavelength is given the colour red, the middle the colour green and the shortest wave-length the colour blue. When these three are combined, we get a new colour picture, which allows us to see that part of the spectrum we cannot actually see.
Opportunities for South African astronomers In South Africa, a large telescope that can take pictures in ultraviolet, visible and infrared has just been built, the South African Large Telescope (SALT). In the next few years South Africa will also build a new telescope that can see in the radio, the Karoo Array Telescope (MeerKAT). Together, these new state-of-the-art instruments will help South African astronomers unravel galaxies and work out how a galaxy is made. ■ Benne Holwerda is a post-doctoral researcher in the astronomy department at the University of Cape Town. His special research interest is in galaxies, using mainly optical and infrared data.u
The spiral galaxy M81.
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Fact File Q
The Hubble telescope
Right: The many-colour-changing Hubble. Our Hubble is a chameleon. It constantly changes its looks according to its environment. Image: NASA Above: These four images are among the first observations made by the new Wide Field Camera 3 aboard the upgraded NASA Hubble Space Telescope. The image at top left shows NGC 6302, a butterfly-shaped nebula surrounding a dying star. At top right is a picture of a clash among members of a galactic grouping called Stephan’s Quintet. The image at bottom left gives viewers a panoramic portrait of a colourful assortment of 100 000 stars residing in the crowded core of Omega Centauri, a giant globular cluster. At bottom right, an eerie pillar of star birth in the Carina Nebula rises from a sea of greenish-coloured clouds. Images: NASA, ESA and Hubble SM4 ERO team Hubble’s law states that the velocity at which various galaxies are receding from the Earth is proportional to their distance from us. The illustration shows the types of information that astronomers can find out by using Hubble’s law.
The Cosmic Microwave Background temperature fluctuations from the 5-year Wilkinson Microwave Anisotropy Probe data seen over the full sky. The average temperature is 2.725 Kelvin (degrees above absolute zero; absolute zero is equivalent to -273.15 °C or -459 °F), and the colours represent the tiny temperature fluctuations, as in a weather map. Red regions are warmer and blue regions are colder by about 0.0002 degrees.
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he Hubble Space Telescope was named after Edwin Hubble (1889-1953), who discovered that the universe is expanding and formulated Hubble’s law. It is a large, space-based observatory that has revolutionised astronomy by providing unprecedented deep and clear views of the Universe, ranging from our own solar system to extremely remote fledgling galaxies forming not long after the Big Bang, 13.7 billion years ago. The Hubble Space Telescope was launched in 1990 and greatly extended in its scientific powers through new instrumentation installed during four servicing missions with the Space Shuttle. The Hubble, in its 19 years of operations, has shown that Lyman Spitzer’s (1914-1997) original concept of an observatory filled with different instruments and orbiting far above the distorting effects of the Earth’s atmosphere could return data of unique scientific value. Hubble’s coverage of light of different colours (its ‘spectral range’) extends from the ultraviolet, through the visible (to which our eyes are sensitive), and into the nearinfrared. Hubble’s primary mirror is 2.4 meters in diameter. Hubble is not large by ground-based standards but it performs heroically in space. Hubble orbits Earth every 96 minutes, 575 kilometers above the Earth’s surface. NASA Goddard Space Flight Center in Greenbelt, MD performs the daily orbital operations, servicing mission development, and overall management of the Hubble Programme. The Space Telescope Science
Institute (STScI) in Baltimore, MD develops and executes Hubble’s scientific programme and is managed by the Association of Universities for Research in Astronomy (AURA) under contract to NASA.
Hubble opens new eyes on the universe NASA’s Hubble Space Telescope is back in business, ready to uncover new worlds, peer ever deeper into space, and even map the invisible backbone of the universe. The first snapshots from the refurbished Hubble showcase the 19-year-old telescope’s new vision. Topping the list of exciting new views are colourful multi-wavelength pictures of far-flung galaxies, a densely packed star cluster, an eerie ‘pillar of creation’, and a ‘butterfly’ nebula. With its new imaging camera, Hubble can view galaxies, star clusters, and other objects across a wide swathe of the electromagnetic spectrum, from ultraviolet to near-infrared light. A new spectrograph slices across billions of light-years to map the filamentary structure of the universe and trace the distribution of elements that are fundamental to life. The telescope’s new instruments also are more sensitive to light and can observe in ways that are significantly more efficient and require less observing time than previous generations of Hubble instruments. NASA astronauts installed the new instruments during the space shuttle servicing mission in May 2009. Besides adding the instruments, the astronauts also completed a dizzying list of other chores that included performing unprecedented repairs on two other science instruments.
Above: This NASA Hubble Space Telescope infrared mosaic image represents the sharpest survey of the Galactic Centre to date. It reveals a new population of massive stars and new details in complex structures in the hot ionised gas swirling around the central 300 x 115 light-years. This sweeping infrared panorama offers a nearby laboratory for how massive stars form and influence their environment in the often violent nuclear regions of other galaxies. The infrared mosaic was taken with Hubbleâ€™s Near Infrared Camera and Multi-Object Spectrometer (NICMOS). The Galactic core is obscured in visible light by intervening dust clouds, but infrared light penetrates the dust. The spatial resolution of this image corresponds to 0.025 light-years at the distance of the Galactic core of 26 000 light-years. Hubble reveals details in objects as small as 20 times the size of our own solar system.Image: STSci Right: Plumes of glowing hydrogen blast from the central nucleus of M82. The pale, star-like objects are clusters of tens to hundreds of thousands of stars. Image: STSci
Quest 5(3) 2009 21
The author collecting information on sun exposure.
Even on a fairly cloudy day, there is a lot of UV exposure.
You, me and UV – Under Dr Caradee Wright from the CSIR Environmental Health Research Group talks about sunny South Africa. Just how harmful are our solar UV rays? What does previous research tell us about how much UV radiation our children are likely to receive and what are the health risks?
n average, places in South Africa experience between six and 12 hours of sunshine per day. That is a maximum of 4 380 hours of sunshine per year. Of course, on heavily cloudy and rainy days, less sunshine reaches us, but generally, South Africans enjoy a frequent supply of blue skies and bright sun. What does this mean in terms of our potential exposure to solar ultraviolet radiation (UVR)? What is solar UV radiation? The sun’s rays may be defined as the solar electromagnetic spectrum, covering a broad wavelength range. The shorter the wavelength, the greater the radiation energy and the capability to produce chemical and biological reactions. Solar UVR is a relatively small part of the spectrum and may be further divided into three bands: UV-C (100-280 nm), UV-B (280-315 nm), and UV-A (315-400 nm). Most UV-C is absorbed by ozone in our atmosphere and only very little reaches us on the Earth’s surface. UV-B and UV-A are the radiation bands that we have to be concerned about because they do reach the Earth’s surface, and they have the potential to do us harm. Adverse health effects of solar UV exposure For humans, exposure to solar UVR has both positive and negative effects. Just the right amount of sun exposure helps our bodies produce sufficient vitamin D to maintain healthy bones, to provide us with a feeling of well-
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being and to help us fight against certain diseases. Too little solar UV exposure means our bodies might not be able to produce enough vitamin D, which can lead to rickets and osteoporosis. Our biggest concern in South Africa is when we ‘get too much sun’: the harmful effects of excess solar UVR exposure affect our skin, eyes and immune system. Sunburn and skin cancer are probably the two most commonly experienced adverse effects of too much sun exposure. Sunburn is described as a photo-injury. While we cannot see or feel solar UVR, we can see the effects it has when it reaches our skin, blood rushes to the damaged area and makes our skin feel warm and look red. The relationship between sun exposure and skin cancer is more complex. Non-melanoma skin cancers, such as squamous cell carcinoma and basal cell carcinoma, are seldom fatal; however, they may be extremely disfiguring and cause pain. Melanoma skin cancers are fatal; in other words, if they are not detected early enough and treated accordingly, they can cause death. Photo-ageing is another consequence of spending too much time in the sun without adequate sun protection. Wrinkling, fine lines, dryness and discolouration are some of the irreversible effects you face as you get older when you have spent too much time outdoors. The ‘skin you’re in’ provides you
with some protection against sunburn and skin cancer. This depends on how much naturally occurring pigment or melanin you have. The darker your skin, the more melanin you have and the greater your natural protection against the sun’s damaging UVR. South Africa: where the sun shines all year long South Africa is situated in the subtropics of the Southern Hemisphere. Several studies suggest a general downward trend in total column ozone over South Africa since 1979. Since ozone absorbs solar UVR and prevents it from reaching the Earth’s surface, less ozone means potentially more UVR reaching the ground. Instruments to measure ambient levels (UVR reaching the ground or a flat surface) are located at several universities and airports around South Africa. However, no single, nationally co-ordinated solar UVR monitoring network exists. Previous personal exposure research in South Africa Too much exposure to solar UVR is one of the few readily modifiable skin cancer risk factors, and exposure during childhood and adolescence is implicated in the development of skin cancer. The amount of solar UVR reaching the ground is not the same as the amount that reaches a person. This depends on whether the person is sitting, lying down or standing and moving around. Also, whether the person is in full sun or in the shade and if they are using sun protection
These children are wearing a small monitor to measure their sun exposure.
Q Everyday science A school playground, with shading over the main play area.
the sun in South Africa – hat, clothes, sunscreen, sunglasses and so on. Three previous studies in South Africa have looked at how much solar UVR South Africans are likely to be exposed to. In 2000, a Health Impact Assessment was carried out to find out how much solar UVR a child, an indoor worker, and an outdoor worker living in Durban were likely to be exposed to during one year. Results suggested that children were highly susceptible to getting sunburnt during peak UVR hours (two hours around midday) since school break times often occur during these hours. Also, an outdoor worker, such as a car guard, was identified as being at highest risk for developing nonmelanoma skin cancer. In 2001, special film called polysulphone was used to measure the daily solar UVR exposure of schoolchildren and teenagers in Durban. This film degrades in sunlight and mimics the reaction of human skin when it is sunburnt. We found that some children experienced very high exposure levels. The most important factor was the activity they were doing, for example, swimming and running. Polysulphone film was also attached to a mannequin to try and work out which parts of the body are most likely to experience sunburn. For an unprotected human body, the top of the head and the shoulders were the body parts most at risk. The nose, tips of the ears and forehead were also risk areas. Knowledge collected in New Zealand that may be useful to South Africa A study, co-funded by the University of Otago, the National Institute for Water and Atmospheric Research (NIWA), the Cancer Society of New
Zealand and the National Research Foundation (NRF) of South Africa, measured the solar UVR exposure and activities of New Zealand schoolchildren using high-tech electronic UVR monitors and activity diaries, respectively. High UVR exposure activities included physical education, athletics and the school lunch break. Children generally received higher exposures on schooldays compared to weekend days. A similar finding was made for South African schoolchildren. Children knew about the dangers associated with the sun but only half of those in the study used sunscreen. The sun protection message is getting through to children loud and clear, but many fail to heed it, partly because the people close to them still like the look of a suntanned body.
What do we need to know more about for the future? ■ How the solar UVR climate may be changing, especially in South Africa. ■ Access to high-quality and up-todate health data about skin cancer mortality and morbidity that will help us identify high-risk areas. ■ Survey to identify sun-related knowledge, attitudes and behaviours of the South African population, especially vulnerable groups. ■ Current sunburn and skin cancer prevention and awareness work, and a way to evaluate success. ■ Caradee Wright currently leads the Environmental Health Research Group at the CSIR in Pretoria. Her postgraduate studies were carried out at the University of Otago in New Zealand (PhD Public Health) and the University of KwaZulu-Natal (MSocSc). Caradee’s research interests focus on human exposure to environmental risks, namely, air pollution and solar ultraviolet radiation.
Health risks and benefits of solar UV exposure Just enough UV
Too little UV
Vitamin D production
Inadequate vitamin D production
■ Healthy bones
■ Osteomalacia ■ Osteoporosis ■ Rickets
■ Activating latent virus infections
Resistance to disease
■ Seasonal affective disorder ■ Schizophrenia
■ ■ ■ ■
■ ■ ■ ■
Non-Hodgkin’s lymphoma Prostate cancer Breast cancer Colon cancer
Psychological and general well-being
Too much UV
Cortical cataract Snow blindness Pterygium Squamous cell carcinoma of the cornea ■ Squamous cell carcinoma of the conjunctiva Skin Sunburn Solar keratoses Photodermatoses Basal cell carcinoma of the skin Squamous cell carcinoma of the skin ■ Cutaneous malignant melanoma ■ ■ ■ ■ ■
Quest 5(3) 2009 23
The fynbos of the De Hoop Nature Reserve.
Mariette Brand, from the South African National Biodiversity Institute, tells us the conservation problems around your bread and honey.
Managed Cape honeybee colonies & conservation Cape honeybees.
ock paintings by San Bushmen in the Late Stone Age show a long history of humans harvesting honey from wild honeybee hives in South Africa. However, people in the Mediterranean were the first to practise bee culture by providing clay or woven pot-like structures as honeybee nest sites to make harvesting honey easier. Today, beekeeping is a thriving industry that not only produces honey, but provides the important service of pollination for the production of various food crops. The place where beehives of honeybees are kept is called an apiary. Traditionally, beekeepers, who are also called apiarists, used to pay rent in honey for the small parcels of land where they kept their bees.
Moving the hives.
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The Western Cape hosts a welldeveloped, large-scale beekeeping industry, both for honey production and to provide pollination services for the production of deciduous fruit (apples, pears, peaches, plums and apricots), almonds and canola (vegetable oil seeds). Pollination services are also essential for the production of lucerne seed and the seeds of a number of vegetables (bulb and bunching onions, leeks, carrots, beets and cucurbits), especially in the dryer parts of the region. A history of honeybees Before honeybees were introduced to America and Australia by European settlers in the 17th century, they could only be found in and are still indigenous to Africa, Europe and western Asia. Twenty-six honeybee
Q Conservation subspecies have been identified to date, with each species adapted to a specific climatic or floristic region. The Cape honeybee (Apis mellifera capensis) is particularly adapted to the Mediterranean climate of the Western Cape and its distribution coincides closely with that of the Cape Floristic Region. The Cape honeybee is therefore the honeybee subspecies used in the Western Cape for apicultural practices.
Honeybees and conservation Introducing managed honeybee hives to a patch of natural fynbos vegetation so that the honeybees can exploit the nectar and pollen resources of the flowers might have several implications, especially when the hives are placed together in one spot – which is usually the case – and not spread out evenly over the landscape. Honeybee colonies are extremely efficient at locating and harvesting nectar and pollen crops because they are social and have sophisticated communication systems to recruit a large workforce to the best quality
floral resources available. This makes them particularly good competitors for floral resources, which means that other insect species that depend on nectar and pollen as a food source might be outcompeted. The conservation of biodiversity is a main priority in conserving natural ecosystems, so the possibility that high densities of honeybees may harm other insect populations that are dependent on floral resources must be investigated. This is particularly the case when managed honeybee hives are introduced into protected areas that may be the only refuge for biologically diverse communities of insect species dependent on the same floral resources. To investigate this potential interaction, biologists carried out a study in the De Hoop Nature Reserve and Marine Protected Area, in the
Bringing in the hives.
Western Cape. They investigated the possible interactions between a collection of managed Cape honeybee hives and other flower-visiting insects on fynbos flowers in the area. Twenty-four managed hives were brought into the reserve during the winter of 2008 and eight hives were placed at each of three experimental sites within the reserve. ▲ ▲
Honeybees in the Cape Western Cape beekeepers depend on several sources of nectar and pollen to sustain Cape honeybee colonies throughout the year. Hived colonies are used to pollinate various crops during spring and early summer. But during the winter, when nothing else is flowering, colonies are taken to flowering fynbos patches, while Eucalyptus trees are also used as refuge during the long, dry Cape summers. However, beekeepers do not always have access to good fynbos patches. Fynbos forms part of the Cape Floristic Region (CFR), the smallest and richest of six floral kingdoms in the world. Because of the many threats to the CFR, it has been classified as a biodiversity hotspot, while most of the protected areas within the CFR were collectively declared as a UNESCO World Heritage Site in 2004. Thus, fynbos is rigorously protected within the existing reserves in the Western Cape. At the same time, Eucalyptus trees are being targeted for eradication by the Working for Water programme initiated in 1995, in an attempt to clear water-thirsty alien invasive trees to conserve our scarce water resources. So the beekeepers in the Western Cape are limited in the number of honeybee colonies they can manage because of a scarcity of forage for the bees.
The author at work.
A new threat South Africa currently imports honey to meet the country’s demand since local production is not sufficient. By making more forage available, beekeepers will be able to sustain more colonies, which will increase honey production. However, recently the beekeeping industry has been struck by an aggressive and dangerous honeybee disease brought into the country by imported honey that was not irradiated. This honey carried spores of the bacteria that cause the disease, American foulbrood. It was first detected in the Western Cape and is thought to have penetrated colonies through honeybees that fed on contaminated honey from dumped containers. The arrival of this serious disease puts more strain on the issue of whether to allow beekeepers access to protected areas where wild honeybee colonies could easily be infected. As the beekeeping industry relies on the supply of new colonies from wild populations, exposing these populations to dangerous diseases might put the whole industry at risk. Therefore, the introduction of managed colonies to protected areas needs to be re-evaluated in the light of this new threat. In the meantime, wild pollinator populations find safe refuges in well-managed reserves in the Western Cape, while we aspire to protect pollination ecosystem services delivered by a diverse pollinator community.
Quest 5(3) 2009 25
Insect activity was observed on the flowers of three fynbos plant species namely Diosma subulata (Rutaceae), Acmadenia obtusata (Rutaceae) and Cullumia squarrosa (Asteraceae). Insect abundance and the number of visits they made to flowers were recorded during 10-minute observations made throughout days when the weather was good. Flying insects are most active on sunny days with higher temperatures. Observations were made before, during and after the managed hives were brought in, to compare the foraging behaviour of flower visitors before, during and after managed hive presence. What the study showed Honeybees accounted for 74.7 per cent of all the insects observed on the flowers of the three plant species, followed by non-Apis bees and anthophile (flower-visiting) wasps (15.2 per cent), flies (7.4 per cent) and ants (2.7 per cent). Interestingly, the number of honeybees seen on the flowers did not increase when the hives were brought in. De Hoop is already home to many ‘wild’ honeybee colonies, so large numbers of honeybees were seen on the flowers even before the hives were brought in. However, it is important to remember that the introduced managed colonies were not guaranteed to forage only on the plant species or flowering patches that the biologists were watching during the study. There were many plants flowering during the study and the foraging honeybees would almost certainly concentrate on the best available nectar and pollen resources, which might have been outside the study area. What is most important however, is that the study found that non-Apis bees and anthophile wasps did not change their foraging behaviour when the managed honeybee colonies were
introduced. These species continued to forage as usual. This is important. All bee species are totally dependent on floral resources (nectar and pollen) as food for themselves and their young. Therefore, bee species will be most at risk from competition for these resources. Wasps, however, are only semi-dependent on floral resources for food as some species feed their young paralysed prey and not nectar and pollen. The study concluded that a collection of eight hives was not enough to disturb the natural density of honeybees in the area. And the foraging behaviour of the insects that would potentially be the most vulnerable to competition was also not disturbed. This suggests that there was no increase in competition, at least for the floral resources provided by the plant species that were observed in this study. The most important conclusion from this finding is that introducing managed hives into the fynbos has no negative impacts on other flower-visiting insects. What this means These findings are highly significant. The lack of competition with native species means that conservation managers can introduce more lenient measures regarding managed honeybee hives within protected areas. However, beekeepers still need to be responsible in the way they exploit the environment in favour of their colonies. To ensure that floral resources are harvested sustainably – without adverse effects on wild populations of flower-visiting insects – floral resource exploitation by managed colonies will need to be regulated and monitored. ■ Mariette Brand is doing her PhD at SANBI, evaluating pollination as an ecosystem service for the production of hybrid onion seed in the Little Karoo. She is also affiliated with the Department of Conservation Ecology and Entomology at Stellenbosch University.
From the top: Cullumia squarrosa, Diosma subulata and Acmadenia obtusata.
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American foulbrood is a disease of honeybees caused by the spore-forming Paenibacillus larvae ssp. larvae. It is the most widespread and destructive of the bee brood diseases. The organisms is a rod-shaped bacterium. Bee larvae up to three days old become infected by ingesting spores in their food, the youngest larvae being the most susceptible. The spores germinate in the gut of the bee larvae and the bacteria grow, feeding on the larvae, which then die. This form of the bacteria produces millions of spores before dying itself. Each infected, dead bee larva may contain as many as 100 million spores.
The succulent Karoo. Image: Adam West
How might drought affect biodiversity in South Africa? What can 20th century rainfall data tell us about the effects of climate fluctuations on the vegetation of the succulent Karoo biome? QUEST looked at the work of Timm Hoffman and colleagues in the region.
redictions of climate change tell us that, in the winter rainfall region of South Africa, the frequency of drought will increase over the next 100 years. This is expected to have dire consequences for the plants and animals of the region – a world biodiversity hotspot. This prediction raises two important questions. First, is there evidence in the climatic record that annual rainfall has already declined and that the incidence of drought has increased over the last 100 years in the winter rainfall area of South Africa? The second question that arises is concerned with the response of vegetation to drought. In other words, will the vegetation of the biomes of the winter rainfall regions change as a result of increasing drought? The two vegetation types that are characteristic of the winter rainfall region are the succulent Karoo and the fynbos. Both are internationally recognised for their high levels of biodiversity and for the high numbers of endemic species. It is thought that
An array of succulent Lampranthus and a non-succulent shrub Penzia incana. Image: Timm Hoffman
Quest 5(3) 2009 27
The studies that have been done have focused on the response of succulent shrubs in relation to the response of the non-succulent evergreen and deciduous shrubs. The results have been at odds with each other. Some studies have reported that succulents were negatively affected by drought, while at other sites they were hardly affected at all, or were less affected than non-succulent shrubs.
the historical oscillations between wet and dry periods, as well as the lack of extreme weather conditions, are the reason for the high level of plant biodiversity in the succulent Karoo in particular. So any trend towards extreme aridity and an increased frequency of drought might be expected to damage biodiversity over time.
Top: The Kamiesberg, near Paulshoek. Image: Timm Hoffman Middle: The location of the four main drought studies (Numees, Paulshoek, Worcester, Steytlerville) in the succulent Karoo biome and six weather stations (Lekkersing, Springbok, Clanwilliam, Worcester, Oudtshoorn, Steytlerville) used in the rainfall and drought analysis. Above: A weather station in the study area. Image: Timm Hoffman
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What we know so far There have been previous analyses of the historical winter rainfall record, which have produced conflicting results. At first sight it appears that there is little evidence for either a decline in rainfall or an increase in drought during the 20th century. But if the records are looked at in more detail it becomes apparent that the situation is not simple. Since 1950, some areas have become wetter while others have become drier. Compounding the complexity in climate, is the complexity of plant communities and the limited number of studies looking at this question. There have been no historical drought studies done in the fynbos and only four in the succulent Karoo. These studies have shown varying responses of the main plant types to drought. In some cases succulents were hard hit by drought, while at other sites non-succulent shrubs were more severely affected. We still need a good explanation for these patterns.
Looking at the patterns In this study, Hoffman and his colleagues looked at the long-term trends in annual rainfall over the period 1900-2000. They used records from six representative succulent Karoo biome sites, which were located at regular intervals along a north-south and a west-east gradient (see map). The weather stations were chosen for the availability of reliable longterm records and the lack of any other influences, such as nearby mountains, on the local weather. To look at the effects of these weather patterns on the succulent Karoo biome plants, the team used the four main studies that have been carried out in the region. Study 1
This was carried out in Numees, in the southern Richtersveld. The results suggested that the impact of drought reduced species richness to about 60% of the average over the subsequent 17 years. The mean annual rainfall in this area was 75 mm and the longest period without rain was 149 days. Study 2
This was carried out in Paulshoek in the eastern Kamiesberg. The results suggested that the impact of drought on mortality in local plants was relatively low, both for succulents and non-succulent species. Mean annual rainfall here was 213 mm and the longest period without rain was 64 days. Study 3
This study was carried out on the Worcester Veld Reserve and suggested that the leaf-succulent shrubs were more drought sensitive than either the stem-succulent and non-succulent shrubs. In fact, two of the four nonsucculent species seemed to survive relatively well after nearly 600 days without rain. Study 4
This was carried out in Baroe, near Steytlerville. There was little difference
Q Climate change The Richtersveld-Rooiberg quarztfield. Image: Timm Hoffman
in the populations of succulents and non-succulents before a period of drought. However, drought seemed to particularly affect the perennial species and more non-succulents died off in drought periods, leaving succulents dominant following a drought. The mean annual rainfall was 240 mm and the longest period without rain was 74 days. Contradictory results The point of this study was to see if indeed there is evidence of an increasingly dry climate in the succulent Karoo biome over the past 100 years. This analysis at least suggests that, except for Springbok, there has been no increase in drought in the 20th century. Indeed, it may be that a curious pattern seen in Springbok of exceptionally heavy rainfall between 1911-1925 – nearly 50% higher during these 14 years relative to the next 75 years – could be the main reason for the apparent significant increase in drought in this region during the 20th century. What is apparent from the analysis is that the first half of the century – from 1900 to 1950 – was drier than the second half of the century. It was also during the first half of the century that the area was heavily farmed, so high stock levels would also have contributed to major vegetation changes in the region. Drought in southern Africa is nothing new. Severe droughts occurred between 1821-1823, 18451847 and 1862-1863. These have resulted in what Hoffman and his colleagues call a ‘desiccationist’ way of thinking, which links decreasing rainfall with human activities, particularly the removal of vegetation. This, of course, reflects international concern over climate change and conservation at global, regional and local scales. This has extended to concerns around climate change and its effects on the succulent Karoo biome, which are based particularly on the future scenarios derived from the general circulation models (GCMs), instead of on any evidence of increasing drought from historical sources. As far as the vegetation is concerned, it seems that some succulent Karoo biome species, particularly the short-lived, more ‘weedy’ species, are more susceptible to the impact of drought than others.
It also appears that most of the longer-lived succulents in the area are remarkably resistant to drought, and there is little evidence to suggest that the succulent plants in the region are more susceptible to drought than the non-succulents. What have we learnt from this study? The general message is that historical evidence is an important reality check to speculation of how applicable general models of climate change are to a particular region. This has broad implications for conservation strategy in regions that are thought to be particularly vulnerable to climate change. However, it also does not allow complacency. However adaptable the succulent Karoo plants may be to the fluctuations in climate that they already experience, if the GCMs do turn out to be correct, it is likely that this region will suffer major changes in biodiversity – as it has in the past as a result of the impact of over-grazing. ■ M Timm Hoffman holds the Leslie Hill Chair of Plant Conservation and is Director of the Plant Conservation Unit, Botany Department, University of Cape Town. His interests lie in environmental history, climate change and the impact of land use on the biodiversity of the fynbos and succulent Karoo biomes. Adam G West is a plant ecophysiologist interested in impacts of drought on plant communities. Adam is currently a post-doctoral fellow at the University of California, Berkeley and the University of Cape Town.
General Circulation Models The general circulation model (GCM) is a mathematical model of the general circulation of the planetary atmosphere or ocean, based on a series of equations formulated by Navier-Stokes. These GCMs are used in weather forecasting, to understand the climate and to predict climate change.
Climate models are systems of differential equations based on the basic laws of physics, fluid motion, and chemistry. To ‘run’ a model, scientists divide the planet into a three-dimensional grid, apply the basic equations, and evaluate the results. Atmospheric models calculate winds, heat transfer, radiation, relative humidity, and surface hydrology within each grid and evaluate interactions with neighbouring points. Image: Adapted from Wikimedia Commons
This article is based on Hoffman MT, Carrick PC, Gillson L and West AG. Drought, climate change and vegetation response in the succulent Karoo, South Africa. South African Journal of Science 2009; 105: 54-60
Quest 5(3) 2009 29
Young concerns HIV is growing in prevalence among young people – young women in particular. QUEST looks at how one community is responding to this challenge.
ince the 1980s HIV has been a growing concern in South Africa. Starting as an infection that affected predominantly men who have sex with men, it now affects the entire population. But it is the numbers of young people who are becoming infected who are of particular concern – specifically young women. In only 12 years, the HIV prevalence rate among 15 to 49year-olds rose from less than 1% of the national population to 20%. The death rate from HIV for South African women aged 25–34 increased five-fold between the years 1997 and 2004. Also, 5% of children between the ages of two and 18 are HIV positive. The immense impact of this disease not only burdens the physical wellbeing of South African citizens, but is scarring our social and economic futures as a nation.
The challenge is to engage young people before they become infected with HIV, something that the Desmond Tutu HIV Foundation (DTHF) has embraced with its youth programmes. Central to any research programme in a disease that affects people as deeply as HIV does is community involvement. One of the ways that this has been initiated in all HIV research programmes is through the formation of Community Advisory Boards, or CABs. Local Cape Town communities, Masiphumelele, Nyanga and Guguletu and Crossroads were chosen for specific youth research programmes and separate youth CABs have been established. Central to these programmes are the Future Fighters. Starting in 2004, the Future Fighters programme has so far enrolled between 30 to 40 young people. Participants A clinic for adolescents.
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are trained in advocacy and basic research techniques. The community programme has also helped several of the Future Fighters qualify for scholarships and university places. Masiphumelele Masiphumelele is an informal settlement close to Cape Town, situated in the scenic Cape Peninsula area. The settlement has grown considerably over the past few years, with a catchment area mainly from Transkei and Ciskei. Work is scarce – and transport to the other side of the Table Mountain chain is poor, so opportunities are limited. The community feels largely forgotten by the authorities – generally with reason. In Masiphumelele alone about 23% of the adult population are HIV positive. Of these infected people, 40% are aged between 20–29 years. Psychosocial research carried out by the DTHF has found that the uncontrolled spread of HIV among adolescents is fuelled by high-risk sexual behaviour, a fear of being tested for HIV because of the stigma attached to the disease, a lack of youth-friendly services and feelings of alienation. As a result of the poor facilities available to the community of Masiphumelele their youth have no place to call their own and the community are partnering with the DTHF to build a youth centre – Kethupila (Xhosa: choose life) – that will provide recreation, education, skills training and sexual health
Q Social science
Young people are the future of South Africa.
services to young people from eight to 24 years of age. Through the centre, the specific objectives of the DTHF’s work are to promote safer sexual choices through education, to increase the rate of voluntary HIV testing and counselling, to create income-generating opportunities and to provide an atmosphere that motivates young people to consistently participate in the centre’s activities. Taking this further Masiphumelele is a pilot project – the same approach is being fostered on the other side of Cape Town – in the older settlements of Nyanga, Guguletu and Crossroads. In Guguletu, for example, older Future Fighters provide support for younger people grappling with the day to day challenges of poverty, poor education and a lack of opportunity. In the midst of this, the importance of developing youthcentred HIV research programmes has become all too evident. Research encompasses sociobehavioural programmes looking at ways to change behaviour, vaccine trials and trials of different antiretrovirals. ■ Research by proxy One of the youth-friendly research programmes is part of the ongoing search for an effective HIV vaccine. There are many reasons for having a specific youth vaccine research programme – from differences in physiology in younger people to differences in social and behavioural approaches to participating in trials. There isn’t yet an HIV vaccine, so how do researchers start to examine the issues around a possible HIV vaccine? One approach is to use a similar vaccine – the recently developed vaccine against the human papilloma virus (HPV) – which is implicated in the development of cervical cancer. This vaccine was introduced very recently, and is in full production and use in the developed world. Researchers in Cape Town are using the HPV vaccine as a substitute for an HIV vaccine in trials of youth preparedness for vaccine programmes. HPV is also spread by sexual contact and is also a virus that is prevalent among young people – so the parallels should make it a good proxy for an HIV vaccine.
You + AgriSciences = Planet Earth : A better place to live! At Stellenbosch University’s Faculty of AgriSciences you will learn how to apply your knowledge of science to the benefit of both people and the earth. South Africa needs well-trained agricultural and forestry experts at all levels to supply our growing population with food and fibre, to ensure that food and food sources are unpolluted and safe, and that the environment is used and managed in ways that preserve it for posterity.
Job opportunities There are wide-ranging and challenging job opportunities in agriculture and forestry, from the most practical to the most high-tech – outdoors, in laboratoria, or in business.
Agricultural and forestry education Our degrees take three or four years to complete. After a bachelor’s degree, you can broaden your career opportunities through postgraduate study.
Admission requirements ● A National Senior Certificate (NSC) as certified by Umalusi with an achievement of at least 4 in four designated university entrance subjects. ● An achievement of at least 50%, calculated in a ratio of 40:60, for the SU Access Tests and the average (excluding Life Orientation) obtained for the NSC. ● Mathematics 4, Physical Sciences 4 OR Physical Sciences 3 and Life Sciences 4. ● In addition to the general admission requirements of SU, admission to the programme BAgric (Elsenburg) requires at minimum: Mathematics or Mathematical Literacy 4; Physical Sciences 4 OR Life Sciences 4 OR Agricultural Scienes 4.
Exciting careers to consider after finishing your degree at Stellenbosch University ● ● ● ● ● ● ● ● ● ● ● ●
Conservation ecologist Winemaker Forester Eco-tourism operator Entomologist Viticulturist Entrepreneur Community developer Animal or plant geneticist Horticulturist Wood processing specialist Quality controller
● ● ● ● ● ● ● ● ● ● ●
Agricultural economist Researcher Environmental impact assessor Plant pathologist Extension officer Food scientist Animal scientist Soil scientist Consultant Water research manager Game ranch manager
Closing date for applications: 30 September Contact our Faculty Secretary at (021) 808 4833, fax (021) 808 3822, or e-mail firstname.lastname@example.org for more information and visit http://www.sun.ac.za/agric
Quest 5(3) 2009 31
Lucinda Backwell (foreground) with Kalahari Bushmen following butchering experiments of large mammals using stone tools.
Scanning electron microscope images of fossil hairs from Gladysvale cave.
Andrea Meyer introduces us to Lucinda Backwell, one of South Africa’s distinguished scientists.
Meet Lucinda Backwell: the woman who found the oldest human hair
Bone tools from the early hominin site of Swartkrans, dated to between 1 and 2 million years ago, and used predominantly in termite foraging.
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lthough Dr Lucinda Backwell is one of a distinguished team of researchers who have, quite possibly, made one of the most important archaeological discoveries in recent times, she describes herself, quite simply, as ‘an old Jo’burg girl and proud’. While investigating the Gladysvale Cave in the Cradle of Humankind, the researchers came across a fossil brown hyaena latrine. The fossilised hyaena dung (coprolites)
surprisingly contained human hair dating between 195 000 to 257 000 years ago – the oldest human hair found to date. This record was previously held by a South American mummy thought to have lived 9 000 years ago. When Backwell’s findings were made known, the discovery garnered international fame through extensive media coverage. Backwell is the youngest of a large Catholic family from Parkview in Johannesburg, and dates the beginning of her interest in palaeontology and anthropology to a conversation she had as a teenager with one of her sisters. ‘She told me that we didn’t always look like this, that when we started walking upright our brains expanded, and she gestured to her forehead,’ Lucinda says. ‘Having never heard the word evolution at school, I was completely intrigued. Her explanation of natural selection
Q Meet the Scientist Left: Gladysvale cave in the Cradle of Humankind.
stirred something in me, and I knew then that this was an interest I wanted to pursue.’ However, despite her fascination with the subject, she did not consider pursuing it as a potential career, thinking her career options were limited to nursing, teaching, or secretarial work. ‘People told me that palaeo-anthropology was a hobby,’ she says, ‘not a career choice.’ However, at the age of 27, having held down a number of jobs, travelled, and feeling ‘terribly unfulfilled’, Lucinda decided it was time for a serious change. She wrote an exhaustive ‘to do’ list, which included getting an education, visiting New York and Egypt, losing 20 kg, seeing the gorillas, and excavating an archaeological site, among others. ‘I’m happy to report having achieved all of these goals, except for seeing the gorillas,’ she says. She went on to obtain an MSc and PhD in palaeoanthropology from the University of the Witwatersrand, where she met her hero, Professor Phillip Valentine Tobias.
‘I adore this gentle and brilliant man, his wonderful mind and turn of phrase. I consider myself privileged to know him.’ When asked about the subjects that should be taken at high school level to prepare a student wishing to enter the field, she says, ‘The sciences certainly helped me to understand better the way in which the world works; however, I don’t believe that subject choice is the beginning and end. Reading is, and we can do that at any stage of our lives.’ Finding herself called upon to teach South African teachers how to teach human evolution in the New South Africa school curriculum, Backwell knew she had realised her dream. As she reflects on her career thus far, Backwell describes some of its high points. ‘I had the time of my life working with Bushmen in Botswana on bone modification, and studying Mary Leakey’s Olduvai Gorge bone tool collection at the National Museum in Kenya. It was also a real highlight matching the wear pattern recorded on the early hominid bone tools from
Swartkrans and Sterkfontein with that created experimentally from digging in termite mounds.’ Turning to the research findings to be published in the Journal of Archaeological Science, Backwell describes the discovery of fossil hairs of probable human origin in a fossil hyaena coprolite from the cave in the Cradle of Humankind. The coprolite is part of a brown hyaena latrine preserved in calcified cave sediment. ‘We weren’t really expecting to find hair in the fossil dung, perhaps an insect carapace or bone fragments, but knowing that modern hyaena scats are essentially balls of compressed hair, we thought we’d take a look. Even at low magnification we could see glass-like structures reminiscent of hair. Scanning electron microscopy revealed that five of the forty hairs extracted have a distinct cuticle scale pattern, which is most like that of modern human hair.’ The fossil hairs from Gladysvale represent the first non-bony material in the early hominin fossil record. This time period (195 000 and 257 000 years ago) covers the period just before modern humans emerged, and overlaps with the existence and end of Homo heidelbergensis. The hairs could belong to either of them, or to a species not yet recognised. Backwell believes that as analytical techniques become more advanced, more in-depth findings could result, possibly shedding more light on what the person looked like, their state of health, and other aspects that cannot be thoroughly investigated with current technologies. The discovery of these hairs supports the theory that hyaenas gathered some of the early human remains in cave sites in South Africa, and also provides a new source of information on fossil mammals in the Sterkfontein Valley. Asked for advice for aspiring palaeontologists, Backwell’s enthusiasm is evident as she says, ‘South Africa is a fossil paradise! Read widely, learn to identify bones, volunteer your services, watch out for snakes in the field (literally and figuratively) and enjoy, sweetheart – enjoy!’ ■ Andrea Meyer is the communication officer for the Academy of Science of South Africa.
Quest 5(3) 2009 33
A year long celebration
Lacea Loader describes the University of the Free State celebrations of Darwin’s life.
his year the 200th anniversary of the birth of Charles Darwin and the 150th anniversary of the publication of his book On the Origin of Species are celebrated all over the world. To commemorate this, the University of the Free State is presenting a year-long programme with the theme ‘The story of life and survival’. We are the only university in the country that is presenting such an extensive lecture programme on life and survival, which is an excellent example of how our university is promoting critical scientific reflection. Darwin was an English naturalist who realised the importance of critical scientific reflection and presented compelling evidence for the fact that all species have evolved over time from common ancestors, through the process he called natural selection. In modified form, Darwin’s scientific discovery is the unifying theory of the life sciences, providing a logical explanation for the diversity of life. On the Origin of Species, which was published in 1859, is recognised today as perhaps the greatest intellectual revolution in the entire history of science. ‘The brilliance of this book lies in its clarity, one can almost say simplicity and the meticulous and comprehensive documentation of vast volumes of evidence for each statement,’ said Professor Jo van As,
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head of the Department of Zoology and Entomology at our university. ‘The accepted view about the origin of biodiversity before 1859 was that all species were created exactly as they are now. Darwin’s work showed that all life forms are interlinked and evolved like the branches of a tree – a tree of life. Species gradually change and evolve into other species under the driving force of natural selection. This is the same process that breeders use to change animals and plants to desired forms – the only difference is that in this case it is artificial and not natural selection,’ said Van As. ‘The same process of evolution also
presentation on what nature tells us about cosmic history. The programme will be concluded exactly a year later on 12 February 2010 with a discussion on the future of evolution. ‘We aim to portray the influence of Darwin’s theory of evolution on a wide range of disciplines. We are celebrating 200 years of scientific progress and the epic 4.6 billion-year journey of life. I see this as a good opportunity to promote science in its broadest context,’ said Van As. Some of the topics that were discussed earlier in the year include the geological evolution of our planet, the origin of life, prokaryotes and
It is a cursed evil to any man to become as absorbed in any subject as I am in mine. Charles Darwin applies to humans. We are not the pinnacle of biodiversity but part of the large spectrum of the incredible creatures living in the only place in the universe that we know of where life exist,’ he said. The lecture programme forms a cycle of the progress of man and does not only focus on Darwin. It started on 12 February 2009, the birth date of Darwin, with a stage play about his life and a
eukaryotes and extinction. ‘Today evolution is no longer considered to be a theory and is widely accepted by most serious scientists as the process responsible for the diversity of life on our planet,’ says Van As. The programme is spearheaded by the UFS Department of Zoology and Entomology, in conjunction with the National Museum and the Central University of Technology. ■
of life and survival Left: At the launch of our university’s year-long programme to celebrate the story of life and survival were, from the left: Prof. Schalk Louw, Department of Zoology and Entomology, Prof. Jo van As, Department of Zoology and Entomology, Prof. Maitland Seaman, Centre for Environmental Management, and Prof. Matie Hoffman, Department of Physics. All four are associated with the UFS. Prof. Louw and Seaman acted in a play about the life of Darwin, while Prof. Hoffman made a presentation on what nature tells us about cosmic history. Image: Hannes Pieterse Opposite page (above left): The story of the life of Darwin was told by means of a stage play at the launch of the UFS’s yearlong programme. Prof. Schalk Louw, from the Department of Zoology and Entomology, played the part of Darwin. Image: Hannes Pieterse Opposite page (above): Prof. Schalk Louw (left) as Charles Darwin and Prof. Maitland Seaman, head of the UFS’s Centre for Environmental Management, played the part of a journalist interviewing Darwin. The play was presented in cooperation with the Department of Drama and Theatre Arts. Image: Hannes Pieterse
Gateways to t he west: understanding ocean circulation at the Mascarene Plateau Oceanographic studies are revealing important information about the marine ecosystems of the western Indian Ocean. In this, the second of two articles on the research voyages of the Dr Fridtjof Nansen, Isabelle Ansorge and Claire Attwood look at the oceanographic research that is being carried out in a remote part of the western Indian Ocean.
L Figure 1: Bathymetry map showing the location of the Mascarene Plateau. Bathymetry is the study of the elevation of the floors of oceans and lakes. Bathymetric charts show the ocean or lake floor as a series of countours and elevations, as you can see in this illustration of the Puerto Rico trench.
ast year, over a period of three months, 33 South African scientists had the opportunity of conducting oceanographic and fisheries research from the decks of the Dr Fridtjof Nansen, one of the most advanced research ships in the world. Working with their colleagues from four other African countries, as well as from Europe and the USA, the scientists surveyed a wide swathe of the western Indian Ocean, paying particular attention to the physical, chemical and biological oceanography of the remote Mascarene Plateau. The Mascarene Plateau The Mascarene Plateau is a submerged volcanic plateau extending over 2 200 km between the Seychelles Bank at 4°S to Mauritius at 20°S (Figure 1). The Mascarene Plateau is a complex bathymetric feature characterised
Figure 2: Map showing the location of the deep channels separating the shallow banks of the Mascarene Plateau. Green shading represents depths <500 m.
36 Quest 5(3) 2009
Figure 3: General circulation of the south-west Indian Ocean. The pathway of the South Equatorial Current around the northern and southern coastline of Madagascar is clearly shown.
by a series of islands, banks and shoals, which are separated by deep channels. Covering an area of over 115 000 km2, the Mascarene Plateau is orientated roughly north–south, in a crescent shape. The main banks are known as the Seychelles Plateau, the Saya de Malha Bank, the Nazareth Bank and the Cargados-Carajos Bank (Figure 2). These are typically 20 m to 100 m deep and topped with coral. On either side of the plateau, steep slopes plunge to abyssal depths of 4 000 m. The general circulation in this region is dominated by the South Equatorial Current (SEC), a broad current between 10° and 16°S sweeping westwards at velocities <0.3 m/s (Figure 3). The SEC is directly driven by the trade wind belt and forms the westward limb of the large-scale subtropical Indian ocean gyre (spiral current) feeding into both the Agulhas Current system and the East African coastal current (Figure 3). What makes this plateau so interesting? The plateau’s islands, banks and shoals form a barrier that modifies the predominantly westward passage of the SEC. Recent studies have shown that as the SEC approaches the Mascarene Plateau, it branches into a number of tributaries, the largest occurring between the Saya de Malha and Nazareth Banks at 12 to 13°S. Here, approximately 50% of the SEC flow is forced through the narrow channel separating the Saya de Malha and Nazareth Banks, with the remainder of the flow passing in roughly equal volumes around the northern edge of the Saya de Malha Bank (8° to 9°S) and between Mauritius and the Cargados-Carajos Bank (18° to 20°S). The modifying influence of this barrier provides a rare example of an extensive shallow-
Q Science in action Buoy overboard! by Michael McPhaden The 2008 voyage of the Dr Fridtjof Nansen provided the Pacific Marine Environmental Laboratory (PMEL) of the USA’s National Oceanic and Atmospheric Administration (NOA) with an opportunity to deploy two ATLAS moorings in the western Indian Ocean. ATLAS moorings were developed at PMEL in the early 1980s to measure surface wind speed and direction, air temperature, relative humidity, solar radiation, rain rate, sea surface temperature and conductivity at several depths in the upper 500 m and ocean velocity at 10 m depth. The two moorings deployed from the Dr Fridtjof Nansen bring to 22 the number of moorings that have been deployed in the Indian Ocean through a multi-national effort called RAMA (the Research Moored Array for African-AsianAustralian Monsoon Analysis and Prediction). Eventually a total of 46 ATLAS moorings will span the Indian Ocean between 15°N and 25°S and provide a key oceanographic and marine meteorological data set for monsoon research and forecasting. The first mooring was installed at a location of 8°S, 55°E and the second was at 12°S, 55°E. The aim of these moorings is to study how shifts in the Intertropical Convergence Zone (ITCZ) as a result of the changing monsoon influence the ocean conditions of this region. For instance, changes in surface conditions occur during periods when the ITCZ is well developed, i.e. during January to March. Then, as the ITCZ migrates northwards and winds become stronger the thermocline deepens. The thermocline is also deeper on average at 12°S than at 8°S, which is consistent with the presence of a the westward flowing South Equatorial Current (SEC) at these latitudes. The SEC is seen in the 10 m velocity data and is weaker and more variable at 8°S than at 12°S (where unfortunately real-time transmissions from the current meter stopped in early January). Monthly time scale eddy activity in both temperatures and currents is apparent at both sites.
Thermocline In the ocean, most of the heat from the sun is absorbed in the first few centimetres of the water’s surface, which heats up during the day and cools at night. Waves mix the water near the surface layer and distribute heat to deeper water so that temperature may be relatively uniform for up to 100 m, depending on wave strength and surface turbulence caused by currents. The thermocline may be thought of as an invisible blanket, which separates the upper mixed layer from the calm deep water below. Tides and currents, seasonal weather variations and latitude can all affect the depth and thickness of a thermocline.
Top right: Isabelle Ansorge, an oceanographer at the University of Cape Town, is dwarfed by an ATLAS mooring prior to its deployment from the Dr Fridtjof Nansen. Image: Isabelle Ansorge. Right: Daily averaged atmospheric and oceanic data at 8°S and 12°S along 55°E. Shown from top to bottom are shortwave radiation, rain rate, surface winds, ocean currents measured at 10 m depth in the mixed layer and temperature in the upper 300 m. Small arrows on the left axis of the temperature plot indicate the depths of temperature sensors. Image: Mike McPhaden
shelf sea completely detached from land boundaries, and remains an isolated and almost completely unexplored marine ecosystem.
What have we found? Having surveyed the entire Mascarene Plateau (Figure 4) we have a better understanding of its influence on the surrounding marine environment. What have we learnt? 1. It appears that the SEC is displaced southwards from its mean position of 10° to 16°S by the obstruction caused by the shallow bathymetry of the Mascarene Plateau. Upstream of this plateau, the SEC exists as a
Why the need to investigate this region? Despite the success of previous investigations under the Shoals of Capricorn Marine Programme in 2002, surprisingly little is known of the role the Mascarene Plateau and the effect its channels and surrounding waters have on the biodiversity of the western Indian ocean. A key aim of the five-year Agulhas and Somali Current Large Marine Ecosystems (ASCLME) Project is to develop a series of well coordinated
oceanographic research cruises aimed at gathering essential information about the oceanography and its interaction with and influence on the biodiversity and economies of the western Indian Ocean region.
Figure 4: Cruise map showing all oceanographic stations occupied during the Mascarene Plateau survey.
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Argo floats – robots of the sea – how do they work?
Figure 5: Temperature section from Mauritius to Seychelles showing the gradual ascent of the thermocline (green line) from 250 m to 50 m with distance north. The location of the deep channels separating the shallow banks is marked.
Four Argo floats were deployed from the Dr Fridtjof Nansen as she travelled west, from Seychelles to Pemba, Mozambique. Argo is an international collaboration that collects high-quality temperature and salinity profiles from the upper 2 000 m of the ice-free global ocean, and currents from intermediate depths. The data come from battery-powered autonomous floats that spend most of their life drifting at a predetermined depth (commonly about 1 000 m). This is known as the ‘parking depth’! At 10-day intervals, the floats pump fluid into a bladder, which inflates, causing the float to rise to the surface over about six hours. During this ascent the float sensors measure temperature and salinity. Satellites determine the position of the floats when they surface, and receive the data transmitted by the floats. The bladder then deflates and the float returns to its original parking depth, drifting along until the cycle is repeated. Floats are designed to make about 150 such cycles.
Steve Kunze and Mike McPhaden deploy one of four Argo floats released from the deck of the Dr Fridtjof Nansen last year. Image: Tommy Bornman.
Dr Fridtjof Nansen Dr Fridtjof Nansen is owned by the Norwegian Directorate for Foreign Aid (NORAD) and staffed by the Norwegian Institute of Marine Research (IMR). It is working in the western Indian Ocean through a partnership between two United Nations projects: the Agulhas and Somali Current Large Marine Ecosytems (ASCLME) Project and the Ecosystem Approach to Fisheries (EAF)-Nansen Project. The latter project is supported by the UN’s Food and Agriculture Organisation (FAO). The ASCLME Project is based in Grahamstown at the world-renowned South African Institute for Aquatic Biodiversity (SAIAB). Its role is to assist the nine countries that share the resources of the western Indian Ocean to document the environmental problems – such as pollution, over-fishing and climate change – that are faced by the region and develop a strategic action programme to tackle these problems. Although the ASCLME Project focuses on the Agulhas and Somali Current ecosystems, it was decided that a detailed survey of the Mascarene Plateau would be required to study the complex nature of the South Equatorial Current, an ‘upstream’ current that influences both the Agulhas and Somali Currents and their ecosystems.
Figure 6: General circulation over the Mascarene Plateau (1 000 m depth contour is shown in red). Note the influence of the deeper channels speeding up the surface flow downstream of the plateau (highlighted by the green boxes) – exactly what we had hoped to find! The blue box shows the prevailing eastward flow associated with the South Equatorial Counter Current.
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broad (~650 km in width) shallow (~1 000 m in depth) current with speeds averaging 0.30 m/s. On approaching the Mascarene Plateau the SEC splits into separate cores centred near 18°, 12° and 8°S and correlated with the location of the deep channels (Figures 2 and 6). Once passed the Plateau it seems likely that these cores continue westwards towards the Madagascar coast at 50°E and there form the North East and South East Madagascar Currents. 2. The SE trade wind field results in a gradual shoaling of water masses between 15° to 5°S. The thermocline depth changed from 250 m close to Mauritius to just under 30 m on the Seychelles Bank (Figure 5). Since nutrients increase with depth, it would be expected that nutrient levels would gradually increase with
distance north, thus influencing the biological productivity of the surrounding region. This probably explains improved fish catches as we moved closer to the Seychelles! 3. Finally, the presence of an eastward flow between 6° and 2°S (Figure 6 – blue box) can be related to the position of the eastward flowing South Equatorial Counter Current. This current lies north of the SEC and flows in the opposite direction. This proved to be extremely interesting with salty warm water being swept into the Seychelles region from as far away as the Arabian sea! ■ Isabelle Ansorge is a lecturer in the Oceanography Department at UCT. She specialises in Southern Ocean research. Claire Attwood is a freelance journalist who works as a public relations consultant to the ASCLME project.
Oceanographers to track our journey into a new, warmer future Long-term oceanographic studies could help African countries to better understand the impacts of climate change and to plan for a warmer future.
and time scales. Furthermore, largescale predictions of change are of little value to decision-makers at the regional, national or community-level, who need fine-scale information that can help them to formulate practical strategies for adapting to and managing the impacts of climate change. The authors offer the example of the ASCLME Project, which is being implemented by the United Nations Development Programme, with funding from the Global Environment Facility (GEF). The Project has a system boundary that runs from Somalia in the north to the tip of South Africa and out beyond Seychelles ▲ ▲
Within the next 10 to 20 years, global climate change is expected to have a significant effect on marine ecosystems and the coastal communities that depend on them. Scientist believe that sea level rise alone will cause increased flood frequency, accelerated erosion, rising water tables, increased saltwater intrusion and a number of associated ecological changes. These biophysical changes will have significant socioeconomic implications as a result of coastal land loss and changes in coastal resources. Such changes will inevitably lead to a loss of livelihoods, reduction in food security and a general decline in the quality of life, health and well-being of coastal communities. Such impacts will also be felt far inland, as climate patterns that are – to a large extent – driven by the sea, change. Predictions such as these are particularly serious for the western Indian Ocean, a region that is shared by nine developing nations, including South Africa, Mozambique, Kenya, Tanzania, Madagascar, Mauritius, Seychelles, Comoros and Somalia. There are an estimated 55 million people living in the coastal zone of the western Indian Ocean and poverty levels in the region are among the highest in the world. All nine nations rely on the sea as a source of food security, subsistence livelihoods and employment, and their coastal populations are considered to be extremely vulnerable to the impacts of climate change. Low-lying island nations are particularly concerned with sea level rise associated with climate change. The potential for the countries of the western Indian Ocean to benefit from long-term oceanographic monitoring was highlighted in a paper entitled Long-term monitoring and early warning mechanisms for predicting ecosystem variability and managing climate change, which was presented at the Ocean Observation Conference in Venice in September 2009. Authored by David Vousden and Magnus Ngoile of the multilateral
Agulhas and Somali Current Large Marine Ecosystems (ASCLME) Project, the paper suggests that it is time to put in place long-term monitoring mechanisms that can identify changes in ecosystem variability and help to provide more accurate regional modelling of climate perturbation and change. In this way, science – in this case oceanography – can help governments to prepare for the changes that climate change will bring. According to Vousden and Ngoile, climate change predictions have so far been limited in their capacity to predict local and regional effects because of their coarse geographic
Figure 1: ASCLME System boundary as defined by currents in the western Indian Ocean.
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and Mauritius to the edge of the Mascarene Plateau (Figure 1). The objective of the Project is to clearly define the ecosystem boundaries, understand the major transboundary environmental impacts that occur within the ecosystems and develop Strategic Action Programmes for their effective management. A major focus of the ASCLME Project is the collection of baseline data within the western Indian Ocean marine environment that will identify the transboundary impacts on human societies, vulnerable species and habitats. A critical component of the project is the translation of scientific information into management and policy briefings that will guide the countries and the region in the overall sustainable management of vitally important marine resources. Community involvement is an important component of this science-to-governance process. It is envisaged that baseline studies will act as a foundation for longterm monitoring, which is considered to be essential for the sustainable management of the ecosystems. According to Vousden and Ngoile, very little is known about the links between ocean and atmosphere in the western Indian Ocean, which is one of the least studied ocean regions in the world. It is against this backdrop that the ASCLME Project is establishing a system for inshore and offshore data collection and monitoring. Figure 1 also shows the planned distribution of oceanographic equipment that will monitor ecosystem variability in real-time and provide the foundation for a western Indian Ocean ‘early warning system’ for climate change
impact and ecosystem variability. The offshore system consists of underwater temperature recorders (UTRs), Autonomous Temperature Line Acquisition System (ATLAS) moorings and Acoustic Doppler Current Profilers (ADCPs). They provide permanent recordings of atmospheric parameters (wind speed, air temperature, humidity, precipitation) and sea surface and seabed temperatures, salinities, carbon flux, seawater acidity, and current direction and velocities. Many of these instruments are already in place, with further deployment and maintenance planned for 2010 and beyond. It is envisaged that inshore, coastal studies will supplement the information generated by oceanographic equipment, so as to better predict long-term impacts and management needs. For example, the authors suggest that monitoring trends in inshore fisheries and the livelihoods of coastal people will reveal the impacts of climate change on coastal communities, along with an inshore monitoring programme covering basic oceanographic parameters such as water temperature and salinity. The monitoring system is likely to expand with the addition of remote sensing satellite imagery, specifically in terms of collecting data on ocean colour (for productivity and photosynthesis), sea surface temperature and sea level altimetry. This will be an integral part of the eventual climate and ecosystem variability modelling process at the regional and sub-regional level, which will then lead to the guidelines and policy briefs at a national level. According to the authors, the
development of this comprehensive monitoring network has been made possible through a number of partnerships. In particular, the United States’ National Oceanic and Atmospheric Administration (NOAA) has provided the ATLAS moorings as part of the organisation’s contribution to the Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA) network, as well as a number of floating data collection systems. Meanwhile, the countries of the western Indian Ocean are each engaged in developing a Marine Ecosystem Diagnostic Analysis in an effort to record baseline ecosystem conditions – including the socioeconomic status of coastal people – in order to record any changes induced by climate change. This is seen as a priority source of information about the impact of climate change on the ecosystems. National efforts will feed into an overall regional Transboundary Diagnostic Analysis. Vousden and Ngoile propose that the long-term monitoring network has the potential to become one of the most sophisticated long-term monitoring and early-warning systems outside the developed world. As such, it can act as a pilot system for regional and sub-regional modelling, prediction and effective, adaptable governance. With the ultimate goal of better preparing African governments for the impacts that climate change will have on their people, the long-term monitoring network is at the cutting edge of global efforts to improve the link between science and governance, say the authors. ■
This year the South African Institute of Aquatic Biodiversity celebrates 10 years as one of the National Research Foundation’s family of research facilities. Situated in Grahamstown in the Eastern Cape, SAIAB houses world-famous collections of marine and freshwater fishes from African inland water systems and surrounding seas. Recognised internationally as a hub for the study of aquatic biodiversity, SAIAB reseach involves: Discovery – Exploring African Aquatic Biodiversity Systematics and Taxonomy, Phylogenetics, Phylogeography SAIAB Somerset Street Grahamstown http://www.saiab.ac.za 40 Quest 5(3) Tel: +27 (0)46 6035800 Email: email@example.com
Conservation Biology – Coastal and freshwater conservation biology and Invasion biology Ocean Exploration – African Coelacanth Ecosystem Programme – 2009SAIAB’s flagship programme Biodiversity Informatics and the National Fish Collection
Q Science news Kenya chops thirsty eucalyptus trees Farmers in central Kenya are following a government directive to chop down water-hungry eucalyptus trees that grow near water sources. The directive was issued three months ago by environment minister, John Michuke, in an effort to lessen the impact of the drought that is ravaging the country. Eucalyptus grows fast and provides ample stocks of timber and firewood, but it is a water-hungry species that may also threaten local biodiversity. Now, eucalyptus trees growing less than 30 metres from rivers, streams, wells and other water sources are being cut down. Already, farmers in central Kenya have felled virtually all trees growing near water sources. ‘We agree that eucalyptus growing near water sources has contributed to water sources drying up and that is why we are removing the trees,’ says Joseck Gatitu, a farmer in the Kamune area of central Kenya, who has cut down 15 trees near a stream that has nearly dried up. James Gitonga, a senior officer at the Kenya Forest Service, says that although eucalyptus trees were a source of income to farmers, the recent rapid planting of Eucalyptus grandis and Eucalyptus camaldulensis, two fastgrowing species introduced to Kenya from South Africa seven years ago, was a threat to the environment. ‘The trees have been planted in great numbers, including near rivers, swamps and other catchments, and being huge water consumers they have greatly contributed to depletion of water, particularly during the current drought,’ he says.
Regenerating eucalyptus forest. Image: Wikimedia commons James Gathage, a forestry consultant trees farmers can cultivate without putting water supplies at risk. He adds: ‘Farmers should be encouraged to plant more Grevillea instead, which is an agroforestry tree with many commercial benefits, including timber, firewood and fodder.’ Source: www.scidev.net
DNA tests show that TB killed ancient Egyptian woman A 200-year-old mystery has finally been solved. A woman, mummified in ancient Egypt and first described by Augustus Granville in 1925, is now known to have died of tuberculosis (TB). The woman, called Irtyersenu, died in Thebes around 600 BC, aged about 50. Hers was the first mummy to be given an autopsy and she was thought to have died of ovarian cancer. However, 20 years ago the autopsy was re-opened and her cause of death queried. The ovarian tumour turned out to be benign. But the woman had signs of malaria and inflammation in her lungs, thought to have been caused by either pneumonia or TB. Most Egyptian mummies either had their organs removed and preserved independently, or the organs were dissolved within the body by a chemical that was inserted through the anus. Irtyersenu’s organs, however, were still in her body but the whole body is coated in an unkown waxy substance, which interferes with molecular analysis. However, scientist Helen Donoghue and her colleagues from University College, London combined DNA amplification with a technique that looked specifically for a short section of DNA from the bacterius that caused TB, Mycobacterium tuberculosis. They found the bacterium in the lungs, bone and liver. This suggests that Irtyersenu had disseminated TB i.e. all over her body, which would have been fatal in ancient Egypt. However, although the mystery of the woman’s death has been solved, the mystery of how she was preserved remains. Source: Proceedings of the Royal Society Right: An Egyptian mummy. Image: Wikimedia commons
Space radiation particularly high According to measurements made by NASA’s Advanced Composition Explorer (ACE) spacecraft cosmic rays are 19% higher than they have been at any time since space exploration began. Galactic cosmic rays are high speed charged particles that include protons and heavier atomic nuclei. They originate outside the solar system and their exact source is still the subject of debate. According to Richard Newaldt of Caltech, who is a member of the ACE team, these levels may have been typical in previous centuries and our own space era may have started in a time of unusually low cosmic radiation levels. This may have serious implications for future space robotic space missions, requiring extra robustness against radiation. Source: ACE
South African scientists use nanotechnology to upgrade TB drugs South African scientists have used nanotechnology to enhance the absorption of tuberculosis (TB) drugs in the body so that fewer, smaller doses are needed. Clinical trials for the antibiotic Rifanano — a combination of the four main first-line TB drugs — are scheduled for 2012 and the drug should be available in government clinics in 2016, Hulda Swai, principal researcher in biomaterials research told SciDev.Net.
Swai and her team from the Council for Scientific and Industrial Research (CSIR) won ‘best science to business opportunity’ at the second SA Bio Plan Competition held during the recent Bio2Biz Conference in South Africa in September. Rifanano needs to be taken just once a week for two months and there are no adverse reactions. Most TB antibiotics must be taken daily for up to six months and often cause debilitating side-effects, such as nausea and fatigue. The new drug is coated with nano-sized particles which are in turn coated with chemicals that make them stick to the intestine wall, enabling the drug to be far more easily absorbed. ‘When the white blood cells see these particles they take them up because they look like foreign objects. But doing so they actually transport them throughout the body while releasing their cargo,’ says Swai. ‘We have not invented a new medicine but have taken existing medicine and made it better.’ Team member Boitumelo Semete says Rifanano will be targeted at government health departments in the developing world. ‘TB is a poor man’s disease, which means it’s not a popular choice for development by commercially driven pharmaceutical companies,’ she says. ‘We are using local science and technology skills to make an existing treatment more effective and affordable for our people.’ Nanotechnology is being used by scientists worldwide to improve the efficiency of treatment for a host of diseases. CSIR now plans to turn its attention to improving medications for a number of other diseases, including malaria and cancer. The Bio Plan award ceremony was attended by Naledi Pandor, minister of science and technology, and Mamphela Ramphele, chair of the board for the new Technology Innovation Agency. The competition was organised in a joint collaboration between Emory University in the United States and South Africa’s Innovation Fund. Source: www.scidev.net
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In this second article on teaching evolution George Branch disusses how to deal with the controversies.
o some, evolution and religion are automatic enemies; to others they are compatible and complementary. Over the centuries, scientists have ranged from those implacably opposed to religion to others who have been deeply committed to a faith. Treading the right path in teaching evolution is important. People who accept evolution as an established fact rebel against what they perceive to be misinformed attacks on the subject. Others turn away from science if they feel their beliefs are derided or threatened. Antipathy feeds on antipathy, and polarisation is frequent – but seldom profitable. Ponder on Paul’s biblical injunction in Romans 14: 19 Let us therefore make every effort to do what leads to peace and to mutual edification. When persecuted by the church for his views on the solar system, Galileo (1564-1642) wrote: ‘It would be a terrible detriment for the souls if people found themselves convinced by proof of something that is made then a sin to believe’. People sometimes express disbelief that I can be a Christian and accept evolution. To glimpse the heat of feelings about evolution, consider this random sample of headlines from newspaper letters: ‘Darwin’s legacy is a recipe for school killers’; ‘Holes in Darwin’s “interim” theory’; ‘No proof for evolution’; ‘Every religion is a cult’; ‘Believe in God’s truth – or burn in hell’ (hardly the spirit of Christian charity); and at least some more reconciliatory, such as ‘Church to admit its Darwin mistake’ and ‘Good science and religion complementary’. Christianity and evolution As a practising scientist, I am absolutely convinced that evolution does take place. It has been my passion and delight to teach it. But as a Christian, I recognise that science is by definition limited to the material world; it provides no moral guidance. For me, science and religion have different but complementary aims.
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Figure 1: Does learning about evolution erode religious beliefs? A story of 4 622 students’ views.
I cannot turn to the Bible for a literal description of how the world operates, and I cannot turn to science for life values. In Part 1 of this pair of articles on evolution, I outlined four aspects that I believe should be presented to scholars: 1. the central ideas of Darwin’s Theory of Evolution; 2. how evolution can be tested against evidence; 3. advances in scientific ideas since Darwin, and 4. the vital relevance of evolution in our modern world. I concluded that evolution is a wellestablished fact, and that Darwin’s ideas were correct but incomplete. In doing so, I distinguished between the phenomenon of evolution and the mechanisms that explain how it takes place. The distinction is useful when presenting the subject to learners, because the phenomenon of evolution is so well established that most scientists regard it as a fact; but the mechanisms are only partly understood and still being researched and expanded. This article is devoted to a fifth aspect: the nature of the controversy and how to deal with it – both in the classroom and in life generally.
Let me begin with an analogy: toss an apple into a group of learners and ask why it descends to Earth. ‘Gravity!’ No hesitations? Nope. Yet science has over the years changed its views on the exact nature and mechanisms of gravity, and may do so again if we develop a ‘Theory of Everything’ as modern cosmologists are attempting to do. This does not negate the fact of gravity. As Steven J Gould (1987) wrote: ‘Facts don’t disappear while scientists debate theories ... Einstein’s theoryof gravitation replaced Newton’s, but apples don’t suspend themselves in mid-air pending the outcome’. Similarly, the fact of evolution remains, regardless of whether scientists agree on all its mechanisms. Does learning about evolution erode religious faith? Mike Anderson, who did a PhD in the philosophy of evolution and taught evolution at university level, used to conduct a questionnaire of students’ knowledge and attitudes about evolution, both before and after they had taken a course on the subject. I continued this tradition for 25 years. Figure 1 summarises the responses of students to five aspects of the questionnaire. This demonstrates several
My guideline on their validity is to ask: 1. whether they are testable by observation or experimentation, and 2. if they are based on information that has been reviewed by independent specialists in the field. It is easy to open up the ‘web’ and be flooded with views on evolution; but be sceptical if it is not based on peer-reviewed information. Let’s explore some of these criticisms. 1. Darwin’s ideas can’t explain the origin of life.
Figure 2: A range of views of evolution, adapted from Pigliucci (2002).
without prejudice to the faith we have received’. The renowned evangelist Billy Graham wrote in 1997 ‘I think that we have made a mistake by thinking the Bible is a scientific book. The Bible is not a book of science. The Bible is a book of Redemption’. St Augustine in a telling passage, as relevant today as when he wrote it, warned about uninformed criticism of science, saying that if non-believers find a religious person maintaining ‘foolish opinions about our books, how are they going to believe those books and matters concerning … hope of eternal life, and the kingdom of heaven, when they think their pages are full of falsehoods on facts which they themselves have learned from experience in the light of reason?’ The diversity of views There is a wide spectrum of views on evolution (Figure 2). One extreme embraces insistence on a flat Earth and anti-Galileo views about the Earth being the centre of the universe – views that are now rare. The other extreme is scientism – which proposes that science is all we need. Between these extremes lie (1) a belief in a young Earth, (2) agreement to an ‘old’ Earth on the grounds that ‘a thousand years in your sight are but a day…’ (Psalms 90: 4), and (3) various levels of acceptance of evolution, ending with theistic evolution, a belief in a God who operates through natural laws such as gravity and evolution. Considering anti-evolutionary views Criticisms about evolution range from simple ignorance of the subject, through to serious scientific concerns.
2. Evolution is ‘just a theory’
Ronald Reagan, then President of the USA, infamously dismissed evolution with these words. Shame on him! If he had down his homework, he would have appreciated that in science, a theory is not some airy-fairy invention sucked up by a scientist (usually referred to as a ‘boffin’ to further denigrate the idea). Ideas are turned into hypotheses, which must be tested with new data to see if they can be upheld. Just like the atomic theory, or the germ theory, or the theory of gravitation, the theory of evolution is a body of evidence that unites and explains a range of observations, and does so to such an extent that it is regarded as fact. Some aspects of evolution can be observed and experimentally proven before our eyes. Diversity among individuals, the fact that not all individuals survive to reproduce, and inheritance of characteristics (three cornerstones of Darwin’s ideas), all fall into this category. As a class exercise, learners
important things. First, the students improved from a scary ‘before’ mark of 20% for their knowledge about evolution, to 69%, much to my relief as an educator! Second, there were significant increases in the proportion accepting (1) both evolution and a belief in a Creator; (2) that evolution could be the Creator’s way of creation; and (3) that evolution has been proved beyond doubt. A diminishing but significant 8% adhered to a belief in a young earth and a literal six-day creation. What did I learn from this? Importantly, learning and accepting evolution does not need to threaten personal religious beliefs. However, an insistence on interpreting the Biblical Genesis account literally does compel a conflict – not just with evolution, but with all of science … astronomy, geology, chemistry, physics … ‘the whole shebang’, to use the title of a delightful book on the origins of the universe. This is the heart of the controversy. Literal interpretation of sections of inspired religious texts such as the Bible, Qur’an and Torah that deal with the creation and life does conflict with science. But there are many religious people who accept that these texts have eternal truths that are communicated in part by allegorical passages and poetic sections that were never intended to be literal word-for-word descriptions of how the world operates. As far back as 400 AD the great religious intellect St Augustine wrote about Genesis: ‘In matters that are so obscure and far beyond our vision, we find Holy Scripture passages which can be interpreted in very different ways
Let’s be fair to Darwin. He made it clear that his ideas applied to life once it had arisen: not to the origin of life. But let’s also be equally honest in acknowledging that scientists have several plausible ideas about the origin of life but they are a long way to being confident that any of them is correct. Once life arose, I am firmly convinced of the power and mechanisms of Darwinian evolution. But just because mysteries remain about the origin of life, this does not negate science – mysteries are a challenge, not a threat to science. For some, the absence of secure scientific explanations is a reason for inserting a divine intervention. I am cautious of this ‘God-of-the-gaps’ approach because many early gaps in knowledge have now been filled.
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can discuss their own family trees, and soon come to the conclusion that all three are facts. 3. Microevolution is OK, but macroevolution isn’t
Many people accept microevolution (adaptation of individual species to the environment) but refuse to take the next step – that evolution leads to the formation of new species – let alone accepting changes from one major group to another. In one sense they have a point. The evidence for these changes is largely historical. It is not something we can easily test by experimentation in our modern world. Some people even argue that because of this, evolution is a religion – a belief – that is untestable. If that is true, then we have to throw out all of geology and all of astronomy. And while we are about it, let’s toss out courts of law, because most times crimes are not observed … they are deduced from other evidence. Development of new species of plants is something that has been observed (and can be experimentally induced) in our own life spans. Indeed, one of the plants of immense importance to humans, bread wheat, was formed by two steps of hybridisation and doubling up of chromosomes (polyploidy) that led to a population that is reproductively isolated from any of its parental stocks and is thus by definition a new species. Most animal species don’t seem to arise this way. They do so by gradual divergence of populations that are geographically separated (geographic isolation). That takes more than a lifetime to complete, and the whole sequence has never been observed. But the circumstantial evidence for this process, derived from the geographic distribution of species (biogeography), is substantial. Similarly the fossil record documents changes of several major groups into other major groups. In South Africa, the Karoo fossils are famous for their transition from reptiles into mammals via a group known as ‘mammallike reptiles’ for the very reason that they are ‘half-way-houses’. Fish to amphibians and amphibians to reptiles have similar intermediates that are arranged in the fossil record in the sequence that would be predicted if ancestors give rise to later groups. In short, the evidence for
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macroevolution is compelling. Certainly there are ‘missing’ links between some groups, but enough links have now been recorded to be confident that large-scale changes from one group to another can and have taken place. 4. Evolution contradicts the second law of thermodynamics
In simplified form, the second law of thermodynamics states that the degree of disorder (entropy) in a system can never decrease. On these grounds, it is argued that evolution cannot occur because it has resulted in an increase in organisation and complexity over time. There is one main problem with this line of thought. The law applies in a closed system. As long as energy can be drawn from outside, part of the system can become more complex (more organised) at the expense of another part losing its organisation. A young student of mine once made a not-very-flattering but amusing cartoon of me eating a Christmas turkey. In it, I get fatter (and maintain my organisation), but the products of the turkey are distinctly less organised than before: the combined level of order for the consumed turkey and myself is less than before the meal. In the bigger picture, the sun fuels growth of plants, which are in turn eaten, allowing herbivores to develop. Thus, there are local events that increase order, but they are bought by inputs of energy or materials, and the net effect is an overall decrease in order (i.e. an increase in entropy). Pause for a moment and think about embryology – the ‘little miracle’ of the emergence of a human child from a simple, single-celled fertilised egg. If we consider an increase in evolutionary complexity as ‘impossible according to the second law of thermodynamics’ we should treat embryology in the same light. Embryos, too, get more complex. We understand how. So why should evolution be considered a problem, when we comfortably accept embryological development? 5. Random mutations and selection never create anything beneficial or ‘new’
Twenty years ago, it might have been defensible to say that mutations produce no increase in complexity. Mutations are random. They can be bad (quite often), neutral (very often)
or good (occasionally). Selection whittles out individuals that are less ‘fit’. For a time, it was possible to argue that changes in genetic composition don’t add to the diversity of genes available, so complexity can’t alter. But two important things must now be added to this story. First, while mutations are random, natural selection clearly is not: it increases adaptation to the environment. Second, we now know that genes quite often multiply. Two copies of the same gene can be produced. Sometimes this is no advantage and the second copy may slowly atrophy and become ‘junk DNA’. But the more interesting case is when one copy retains its original function, and the other is free to mutate and take on a brand new function. We call these ‘homologous genes’ because they have almost identical structures except for mutational changes, but they may have quite different functions. A clear example of this occurs in ‘ice fishes’, which live in Antarctica under freezing conditions. They have a gene coding for a precursor of trypsin – a digestive enzyme. This gene has multiplied and been re-arranged to develop another gene, which codes for antifreeze proteins that allow the fish to live under freezing conditions. Something new from something old. The antifreeze genes appear to have developed about 5-14 million years ago, coincident with both the time when Antarctica cooled to freezing and the period when the ice fish family started diversifying into the 95 species that now exist. 6. ‘Irreducible complexity’ disproves evolution
‘Irreducible complexity’ is a mouthful for an old idea that if any complex organ or biochemical pathway can be found that could not be simplified and still have a function, then it could not have evolved from simpler beginnings. And if this is true, it implies an ‘intelligent design’ (and an intelligent designer) for its origin. The idea has its root in words taken from Charles Darwin himself: ‘If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down…’ When I first encountered ‘irreducible
Figure 3: Darwin’s views on the eye
complexity’, I was fascinated. Initially, I felt it was a legitimate scientific approach to testing the validity of evolution. Its status is best explored by examples, starting simple and getting more complex. First, the mammalian eye (Figure 3) is often held up as an example of a complex structure. Indeed, it is. ‘What use is half an eye?’ is the clarion challenge of proponents of irreducible complexity. But the animal kingdom is full of examples of eyes that are much simpler, right down to the pigment spots in unicellular plankton that allow detection of light and orientation with respect to it, and they are all clearly an improvement on having no eye. Simpler structures do exist and do ‘work’. So the eye, wonderful as it is, is a poor candidate for irreducible complexity. It certainly could have evolved by gradual improvements from a humble origin. A second oft-quoted example is the bacterial flagellum, which has nine outer and two inner microtubules and 27 complex proteins, all said to be necessary for it to function. Yet simpler flagella are known: 9+1, 9+0, 6+0 and 3+0 arrangements of microtubules exist. Moreover, some parasitic bacteria use a subset of the 27 proteins for a completely different purpose … to drill through the cell walls of their host. So, again, simpler structures do exist. The bacterial flagellum is not ‘irreducibly complex’. My third example is perhaps the most interesting. The human bloodclotting mechanism is extremely complex. Ultimately, it depends on a protein (fibrinogen) being acted upon by an enzyme (thrombin) that converts it into fibrin – which has sticky portions that adhere to form a clot. But thrombin itself depends on a ‘Factor X’ being produced, and that in turn needs another factor … and so on until eventually a chain of 15 different chemicals called ‘serine proteases’ is involved. Complex? Yes indeed. Irreducible? No. Simpler clotting systems do exist in invertebrates. Moreover, the serine proteases are all closely related (homologous) and arose by gene duplication. Even thrombin itself is homologous to trypsin, and probably arose by duplication of the gene producing trypsin … now where have
Figure 4: ‘Blame all the maladies of humanity on evolution…’ Pigliucci (2002).
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Table 1: A range of views on how science relates to religion. Adapted from Pigliucci (2002) No God
Atheism and scientism
Faith and reason
Irreducible complexity and intelligent design Classical ‘young Earth’ creationism
Science can prove religion
Separate but complemetary worlds
we heard that name before? Aha: it seems that this is not the only time that gene duplication has led to the development of ‘new’ proteins. In short, we still do not have a convincing case of irreducible complexity. The quote above from Darwin ends with the words: ‘…but I can find no such cases’. That remains true today. Irreducible complexity and intelligent design have been cast as legitimate scientific enquiries into evolution and alternatives to Darwinism. They became the subject of court cases in the USA when they were advocated for inclusion in the science curriculum. This in itself says much about the origins of these ideas. Federal policy in the USA separates church and state, and religion may not be taught in schools. But if these ideas are scientific, they can (and should) be taught. If they are based on religion, they may not. The courts have ruled that ‘intelligent design’ is identical to ‘creation science’, which is inherently religious in nature. In South Africa we do not have such constraints on teaching religion. I believe that irreducible complexity and intelligent design should feature in a curriculum dealing with evolution, and that the evidence for and against the ideas must be examined as rigorously as it is for evolution. That way, scholars learn to evaluate different ideas based on tests of their validity. 7. Evolution is responsible for the social ills of the world
If scientific attacks on evolution fail, it is possible to turn to moralistic assaults, such as ‘blaming all the maladies of humanity on evolution’. I have borrowed this phrase and Figure 4 from Massimo Pigliucci’s book Denying Evolution. Variations of the figure appear in several anti-evolutionary publications.
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The heart of the idea is that if natural selection acts on random mutation to produce adaptations via competition between individuals, then what room is there for absolute moral guidelines and constraints on how we should behave. Quite how some of the items listed in the figure – such as inflation – can be blamed on evolution, is obscure. But before we glibly dismiss this diagram with a derisive laugh, it should not be forgotten that Darwin’s concepts have been used to promote views that most of us would now find offensive, as indicated by the following quotes justifying colonialism and racism: ‘The British colonist is… carrying out a preordained rule…the inexorable law which Darwin has aptly termed ‘survival of the fittest’…’ (FC Selous 1896); and an injunction to ‘draw a sharp boundary … between the most highly developed civilised people … and the crudest primitive people … and unite the latter with the animals’ (Ernst Haeckel 1868). But in reality, Darwin’s ideas cannot validly be extended to the political and social sphere. In the words of Massimo Pigliucci: ‘The theory of evolution tells us how living things have changed and come to be … it is not a guide to how we should live our lives, nor was it intended as such by Darwin’. It is possible to take Figure 4 and mischievously alter it to put ‘religious dogma’ as the root of all evil and ‘science’ as the axe that chops it down, and to blame everything on religion. Indeed, many sins can be laid at the door of religion, including examples of terrorism, sexism and racism. But whether the diagram is anti-evolution or anti-religion, it is a meaningless cheap device to score points rather than rationally examining ourselves and our world. Rejecting religion on these grounds misses the
point that all of us have free will to decide for ourselves how we should behave. And rejecting evolution because it has been corrupted by some to promote a false social agenda is equally invalid. None of this denies that evolution has philosophical, social and moral implications. For example, modern evolutionary and molecular biology have taught us two things about the human race: We all originated in Africa, and comparatively recently – perhaps 80 000 to 120 000 years ago; and there is less genetic diversity within our species than within almost any other species that has been examined. The racial division and supremacy that have bedevilled our country are based on myths. Science and religion, or science versus religion? A wide range of views exists in human societies about how science and religion relate to each other, as summarised in Table 1 – which is neither complete nor rigid in its ‘boxes’. The columns show three options: (1) science can uphold religion; (2) Science and religion are different and neither can prove or disprove the other, (3) the two are at war. In the first row of ‘no God’ is atheism, the belief that God does not exist, and scientism, which argues that all we need in the world is science. Under ‘deistic God’ are people who have a distant view of God who created the universe and then let it run; and who accept that religion and science are different worlds. A ‘naturalistic God’ created the laws of the universe, including the process of evolution, but intervenes rarely at miraculous and sometimes very personal points. ‘Theistic evolutionists’ like myself would place themselves in this ‘box’, as would people who believe in the ‘anthropic principle’ that the universe and its constants (the rate of expansion of the universe, the strength of nuclear forces, gravity etc.) are so finely tuned that they reflect God’s creation. Stephen Hawking, one of the world’s most extraordinary scientific minds, wrote in A Brief History of Time: ‘It would be very difficult to explain why the universe should have begun in just this way, except as the act of a God who intended to create beings like
us’. At the bottom of the table is a final category, a ‘personal God’ who intervenes in our lives and our world continuously: whose actions can be examined scientifically (scientific theism), or run in parallel with scientific laws (faith and reason). Pope John Paul II would probably fall in the latter group, and it was he who accepted ‘evolution as more than a hypothesis’, and who officially recognised that Galileo was not in conflict with the church (albeit 350 years after Galileo’s death). Only in the left of the table do worldviews create conflict between science and religion. Classical creationism adheres to a literal belief in the Bible, including a young Earth, about 6 000 years old, and the individual creation of all ‘kinds’ of life in a six-day period, bringing it into conflict with not just evolution but all fields of science. ‘Irreducible complexity’ and ‘intelligent design’ are more sophisticated offspring of creation science (once caustically described as ‘creationism dressed up in a cheap tuxedo’), and vary in their acceptance of different ages of the earth and different aspects of evolution; but at their heart they attempt to discredit evolution or at least aspects of it. Similarly, atheism and scientism are at loggerheads with religion. For me, science cannot either prove or disprove the existence of a God, which is by definition a faith. Nor can it supply the wisdom to judge how to use the knowledge we gain from science. ‘Science without religion is lame, religion without science is blind ’ – Albert Einstein. Where do you belong? Two of the joys of humanity are the capacity for conceptual thought, and the free will to decide our destinies. Joys they may be; but with them they bring awesome responsibilities. For teachers especially, the responsibilities are huge, for they powerfully influence the lives of the next generation. How should teachers handle evolution? In my previous article, I outlined aspects that should be covered. Building understanding, testing ideas, comprehending how science operates and is ongoing, and appreciating the relevance of evolution in our lives today are all prerequisites to handling
‘There is a grandeur of this view of life, with its several powers. Having been breathed into a few forms or one; that … from so simple a beginning, endless forms most beautiful and wonderful have been, and are being, evolved.’ Charles Darwin’s concluding words to On the Origin of Species 1859. the controversies. But the ‘how’ of teaching is a different question. From discussions with teachers and learners, five principles have emerged: 1. Respect the views of others. Scorn and arrogance simply close people’s minds. Sympathetic understanding, rational discussion and exchanges of views break barriers. 2. Insist on testability of ideas. You are teaching a science curriculum, and evolution is science. If opposing ideas arise, ask if they can be tested by observation or experiments. 3. Acknowledge ignorance. No-one knows all the answers; nor can science provide answers to all things. If you don’t know the answer, say so (but search for it later!) If science doesn’t yet have an answer or will never be able to provide one, say so. 4. Encourage discussion and thought. No subject is better suited than evolution to generate discussion and encourage independent thought. Use this to advantage. 5. Distinguish the goals of science and religion. Science and religion have different objectives and methods. Separate the two and you avoid many of the potential conflicts. 6. Enjoy yourself. Some teachers dread teaching evolution because they haven’t been trained in the subject, fear the controversy, and don’t know how to tackle it. Ironically, the subject is enormously rewarding for the same reasons. It is a never-stop-learning topic; it invokes intense interest in young minds; and it teaches one to think about ‘big’ issues. Conclusions ■ Evolution is a well-established fact, supported by multiple lines of evidence. ■ Science doesn’t answer all questions, especially moral, spiritual, philosophical and ethical ‘why?’
questions. ■ Science and religion cannot be used to test one another; their goals, methods and philosophies are far apart. ■ But they can be complementary, not antagonistic. ■ George Branch is Emeritus Professor in the Department of Zoology at the University of Cape Town. He is an ‘A-rated’ scientist and winner of the Gilchrist Gold Medal and the 2006 International Temperate Reef award for life-time contributions to marine science. He has spent a lifetime studying the shoreline of South Africa, and has published numerous scientific articles and books on the subject. He has spent decades teaching undergraduate and postgraduate zoology students, inspiring generations of young scientists and offering a balanced approach to the science of evolution. SUGGESTED READING Collins FS. The Language of God. New York: Free Press, 2006. (The perspectives of a Christian who led one of the groups unravelling the human genome.) Collins FS. Faith and the human genome. Perspectives on Science and Christian Faith 2003; 55: 142-152. (A brief summary of his views.) Miller KR. Finding Darwin’s God. New York: Harper Perennial, 2007. (A careful analysis of the controversies from someone who is both a Christian and an authoritative molecular biologist.) Pigliucci M. Denying Evolution. Creationism, Scientism and the Nature of Science. Mass., USA: Sunderland, 2002. (An exposé of the errors of creationism and the limits of science.) Bryson B. A Short History of Nearly Everything. London: Black Swan, 2004. (A magnificent popular guide to everything from the big bang to mankind. If you can afford it, luxuriate in the fully illustrated version.) Dobzhansky T. Nothing in biology makes sense except in the light of evolution. The American Biology Teacher 1973; 35: 125-129. (A succinct view from a leading evolutionist and Christian.) Bateman PW. and Moran-Ellis J. The science in the intelligent design debate: teach it like it is. South African Journal of Science 2007; 103: 271-273. (A concise review of intelligent design, advocating that it should be taught in our schools.) http://www.maropeng.co.za/index.php/exhibition_guide/ sterkfontein/creation_beliefs/ (The website of the Maropeng world heritage site, with a brief review of different religions and their creation beliefs.)
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Where we come from A Search for Origins: Science, History and South Africa’s ‘Cradle of Humankind’. Edited by Philip Bonner, Amanda Esterhuysen and Trefor Jenkins. (Johannesburg. Wits University Press. 2007.) The foreword to this book, by Phillip V Tobias, is called ‘The deep roots of history and prehistory around Sterkfontein, South Africa’. And this is what this book covers in exquisite detail. The ‘Cradle of Humankind’ is now listed as a World Heritage Site. This listing is a recognition of not only the site itself, but South Africa’s emerging status as a democratic nation. The World Heritage Sites fall under the United Nations Educational, Scientific and Cultural Organisation (UNESCO), which South Africa withdrew from in 1956 as the policy of apartheid became fully formed. South Africa rejoined UNESCO in 1994, when Nelson Mandela’s government brought us back into the international fold. This book tells the story of how human origins were uncovered in the Cradle area, which contains some of the richest fossil sites in Africa. Swartkrans, Sterkfontein and Kromdraai are almost household names among those who follow human origins. As Philip Bonner says in the introduction,
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the Cradle offers ‘… a privileged vantage point from which to understand what it means to be human and what it meant and currently means to be South African.’ And herein lies the strength of this book, which is separated into sections. Chapter 1 does not plunge us straight into palaeoanthropology. Saly Dubow takes a look at the history of South African sciences in terms of the growing understanding of human evolution over the past few decades. He describes how in South Africa, scientific and other forms of knowledge have always been bound up with views of national identity and belonging. In other words, how science was used, and misused, to prop up political idealism – in our case the justification for institutionalised racism. This theme of science in society continues through the book. In Part 2, the hominid fossils found in the ‘Cradle of Humankind’ and which span a period from three to four million years ago to around 500 000 years ago are described in Chapter 3, along with the plants that were common in the area at the same time. Chapter 2 introduces us to the start of palaeoanthropological research in South Africa and how it became a scientific discipline. Of course we had the discovery of the Taung child by Raymond Dart in 1925 and Robert Broom’s 1936 discovery of the adult fossil skull of Australopithecus transvaalensis, as it was called at the time. At the time, Broom thought that this area would yield still more discoveries that would add to the sum of our knowledge of human origins, and 56 years later the sites opened up by Broom have still not been fully excavated and as other sites in the Cradle are opened up, exciting discoveries are still being made. Chapter 4 introduces us to the contribution of genetic studies to the history of modern humans in southern Africa. Himla Soodyall and Trefor Jenkins discuss
the contribution of genomic research to our understanding of the relationship both between humans and other primates and to each other – important concepts in the understanding of the artificial constraints of ‘race’. Part 3 deals with the ‘Emerging stone age’. Amanda Esterhuysen starts the section with a discussion of the way that contemporary creationist opinion effectively prevented any real study of stone tools. It was not until the 1860s when the work of Charles Darwin, Charles Lyell and Thomas Huxley that archaeology was able to start to develop and with it early Stone Age studies. This led to the division of the Stone Age into its three divisions, based on the types of stone tools found at archaeological sites, along with the emergence of rock engravings, indicating growing social development among early humans. Part 4 explores the myth that this part of southern Africa was essentially vacant land – ready for settling, which it was by white farmers in the early years of colonisation. In fact, this area was densely settled – probably one of the most densely settled African societies in South Africa. As Philip Bonner says ‘… this deep history of African occupation experienced a double obliteration: the first one physical, the second intellectual.’ Part 4 attempts to explain how this occurred by examining the early Iron Age settlements, Tswana history in the area and finally the early Boer republics and the changing political forces that came with these. Part 5 tackles the so-called ‘racial paradox’ that must have troubled Smuts – as Philip Bonner suggests given Smut’s obvious intellectual range and accomplishment. The problem was that of ‘poor whites’ – how, when whites were obviously intellectually vastly superior to all other races, did these people require so much help? The section covers gold and all that it has meant to the history of South Africa, The South African War of 1899-1902 and poor whites and the Hartebeespoort Dam. This book is enormous in the scope of what it covers. Rather than simply telling the story of the palaeoanthropology of the Cradle area – interesting enough with its implications for human origins, Wits University Press have put together something that takes science beyond its pure form and into the implications that scientific discoveries have for society. This is particularly pertinent in South Africa today – 15 years into our new democracy with all the successes and problems that this has brought. Without this kind of understanding we cannot progress.
A singular man Tobias in Conversation: Genes, Fossils and Anthropology By Phillip V Tobias with Goran Štrkalj and Jane Dugard. (Johannesburg. Wits University Press. 2008.)
Botany in the garden Clivia: Nature and Nurture. By Dirk Swanevelder and Roger Fisher. (Pretoria. Briza Publications. 2009.) As people become more environmentally aware there is a growing attempt to fill our gardens with indigenous plants. For some of us who live in areas where the real indigenous species are not necessarily particularly attractive, it is good to be able to take from other areas of South Africa and still cultivate a hardy, attractive plant. Clivia species fill this role ably in many parts
of the country. I manage to grow them successfully on what is essentially reclaimed beach in Noordhoek in the Cape. This book apparently arose through a conversation with a professor of botany at the University of Pretoria, Bram van Wyk and, as you might expect from such beginnings, it is far from simply a book about the best way to clutivate clivias. The account of the species starts with its origins in geological time. The genus Clivia is part of the family Amaryllidaceae and the current hypothesis is that it originated in western Africa, while this part of Africa was still part of Gondwana. There is still some controversy about how the plant is pollinated – its form and colour suggest bird pollination, but an insect is also possible. However, the true pollinator is still under study. This is the strength of this book. The authors discuss everything about the genus – its origins, its biology and where it sits in the family Amaryllidaceae. There are text boxes that deal with interesting issues such as the molecular techniques that are used in taxonomy and ecology. The classification and nomenclature is outlined in a way that would readily complement any discussions about species and classification – helping to promote an understanding of systems of biological nomenclature. The text takes us through the different species in the genus and where they are found leading to the issue of conservation. It may be that gardens, particulalry if they mimic the natural environment of Clivia, will be a refuge for this genus because they are largely limited to the Afromontane forests and their remnants – which are themselves threatened biomes. The closing section of the book deals with growing Clivia and is a must for any gardener interested in this spectacular species that can be a feature in any garden. The text is beautifully illustrated with fullcolour photographs and illustrations, which include electron micrographs showing plant ultrastructure. It is altogether a ‘must have’ for anyone who loves our environment and enjoys learning about the world about us. Natural medicine Medicinal Plants of South Africa. By Ben-Erik van Wyk, Bosch van Oudtshoorn and Nigel Gericke. (Pretoria. Briza Publications. 2009.) This is the second edition of this popular book. As a medical doctor myself I am careful about interpretation of what is called ‘natural’ medicine, understanding that anything that has a pharmacological effect on the body may also have adverse
My copy of this book is signed by Phillip Tobias himself because I was lucky enough to be able to attend the Cape Town launch of a book that delves into the mind of an extraordinary man. Tobias’ autobiography, Into the Past, is a riveting account of the life of the man who was perhaps most instrumental in uncovering the secrets of human origins in southern Africa. That book clearly shows his enormous intelligence and finely tuned and enquiring mind – in his own words. Tobias in Conversation does this again – but this time in conversation with two other intellects – Goran Štrkalj and Jane Dugard – themselves no strangers to analytical thought. Tobias is not simply a palaeoanthropologist and medical doctor. He is a well-rounded man – what in previous eras would have been called a Renaissance man. In this book he has been asked to talk about himself, who he is, what he is and what he believes. One of Tobias’ lasting legacies to the University of the Witwatersrand was his fight against apartheid and racism in general in South African society. The interviews took place over a period of five years, which makes it all the more extraordinary that the book holds together so well. The reader is taken on a journey through the mind of a scientist and a philosopher and a humorous observer of society. Most well-known scientists are known only for their main achievements, so it is
illuminating when one has the opportunity to delve a little deeper into the processes by which the person became a groundbreaking achiever. What comes across most strongly is the pure energy with which Tobias has lived his life. And in this book, through his conversations, we see how his life unfolded – from his early times in Durban and his heartbreak over his sister’s death from diabetes – to his relationships with some of the greatest minds in evolutionary biology – from Raymond Dart to the Leakeys – and his admiration for Francisco Ayala (a Jesuit priest) who became an evolutionist after listening to a lecture by Dobzhansky. Now retired, Tobias has lost none of his intellectual energy, despite battling illness and increasing frailty. He continues to supervise post-graduate students and is still active in research. ‘Retirement is,’ he supposes ‘a necessary evil in our society.’ If you are looking for inspiration for yourself or for others, Tobias in Conversation should provide this in abundance. It is a journey through the mind of a man who has lived his life to the full and is a vivid description of how to blend scientific thought with other intellectual pursuits – a journey through the mind of a true ‘Renaissance man’.
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Birds and birding Pocket Guide: Birds of Southern Africa. By Ian Sinclair. [Cape Town. Struik Nature. 2009.)
effects. So these types of books must be used with caution and it is good to know that one of the authors, Nigel Gericke, is a medical doctor and another, Bosch van Oudtshoorn, is a pharmacist. However, having said that, this book is far from a self-help manual. It is instead a beautifully illustrated and carefully put together account of the wealth of medicinal plants that are found in South Africa. As is pointed out, plants were once the primary source of all medicines in the world and they still continue to provide new remedies. Their role in traditional healing is discussed, as are the parts of the plants that are used and how they are collected and stored. There is also a section on dosage forms and methods of preparation as well as methods of administration and the active ingredients. These sections allow an understanding of the process by which a medicinal plant actually becomes useful – it is not simply a matter of picking it and taking it. The plants themselves are described under a main heading of their scientific name, while the names in other languages are also given. There is a botanical description, a listing of the plant parts used, their medicinal uses, the preparation and dosage, the active ingredients and the pharmacological effects and distribution for each plant in the book. This is clear and easy to follow. My only slight concern is that some of the plants that are actively poisonous have not been more clearly marked as such. That said, I would recommend this book to anyone with an interest in the medicinal uses of plants.
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I first met Ian Sinclair in the early 1970s on a seawatching trip out of Cape Town – predictably enough in a howling southeaster, which meant that many of us were unable to use our binoculars effectively! Ian did not appear to be affected by seasickness, however, and was happily pointing out albatross and petrel species to an audience coming mainly from the northern hemisphere. When I moved permanently to Cape Town some years later, Ian was still on the scene and he is one of the best-known ‘birders’ in southern Africa, with years of experience and knowledge that make him the perfect author for this kind of book. Pocket guides are invaluable simply because they are easily carried, but they need to have the information that you require to identify a species to be really useful. And this one does. There is a brief description of the different habitats in which you will bird watch in South Africa, complete with a vegetation map. Then follows a useful ‘How to use this book’, a glossary and a diagram of the parts of a bird. Each species is shown as a clear photograph, alongside a brief description of the bird, a distribution map, its size and the months in which it breeds – and for the migratory species – the months in which you will see the species; a true birdwatcher’s handbook. Bird Calls for Beginners. by Doug Newman. (Cape Town. Struik Nature. 2008.) Doug Newman’s name is well-known in the birding fraternity and
he has developed a keen interest in helping people to enjoy bird watching in a number of different ways. And, as any bird watcher will know, there are times when all you hear is the call – very frustrating if you do now know the different bird calls. Not everyone has the opportunity to go bird watching with someone more experienced, so this little book will happily fill this gap. It contains a CD that features the calls of 60 common birds and presents full-colour photographs of the birds, their distribution and text about their habits and feeding and nesting routines.
Creepy crawlies My First Book of Southern African Insects. By Charmaine Uys, illustrated by Sally MacLarty. (Cape Town. Struik Nature. 2009.) Field guides to insects are rare. Those for a younger audience are particularly unusual. So this book is a welcome addition to the literature on our natural world, aimed specifically to encourage an interest in insects from an early age. Another particular feature is that the book is in English, Afrikaans, Zulu and Xhosa – making it a particularly useful teaching resource. The book is illustrated with large, fullcolour drawings of the different insects, along with their larvae where appropriate. There is a brief description of the insect, along with a diagram showing whether it is nocturnal or diurnal, what it eats and its size in relation to a matchstick. Each page of the book has the Afrikaans, Zulu and Xhosa wording clearly marked in different colours, making the book particularly easy to use.
Q Diary of events Shows and exhibitions Iziko Planetarium, Cape Town School Programme 2009 Iziko has programmes for all school grades. Grade R to Grade 3 Davy Dragon and the Planets (English) Dawie Draak en die Planete (Afrikaans) U Davy Dragon kunye nee Planets (Xhosa)
One day something fell right onto Guinea Minnie’s head. She and her feathered friends try to discover what it was. Content: What is visible in the night sky. Basic characteristics of the sun, moon, stars and planets of our solar system. Grade R to Grade 5 Michael Lion & the Star Pictures (English only)
Look back in time over 15 billion years to the edge of the observable universe. Learn about the structure and components of the universe and learn to recognise the star patterns we see with the naked eye. Grade 8 and older A basic guide to Stargazing (English only)
Drawings by Tony Grogan In this 45-minute presentation we give you a basic understanding of the night sky and how it changes throughout the year. We introduce some easily recognisable constellations, explain the nature of stars and the galaxy in which we live and give basic information on using binoculars and small telescopes. Davy Dragon tries too hard to fly and gets lost among the planets. The planets try their best to help him find his way home again. Content: all the planets of our solar system and their basic characteristics. Grade 2 and older Imimangaliso Yesibhakabhaka (Xhosa only) Le yimigaqo kwabo baqalayo ukufunda ngesigbhakabhaka nonxulumano phakathi komhlaba, iinkwenkwezi kunye nezinye iiplanethi. Ikwayingcaciso emfutshane ngembali yomatshini oyi – telescope kunye nokuhlolwa kwenyanga. Grade 1 and older Umlilo Esibhakabhakeni (Xhosa only) U tatomkhulu ufundisa u Sipho no Thandi ngesibhakabhaka nokuqulathwe siso. Isiqulatho: Iimpawu zemo yelanga, inyanga iinkwenkwezi kunye nezijikelezi-langa. Grade R to Grade 4 Guinea Minnie & the Piece of Sky (English) Tobie Tarentaal & die Stukkie Lug (Afrikaans)
Michael, a little toy lion, and his friend, Bertie Bug, leave their home in the toy room and go on a magical quest to the stars. Content: star constellations and their identification; sky legends and the origin of the legends. Constellations – Orion, Canis Major, Canis Minor, Scorpius, Leo. Grade 6 to Grade 8 Journey to the Stars (English) Reis na die Sterre (Afrikaans) This programme examines the different kinds of stars within our galaxy, the Milky Way. We look at the Sun, Alpha Centauri which is a multiple star system, Sirius the double star and Betelgeuse, a red giant. The life cycle of a star is shown, as well as the constellations of the Southern Cross, False Cross and Orion. There is also some discussion on galaxies. Grade 8 and older 15 Billion BC (English) 15 Miljard vC (Afrikaans) 15 Billion BC (Xhosa)
Grade 8 and older Table Mountain (English only)
This programme explores the remarkable geology of Table Mountain which started several hundred million years ago with the shifting and colliding of continents. Table Mountain is the only geographical feature on Earth to be represented by a constellation in the sky. We examine this constellation Mons Mensa, the Southern Cross, Herschel's Jewel Box, etc. Grade 11 and Grade 12 Astronomy of the Great Pyramid (English only)
Quest 5(3) 2009 51
Diary of events Q
The largest of all the pyramids in Egypt – the Great Pyramid of Khufu – contains an elaborate system of shafts. At the time the pyramid was built, these were directed towards the most important stars in the sky. These alignments are demonstrated and recent speculations explored. Booking procedure for schools and collages n Phone the Planetarium, 021 481 3823 weekday mornings 08:30 – 13:00 to secure a booking. n A detailed letter of confirmation will then be sent to you. n You will be required to pay for your booking at least 10 days before the date booked. Please note – we cannot accommodate spontaneous arrivals. For adults THE SKY TONIGHT ONGOING
An interesting live lecture on the current night sky is presented every Saturday and Sunday. You will receive a star map and be shown where to find the constellations and planets that are visible this month. Saturday – 13:00 Sunday – 13:00 Suitable for teenagers & adults. THE LONGEST DAY
Days come and go and we take them for granted. But an outside force is putting a brake on the Earth's spin and the days are getting longer. Life on Earth will have to continue to adapt to the lengthening of the day, until we finally reach... the longest day. Until 6 December, Monday to Friday – 14:00 Tuesday evening – 20:00 (& sky talk) Saturday – 14:30, Sunday – 14:30 Suitable for teenagers & adults. PLANETARIUM ENTRANCE FEES Adults: R20,00; Children: R6,00; Adults (children’s show only): R10,00; SA Pensioners & Students (with cards): R8,00 The Planetarium reserves the right to change or cancel advertised shows without prior notice. The Iziko Planetarium is closed for maintenance on the first Monday of the month, excluding school holidays.
Talks, outings and courses Botanical Society of South Africa, Limpopo: Walk and talk: Makhado Sweet Bushveld 10h00 Zulani Safari Lodge Gordon and Elizabeth Brace will be hosting BOTSOC at their lodge and sharing their knowledge of biodiversity. Both are FGASA and THETA qualified guides. Overnight accommodation can be arranged at an additional cost. Please bring own picnic lunch. Members free. Non members R20. (21 Nov 2009) Contact: Contact: Elizabeth on Tel/Fax: 015-593-0212 or Email: firstname.lastname@example.org Walk and talk: Zulani Safari Lodge. Makhado Sweet Bushveld. 10h00 Gordon and Elizabeth Brace will be hosting BOTSOC at their lodge and sharing their knowledge of biodiversity. Both are FGASA and THETA qualified guides. Overnight accommodation can be arranged at an additional cost. Please bring own picnic lunch. Members free. Non-members R20. (21 Nov 2009) Contact: Elizabeth on Tel/Fax: 015-593-0212 or Email: email@example.com South Africa’s Birding Big Day 2009 More than 15% of South Africa’s birds are listed in the Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland, with many requiring urgent conservation interventions. BirdLife South Africa currently has several vitally important projects which aim to improve the conservation status of our threatened birds, including albatrosses and petrels, the African Penguin, bustards and korhaans and the Southern Bald Ibis. This year, 50% of all funds raised during Birding Big Day will go towards BirdLife South Africa’s Bustard Working Group and
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the Southern African Bird Atlas Project 2, ensuring that your participation makes a positive difference to bird conservation in South Africa. There are lucky draw prizes for all categories valued at over R100 000, which include weekend getaways, books, guided tours and much more! The winners of each category will receive certificates of recognition and Birding Big Day cloth badges will also be issued to all participants who raise R250 or more for BirdLife South Africa's work. (28 Nov 2009) Contact: Sadie Halbhuber on +27 (0) 11 789 1122 or e-mail firstname.lastname@example.org
Diarise n World Diabetes Day, 14 November 2009. The theme for World Diabetes Day for 2009-2013 is Diabetes Education and Prevention. This broad and long-term theme will allow all diabetes stakeholders to take part in the campaign. The broadest possible alliance of stakeholders is required to make World Diabetes Day a global success. World Diabetes Day is an official United Nation’s World Health Day. It is celebrated every year on 14 November. The date was chosen because it marks the birthday of Frederick Banting, who, along with Charles Best, is credited with the discovery of insulin in 1921. World Diabetes Day was created by the International Diabetes Federation (IDF) and the World Health Organization (WHO) in 1991, in response to concern over the escalating incidence of diabetes around the world. The International Diabetes Federation leads the World Diabetes Day campaign – develops the themes, runs the global website, creates all the materials and drives the global outreach. n World AIDS Day, 1 December 2009. The World AIDS Day theme for 2009 is 'Universal Access and Human Rights'. World AIDS Day is important in reminding people that HIV has not gone away, and that there are many things still to be done. According to UNAIDS estimates, there are now 33.2 million people living with HIV, including 2.5 million children. During 2007 some 2.5 million people became newly infected with the virus. Around half of all people who become infected with HIV do so before they are 25 and are killed by AIDS before they are 35. Around 95% of people with HIV and AIDS live in developing nations. But HIV today is a threat to men, women and children on all continents around the world.
Q CSIR News CSIR laser scientist scoops prestigious James Moir Award The South African Chemical Institute (SACI) has awarded one of the CSIR’s brightest young minds, laser researcher Itumeleng Paballo Tshoke, the prestigious James Moir Medal. The James Moir Medal is awarded by SACI to the best BSc Honours and BTech students in chemistry at a university and university of technology, respectively, achieving a minimum aggregate final-year mark of 75%. Tshoke passed her degree cum laude with an average of 79% to become the first student in 15 years to receive the award at the Tshwane University of Technology (TUT). She says the fact that it took so long for this award to be bestowed again upon someone at TUT shows how difficult it is to achieve. ‘It is truly an honour for me to be that person who persevered through various challenges to finally obtain this award,’ she says. ‘I hope that other TUT chemistry students will believe that it’s possible to achieve anything through prayer, hard work and determination.’ Tshoke’s research at the CSIR focuses on a therapeutic cancer technique called photodynamic therapy (PDT). She explains that PDT is a non-invasive cancer treatment; a treatment modality whereby light is absorbed by light-sensitive drugs to destroy cancerous tissue while causing minimal damage or harm to healthy tissue. These drugs can either be ingested or applied topically and once in the bloodstream, they then accumulate in the cancerous tissue. It is at this point that a beam of light is applied to the cancerous tissue and the drug absorbs the light and produces a form of oxygen, which kills off the cancerous or unhealthy tissue. Cancers that can be treated through PDT include metastatic breast tumours, bladder tumours, gastric cancer and others. Tshoke obtained her BTech degree at the TUT and is pursuing her Master’s in chemistry at the same institution.
The Sun Microsystems hybrid supercomputer.
Centre for High Performance Computing puts new supercomputer into operation The Centre for High Performance Computing (CHPC) has launched phase 2 of its operations. The latest addition to its facilities is the Sun Microsystems hybrid supercomputer. The Minister of Science and Technology, Mrs Naledi Pandor, was the guest of honour at the launch event, which took place on 8 September 2009 at the CHPC in Rosebank, Cape Town. The event was hosted by the CSIR (Council for Scientific and Industrial Research). Dr Sibusiso Sibisi, CSIR President and CEO, noted, ‘Through the addition of this Sun Microsystem hybrid supercomputer, the CHPC has become a facility that holds its own among the best in the world. It is a resource, along with the other elements of the unfolding national cyberinfrastructure, which provides us as South Africans with the tools and infrastructure to tackle major challenges collaboratively, by drawing on our own and international expertise.’ This new supercomputer provides a variety of platforms for the local and regional research community that grapples with challenges in the domains of climate change, energy security and human health. Its powerful capacity will support research in pursuit of solutions to, for example, global warming, and to finding safe and reliable energy sources, and cures for or prevention of communicable diseases. The CHPC is managed by the Meraka Institute of the CSIR. The supercomputer has been installed in the CHPC’s newly refurbished data centre. Green computing interventions have been included in the design and construction of this facility.
The Sun Microsystems hybrid computer complements the existing supercomputers, notably the IBM (e1350) Linux-based cluster and the Blue Gene®/P system. Technical specifications With a peak performance of 31 trillion calculations per second, the Sun Microsystems hybrid supercomputer is the fastest in Africa and ranks among the top 500 supercomputers in the world. At the core of this computing power is a Sun SPARC Enterprise® M9000 server with 64 SPARC64® VII quad-core processors, and a cluster of four Sun Blades 6048 modular systems. This was delivered in two stages. Stage one consisted of one Sun Blade 6048 modular system with 48 blades based on Intel® Xeon® E5450processors; stage two consisted of three Sun Blade 6048 modular systems that house 144 blades based on the next-generation Intel® Xeon® processor (code named Nehalem). At the front-end, the CHPC has the Sun visualisation system, which allows users to assemble and view 3D models of their data. The open storage solution is based on 10 AMD Opteron-powered Sun Fire X4540 open storage servers, providing half a petabyte of data with the Lustre parallel file system for extreme input/ output performance and reliability. Rounding out the hardware part of the solution, all the components will be connected via a Voltaire Infiniband switch. Software for the solution consists of Sun HPC software, Linux Edition, SunVM Ops Center and software from Totalview. The new machine is fully integrated into the CHPC platforms through an intelligent resource management system, MOAB, making it easier for users to choose a relevant platform for their computation.
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Q ASSAf News
organisation, founded in 1983 in Trieste, Italy, by a distinguished group of scientists from the South under the leadership of the late Nobel Laureate Abdus Salam of Pakistan. Its mission is to promote scientific excellence and capacity in the South for the purposes of advancing sustainable development. TWAS operates under the administrative umbrella of UNESCO and receives generous core funding from the Italian government. Currently it has more than 900 members from 100 countries. Nearly 85% of its members live and work in developing countries.
Open Access first for South African Journal of Science
The winners of the Minquiz finals.
ASSAf sponsors Minquiz finals The Academy of Science of South Africa cosponsored the Minquiz 2009 finals, an annual national science competition for grade 12 learners. The event was hosted by Mintek in Randburg on 24 July 2009. The Academy sponsored the event by offering one-year QUEST gift subscriptions to learners in the top three winning teams. QUEST also exhibited at the event, which was well attended by learners and educators from the nine provinces. Limpopo province was the overall winner, with the Eastern Cape and Gauteng coming in at second and third place respectively. The winners walked away with cash prizes and learners from the Limpopo province each received a halfounce Kruger Rand, sponsored by Rand Refinery Limited, valued at approximately R4 000. All learners who participated in the finals received a certificate of participation. The Minquiz competition aims to encourage learners to pursue careers in science, engineering and technology, with the main focus being minerals and metallurgy. The Academy is proud to be part of an initiative that aims to encourage young people to pursue careers in science.
ASSAf reaches out to learners and educators Members of the Academy of Science of South Africa (ASSAf) presented mentorship lectures to learners and educators in the Free State, Eastern Cape, Mpumalanga, and KwaZulu-Natal provinces during the recent National Science Week. The National Science Week is an initiative by the Department of Science and Technology (DST), through the South African Agency for Science and Technology Advancement (SAASTA), which aims to celebrate science. It involves various stakeholders from government, private and non-profit sectors of
society who conduct and exhibit multiple sciencebased activities during the week. This year, the National Science Week ran from 1-8 August 2009 simultaneously at multiple sites in all nine provinces. Through ASSAf’s regional mentorship lecture approach, targeting learners and educators alike, scientists were able to interact with learners, to provide guidance on science-based careers, and understand some of the challenges that are facing educators within the science system in South Africa. This provided an opportunity to increase the awareness of ASSAf among learners, educators, and other key stakeholders.
TWAS conference approaches Preparations for the Academy of Sciences for the Developing World (TWAS) 11th General Conference to be hosted by ASSAf at the International Convention Centre (ICC), Durban from 19-23 October 2009 are well underway. Over 400 TWAS Fellows and invited guests are scheduled to attend what promises to be a momentous event. The theme for this year’s conference is ‘Science for Africa’s Development’. Other symposia in which South Africa will feature strongly are those on ‘Astronomy in Developing Countries’ and ‘S&T Education for Development’. The programme features a large number of invited presentations from distinguished scientists such as Michael Atiyah, whose lecture is titled ‘Truth and beauty in mathematics and physics’, as well David Block and Monty Jones. The presence of a large number of eminent scholars in the country has prompted the DST, through the South African Agency for Science and Technology Advancement (SAASTA), to mount a ‘Meet the Scientists’ initiative, which will connect TWAS fellows with teachers and learners in three KwaZulu-Natal centres in an attempt to promote science and careers in science among Grade 11 learners. TWAS is an autonomous international
The South African Journal of Science (SAJS) is one of the first South African journals to be hosted on the fully Open Access platform, SciELO South Africa. This represents a major achievement in South Africa that will benefit researchers and scholars in providing a freeto-publish, free-to-access platform for the best scientific thinking the country has to offer. SciELO focuses on developing countries where few end-users have access to traditional peer-reviewed academic journals either online or in print form. Access to journals is subscriptionbased and can be very expensive. Only certain libraries carry them, meaning that there have been severe restrictions in accessibility and affordability up to this point. The Open Access platform for these journals aims to combat these restrictions, while simultaneously enhancing the international visibility of South African research. Open Access publishing allows research literature comprising academic peer-reviewed journals, conference papers and theses to be placed in an online portal from which they can be downloaded for use. The authors do not have to pay any type of publishing fee. However, it is important to realise that Open Access by no means equates to ‘self-publishing’ – all articles conform to the traditional process of journal publishing, entailing critical reading by several peer-reviewers who ensure that a rigorous standard of research is upheld. Open Access publishing merely makes these research results available and affordable to a wider audience. The initiative is led by Susan Veldsman, a specialist in the field of Open Access and Director of the Scholarly Publishing Unit at the ASSAf. She has been working in the information science sector for over twenty years, with a recent focus on Open Access journals. The implementation of this open and freely accessible online journal platform has been pioneered by the Scientific Electronic Online Library (SciELO) project, based in Brazil. Fully indexed, it has been successfully implemented in eight countries, mostly in Latin America, with others being in the developmental phases. SciELO South Africa is the first site of this growing system on the African continent. Visit www.scielo.org.za.
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Q Back page science Greenland's melting ice threatens India’s monsoon As Greenland’s ice sheet melts, it could make India’s monsoon much weaker and subject the subcontinent to an endless drought. How can this happen? Well, according to Bhupendra Nath Goswami, director of the Indian Institute of Tropical Meteorology (IITM), as the ice sheet melts and more fresh water is added to the North Atlantic, the ocean’s salinity will fall. That in turn could weaken both the circulation of the ocean’s waters and temperature variations over the Indian subcontinent – and these two key factors could also weaken the Indian summer monsoon, says Goswami. Some studies by the IITM have indicated that the monsoon is already weaker than it was, and the weather is becoming more and more difficult to predict. If Goswami and his fellow researchers are correct, Greenland’s melting ice sheet – many thousands of kilometres away from India, could change that country’s weather – affecting food production and other sectors. Source: SciDev.Net (http://www.scidev.net/en/)
NASA's Orion spacecraft passes significant design milestone
The Orion capsule could take astronauts to the moon and back. The National Aeronautics and Space Administration is closer to building the next crew exploration vehicle by completing the Orion Project's preliminary design review, or PDR. Orion is being designed to carry astronauts to the International Space Station and other destinations. The PDR is one of a series of checkpoints that occurs in the design life cycle of a complex engineering project before hardware manufacturing can begin. As the review process progresses, every detail of the vehicle's design is assessed to ensure the overall system is safe and reliable for flight and meets all NASA mission
Dunlop from dandelions?
requirements. The Orion features a capsule-shaped crew module designed for maximum crew operability and safety, a service module housing utility systems and propulsion components and a launch abort system for improved astronaut safety. The preliminary design review evaluated the vehicle's capability, as currently designed, to support three types of missions: flights to the International Space Station, week-long missions to the moon and missions to the moon for up to 210 days. Source: NASA
Improving crash performance Crash tests used by car manufacturers often produce startling results but a new simulation process that factors in deformation during production can predict the results of a crash test more accurately than ever. There are key components that save lives: if a car rolls over during an accident, the ‘Bpillar’ plays a major role. It forms one of the connections between the floor and roof of the vehicle and is designed to prevent the passenger cell from deforming. The materials from which the B-pillar is manufactured therefore need to meet very exacting requirements; to save fuel they need to be ultra-lightweight but tremendously strong and unbreakable. But what does the optimum component actually look like? Usually, car manufacturers have run test after test in order to refine designs and manufacturing processes, which can actually damage the materials, but now Fraunhofer researchers are providing further impetus to development. Says Dr. Dong-Zhi Sun, group leader at the Fraunhofer Institute for Mechanics of Materials IWM, ‘A B-pillar, for instance, goes through a complicated manufacturing chain and as it is deformed and stretched, minor damage such as pore formation may occur. With our failure model, we can simulate manufacturing processes more effectively and precisely model and analyse the deformation of the component during manufacture’. The engineers combine the results of the process simulation with a crash simulation, which is conducted using a newly developed material model. The new method enables components with optimum properties and improved crash performance to be developed. ‘Unlike conventional crash simulations, we can predict far more accurately how extensively the component will deform during the crash before it fails,’ says Sun. Source: Fraunhofer-Gesellschaft
Dandelion rubber in the greenhouse. Anyone who has picked dandelions as a child will be familiar with the white liquid that seeps out of the stalks as you break them off. Viscous, sticky – and a much sought-after material: natural latex. Around 30 000 everyday products contain natural rubber – car tyres being just one of them, and the bulk of this material comes from rubber trees in Southeast Asia. Now, however, a fungus is creating concern for rubber cultivators and if the fungus disease were to reach epidemic proportions, chemical crop protection would be rendered useless – and experts fear that the natural latex industry could collapse if that were to happen. Researchers are therefore turning to other sources – such as the Russian dandelion. Once it is cut, latex seeps out, but it’s difficult to use as it changes its composition immediately and cannot be used. Scientists from the Fraunhofer Institute for Molecular Biology and Applied Ecology (IME) in Aachen have now come a step nearer to largescale rubber production from dandelions. ‘We have identified the enzyme responsible for the rapid polymerisation and have switched it off,’ says Prof. Dr. Dirk Prüfer, head of department at the IME. ‘If the plant is cut, the latex flows out instead of being polymerised. We obtain four to five times the amount we would normally. If the plants were to be cultivated on a large scale, every hectare would produce 500 to 1 000 kilograms of latex per growing season.’ The dandelion rubber has not caused any allergies so far, making it ideal for use in hospitals. In the lab the researchers have genetically modified the dandelion. Their next step will involve cultivating the optimised plants using conventional breeding techniques. In around five years, Prüfer estimates, they may well have achieved their goal. Source: Fraunhofer-Gesellschaft
MIND-BOGGLING MATHS PUZZLE FOR Q uest READERS Q uest Maths Puzzle no. 11
Win a prize!
1 1 1 If __ = __ + __ where A and B are 3 A B different whole numbers, what is the value of A + B ?
Send us your answer (fax, e-mail or snail-mail) together with your name and contact details by 15:00 on Friday, 13 November 2009. The first correct entry that we open will be the lucky winner. We’ll send you a cool Truly Scienctific calculator! Mark your answer “QUEST Maths Puzzle no. 9” and send it to: QUEST Maths Puzzle, Living Maths, P.O. Box 478, Green Point 8051. Fax: 0866 710 953. E-mail: email@example.com. For more on Living Maths, phone (083) 308 3883 and visit www.livingmaths.com.
Solution to Q uest Maths Puzzle no. 10 1. AMTUVWY=symmetry about vertical axis 2. BCDEK=symmetry about horizontal axis 3. FGJLNPQRSZ=no symmetry
4. HIOX=symmetry about both axes. (Depending on the font and the way you write down certain letters, there would be alternative answers)
Quest 5(3) 2009 57