I, Science THE SCIENCE MAGAZINE OF IMPERIAL COLLEGE
EARTH
Contents Editoral 2 Science News 3 Facts ABOUT EARTH 4 An Unexplored World 5 Living in an Insectless World 7 The Reptiles that rock our world 10 Do Aliens live among us? 11 Our Sun: A Ball of Weather in Our Sky 13 The Story of a Lonely Planet 15 Are We the Special Ones? 17 mOVING HOUSE IN THE SOLAR SYSTEM 19 Mass Extinction on the horizon 21 The Secret Science HIDDEN IN STORIES 23 SEX AND TABOOS 25 HUMANS AND THE ALMIGHTY WATCHMAKER 27 Searching for the Elixir of Life 29
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Dear Reader, Wherever you are, and whatever you are doing as you read this, you are spinning through space at 1600km/hr on a lump of rock which is orbiting a star we call the Sun at a speed of 107,000km/hr. This lump of rock you are on does not seem all that special when we look at it from a distance. Within our own solar system, Earth is not the biggest planet, and nor is it the smallest. It is not closest to our sun, and it is not furthest away. Like other rocky planets, Earth has mountains, volcanoes, earthquakes, and weather, but Earth is special to us beyond all other planets, for the obvious reason that it is the planet we call home. We, and all living things on this planet, are Earthlings. We owe an awful lot to this little planet that is hurtling through space. Earth has grown life as if in a cradle, occasionally it has had tantrums and bashed continental plates together, or spewed out some lava, or had massive storms and nearly wiped life out, but always it has managed to return itself to the state needed to sustain life. Earth lived through fiery days where volcanoes erupted frequently, the freezing cold which came during Ice Ages and saw the dinosaurs rise to power only to be wiped out, showing just how fragile life can be. At some point during Earth’s life, humans evolved. They travelled across the Earth, settling down and finding ways of coping with new climates. They formed communities, they fell in love, they had children, and their children had children, and one day, the humans started to poison the Earth on which they were dependent. The poisoning never stopped, and Earth started to become sick, and then sicker and sicker, and still the humans did not stop, but maybe it is not too late for Earth to be healed. This is where we are today, we stand on the edge of irreversible damage to our planet’s climate which could wipe out all life, including humans. We owe so much to this planet, it has given us everything we have, and we are returning very little. That is why we decided our first issue would be the Earth Issue; to celebrate our planet, to showcase just why it, and life upon it, is so special, and to hopefully inspire you, our readers, to take action and help heal our planet. Read on and join us in celebrating our planet as we all journey around our Sun and spin through space, together.
Aoife & Jacqueline
Image [background]: CĂŠleste Nilges
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heAlth ineQuAlitieS in the uk On the riSe
chineSe ScientiSt
By Madeleine Openshaw
puSheS ethicAl BOunDArieS
Researchers here at Imperial College London have found that the gap between the life expectancy of the richest and poorest sectors of society in England is increasing. The research, funded by the Wellcome Trust and published this week in the journal Lancet Public Health, analysed 7.65 million death records in England between 2001 and 2016. The study also found that the most deprived communities are now seeing no life expectancy gain at all, in what researchers describe as a “deeply worrying” trend.
By Gina Degtyareva
A Chinese scientist has helped create the world’s first genetically edited babies. The news has sent shockwaves through the scientific community, many calling it ‘premature’ and ‘human experimentation’. He Jiankui says he used CRISPR technology to alter a gene in a fertilised egg. The edit is intended to make the offspring, in this case twins, resistant to HIV infection. Research of this nature is banned in most countries and highly controversial, as the edit will exist in future generations.
MeDicAl MAriJuAnA hAS Been MAppeD
By Christine Parry The genome of the cannabis plant has been mapped in a world-first, identifying the origins of the cannabis ‘high’ and paving the way to breed better medicinal cannabis. The project from the University of Toronto was published in the journal Genome Research, and located the genes for the psychoactive constituent THC and the non-psychoactive, but medicinal CBD, and discovered these genes share an ancestral gene long ago in evolution. This genetic map will assist future research to breed cannabis strains for medicine by disrupting the THC gene and increasing medicinal CBD content.
MARS’ SECRETS COULD BE INSIGHT
By Harry Lampert
As of November 26th, the family of Mars-based robots have a new friend. InSight is the latest man-made DiScOVery BrinGS uS clOSer object to be sent to the red planet, but unlike its predecestO treAtinG AlZheiMer’S DiSeASe sors it is not a rover. InSight is a stationary laboratory which By Dani Ellenby can peer inside the planet, measuring the seismology and heat flow. Its mission? To seek out new information on Californian scientists have found that neurones in the brains the formation of rocky planets; to boldly go where of patients with Alzheimer’s disease contain altered forms of the no rover has gone before. gene APP. Scientists have long known that the APP gene is linked to the toxic accumulation of certain proteins, but they now know that the gene is changed at the molecular level to give rise to thousands of variants of the gene. Each genetic variant is formed by recombination, a process which involves sections of the gene being copied and re-inserted back into the genome by an enzyme called reverse transcriptase. Drugs that target reverse transcriptase could be used to block this gene recombination, potentially providing a novel treatment for the disease.
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Science News
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eArth triViA Images: Katy Pallister
It is estimated that more than 99% of all species that have lived on the Earth are extinct, with with estimates of the number of extant species ranging from several million to one trillion. While Mt Everest is well known as the higest altitude on Earth, when measured from base to tip the tallest mountain is actually Mauna Kea in Hawaii, although most of it is found underwater. Meanwhile, the furthest point from the Earth’s centre is the peak of Chimborazo, in Ecuador, due to the non-spherical shape of the planet. Lake Vostok is Antartica’s largest subglacial lake, with the lake surface living some 4kilometres below the ice sheet and 500m below sea level. This places its surface around 70 metres below the Dead Sea, the lowest land surface on Earth. Of all the estimated 100 billion planets in our galaxy, Earth is the only one known to contain and sustain life. Most volcanoes on earth lie beneath the ocean’s surface, but an estimated 1500 have been active on land in the past 10000 years. The Mariana Trench is the deepest place on Earth. It is a 2,550 kilometres long trench naturally carved into the Earth’s crust under the Pacific. Its deepest point has been measured at 10994 metres below sea level. The Grand Canyon in California runs 446 kilometres long, and has been carved out by the Colorado River to a maximum depth of 1875 metres. Due to its length and steepness, it takes two months to hike the entirety.
13700 BILLION YEARS AGO: START OF UNIVERSE - THE BIG BANG 4
An uneXplOreD WOrlD In the Age of Exploration from the 15th to 17th century, every expedition was a venture into the unknown. European explorers would set sail and return with strange spices, fruits, and animals, and talk of lands covered in snow or where the sun never sets. Since then, humans have travelled to the tops of the tallest mountains and to the depths of the deepest waters. So, is there really much of our Earth left to explore? In modern times when we think of exploration we tend to look up; up at the stars and galaxies and universes that all remain to be discovered. We have entered a new Age of Exploration, the Age of Space Exploration. But in doing so, are we overlooking the unexplored areas of our Earth? We currently know more about the surfaces of Mars, Venus, and Jupiter than we do about our own oceans. But with new technology we can now explore these oceans and make exciting discoveries here on Earth.
It wasn’t until 2012 that humans first travelled to the bottom of the Mariana Trench, the deepest point in our oceans. Since then, expeditions to the Mariana Trench have encountered fields of fluffy spheres, transparent ghost fish, and, in 2017, the deepest recorded fish; the Swire’s snailfish at a depth of nearly 8,000 metres. It is thought that at any deeper than 8,200 metres, a fish wouldn’t be able to withstand the de-stabilising effect the enormous pressure would have on its proteins. Deep sea dives across the planet are uncovering creatures beyond our imagination; a ghostlike octopus off the coast of Hawaii, a faceless fish off the coast of Australia, a Game of Thrones brittle star in the waters of New Caledonia, and ‘zombie worms’ in Monterey Bay. All deep-sea creatures have evolved incredible adaptations that allow them to live at extreme depths. Most are bioluminescent and produce their own light. Some have no eyes, some are
jelly-like, and others are partially calcified. We don’t need to look to space to find weird and wonderful creatures, they are already dwelling on this planet, beneath our ocean’s surface. Ocean discoveries are even challenging things we thought we knew about the world around us. The discovery of a thriving ecosystem around a hydrothermal vent along the Galapagos Rift challenged the idea that life at the bottom of the ocean could only exist by food drifting down from the sunlit surface. This community was surviving because of certain microbes’ ability to convert carbon dioxide from the ocean into food for themselves and their hosts, a process known as chemosynthesis. This discovery made it clear that life without sunlight could exist. New satellite and mapping data challenged the assumption that
Image: May Vilailuck
4560 MILLION YEARS AGO: FORMATION OF OUR SOLAR SYSTEM AND THE PROTO-EARTH 5
Gone are the days of setting sail to ‘discover’ new lands. Sadie Sweetland explores what remains undiscovered on Earth.
there are seven continents when it uncovered the world’s eighth continent in the southern Pacific Ocean. Part of the Pacific Ocean sea floor makes up 94% of this newly assigned continent, though it also includes New Zealand, New Caledonia, Lord Howe Island, and Norfolk Island. Scientists have suggested that the hidden section detached from Australia and sank to the sea floor between 60 and 85 million years ago. Only this year, a new ocean zone named the Rariphotic Zone was discovered off the coast of Bermuda in waters thought to have been relatively well studied. This zone runs between depths of 130 and 300 metres and was found to be home to more than 100 new species (2). Even in shallow waters there are discoveries to be made. Scientists have suggested that this new knowledge means there could be more ocean species, and a greater variety, than previously imagined.
“It has always been science which has underpinned exploration.” We have only explored 20% of our oceans but still have uncovered unimaginable wonders. Who knows what might still be lurking down there waiting to be discovered? We don’t need to leave land to make discoveries however. There are still parts of our terrestrial Earth to uncover, and new species and organisms to be found. Even within the last year there have been some
amazing findings. The Tapunali orangutans of Sumatra were recorded as a new species almost 100 years after scientists first heard rumours of their existence. Of the three different orangutan species, the Tapunali are the most endangered, with a population of less than 800. When observing the army ants Eciton mexicanum, a tiny beetle the exact colour and shade of their abdomen was spotted. This beetle, known as Nymphister kronaueri, attaches to the ants so that they can travel with them to feed. In Japan, where flowers are thought to be well documented, a new species of plant called the Sciaphila sugimotoi has been found. It is heterotrophic, meaning it gets its food from other organisms, and in this case, the planet feeds from the roots of fungi. As it has only been found in two places, it is thought to be critically endangered. These recent discoveries are proof of how much exploration can still be done on Earth. It is estimated that 90% of species on Earth are yet to be discovered by humans, although many of these will become extinct before they are even found. Many more discoveries remain waiting in the unseen areas of our world. The Vale do Javari region of Western Brazil, which is virtually unexplored by the Western world due to dense rainforest, is home to at least 14 of the Amazon’s uncontacted tribes. So too is the Darien Gap, an area of jungle that separates the Pan-American Highway in Panama from Colombia; the Ganghkar Peuensum mountain
in Bhutan, the highest, unclimbed mountain in the world; and North Sentinel Island in the Bay of Bengal, home to the Sentinelese people who are among the last people in the world to be untouched by modern civilisation. Like the ocean floor, we know very little about Earth’s cave systems. Humans have explored about 30,000 kilometres of cave passages around the world, but it is estimated that there are 10,000,000 kilometres of passages still to be explored and mapped. San Doong Cave, the world’s largest cave, is so big it even contains its own river, jungle, and weather system. The deepest cave in the world, the Krubera Cave in Georgi, is so deep it would take several weeks to reach its lowest point. Exploring these caves is comparable to exploring new worlds, as they hold minerals and species that have evolved in isolation from the rest of the Earth. Many animal species that live in cave systems have evolved to lose their eyesight as it is unneeded in the dark depths of the Earth. For modern day explorers, the journey of discovery isn’t over. Why, though, is it important that we push to find these unexplored worlds? The answer is science. Who knows what materials and compounds are waiting to be discovered in places like the jungles of Western Brazil and the trenches of the South Pacific Ocean? As Paul Smith from Kew Gardens has said, “It has always been science which has underpinned exploration.”
4400 MILLION YEARS AGO: FORMATION OF THE MOON: A MARS-SIZED PLANET NAMED THEIA IS THOUGHT TO HAVE COLLIDED WITH THE PROTO-EARTH, AND THE MOON FORMED FROM THE DEBRIS 6
liVinG in An inSectleSS WOrlD
Insects are generally despised by humankind, but could life continue on our planet without them? Skylar Knight ponders this question.
In many mythologies the coming of locusts is a sign of the impending apocalypse and the flying insects are symbols of carnage and destruction. Ironically, it is not the coming of insects that may bring about our gristly end; but the absence of them. A study published this past October in the Proceedings of the National Academy of Sciences has described a startling reduction in insect numbers in Puerto Rico’s Luqillo rainforest. The researchers, who conducted a similar study in the Luqillo rainforest in the late 1970s, recognised the difference in the forest even before taking any measurements. “Boy, it was immediately obvious when we went into that forest,” Dr Bradford Lister, a biologist at Rensselaer Polytechnic Institute and author of the study, told the Washington Post. But it was only after measuring the biomass (a measure of the overall weight of certain animals in an area) that Lister and his colleague Andres Garcia could see just how dramatic the change was. Between 1977 and 2013, the insect biomass had declined by up to 60 times.
This study comes a year after an equally distressing report published in PLOS ONE showed more than a 75% decline in insect biomass over 27 years in protected German nature preserves. The results of this study prompted Dr Dave Goulson, a researcher at Sussex University who authored the paper, to warn The Guardian that we are “currently on course for ecological Armageddon.” At first, this statement may seem alarmist. After all, recent figures show that there are around 1.4 billion insects for each human on our planet. So what if a few billion are missing from German nature preserves? n fact, some people probably feel the fewer insects the better. Without them,mosquito-borne diseases such as Malaria and Zika would be eradicated, saving countless lives each year.
IAll of our produce could be grown without the need for harsh chemical pesticides, and think of the picnics we could have without those annoying ants or buzzing bees ruining the serenity of a summer’s day. Nevertheless, before we begin boycotting bugs, what else would happen in a world without insects? Within the first few weeks, millions of animals would die and thousands of species would go extinct. Due to their abundance and high protein content, insects form the base of the food web in most environments. Ecologists estimate that around 60% of all birds rely on having insects in their diet. Without insects, the animals that eat them (aptly named insectivores) will starve. In turn, the animals that eat the insectivores will also starve. After several more weeks the apex predators of the world’s food webs, such as tigers, lions, and bears, will perish as well.
4370 MILLION YEARS AGO: OLDEST MINERALS - ZIRCON CRYSTALS FROM AUSTRALIA 7
Image: Tanya Hughes This literal and metaphorical butterfly effect is called a bottom-up trophic cascade and is already being seen in the Luqillo rainforest. Dr Lister and Dr Garcia found that there was a synchronous decline in the insectivorous lizards, frogs, and birds in the study area, which they characterised as a “collapse of the forest’s food web.” Animals will not be the only victims of the bug apocalypse. According to a 2011 study, over 80% of wild plants depend on insects for pollination. Bees, butterflies and other pollinators allow many flower-bearing plants, called angiosperms, to reproduce by distributing pollen from the male organs of one flower to the female organs of another. These insect-dependent plants make up around 35% of global food crops and include many fruits and vegetables such as avocadoes, coffee, and apples. While certain crops can survive without pollination, insects provide another key ingredient to plants: nutrient-rich soil. One way that insects do this is through soil aeration. In order for plants to thrive they not only need plentiful oxygen in the atmosphere, but also in the soil to nurture their roots. Currently, this aeration process is largely dependent on burrowing bugs that create tunnels on the surface of the soil that oxygen can travel through. However, insects do not just aerate the soil; they help create it. nsects such as Adonis blue butterflies and earthworms are adept at breaking down organic matter from decaying plants and animals and turning it into arable soil. In most environments, fungi will be able to pick up much of the slack, as they are usually the primary decomposers, but the surplus of dead animals due to the bottom-up trophic
cascade will overcome their valiant efforts, leaving behind a lot of decay for us to deal with. We better move quickly to make sure the bacteria-infested rot doesn’t infect our streams, wells, and other water sources. Conveniently, humans already have some solutions to the problems we would face in a world without insects. For one, the pollination problem could be resolved by hand pollinating crops. This is already used in rural China as a response to decimated bee populations. Unfortunately, the inefficacy of hand pollination would mean much of the produce we eat today would be gone. Additionally, as we lose the crops used to sustain our livestock, meat would no longer be an option.
So could we survive the ecological Armageddon? No.
As for soil aeration, farmers have been using aerating tools for centuries. Although, aerated soil is not much good without the nutrients from insects breaking down organic matter. When scaled globally these solutions would come at a steep cost which, for many countries, would be impossible to afford. In the United States alone, it is estimated that insects provide equivalent ecological services valued at USD $57 billion per year. So, could we survive the “ecological Armageddon?” The short answer: no.
imals, relying on overworked fungi to decompose the remains. Meanwhile, we would be busy figuring out how to prevent our food production infrastructure from coming to an inevitable halt. Whether by disease or starvation, we would not survive the insect apocalypse. Luckily, for now, bugs are still here. But what is happening to them? While there is disagreement about what is causing the insect decline, there is a consensus that human activity is largely to blame. The fragmentation of natural habitats has forced many species into new environments where they may not survive. Furthermore, the widespread use of pesticides frequently contaminates the areas surrounding farms, killing or displacing native insects. Finally, insects are extremely well adapted to the environments they live in, variations in temperature resulting from climate change can have a massive impact on their survival. In the Luqillo rainforest, Dr Lister and Dr Garcia found that there had been an increase in temperature of 2° Celsius, a change that they say is responsible for the dramatic insect decline. Even though these recent studies have been shocking, they have brought about awareness of the plight of our six-legged friends. But it will take more than awareness to prevent the worst of this dystopia. The next time you find yourself imagining a world without bugs, try to remember that insects do not plague our lives: they make them.
The collapse of food webs and ecosystems across the planet would create an unstoppable wave. The Earth’s surface would be littered with excesses of dead plants and an-
4000 MILLION YEARS AGO: OLDEST ROCKS - GNEISS FOUND IN THE SLAVE CRATON IN CANADA 8
Jason Murugesu dissects the human fascination with our prehistoric friends. I asked my six-year-old dinosaur crazed cousin a simple question: “What’s so special about dinosaurs?” and he looked at me in disgust. The adults too that I have talked to for this story (i.e. drunkenly brought up in the pub), have all in essence made the same face. “The answer is obvious!” they decry, “dinosaurs are big and scary. Dinosaurs are cool. Is this what journalism means now? Sort your life out man.” Some of my more artsy friends at least pretend to consider the question. They put a finger to their chin and ponder. “Dinosaurs used to tule this planet- didn’t they? And now they’re gone. Dinosaurs make humans consider the fragility of their existence on this planet,” is what I hoped someone would have said. Alas my artsy friends were not actually that deep. Do we only care so much about dinosaurs because of Jurassic Park? The quick answer is no. We have loved dinosaurs since they were discovered in the 1800s. Dippy the Dinosaur took centre stage in London’s Natural History Museum for wellover a century before it was replaced last year by a great Blue Whale. There’s even a name for a dinosaur enthusiast: dinomaniac. The pronouncements that “dinosaurs are big and scary and that’s the only reason why we love them” ring and echo in my head, but I’m certain that this cannot be the whole
the reptileS thAt story. Sharks are big and scary, and not extinct, and we aren’t all proshark. More importantly, there’s only two shark films of any note: Jaws and Sharknado 4 (trust me), compared to many more noteworthy dinosaur-themed films. Dr Hilary Ketchum, the Collections Manager at the Oxford University Museum of Natural History, shares my enthusiasm for this question, and tells me that he’d be really interested to find out the answer too, and asks me to pass on any research that I find. To better understand our fascination with dinosaurs, I delved into the history of dinomania. The oldest sculptures of dinosaurs in the world exist do not exist in one of London’s grand museums. No; they are in a little-visited park in SouthEast London. The Crystal Palace Dinosaur Park was unveiled in 1854, more than fifty years before the first dinosaur bones would go on display in the Natural History Museum. These sculptures are not scientifically accurate, nevertheless Sarah, a trustee of the park tells me that they “challenged people’s convictions regarding the history of the Earth,” noting that “even now we have people telling us they’re not quite convinced that dinosaurs existed.” The Crystal Palace sculptures were influenced by the paleoart of the time. Image left: Mat Reding [Unsplash] Image right: Dimitri Vereshchagin [Adobe Stock]
3700 MILLION YEARS AGO: EVIDENCE OF PROKARYOTIC ORGANISMS LIVING IN MICROBIAL MATS
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rOck Our WOrlD The first paleoart was a watercolour called Duria Antiquior- A More Ancient Dorset, and was painted by Walter Ford in 1830. This painting was based on fossils of marine reptiles found in Lyme Regis by Mary Anning. The art form flourished for the next hundred years, with artists pouring their imaginations onto any new fossil found. It was in a way, a merging of sci-fi and history. Dippy the Dinosaur, a skeletal longnecked diplodocus was a mainstay of the Natural History Museum ever since it was unveiled to the public in 1905. Dippy has achieved some controversy because the skeleton is not real and is in fact a plaster replica of bones found in Wyoming in 1898. Nevertheless, Dippy was the first life-size replica of a real dinosaur. Last year Dippy was replaced as the main star of the museum by the bones of a 25-metre-long Blue Whale named Hope.
enthusiasm. In the year the film came out, the dinosaur exhibition at the Natural History Museum had 100,000 more visitors, and its shop sales went up by 24%. The film is the first representation of dinosaurs as fast-moving dangerous creatures. This was in-part due to the so-called ‘dinosaur renaissance’ of the 1960s. This period is characterised by a series of discoveries about dinosaurs that we all take for granted today. The big debate until this time was whether or not birds had descended from dinosaurs. John Ostrom then found a dinosaur that a skeleton that was near identical to one of a bird. During this time, it was also discovered that dinosaurs were warm-blooded and fast moving.
Across the globe, cultures have been fascinated by mythical monsters such as dragons which scientists believe were based on early dinosaur discoveries. The imagery of large and ferocious dragons can be found in history all across the globe, maybe future generations will see evidence of our fascination with monstrous dinosaurs. Professor Paul Barrett, a researcher at the Natural History Museum, echoes what most tell me in their answers about why dinosaurs are so popular, “Most people’s fascination with dinosaurs can probably be summarised in three words: big, fierce, and extinct.” He then goes on to give me the best answer I’ve heard yet: “almost everything about extinct dinosaurs, from their biology to their demise, is fuel for the imagination.”
Dinosaurs make humans consider the fragility of their existence on this planet,
Of course, most dinosaur enthusiasts point to their favourite film of all time: Jurassic Park marking the beginnings of their dinosaur
3500 MILLION YEARS AGO: OLDEST FOSSILS - FOSSIL MICROBES 10
Do Aliens Live Among Us? Aoife Hardesty searches for extra-terrestrial life on Earth. Children learn to make wishes on shooting stars, wishing on clumps of rock which fall from the sky to the earth below. The ‘stars’ are not actually stars but meteors or asteroids, and they travel great distances in space before crash landing on our planet. But what if the meteorites carried passengers? Hitchhikers from across the galaxy bringing with them the building blocks of life for planet Earth. If you are so inclined it is not difficult to search the internet and find ‘evidence’ that aliens have lived on Earth in the past, that they have played significant roles in shaping human history, and that indeed, aliens still do live on our planet and call it home. Such theories are not just confined to the webpages of conspiracy theorists, several months ago, scientists published a paper claiming we have extra-terrestrial life on Earth, lurking beneath the ocean’s surface. Questions have long plagued humanity about the origins of life, humans have conjured myriad answers; life was created by an all-powerful deity, life popped into existence thanks to molecules being struck by electricity, and (a popular idea, even within the scientific community) the building blocks of life were carried to Earth on a shooting star. The suggestion that life could have originated elsewhere in the Universe then raises the question of whether life brought to Earth was intelligent, or primitive such as bacteria. In scientific circles, primitive life
travelling to Earth from across the galaxy is favoured over the arrival of intelligent life, but conspiracy theorists provide an abundance of evidence that beings more intelligent than humans have lived on our planet, and indeed that governments have worked to hide such knowledge from Earth’s citizens. In 1965, residents of the USA and Canada witnessed a fireball flying through the sky. The fireball ultimately fell to Earth in Kecksburg Pennsylvania where witnesses claim they saw a car-sized capsule covered in writing which looked like Egyptian hieroglyphics. The area surrounding the site of the crash was sealed off until the arrival of US Army and police officials who were said to find nothing, and astronomers believe the fireball was a meteor bolide. Some people claim that the Nazca lines found in Peru are evidence of alien-made artwork. The lines are trenches which were dug to form a variety of designs including animals, the total area covered by the Nazca lines is roughly 50km. “In total there are over 800 straight lines, 300 geometric figures and 70 animal and plant designs.” Because the drawings can be best viewed from above, and due to their complexity, their creation has been credited to extra-terrestrials. Caves within the Chhattisgarh region in India feature 10,000-year-old drawings on their walls. The drawings are believed to illustrate people meeting aliens who come from discshaped spaceships. Local legends tell of the ‘small sized ones’ who
travel in rounded flying objects and take away people who never return. These theories about alien life on Earth exist in popular media and culture, and have not been scientifically verified (in some cases such as Kecksburg they have been clearly refuted by scientists) but in March this year, the first peer-reviewed paper claiming that extra-terrestrial life lives on Earth was published. The alien in question is as far from a human as could be possible. It can squeeze its body (of up to two metres in length) through spaces as small a pound coin. It has three hearts which pump blue blood around its body. Perhaps most importantly for proponents of the intelligent design theory; this creature has a huge network of 500 million nerves spread throughout its body (dogs have 600 million), and most of nerves are found in its eight arms. The aliens that scientists say live on Earth are: octopuses. The 33 scientists who authored the paper suggest octopuses arrived on Earth via asteroids; that viruses on asteroids infected squid transforming them into octopus, or that maybe fertilised octopus eggs were transported to Earth via asteroid. The scientists believe that it is possible octopuses might be aliens because of their incredible intelligence, which is so different to human intelligence. Octopuses have been known to escape from their tanks in aquariums to travel to other tanks (octopuses can survive outside water for a short period of time) where they feast on
2700 MILLION YEARS AGO: LEWISIAN GNEISS - OLDEST ROCKS IN BRITAIN
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the fish living there, before returning to their own tank to await the arrival of confused aquarists in the morning. In aquariums, octopuses prove demanding, not just because they are eight-armed Houdinis, but because they are like dogs; they get bored and misbehave if they do not receive sufficient mental stimulation, so octopuses tend to be given toys to play with and puzzles to solve in order to receive their food. In the wild, octopuses have been observed carrying coconuts and using them to hide in to avoid being eaten, or to lie in wait to catch their next meal, a clear sign of tool-use in an ocean dwelling invertebrate.
suggestions do not ring true to the biology of octopuses or their close cousins the squid. That animals that do not resemble humans could be aliens is a typical suggestion from the elitist human, but actually, humans have for many years underestimated animal intelligence and just because an animals’ anatomy or intelligence may look different to ours does not mean they have to come from another planet. Earth has proved herself more than capable of evolving wacky animals, just look at Homo sapiens.
All the same, if aliens were to exist somewhere out there in the vastness of space, I hope they are like octopuses, and that we can communicate, because then I could have an octopus best friend. And that, would be awesome.
As exciting as the idea sounds that octopuses may in fact be aliens from another planet, but the
Image: Céleste Nilges
2500 MILLION YEARS AGO: GREAT OXYGENATION EVENT EXPLOSION OF PHOTOSYNTHETIC MICROORGANISMS BEGAN POPULATING THE
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Our Sun: A Ball of Weather in Our Sky Aaron Hadley investigates the effects the Sun’s weather has on Earth.
We Brits love to complain about the weather. It will come as good news then that in addition to the weather on Earth, we can also complain about the Sun’s weather. The Sun has weather and seasons, both with real consequences for life on Earth.
On May 18th, 1967, the sun’s weather had a dramatic impact on Earth. It was the height of the Cold War and tensions were running high. 150 million kilometres from Earth, dark spots formed on the Sun’s surface. Suddenly, a huge eruption of light occurred. The eruption was so bright it was visible to the naked eye on Earth. A massive eruption of radio waves propagated from the Sun, followed by highly energetic particles. 480 seconds later the USA communications system went down, and nuclear war was declared. Luckily, some American scientists were observing the sun and telephoned the USA military, just in time to prevent planes carrying nuclear weapons to be deployed. However, the threat that ‘space weather’ poses to life on Earth goes beyond that of simple communications.
Space weather is not just solar flares. The Sun releases a constant stream of highly energetic, charged particles such as electrons which make up a solar wind that constantly barrages the Earth. On occasion, often accompanying a solar flare, the Sun ejects huge amounts of hot plasma in a Coronal Mass Ejection (CME). We are protected by the Earth’s magnetic field, which forms a defensive umbrella and deflects solar wind around it. However, this umbrella is not impenetrable. Each particle in the solar wind contributes to a magnetic field that can poke holes through our defensive shields, leaving it looking far more like a sieve than an umbrella. The sieve allows the energetic particles to stream through and approach the Earth. The Earth’s protective magnetic field comes from its iron core, which behaves similarly to a bar magnet: The magnetic field surrounds the Earth and responds to the charged solar wind, becoming compressed on the day side of the Earth, and dragged far out into space on the night side. The magnetic field ends up looking like a tear drop, with the tail extending beyond even the orbit of the moon. Imperial College London’s Professor John Eastwood is the lead researcher of a 2017 paper detailing the economic consequences of space weather. Experts in space weather refer to extreme weather events as Carrington-like. This is based on the Carrington event, an 1859 geomagnetic storm (a disturbance in the Earth’s magnetosphere), which resulted in sun spots visible to the naked eye and the Northern lights to be seen in the Caribbean. Should such an event occur today, it is likely that the entire power grid of the UK and USA would collapse, causing severe damage to electrical transformers. The repairs would take up to a year, leading to a worldwide economic cost of up to USD$3.2 trillion. The immediate cost to human life would be astronomical, with life support machines, surgery operations and GPS networks instantly cut off. Perhaps reassuringly, there is only a 12% chance of a Carrington event happening in the next decade, according to Eastwood’s paper. Eastwood is currently attending the European Space Weather Week, an assembly consisting mainly of researchers, policy makers and
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spacecraft operators. The agenda of this conference includes plans to protect satellites from space weather, and plans to send warnings back to Earth in the event of a CME. Launched in 2006, the Stereo satellites observed CMEs in order to warn Earth of their trajectory through space. One of the satellites was launched so that its orbit preceded the Earth, with a solar orbit of 347 days. The other was launched behind the Earth, and orbits the sun every 387 days. The satellites could take pictures of parts of the Sun not visible from Earth, to identify areas with increased surface activity like sun spots; precursors to solar flares and CMEs. As the Sun rotates every 25 days, and the two satellites move further apart, in 2011 they were on exact opposite sides of the Sun. This allowed the entire Sun to be photographed simultaneously for the first time. Unfortunately, signal with Stereo-B was lost in 2014, when the satellite began to spin out of control. The solar panels on the spacecraft are less effective due to the uncontrollable spin, and the power on-board will continue to fall. It may be many years until the satellite is in a more stable orbit and the European Space Agency can regain control over it. The sun’s outmost layer is the corona, an aura of plasma, from which CMEs and solar wind originate from. Like how twisting a rubber band stores energy, the twisting and untwisting of the Sun’s magnetic field throughout the corona fuels the propulsion of solar wind. Solar wind supplies a constant bombardment of highly energetic particles to satellites, causing those that are orbiting Earth to sustain serious damage over time. To understand the magnetic fields at work, Imperial College has built and placed a magnetometer on the recently launched Parker Solar Probe. This satellite is the first of its kind. It will fly into the outer reaches of the corona to observe the magnetic field and collect actual samples of the Sun’s plasma. “The Sun’s magnetic field is central to its dynamics; the magnetic field drives all activity on the Sun,” says Imperial’s Professor Tim Horbury. The Parker Satellite Probe will spend the next 6 years getting closer to the Sun, by flying close to Venus and using its gravitational field to slow the Probe down. A new satellite, SolO, will accompany the Parker satellite in two years’ time. Professor Horbury is a principle investigator on the SolO mission, which aims to point a telescope at sun spots on the surface in order to photograph layers inside the Sun. The Sun’s magnetic field, as well as posing a threat to the Earth, plays an important role in shielding Earth against space weather and cosmic rays from outside of our solar system. Finally, although space weather is deadly, it can be beautiful too. For millennia, the auroras around the Arctic and Antarctic have inspired and mystified the people living there. The flickering Northern lights heralded the Norse Valkyrie warriors in their armour, and, to the indigenous people of Southern Australia, held the spirits of their dead. So, when a solar flare destroys our power grids, plunging us into darkness and disaster, at least we can see the light of a stunning aurora. Unless it rains. Image: Courtesy of NASA_SDO and the AIA, EVE, and HMI science teams
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the StOry Of A lOnely plAnet The Universe is so unimaginably large that it seems impossible that Earth could be the only planet to have grown life. Katy Pallister examines the science that is searching the skies for signs of other life. Once upon a time there was a small rocky planet called Earth. For billions of years life evolved on Earth, from microorganisms to our Neanderthal ancestors. One day in 1609, the astronomer Galileo Galilei opened Earth’s window to the Universe through his telescope, which could see to the moons of Jupiter and beyond. Ever since then, humans have stopped and wondered - what else is out there? As the map of the Universe became ever larger, more people found it hard to believe that in this vast space, Earth was completely unique in its ability to produce and sustain life. At first the search for extra-terrestrial life was focused on our solar system. In the late 19th century, Mars was speculated to display channels of water from a long-gone civilisation. Although this was shown to be an optical illusion, the desire for there to be someone other than us existing in the incomprehensibly large and continually expanding universe remained. As SETI (Search for Extra-terrestrial Intelligence), the collective term for all efforts to find other life in the universe gathered momentum, there appeared to be a great silence from any radio transmissions from other technologically advanced life. This led the physicist Enrico Fermi to exclaim ‘Where is Everybody?’ Towards the latter half of the 20th century, technological advances allowed us to observe space further afield. This gave rise to an area of astrophysics known as exoplanet
exploration. Exoplanets, which are planets existing outside of our solar system that orbit another star, were first observed in 1995 and since then scientists have approximated that there is roughly one planet for every star. In our galaxy, the Milky Way, this amounts to approximately a trillion exoplanets. Currently NASA have confirmed 3,826 exoplanets, with a further 2,899 candidates waiting for classification, and billions more to be discovered. However, not all exoplanets have the potential to produce and sustain life like on Earth. As we know from our own solar system, Earth’s proximity to the Sun is crucial for the sustainability of life. One reason is that Earth lies in the Habitable Zone, also known as the Goldilocks Zone, of the Sun. The Goldilocks zone of a star is the region surrounding it where liquid water can exist. Therefore, the parameters of the zone varies depending on the intensity and size of the star. Some exoplanets discovered by instruments such as Kepler and the Hubble Space Telescope have fallen within the goldilocks zone of their respective stars, and some are approximately the size of Earth. In the last three years, the discovery of the planetary system orbiting the TRAPPIST-1 ultra-cool red-dwarf star 40 light years away from Earth, has become one of the most exciting findings in the search for Earth-like planets. To explore this system in more detail, and the potential of discovering life in it, let us find out how
Goldilocks would fare if she were to live on some of the planets near TRAPPIST-1. Too Hot: TRAPPIST-1d TRAPPIST-1d is one of the six planets orbiting TRAPPIST-1 that lies in its optimistic habitable zone. As this planet is situated in the innermost region of the habitable zone, there are several problems for Goldilocks. A 3D climate model of the planet produced by Eric Wolf, a researcher at University of Colorado, shows that its extreme proximity to the star would cause a runaway greenhouse effect, which scientists believe could also have happened in the early history of Venus. This occurs when a build-up of a thick atmosphere of water vapour heats the planet to the point where oceans boil off, leaving no liquid water behind. Goldilocks unfortunately would be left to die on a hot, dry planet. Too Cold: TRAPPIST-1f Located in the outermost region of the habitable zone, TRAPPIST-1f has a radius incredibly similar to Earth, however that cannot compensate for the −54 °C surface temperature on the planet. Goldilocks would be effectively living on a snowball, as the extremely cold conditions would freeze any surface water. Furthermore, Wolf’s 3D climate model concluded that no combination of gases in TRAPPIST-1f’s atmosphere could counter the freezing conditions. In fact, when he added carbon dioxide into the atmosphere the conditions meant that the CO2 condensed and
2400 – 2100 MILLION YEARS AGO: HURONIAN GLACIATION HYPOTHESIZED SNOWBALL EARTH EVENT WHICH SAW MOST OR ALL THE
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PLANET COVERED IN ICE
and fell out of the atmosphere. Again, Goldilocks unfortunately would be left to die on a cold, icy planet. Just Right?: TRAPPIST-1e Situated between TRAPPIST-1d and TRAPPIST-1f, Wolf’s 3D climate model predicts that TRAPPIST-1e would prove to be the best planet for Goldilocks to settle on. With a surface gravity approximately 93% as strong as Earth’s, amongst other data, TRAPPIST-1e is comparable to Earth in many ways. In Wolf’s model, TRAPPIST-1e was the most likely candidate to sustain liquid water on its surface. If modelled with an Earth-like atmosphere, 20% of the planet’s surface wouldn’t be icy and with some additional carbon dioxide in the atmosphere, the temperature would be similar to Earth’s, enabling the liquid water to survive.
that our planet is the only one where intelligent life exists is incredibly low and contradicts the current lack of evidence of extra-terrestrial life. This contradiction is commonly known as the Fermi Paradox. British people believe that the main reasons we have not discovered other life in the universe, is that intelligent life is too far away to contact us and our own technology is not advanced enough to communicate with them. In reality the search for extra-terrestrial life is a multi-disciplinary endeavour, the conclusion of which could affect all of mankind. No-one truly knows whether Earth Image: Rachel Ng
is alone. Until we discover microbial life on an exoplanet, or detect a radio signal elsewhere in the universe, we cannot disprove the many theories and portrayals of extra-terrestrial life society has conjured up. Likewise, we cannot predict what will exactly happen if we were ever to make contact with another civilisation in the universe. However, it is comforting for many to believe that humans are not alone, and that maybe there exists a civilisation where an incompetent, egotistical and idiotic man wasn’t elected as a world-leader. In the end all we can hope for is to live happily ever after.
However, Goldilocks may not have found her forever home just yet. Further data from the planets, including their atmospheric make-up, does not write off all the planet’s orbiting TRAPPIST-1. Although Wolf’s climate model focused on the sustainability of liquid water, other planets currently have some in abundance; TRAPPIST-1d has approximately 250 times more water than all of Earth’s oceans. The James Webb space telescope, due to be launched in 2021, will allow the TRAPPIST-1 planetary system, and other exoplanets, to be studied in greater depth with the hope of finding the building blocks of life elsewhere in the universe. Many people are certain that this fairy-tale ends with the discovery of extra-terrestrial life. A study conducted by YouGov in 2015 concluded that 52% of Britons believe there is extra-terrestrial intelligent life whilst a further 20% didn’t know what they believed. The probability
1100-900 MILLION YEARS AGO: ASSEMBLAGE OF RHODINIAN SUPERCONTINENT 16
Are We the Special Ones? Andrew Dixon examines what sets humans apart from other animals and questions if we are as special as we think.
The impact that humans have had on the environment is undeniably huge. The damage we have caused to our atmosphere, our oceans, and our forests has been immense. Many would argue that the changes we have seen have been so great that we have entered a new geological epoch; the Anthropocene. Our influence will surely be felt long after we are gone. Some may argue that this is what makes us unique. We are unrivalled in our destructive ability. It would be wrong, however, to argue that we are alone in our competitive nature, our penchant for destruction. There is a battle for survival, and all species play a part. So, I ask, what is it that makes us special, that has allowed such a conquering of those around us? Why was it humans who polluted the air and poisoned the seas? Our forbearers may have seen this as a result of our divine origins, made in the image of God. However, in an increasingly secular society, our search for answers demands more. It requires us to question the very nature of what it means to be human. We start with what was once thought to make us unique; our tool use. A signifier of our greater intelligence. What humble creature would look to its surroundings and see opportunity as we do? To peer at a rock and see a hammer or a stick a spear? This must be what defines us: our creative ability and problem solving. Yes, we could have continued with this rule had we not discovered tools created and used by not one but many creatures other than man. To list a few: the spears chimpanzees use to impale bushbabies, the nut-cracking rocks of capuchins, the sponge beak sheaths of bottlenose
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dolphins, and the hooked insect probes of the New Caledonian crow. This illustrates just how wrong we were in assuming that tool use could define us. Culture, we declare, that must be it. Never before have I seen a vulturine Van Gogh, a porcine Picasso. We have created things of beauty, of dreams, and what of our animal compatriots? What culture in beasts? For this we must define culture. At its heart culture is the transmission of socially learned behaviours between individuals. Such a process should lead to the creation of uniquely behaving groups of individuals, groups exhibiting different cultures. When viewed like this, in such rudimentary terms, our cultural pedestal appears anything but secure. Again, our closest relatives, the chimpanzees, provide us a mirror with which to compare. In their toolmaking they are seen to vary between groups, displaying individual learned traditions not dissimilar from our own. Cetaceans too, the dolphins and whales, have been proposed as bearers of culture. Foraging behaviours, likely to be socially learned, have proved to vary greatly between populations. Some groups have even been discovered to display complex hydroplaning behaviours. This is where fish are chased onto land, trapped and consumed by the self-beached dolphins. In other dolphin populations they learn that sponges can be used as beak sheaths to protect their rostrums from damage by the sea floor. If culture can no longer be seen as unique to our tribe, then we must look elsewhere for distinction, but not far.
Cumulative culture builds on the concept above. Learned behaviours are passed from one individual to the next, just as before, but differ as a result of their complexity. With cumulative culture beneficial traits are selectively preserved and built upon over many generations. The complexity of resulting behaviours far exceeds that which the abilities of a single individual would allow. A human raised alone, without the influence of its peers, their existing culture, would scarcely be able to tie a knot, let alone solve complex arithmetic or compose a symphony. In essence, one could view all of our great achievements as a product of this trait. Our skill lies in cooperation. Can we, however, claim it as an achievement unique to ourselves? Some have claimed that such achievements, of cultural descent with modification, have been seen in species other than our own. Do the hand clasping games seen in a population of capuchins represent just that, or the complicated nut cracking procedure of some chimpanzees? Are such behaviours truly beyond the scope of a single individual? Do they change with time, increasing in complexity? The jury’s still out, and although others may approach the cumulative cooperation we display, they do not approach its complexity. The difference may only be one of scale, not form, but it would be hard to argue that it does not exist. So, what feature can we assign as responsible for our superiority? The social aspect of our species is key. Another superior human trait is our brilliant ability to experience the world through another’s eyes; our theory of mind. Research, however, increasingly suggests that an ability to empathise is far from unique to us, with chimpanzees, rooks, and even the humble coral trout thought to display the trait. What we do have, which enables cooperation, learning and invention, that’s not seen in any other species is our language.
Language allows the accurate transmission of complex information from one individual to the next. It allows us to understand another’s beliefs and build on them. Our language makes us special. Whilst we have found our language to stand out amongst our animal kin we must ask the question of when. When were we able to finally share what was on our minds? For this we must look to a place lacking in certainties, we must look to the dead, the extinct. Language is a notoriously difficult feature to observe in a fossil. In their interrogations, palaeontologists have looked towards our closest relatives to determine how our ancestors may have been. Neanderthals, our northern cousins, provide ample comparison, but what features to ponder to determine speech? The hyoid bone through its importance in tongue movements, or middle ear and its importance with hearing? Both vary little from those found in ourselves, and so are not definitive proof.
We clearly differ from those around us, and those that have come before us, but by how much, we cannot be sure. The complexity of our behaviour owes its presence to our ability to cooperate, which itself is only possible as a result of our language. At a time when our impact on the environment is being felt all too
clearly, we can only hope that our unique ability for cooperation may provide us with a final means of self-preservation, and help to save the planet on which we rely.
With recent advances DNA is used in addition to bone analysis. Errors in the FOXP2 gene in living humans is known to be linked to speech impediments. Therefore, it has been touted as a possible source of our ability to talk. Our version of the gene is unique in its structure, varying even from the Neanderthals’. If we are to take this to mean that we are the sole owners of speech then we must also note a key finding. Our FOXP2 mutations, unique to our lineage, arose 200-100 thousand years ago. When combined with the excavations of human remains predating this by more than 100 thousand years, we would take it to mean that speech was not present in our earliest human ancestors, nor was it present for more than a third of our species’ history. Such assumptions may be too great to make at the moment, and further study will only aid our understanding. However, they do go to highlight our ignorance of what it truly means to be human.
A human raised alone, without the influence of its peers, their existing culture, would scarcely be able to tie a knot.
Image: Tanya Hughes
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MOVinG
hOuSe
May Pimchanok investigates what it will take for humans to rehome elsewhere in our solar system. Legend has it, the first astronaut was Chinese official Wan Hu who tied rockets to his chair to go to the Moon. The rockets exploded, and neither he nor his chair was ever seen again. A crater on the far side of the Moon was named in his honour. Some three thousand years later, in 1543, Nicolaus Copernicus published On the Revolutions of the Heavenly Spheres, stating that Earth revolves around the Sun, and stirring controversy from religious institutes. Decades later, in 1610, Galileo invented his own version of the telescope only to discover the Moons of Jupiter and the phases of Venus. Centuries later in 1942, the first rocket reached the boundary of what we define as space, a height of 100 kilometres from the Earth’s surface. Fuelled by the Cold War during the 1960s, scientists and astronomers from the Soviet Union and the United States raced for dominance in space exploration until 1969, when the first men landed on the Moon. We have come a long way since Wan Hu’s chair, from humans landing on the Moon to orbiting the farthest planets in our solar system. In 2012, Voyager I became the first manmade probe to make it to interstellar space, beyond our solar system and the reaches of the Sun. Shy attempts to leave our planet has been hap-
pening for thousands of years; but how close are we to actually colonizing the solar system? In 1964, Soviet astronomer Nikolai Kardashev proposed what is known as the Kardashev scale, a scale measuring how much energy a civilization is able to utilise. There are three types of civilisation, Type I, II, and III. Type I civilisations, or planetary civilisations, are able to capture and exploit all of the energy released from its parent star to the planet. For our planet Earth, this is more than ten thousand times the energy we can currently optimise. Type II, also known as a stellar civilisation, are civilizations that are capable of harnessing all the energy from its parent star. The total energy Earth can use would equal to the luminosity, or power generated from, the Sun. The final Type III is a highly-advanced civilisation that has control over its whole galaxy and energy. Hypothetically, we’d be able to harvest energy equivalent to the luminosity of the Milky Way. Regarding energy, physicist Carl Sagan claimed that humans are around Type 0.7, and will reach Type I status within a couple of centuries. Astronomer Robert Zubrin adapted the Kardashev scale to illustrate how widespread a civilisation is, with types I, II, and III suggesting a civilisation that has spread across its planet, colonised its stellar system, and colonised its galaxy, respectively.
541 MILLION YEARS AGO: CAMBRIAN EXPLOSION 19
in the While attaining the Type II civilization status is still a far cry, a few thousand years to be more precise, we can start by building a Moon base. Supposing we do have sufficient funding and research; a Moon base would be the perfect sandbox to provide endless opportunities for developing new technology needed to colonise our solar system. Similarly to the colonisation of newly “discovered” lands a few centuries ago—minus the mass physical and cultural genocide of innocent people— conquest of the Moon started with the lunar landing in 1969. While the Moon’s surface has been mapped and its compositions studied, the Moon is a rough terrain. One day is equal to almost one month on Earth, but also with extreme temperature differences of up to 300°C between day and night. The Moon also lacks an atmosphere, which means no protection from cosmic rays. The first settlements on the Moon would comprise of astronomers and researchers who would stay temporarily to find ways to extract and utilise energy and resources for future settlements. Because the Moon only has a fraction of Earth’s gravity, it would be easier and cheaper to launch rockets off there into orbit. Colonising Mars may start from the Moon. To be an actual colony, however, the Moon must be self-reliant, that is, having its own social structure and economy. Rocket fuels, mineral, and metals can be exported
SOlAr
SySteM
back to earth. The birth of the first extra-terrestrial child would signify that the Moon is no longer just an outpost. Only from then can we materialise our dreams of colonising our Solar System one planet by one and become a Type II civilisation. Before we can become the conqueror of our solar system, we must become a Type I civilisation by being able to harness all the energy Earth has available fully. From fire to electricity as power, we have gone from hunting and gathering to instantaneous communication and transportation. What we have yet to master fully is nuclear energy. One depressing hypothesis, however, is that once a civilisation takes control of its whole planet, it is on the path to impending self-destruction. That is, we are already on the road to destroy Earth and life. We can easily see the consequences of technology such as nuclear power, nanotechnology, artificial intelligence, and genetic engineering go terribly wrong. Chain reactions such as climate change, or competition amongst ourselves could easily become our demise. It can also be said we are our own Great Filter, which is among one of the many explanations of the Fermi Paradox. Named after physicist Enrico Fermi, it is the conflict between the enormous probability and lack evidence in encountering alien life forms. The Great Filter is a barrier that is so challenging for life to overcome, that it prevents life from developing beyond that point. There are two scenarios: the great
filter lying behind us or lying ahead of us. The former would mean that it is so complicated for life to develop and that we may be one of the very lucky, if not the only, advanced civilisation. The latter would be quite worrying. It means that life our level exists, perhaps everywhere, but is yet to overcome a barrier. Could ultimately attaining Type I status be our great filter? Harnessing all the power Earth has available could also mean simultaneously destroying Earth. That may be why we have never encountered aliens. Harnessing such great energy may come at the expense of a whole civilisation, and that we may never be able to move beyond our planet, or detect any civilisation that has moved beyond its planet. The discovery of alien life would undoubtedly be one of the most exciting discoveries of our humanity, but also our doom. It would show that the great filter is ahead of us, proving that there are limits to what humanity can achieve. At least, for now, the good news is that we have not detected any signals or evidence of life in our solar system or beyond, so it is safe to say that we could colonise our solar system if we first don’t annihilate humanity. If we are ambitious enough to take control of our planets, it is improbable that we will stop there. Moving house and colonising the solar system isn’t just a race to colonise or be colonised; it is a race between humanity and its limitations.
Image: Skeeze [Pixabay]
470 MILLION YEARS AGO: FIRST TERRESTRIAL PLANT LIFE 20
MASS eXtinctiOn On the hOriZOn Louis van der Linden takes an honest look at how we as a species are impacting all other life on our shared planet. The Holocene extinction began a long time ago: 10,000 years ago, in fact, when human hunting drove megafauna, including woolly mammoths, to extinction. An alternative, more accurate, name for the next mass extinction event is the Anthropocene extinction. After all, we live in the anthropocene; the planet is ours. In order to keep living on earth, we may need to loosen some of our ownership of it. There is a coral reef in the Southern hemisphere that saw consecutive years of mass bleaching in 2016 and 2017. Coral gets its colour from the symbiotic algae, zooxanthellae, that live in its tissue and bleaching occurs when the coral experiences external stress from its environment and is forced to expel the algae. When stress conditions persist, both the coral and the zooxanthellae die. If this year’s Southern summer proves to be a particularly warm one, there is a 60% chance that the entire reef may reach Alert Level One. In other words, our coral reef’s situation is dire, teetering on catastrophic. Though there is a lot to admire, my favourite aspect of the world’s largest organism, spanning 2,300 kilometres along the Queensland coast, is its resilience. This December and January’s milder temperatures has allowed for regrowth of bleached coral and the birth of large numbers of new colonies. After 1998, when reefs off the Seychelles islands
suffered bleaching of up to 90% due to a rapid influx of warm water, 12 out of the 21 reefs eventually fully recovered. It really helps in these situations if we leave the reefs alone for a while: “Reducing local impacts as much as possible will give them the best chance of survival. Managing the impacts to reefs is really about understanding and managing human actions”, says Nicholas Graham, a coral researcher at Lancaster University. The reefs that survived 1998 had grown stronger from the experience, as shown by their mettle in the face of storms originating from Indonesia in 2010. These anecdotes have augmented hopes that coral reefs may be capable of adapting to climate change. Researchers at the University of Miami are currently looking at the sensitivity of different coral species. “Stressful periods of high temperature and increasingly acidic conditions are becoming more frequent,” says Chris Langdon, professor and lead author of the study. “But we found that not all coral species are equally sensitive to climate change: there’s hope that some species that seemed doomed may yet develop adaptations that will allow them to survive.”
With increased focus on conservation, battles are being won: the tiger population in Nepal has almost doubled, partially by introducing rangers that poach poachers. The Mauritius kestrel population reached a low of a mere four individuals in 1974, making it the rarest bird in the world. Due to rigorous conservation efforts, 400 mature birds are thought to exist in the wild today. Nonetheless, the war is being lost. Unfortunately, stories such as these are the exception. The World Wildlife Foundation reported an average 60% decline in population across 4,000 mammal, bird, fish, reptile, and amphibian species over the past 40 years. “We need to address the root causes before we can affect any change,” says the Louise McRae, a researcher at the Zoological Society of London. “While conservation does work, we don’t want to have to keep bringing populations back from the brink of extinction.” Like other mass extinction events, the current one can be described as a perfect storm of multiple factors. The Permian–Triassic extinction event, 251 million years ago, was initiated by a gargantuan volcanic eruption near modern-day Siberia, yielding high CO2 levels in the atmosphere. Suspended methanogenic bacteria, common at the time, then secreted large amounts
375 MILLION YEARS AGO: FIRST TERRESTRIAL ANIMALS 21
Image: Hannah Ryan-Leah
of methane, yielding a Greenhouse effect and, this is starting to sound very familiar, rising temperatures and acidifying oceans. This extinction event resulted in a 95% loss of life, setting evolution back an estimated 300 million years. Today, three factors: humanity’s domination of nature, our overpopulation and profligate consumption, have already led to the first mass extinction event since a comet 15 kilometres in diameter hit Mexico 66 million years ago. The stakes, in other words, are high. However, like the 1987 Montreal Protocol proved that changes in the chemicals we use can lead to repairs of the ozone layer, coral reefs prove that not all hope is lost. Coral reefs are often called “rainforests of the sea”. They occupy 0.1% of the global oceanic area yet house a quarter of all marine species. Impressive as that is, rainforests outshine coral in this category, with about half of all biotic species indigenous to these green canopies. They also act as the world’s most abundant carbon sink, though decreasingly so, as deforestation has erased 90% of West Africa and Indonesia’s rainforests. However, as reported by the New York Times in 2009, the combination of intentional reforestation measures and unintentional migration away from rainforests are gradually starting to reverse these trends. Many countries, like Canada, have declared deforestation a national emergency and introduced measures that have had an impact: 94% of Canada’s forests are public land where planting trees subsequent to harvesting is obligated by law. In Latin America, Asia and other tropical regions, people have increasingly been moving away from rural farmland to cities. Two or three
decades later, secondary rainforests emerge, reclaiming the land that was once occupied by humans. This reforestation is happening at such a fast rate that saving primeval rainforests, once the iconic environmental cause, may be less urgent than commonly thought. By one estimate, for every acre of rain forest cut down each year, more than 50 acres of secondary forest are growing on land that was once farmed, logged or ravaged by natural disaster. Professor Claudio Sillero, a conservation biologist at the University of Oxford, argues that, though this is encouraging, there are still root causes that need to be addressed: “Forest cover has increased in many nations, rewilding and habitat restoration are becoming mainstream interventions, and financial efforts from philanthropists continue to increase. But in order to slow down biodiversity loss any further, and even revert it, some large scale impacts will have to be addressed.” As we are the problem, so we are, or must be, the solution. Natural biomes show a remarkable ability to recover balance when left to their own devices, but removing human interventions from many areas in the world is a complicated endeavour. What this will require is a pervasive attitude change to life in the 21st century, learning to live with less comfort and consumption. This news may not be bad. Yuval Noah Harari, author of Homo Deus, suggests that modern humans misunderstand happiness. Following Buddhist ideas, he suggests that “to attain real happiness, humans need to slow down the pursuit of pleasant sensations, not accelerate it.” In doing so, we may be able to save two birds with one stone.
335 MILLION YEARS AGO: ASSEMBLAGE OF PANGAEAN SUPERCONTINENT – THE MOST RECENT SUPERCONTINENT
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Storytelling has long been used to communicate knowledge, but in modern times, knowledge passed along in this way has been deemed lesser than modern science. Jacqueline Darkwa shares stories from ancient cultures.
n ci e S S c e h e t c re orie e.. T t s S d i d e n H in
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We all know what fairy tales sound like; lessons in school are centred around the mystic magic of myths, and heroes and villains of history are forever preserved in legends. Such forms of storytelling are perhaps the oldest and most natural ways humans communicate, yet there is a sharp distinction between it and science. Across ancient civilisations, from the far Eastern tips of Asia to the lush forests of Africa, storytelling was the primordial form of transporting knowledge among and between communities. Such civilisations were also home to magnificent feats in technological advancements, as well as vast understanding and appreciation for the natural world. Fast-forward a millennium and the scientific revolution (within the context of the relentless colonising power of the British Empire) knowledge became defined by its relation to pure objectivity and, above all else, adherence to the ‘scientific method.’ In the wake, ancient traditional teachings passed down in cultures were viewed as inferior to European science, even if contained held valid information. Unlike within science, the ‘knowledge’ held within myths, legends, and fairy tales, is not separated from spirituality, religion, and culture. The pedestal on which European culture places science does not allow science to be linked with other aspects of society, and led to a blindness towards the knowledge passed along through storytelling. Across the world, civilisations linked scientific endeavours to stories. Deep in the world’s largest desert lake in the Kenyan Rift Valley, Lake Turkana, is Namoratunga. Dated back to around 300BC, Namoratunga
is the oldest archaeo-astronomical site in sub-Saharan Africa. The site is made up of 19 basalt pillars which align with seven constellations in the night sky. Namoratunga translates as “people of stone” and legend holds that the stone pillars are actually men whom the devil turned to stone. In a 1978 study, archaeologists Mark Lynch and L.H. Robbins described the site, highlighting that much of the archaeological investigations surrounding megaliths erected by ancient civilisations and their relation to the positions of constellations have largely been focused on European sites, such as Stonehenge. However, upon visiting Namoratunga, the pair had uncovered a potential relationship between the positions of the pillars, the pattern of the night sky, and the Borana calendar used by the ancient Cushite people that lived in the Horn of Africa.
Unlike within science, the knowledge held within myths, legends, and fairy tales, is not separated from spirituality, religion, and culture.
Colonisation could have resulted in the loss of cultural knowledge, but in post-colonial India, medical practices that were believed to be passed down from the gods survived in mythical stories and spiritual teachings. Ancient Indian scholar Chakara, well-known as the ‘Indian father of surgery,’ was the author of one of two foundational Sanskrit texts on Ayuverda, a historical system of medicine originating in ancient India. Chakara was believed to have received his knowledge from a seer who themselves had been given the
knowledge from Dhanvantari, the Hindu god of Ayurveda. Chakara’s work on surgical techniques and medical ethics was so profound it went onto transverse cultures across the globe and was translated to both Arabic and Latin.
Across the world, civilisations linked scientific endeavours to stories.
In Egypt, Imhotep became a deity to modern-day humans, despite living 27 centuries BC. Imhotep or ‘He who comes in peace’ was an Egyptian chancellor and ancient scripts show him to be the potential ‘father of medicine.’ His status reached mythological heights in his death, when he became the anointed god of healing. While Hippocrates has been largely attributed with the status of having laid the foundations for what we call medicine, medical papyri dated 1500BCE suggests sophisticated medical practices were in use by ancient Egyptians nearly 1,000 years before Hippocrates was born. The merits of the intellect preserved through ancient and, not so ancient, storytelling, myths and legends are far reaching and evidently worthy of appreciation, or at the very least acknowledgment. Perhaps the next time you look up at the night sky, tackle a differential equation or head to the GP you will feel the weight of a history of science unbound by textbooks or confined to definitions.
Image left: Nur Pirbhai Image right: Amelia Brown [Unsplash]
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Sex. The word that fills the minds of everyone from teenage boys to Queen Elizabeth II herself: sex is inescapable. Every creature on the planet has sex, either with another of its kind or with itself. Sex is as inevitable as death and taxes (or so the saying goes). So why then, in the six million years we as human-like apes have populated this earth do we still find it so uncomfortable to talk about? Generally speaking, when we talk about sex it is with friends and partners (it is less likely you’ll ask your boss when their last good shag was, for example). We share stories with people who we can trust with our deepest and dirtiest secrets, without fully realising why they make us feel SO dirty. To uncover our own embarrassment, we must look at how our society is and how it has been structured from the top down. As the saying goes, ‘everything is about sex, but sex. Sex is about power.’ Power is incredibly important when we look at other taboo subjects in society, for instance money. Though attitudes are changing, a 2015 Study by University College London showed that around 80% of people would feel highly uncomfortable discussing salaries at a dinner party, and this is due to the power dynamic that is created. When something like money is discussed, an imbalance forms; the person who
has more, versus the person who has less, generating an immediate implicit competition.
is regulated by organisations, e.g. sex being permitted only with the blessing of a spiritual leader.
Sex, in all animals, is inherently competition, and this bears true for everything from flowers to the birds and the bees themselves. Sex is valued so much by animals due to its essentiality to our maintenance as species’, thus the rewards we get as humans from the act itself in the form of dopamine. There is so much value placed on sex and the competition that comes with it, that it is impossible to deny the potential for embarrassment in a scenario where sexual competition happens.
While sex started to become regulated by powers, it was also at risk of being oppressively commodified. Sex, and the offspring produced of it, became a bargaining tool in the eyes of the patriarchal powers. With sexual acts now policed, women could be used as bargaining tools by the wealthy to join families, transfer wealth, and build empires. With so much power placed in the hands of controlled sexual practices, women being free to make their own sexual choices (even down to the language they used) presented a challenge to patriarchal dominance, and so continued to be vilified, adding to societal shame about discussing sex.
Sadly, the power that sex commands also enables an abuse of power. Sex has been used as a means of control in all mammal life, with coercive mating presenting frequently throughout the animal kingdom. In humans, society has developed deplorable practices like this for widespread sexual control, with oppressive powers creating laws and customs which allow people with the highest power to have the highest control over sex. Widespread condemnation of many sexual practices by governments and religious organisations have transformed sex into a moral issue, where sexual activity
The oppression of women’s sexual choice also impacted how a lot of different sexualities were then perceived in society, and the freedom of which they could talk about their own sex lives. Many queer theorists view misogyny as the root of anti-queer language when discussing sex, as it would be presented as an attack on the heterosexual male power position of what kind of sex could be discussed, and by whom. When we look forward, it is no coincidence whatsoever that a lot of queer rights and women’s rights movements happened simultaneously in the West, as both
The internet acts as a screen in which the real world is reflected.
252 MILLION YEARS AGO: PERMIAN-TRIASSIC MASS EXTINCTION – MOST CATASTROPHIC MASS EXTINCTION PRESENT IN THE FOSSIL RECORD
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Anthony McGarry undresses the stigmas we all face around the one thing we have in common: sex. aimed to challenge the heterosexual male power position of what kind of sex could be discussed, and by whom. When we look forward then, it is no coincidence whatsoever that a lot of queer rights and women’s rights movements happened simultaneously in the West, as both aimed to challenge the heterosexual patriarchy on its control over sex.
habits when it comes to sex in the media. Most of what we are shown, particularly through pornography and social media, is highly stylized and incredibly unrealistic to the average person (anyone up for a completely synchronised orgasm?),
In today’s world, our own confusion about what kind of sex other people are having is a huge contributor to lack of open discussion societally. However, 21st century revolutionaries are breaking these trends. One of these such people is award winning sex and relationship content creator ‘Oloni’ (@oloni / @ laidbarepodcast). It is impossible to be a millennial on Twitter and not have read a Twitter thread by Oloni, discussing all matters of sex, love and relationships. The completely open platform of Twitter for discussion enables a wide conversation to happen about sex, helping its users to realise that we have all had more similar experiences than we would have previously thought.
Today, in the UK in 2018, we enjoy a lot of sexual freedoms a result of these mid 20th century revolutions: we have reduced the stigma about no-strings-attached sex, non-heterosexual relationships, and government sponsored sexual health campaigns. However, samesex marriage is still not permitted in Northern Ireland, and these political barriers to accepting non-heterosexual relationships greatly affect how we discuss them in society. Who wants to admit they can t in fact do the splits upside down for threehours yet instead got a stitch three minutes into missionary? Even with greater social acceptance of sex in all its forms, we have a long way to go when it comes to the discussion table about sex. In spite of our reluctance to talk about sex, we are constantly surrounded by it. Sex is used to sell us everything and is ever present on TV, the internet and social media. Herein lies some of the issues that surround sex as a topic. The type of media with which we see sex is relatively new compared to human society (internet porn itself only came into fruition just over 20 years ago) and so we are still establishing our societal rules and
which creates even more stigma about what we choose to say. Again, this feeds back to our fear of the potential for embarrassment: who wants to admit they can’t in fact do the splits upside down for three hours yet instead got a stitch three minutes into missionary?
Image: Charles Deluvio [Unsplash]
The internet acts as a screen in which the real world is reflected. Perhaps the more we all take active responsibility for our taboos and start to read and talk about sex on the internet, the more we will naturally find ourselves talking about it in real life as well. The taboos surrounding sex are symptomatic of an era of greater oppression and reflect on a deeper-ingrained global misogyny. When we start viewing our reluctance to talk about sex as such, it may make it easier to throw away these old prejudices and start to have more healthy, more natural conversation about all our sex lives.
230 MILLION YEARS AGO: OLDEST DINOSAURS
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Imagine you were walking through a garden and happened to stumble across a rock. Would you question how the rock came to be there, or would you assume it had lain there all along? How about if you stumbled upon a pocket watch in the same way. Would you have the same response? Naturally, you would assume someone else had walked this path before you and accidentally mislaid it. The watch isn’t just there by accident. This has been a longused analogy, elaborated from the ideas of William Paley, to support notions of a great Watchmaker, a designer of our world and all life on Earth, including humans ourselves. The ongoing debate of evolution versus creation has a long history that needs little introduction, and there remains no definite understanding of how humans came to be in their current form. On the one hand, we have the concept of creation, which states that we were intelligently designed by an omnipresent force, borne of divine intervention, appearing fully formed. Conversely, we have science and the theory of evolution, the idea that the human race has developed, and will continue to develop, through something of a trial and error process over millions of years. Philosophers have long used time-
pieces to display arguments about purpose, and Paley’s Watchmaker analogy is no exception to this. His argument states that if a pocket watch is accidentally discovered by a bystander, the most reasonable assumption to make would be that it was simply dropped, and that it was made by at least one Watchmaker, making it somewhat absurd to think it was created over a period of timeby natural forces.
Some of the earliest examples of rituals performed by humans were built on the belief that death was not the end of life, but merely a transition to something greater. Now, you may be thinking that watches are in no way similar to humans, or the planet for that matter, but for the sake of a purely philosophical argument, it’s worth hearing Paley out. He argued that living things tend to have very complex and intricate structures, and that we are very cleverly and elaborately designed, to the point where deliberate creation seems like the only explanation for our existence. We were designed: we must therefore have a designer. Paley sees this designer as God, and believes that out of all the organisms living on this planet, humans were God’s top priority.
However, there are some criticisms of this analogy. The first of these is that complexity does not strictly point towards the idea of a designer. Philosophers such as David Hume have used naturally occurring objects such as snowflakes and crystals to argue against Paley’s analogy. Snowflakes and crystals are as intricate as pocket watches, but their designs are spontaneous and unique and require little in the way of further investigation. The role and nature of the Watchmaker have also come into question. It is argued that, although the pocket watch itself is complex, the Watchmaker must surely be even more complex. Paley, however, did not suggest an argument over who designed such a complex Watchmaker to begin with. In fact, any suggestion of a higher being than the Watchmaker could lead to potentially recursive and unending investigations, resulting in there being the possibility of a chain of designers, each more complex and superior than the last. The pocket watch itself would fade into irrelevancy at this stage, as the ever-increasing string of Watchmakers causes us to seriously question the many levels of creation. Many scientists have also questioned the Watchmaker analogy
65 MILLION YEARS AGO: END CRETACEOUS MASS EXTINCTION – SAW THE EXTINCTION OF THE DINOSAURS
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Nur Pirbhai asks if there really may be a creator of life, the Universe, and everything....
and prefer the approach of explaining the current human state with evolution by natural selection. As is commonly known, the theory of evolution by natural selection was proposed and developed by Charles Darwin and Alfred Russel Wallace in the 19th century. The concept of natural selection proposes that offspring produced by individuals show great variation, and that many species produce more offspring than will eventually survive. Essentially, the chances of an offspring’s survival are dependent on whether their traits are favourable and aid in their survival. As this continues, the variation within a species decreases, as the more favourable traits are selected and reproduced. The aim, therefore, is to have an ‘ideal’ product: an organism of that particular species which has survived through the waves of variation, having already filtered out the undesirable characteristics. Following this line of argument, it becomes increasingly difficult to compare humans with pocket watches. Although the science behind our existence is supported with evidence linked to Darwin and Wallace’s theories (which, as we know, have become popularised in an increasingly secular world), belief in creationism remains fierce. Religion has taken many forms throughout human history and the development of human culture, but it has
remained a constant all the same. Some of the earliest examples of rituals performed by humans were built on the belief that death was not the end of life, but merely a transition to something greater. Death in this life meant you would meet your ‘Watchmaker’ in the next one. Most known human cultures have established myths and stories concerning creation and our world. At present, data from the Pew Research Center’s Forum on Religion and Public Life suggests that around 84% of the world’s population identify as being part of a religious group, or state that religion is an important part of their lives. Religion has taken many forms throughout human history, but what seems to unite the spectrum of religious belief is a sense of purpose, of serving something greater. It attempts to embed ethics, values and a particular state of morality into a person during their developmental phase that will reward them once this life is through. Many scientists have suggested explanations for our natural predisposition to believe in a god or higher power, and for the role religion plays in our lives. Might it be the human mind’s method of confronting mortality and existence? Is it an expansion of how we view other people in our lives, or a symptom of our predisposition to attempt to
comprehend the incomprehensible? As humans, we project our emotions onto what surrounds us, and it is likely that this predisposition forms the foundations for what we recognise as faith and religion. Searching for tangible evidence of this predisposition, neuroscientists from the USA National Institute of Neurological Disorders have analysed the structure of brains belonging to both believers and non-believers to find what is theorised to be a “God spot,” an explanation for our predisposition towards believing in a creator. They have also attempted to observe differences in the brain during prayer. While it has been identified that certain regions of the brain are more active in believers than sceptics, especially during times of prayer, these differences are considered to share a closer relationship with community spirit as opposed to spiritual beliefs, and there remains no finding of any undisputed and specific “God spot.” What we do know, however, is that the human brain is the most complex in the animal world, and it’s going to take a lot more work to understand this complexity. If only there were a Watchmaker we could ask. Image left [words]: Céleste Nilges Image left: [background] Gaspard Nilges Image right: Ivan Mogilevchik [Adobe Stock]
0.35 MILLION YEARS AGO: FIRST EVIDENCE OF HOMO SAPIENS
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Searching for the Elixir of Life Could humans ever find the key that would allow us to live forever? Dani Ellenby investigates. Over two thousand years ago, the first Emperor of a unified China, Qin Shi Huang, died suddenly at the age of 49. But despite numerous assassination attempts against him, his death was ultimately by his own hand. In a cruel twist of irony, Qin Shi Huang died of poisoning after ingesting an Elixir of Life containing mercury, which he believed would make him immortal. Qin Shi Huang may have been the first, but over the centuries, many others would also die in pursuit of immortality. Immortality has long been an obsession of humankind. Our most primal instincts are there to ensure our survival. We have a deeply entrenched fear of death. Ideas of immortal beings or eternal life have permeated our religions, works of literature and core societal values. And now, potentially within our lifetime, science may progress far enough to finally put immortality within our grasp. In order to cheat death, scientists must first understand why we die. There are three main causes of death in humans – disease, physical trauma and ageing. In developed countries such as the UK, the most common cause of death is ageing, due to the onset of aging-associated diseases such as cardiovascular disease, cancer and Alzheimer’s disease. While society has made leaps and bounds towards treating and curing diseases, ageing still remains an impenetrable barrier to humanity’s quest for immortality. But why do we even age at all? Ageing is an extremely complicated process that scientists are still trying to understand, with many factors at play. However, ageing has been found to be strongly associated with our cells losing the ability to divide.
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Throughout our lifetimes, our bodies are constantly receiving damage from the external environment and from the internal reactions inside our cells. Our bodies contain populations of cells called adult stem cells, which divide to replace old or damaged body cells. But as we get older, our adult stem cells lose their ability to divide and damaged cells build up, resulting in the deterioration of organ function and leading to ageing-associated diseases. Although currently an inescapable part of human biology, many creatures on this planet have successfully evolved ways to avoid the ageing process. By studying these organisms and their underlying cellular mechanisms, scientists hope to discover the key to immortality. One team of scientists, led by Professor Aziz Aboobaker, previously at the University of Nottingham and currently at the University of Oxford, has been researching one of these species – the flatworm, Schmidtea mediterranea. This somewhat kooky-looking creature, with its big cartoon eyes, hides a powerful secret. The asexual strain of this flatworm (or planarian) does not appear to undergo ageing. Therefore, if this planarian successfully manages to avoid predation, starvation or disease, it has the potential to live forever – a concept known as biological immortality. But how are they able to achieve this extraordinary feat? The incredible longevity of these flatworms is due to a large population of stem cells in their body, which differ from human adult stem cells in two crucial ways. Firstly, they are capable of forming all the different types of cell found in a
flatworm and secondly, they can divide indefinitely, therefore creating new, undamaged cells. These stem cells are called neoblasts and as well as preventing the flatworms from ageing, they also give the species incredible powers of regeneration. “We can take a worm, and cut it into several pieces, and each new piece regenerates into a whole new worm,” Professor Aboobaker told Test Tube. This regenerative power is exploited in the asexual strain of Schmidtea mediterranea, with the flatworm naturally tearing itself in two in order to reproduce, in a process known as fissioning. In order to cheat death, scientists must first understand why we die. Research is currently being conducted into the special properties of neoblasts in order to figure out why these cells capable of dividing indefinitely, while our adult stem cells cannot. Scientists from Professor Aboobaker’s team investigated whether neoblasts showed unusual activation of an enzyme called telomerase, also dubbed the “immortality enzyme”. This enzyme is integral to allowing cells to divide indefinitely. When a cell divides into two cells, all the genetic information inside the cell must also be copied. In animals, the DNA that encodes the genetic information of a cell is stored as long, linear strands called chromosomes. However, the mechanism by which our chromosomes are replicated means that a tiny piece of DNA at the end of each chromosome cannot be copied.
This results in our chromosomes becoming shorter after every round of cell division. In order to prevent important genetic information from being lost, the ends of our chromosomes contain protective caps called telomeres, which are repetitive lengths of DNA. High telomerase activity allows cells to divide without limit, but our telomeres become shorter and shorter every time a cell divides until they reach a critical length which prevents the cell from dividing further. However, the enzyme telomerase can re-lengthen these telomeres. We all carry the gene for telomerase inside us and this enzyme remains active in our egg and sperm cells. Without any telomerase activity, every subsequent generation of humans would have shorter telomeres and our species would quickly become extinct. However, once born, telomerase has a very low rate of activity inside our adult stem cells, which increases the number of times adult stem cells can divide but is not high enough to maintain telomere length. In our specialised body cells, the gene that codes for the telomerase enzyme has been completely switched off and there is no telomerase activity at all. However, a very different story was seen in the asexual strain Schmidtea mediterranea. When this flatworm undergoes fissioning or is manually cut into pieces, the activity of the telomerase enzyme is increased in neoblasts during the process of regeneration. When scientists measured the length of the telomeres before and after regeneration, they found that the telomeres had increased in length. The regenerative process therefore allows the planarians not only to regrow their body, but also to rejuvenate their cells, through the mechanism of the enzyme telomerase. Further investigations into how planarians
avoid the ageing process, such as the specific cellular processes that increase telomerase activity during regeneration, could allow scientists to shed light on how to avoid the ageing process in humans. However, increasing the activity of the telomerase enzyme in humans could be a double-edged sword. This is because we are walking a biological tightrope between ageing, when cells stop dividing, and cancer, which is caused by uncontrollable cell division. It is thought that inhibition of telomerase activity in our body cells may have evolved for an important reason; to suppress the development of tumours. It is feared that if we increase telomerase activity in human cells, we may also increase the risk of developing cancer. It may be that just like the Elixir of Life ingested by Emperor Qin Shi Huang thousands of years ago. Activation of the telomerase enzyme in human cells could potentially extend our lifespan, or it may disastrously shorten the already precious time we have to live our lives.
Images: Hannah Ryan-Leah, Guilio Bernardi
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Cover Images [Front, Back]: Harry Lampert