UoB LIFE SCIENCES MAGAZINE
THEMISSINGLINK Issue 8
February 2008
Feature: Butterfly larvae hitch a ride with the red ants New: In Focus
WHAT’S ON THIS MONTH?
Mon 4th 1:05 B37 Biological Sciences (BS) Research Seminar: Professor Steve Redpath, University of Aberdeen, Population dynamics and the role of intrinsic and extrinsic mechanisms. Tue 5th 1:00 2D24 Psychology Department (PD) Talk: Sven Mattys, Effects of processing load on speech recognition 5:15pm Staff Common Room (BS) Workshop in Ecology and Behaviour: Ashleigh Griffin, University of Edinburgh, Social evolution and communication. Lunchtime (BS) Biosoc film: Check email for details
Mon 18th 1:05 B37 (BS) Research Seminar: Dr Simon Webster, Bangor University, How crabs moult - neuroendocrine reflections. 1pm 2D24 (PD) Talk: Marcus Munafo, Pharmacogenetics of Smoking Cessation Tue 19th 5:15 Staff Common Room (BS) Workshop in Ecology and Behaviour: Joah Madden, University of Exeter, Sexual selection and communication in bowerbirds Lunchtime (BS) Biosoc film: Check email for details
Wed 6th 4:00 2D2 (PD) External Talks: Geraint Rees, UCL, Decoding Conciousness
Wed 20th 4:00 2D2 (PD) External Talks: Professor Susan Gelman, Michigan, Generic language as a window onto conceptual development
Thurs 7th 5:00 Staff Common Room (BS) Round Table Talks: Chloe Onoufriou Charophyte distributions in the Cotswold Water Park, Richard Sherely Spotting the difference: Towards automatic population monitoring of African penguins (Spheniscus demersus), Dr Deirdre McLachlan Light-induced motility in benthic diatoms and the role of calcium signalling in a photomotile response
Thurs 21st 5:00 Staff Common Room (BS) Round Table Talks: Hugo Rebelo Where to go when it’s too hot? Effects of global warming in the future distribution of tree-dwelling bats, Catherine Davey The effect of game management for pheasant shooting on vertebrate biodiversity in UK woodlands,Dr Stuart Casson Meristem maintenance in the Arabidopsis root
Mon 11th 1:05 B37 (BS) Research Seminar: Professor John Endler, University of Exeter, Testing hypotheses about elaboration, innovation and species recognition with Australian Bowerbirds
Mon 25th 1:05 B37 (BS) Research Seminar: Professor Rod Scott, University of Bath, Engineering seed yield - lessons from Arabidopsis
Tue 12th 1:00 2D24 (PD) Talk: Tom Troscianko, Shadows Lunchtime (BS) Biosoc film: Check email for details
Tue 26th 1:00 2D24 (PD) Talk: Ian Penton-Voak, TBA Lunchtime (BS) Biosoc film: Check email for details
Wed 13th 4:00 2D2 (PD) External Talks: Dr Christian Keysers, Groningen, Mirror systems and social cognition
Wed 27th 4:00 2D2 (PD) External Talks: Dr Gemma Calvert, Bath, Commercial applications of neuroimaging methods
Thurs 14th 5:00 Staff Common Room (BS) Round Table Talks: Ben Knott Line of sight: Intra-retinal variation in the visual physiology of Platycercus elegans, Michael Panagopulos TBA, Professor Tony Walsby Measuring turgor pressure in cyanobacteria
Thurs 28th 5:00 Staff Common Room (BS) Round Table Talks: Crawford Winlove TBA, Christopher Thorogood TBA, Professor Gareth Jones Molecular evolution of a protein involved in mammalian active hearing
Missing Link Editorial Team
Head of Production: Anna Leon Editor: Ariane Whitehead Assistant Editor: Agata Staniewicz Design Editor: Emma Clark Art Editor: Nadège Laici Secretary and Treasurer: Sophie Morgan Proofreaders: Anita Singh, Sarah Haigh, Angharad Rolfe Johnson, Katy Blatch. Supervisors: Laura Saez, Nick Easton Head of Marketing: Carsten Reinhard
The Missing Link Dear Life Scientists, Welcome to the first issue of 2008. The New Year sees in a new editorial team and a new look for the magazine.
This new issue brings you fabulous articles from very talented writers within the life sciences that can be both entertaining and controversial.
Firstly I would like to thank the previous editorial team for all their hard work and, in particular, Laura Saez – founder of the Missing Link. Had she not had such insight and dedication, the life sciences would certainly be lacking what has become an important magazine for all those who have an interest in science communication, and reading everything from the latest scientific research to people’s experiences of travel and working in the field.
We hope that you enjoy reading this issue as much as we’ve enjoyed putting it together and hope that you will be inspired to join us as we expand our scope into new fields. Ariane, Editor
CONTENTS
FEBRUARY 2008
Features The birds and the bees A fool’s guide on how to impress your mates The scent trail Hannah Welham discovers that the Alcon blue butterfly dumps its babies on unsuspecting red ants Global warming Who cares about it anyway?
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Life insurance and life assurance 10 Could we be facing higher insurance premiums as advances in genetics allow us to determine our fate? Psychological assumptions 14 The psychology behind experimenter bias Evolution 16 What do people really know about the theory of evolution?
Regulars News and events How the Might Fall “1000 Genomes Project” Curried Bird Flu In focus Showcasing your favourite photographs Cockatiels and cocktails Stories from the field
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Interview 20 Dr Simon Braddy: The giant sea scorpion Comment 22 Arthur Goldsmith voices his opinions Review 23 “Elephantoms: Tracking the Elephant” by Lyall Watson Entertainment 24
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News and events
News The latest updates from Theo Webb How the Mighty Fall During the last 5 months the Amazon rainforest in Brazil has suffered the worst deforestation on record. The announcement was made by the Brazillian government based on satellite imagery from the National Institute of Space Research, which shows that during the last 5 months of 2007, 1,250 square miles of rainforest were lost. It is suggested that increases in commodities such as soya have encouraged the illegal deforestation of areas to allow for the cultivation of these crops. This data comes after the success of pioneering legislation in early 2007, which saw a significant decrease in illegal logging. www.bbc.co.uk/news
“1000 Genomes Project” Tuesday 22nd January 2008 saw the launch of the “1000 Genomes Project”, an international project aiming to sequence 1000 individuals’ genomes with the hope of guiding researchers to disease-associated regions on the genome and to hasten supplementary follow-on research. Although some observers have questioned whether the project is ambitious enough, the high number of people will allow scientists to look at a greater variation of structural differences than in previous studies and will compare areas of DNA deletion, duplication and rearrangement. www.nature.com/news
Curried bird-flu The much-forgotton bird-flu virus is still continuing it’s spread across the world with the virus spreading through domestic fowl populations in India. The state of West Bengal in northeast India has seen the H5N1 virus spread into more of the state’s districts, however people are releuctant to hand over the birds for culling. It has been estimated that two million birds need to be destroyed to prevent further spread of the highly pathogenic virus, which can infect most birds and has been known to spread to humans. www.bbc.co.uk/news
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Events What’s on in and around Bristol this month Shell Wildlife Photographer of the Year 2007 - Winning and commended images from this year’s competition. Until 27 April 2008: Natural History Museum, London. Nature in Art, Gloucester www.nature-in-art.org.uk It’s a bird’s life - Tuesday 5th February. Bristol Zoo. Ed Drewitt will give an intriguing insight into the wild antics and behaviour of birds on the Downs and in your gardens. 7.00pm – 8.00pm £3.00 Identifying mosses and liverworts - Saturday 23rd February. Delve into the wonderful world of mosses and liverworts with expert Justin Smith. We’ll venture into Nightingale Valley in Leigh Woods to learn how to identify these marvellous flowerless plants. 10.00am – 4.00pm £15.00 Run jointly with the National Trust. Environmental Photogrpaher of the Year - Entries are now being welcomed for this annual competition. Closing date 31 July www.ciwem.org/awards/epoty Biosoc Photography Competition The theme is “Making the most of our time on Earth”. The limit is 3 photos per participant and you should send them to either Robin (rl5766) or Jeremy (jc6135). The deadline is the 7th of Feburary. www.bio.bris.ac.uk/biosoc
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Biology
The birds and the bees A fool’s guide to how to impress your mate Agata Staniewicz Flowers, a romantic candle-lit dinner or even just a heart-shaped card may for some people appear to be more than enough effort put into celebrating Valentine’s Day. Yet, none of it seems very impressive when we look at other species’ mating habits. The purpose of life – reproduction – has led to many interesting and extraordinary examples of mating behaviour. So if you’re trying to think of a new way to impress that special person, here are a few tips based on what has worked well for birds and bees. Looking good is an obvious way to attract a mate and the reason why male peacocks have such huge colourful tails. The more beautiful the tail is, the bigger the chance of the male succeeding in finding a partner. However, there’s still hope for the less attractive peacocks as they often decide to join leks – groups of males displaying together. This is because peahens are often attracted to large groups rather than individual males, so as a lek there is more chance of getting yourself more females. Boogie on down This is all very well and good but displaying the plumage is only one of the ways to impress a girl and
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some less colourful species have to think of other ways to show off. Many birds sing but male manakins have gone one better and perform a dance that would make Michael Jackson proud. The main steps are as follows: fly quickly up into the air, swoop down and land on your perch, then lean over and quiver your tail, flap your wings against your sides and then start to moonwalk backwards – just like the King of Pop! Bowerbirds have a different approach. They do not dance but use twigs to build a very complex hutlike structure called a bower. They then decorate it with various ‘gifts’: stones, flowers, leaves, feathers, and even pieces of glass or dead beetles – all of which they arrange in separate, monochromatic piles. This gives them a slight advantage over the species that display their feathers: they can choose which colour they prefer to seduce the female with. Obviously, making a nice bower takes time and indeed bowerbirds spend hours arranging their huts and will only stop in order to go to other males’ bowers to steal things or mess up their rivals’ displays having potentially disastrous effects – we all know how ladies like to keep things tidy!
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Love gardens A similar behaviour can be observed in red velvet mites – the tiny red arachnids (you may know them as ‘bloodsuckers’) that can sometimes be spotted on stones and bricks. Male red velvet mites leave their sperm on twigs and stalks in what is called a ‘love garden’ and then perform a ‘mating dance’ leaving a silken trail leading to their place. When the female finds the trail she will follow it to find the mite. If she likes his work, she will sit on the sperm in his garden. However, if another male stumbles upon the garden, he will destroy it in order to place his own sperm there. Sometimes it’s the female that leads the males to her. When the female red-sided garter snake emerges from hibernation, she releases a pheromone that attracts hundreds of males to come and create a huge ‘mating ball’. Each male snake has two hemipenises (left and right) and will use whichever one is more convenient to try to mate with the female in the centre of the ball. In case of the barnacle – small marine crustacean that sticks to stone and boat surfaces – approaching a female can be rather problematic. It doesn’t have to compete with hundreds of other males, but once the barnacle sticks to a surface it won’t move again (unless you kick it off… though of course we do not condone this kind of behaviour!). So in order to mate, it evolved a huge inflatable penis that can reach the length up to seven times the barnacle’s body size. The barnacle will then reach out probingly with its penis to mate with its neighbours. But what to do if despite all our efforts there are no mates around? A good way to solve
the problem of finding a mate is to create your own! A parasitic mite of earthworm cocoons lays unfertilized eggs that turn into male mites. She then copulates with them (after which they quickly die) and lays another batch of eggs. Women Only For some reptiles, no males are necessary – whiptail lizards are all female. They reproduce by parthenogenesis – females lay unfertilized eggs out of which hatch more baby females. In other words – they clone themselves, which solves the problem of finding a mate. However, the female needs sexual stimulation to lay eggs – this can be a little difficult if there are no males. The lizards cope with this problem by pseudocopulation: two lizards play a sex game where they act out roles of a male mounting a female. I am not suggesting we try to copy all of the ideas found in nature but I’m sure there are some useful tips to be found here for those who are a little less lucky in love! Moonwalking turned out to be a huge success, though please take note that piles of dead beetles may not be the best idea for a romantic Valentine’s gift even if they are colour co-ordinated to match her room. Especially since in some cases mating can end rather lethally – the male honey bee explodes during copulation leaving its penis as a permanent reminder inside the female. This approach clearly has an advantage as the penis stuck inside the body will prevent the female from copulating with someone else, so even though the male died, at least he can be sure he will be the father of the offspring and rest in peace.
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Biology
The scent trail Cover feature Hannah Welham discovers that the Alcon blue butterfly dumps its babies on unsuspecting red ants – how come they’re so easily fooled?
Causing chaos and commotion throughout the animal kingdom, mimicry is a process that biologists the world over are fascinated by. Of course, as humans we can often be found guilty of some spiteful imitation and it is all too easy to assign the anthropomorphic trait to the rest of the animal kingdom. However, for many species the manipulative phenomenon lies at the very heart of survival and persistence. Hopefully by now most of us will be aware of the usual suspects, in particular the cuckoo tricksters who manage to be reared by unwitting songbirds, often at the expense of four or five true progeny. A not so common example is that of the Alcon blue butterfly grub, Maculinea alcon, who deceitfully mimics its neighbouring ant larvae to earn a feeding place in the underground colony of the adult Myrmica ants. Smelly fats This unusual habit is fuelled by
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an unusual life cycle for the butterfly, who starts life as an egglain deftly on such marsh gentian plants as Gentiana pneumonanthe. Here, it comfortably lives out its first three larval stages, feeding on these abundant marsh plants. On reaching its fourth larval stage, the Alcon blue drops to the unwelcoming ground, where its trickery begins. The marsh floor is also home to two species of red ant, Myrmica rubra and Myrmica ruginodis, which carpet the ground in densely populated colonies. In such large and busy communities, communication is key and is achieved by the ants through the formation of colony-specific hydrocarbon odours. These scents lie as fatty residues on the surface of the ants’ bodies and act as friendly markers. Normally, adult workers of the Myrmica genera identify their larvae by recognising these hydrocarbon molecules. Once identified, the young are swiftly carried away to the safety
of the nest site. Cleverly, Alcon blue grubs have adapted to produce the same hydrocarbon molecules on their surfaces, generating perfect chemical matches to the ant larval scent. Unsuspecting Myrmica adults are then easily duped as they carry what they believe to be a vulnerable member of their own colony straight into the thriving, energy rich nest. The higher the degree of scent matching achieved by the Alcon blue grubs, the more likely they are to reach the heart of the nest. Here, Alcon blue grubs act as unforgiving social parasites, receiving food before nest natives and even killing Myrmica larvae to ward off competition. Decline in numbers Despite having developed such clever survival mechanisms, the Alcon blue is rapidly dwindling in its European and Asian strongholds, making it the perfect target for conservation efforts. Working on one such conservation project from the University of Copenhagen’s Centre for Social Evolution (CSE), Danish scientists David Nash and Jacobus Boomsna have recently uncovered some fascinating evolutionary history within the Alcon blue’s mimicry. Whilst mapping out locations in Denmark where the rare butterfly can be found, the scientists noticed that the Alcon blue have an even smaller geographic range than expected, living in small patches on the Jutland peninsula. Here, their habitats only overlap with those of the Myrmica
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environment is changing, the Alcon blue parasites then adapt their hydrocarbon secretions to once again match those of their hosts. This concept of alternating success for opposing populations is a very common one in biology.
“The matter of attack versus resistance isn’t that simple” species in small areas, meaning
that where you find the host, you don’t normally find the parasite. The arms race With numbers of Alcon blue butterflies falling and ant colonies continuing to thrive, you might be surprised that the Myrmica workers put up with the parasitism at all. Of course, despite the differences in population size, the
matter of attack versus resistance isn’t that simple, as both species become locked in an evolutionary arms race. As the number of parasites in an ant colony increases, the selection pressure for resistance within the Myrmica colony also rises. The workers quickly adopt new ways of smelling, literally sniffing out the intruders within their midst. Sensing that their once unwittingly hospitable
By mapping out the habitat regions of both the Alcon blue and the Myrmica species so specifically, Nash and his colleagues were able to go one step further with their evolutionary analysis. They have been able to show that due to the relatively small overlap of host-parasite populations, the Alcon blue is not in imminent danger of extinction as long as it can keep up in the arms race. While the Myrmica populations remain more widespread than those of their social parasites, they will never be able to achieve full resistance. Nash explains that resistance can only work in the Myrmica colonies when a parasitised ant queen mates locally with males that are also under pressure to develop resistance. As it stands, males from colonies that are free from social parasitism migrate to mate with these same queens, diluting any potential resistance. In this way, the next generation of Myrmica workers must always start from the drawing board in terms of fighting the Alcon blue. Whilst the Alcon blue appears to be at no immediate risk, Nash’s groundbreaking work shows just how important an understanding of evolutionary theory can be in aiding a conservation interest.
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Devised by Ariane Whitehead, Illustrated by Louisa Steaton.
Who cares about global warming anyway? Anita Singh delves into our psyche to try to understand why no-one seems to get the urgency of ‘climate change’ The effects of global warming are becoming increasingly difficult to ignore. The extreme weather patterns, the melting ice caps, the rising sea levels. It’s hard to find a climate scientist these days (apart from perhaps those funded by oil companies) who will deny global warming and it’s potentially catastrophic consequences; even your average-Joe knows there’s something going on. So why is no one doing anything significant about it? Why aren’t our governments giving this crisis the attention it requires? Without wanting to launch into a full scale rant about how we are slowly killing the planet we are living on, here are a few psychological explanations of why the world insists of being so blasé in the face of global warming. The bystander intervention (or lack there of) phenomenon should
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be familiar to most people, all of us have used the excuse “Well no one else is doing anything, why should I?” at some point in our lives. So what if global warming is threatening our planet? Why should I give up my cheap flights to Europe or my imported clothes/ food/gadgets? If it is so important why isn’t someone else doing something about it? This rather depressing human trait seems to be unavoidable, but surely we, creatures so praised for our free will, should be able to override this initial reaction. Well, there may be more to it than simply skipping out on a sense of personal responsibility. Incentives It seems that in order for us to react appropriately to what is essentially a risky situation we need a negative emotion, e.g. fear or anxiety, to motivate us. This fear
typically comes either from personal experience of what will happen if we take the risk (the same way that you’ll never go back to that Chinese take-away place that gave you food poisoning) or from simply thinking about what might happen if we take the risk. Obviously personal experience is far more effective (it takes the full painful ordeal of a 9 o’clock lecture with a hideous hangover to make you think twice next time you want a night out, a mere thought experiment never works) but sadly in the case of global warming we don’t have enough personal experience of what will happen if we take the risk not to do anything about it. And of course, the irony is that although one day we may have very personal experience of exactly how bad it can get, by that point it will be far too late. So what can we do to make people care?
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We can try to make the costs of taking the risk not to do anything about global warming more vivid and conceivable to people, but unfortunately governments around the world appear to be doing the opposite to this, insisting on the use of the much less threatening term ‘climate change’. We could try to redirect people’s worry about terrorism towards a more global threat, as it is claimed we have a finite pool of worry and tend to worry about a limited range of things. The media could step in and make the world as concerned about global warming as it was about the ‘Millennium Meltdown’ only a few years ago. But still we would face the problem of bystander intervention which leaves us with no one willing to commit to a change in lifestyle. Perhaps it’s too late and we should just live what life there is left to the full? Or perhaps the governments should institute laws, effective immediately, to cut carbon emissions? Globally no one can agree on what steps to take and this opens up an entirely new can of worms – I could go on but I shall cease my rant for now before it gets from me...
Feeling inspired to make a difference?
Join Earth Hour Ariane Whitehead
Yes – even though you thought it was futile and that we were all doomed to an unimaginable destruction as the planet spirals uncontrollably down into an abyss of nasty globally-warmed goop… it turns out you actually can make a difference. It will take you only one hour, and you needn’t leave the comfort of your own home. All you need to do is turn off the lights. Really – it’s as simple as that! Earth Hour 2008 is being hosted by the WWF and will take place on Saturday March the 29th at 8pm. It is the successor to an incredibly successful energy switch-off in Sydney last year where the whole city turned off its lights for just one hour – individuals and businesses alike were united in their cause as the city was plunged into darkness. The resulting dip in energy
consumption for this one city was immense and, according to the WWF, amounted to a reduction by 10.2% in Sydney’s energy expenditure during the switchoff. They went on to reveal that this was “double the anticipated energy saving and represents a reduction of 24.86 tonnes of carbon dioxide – the equivalent of taking 48,613 cars off the road for an hour.” This year Earth Hour is not confined to Sydney alone, but is a global event in which you need to be involved. Please sign up and encourage all your friends to join you in perpetual darkness (or for at least an hour of it) on March 29th, and be instrumental in saving your planet from the brink of destruction.
For more information visit http://www.earthhour.org/ [9]
Could we be facing higher insurance premiums as advances in genetics allow us to determine our fate? Sophie Morgan
Life insurance and life assurance Life insurance has existed since Roman times, when families paid monthly contributions to funeral directors to ensure an impressive ceremony. Most people in the UK today will have some sort of policy, funded by their employer, their partner or themselves. In the past, life insurance was almost always a gamble. Who could possibly know when the inevitable would eventually happen? Today however, science has raised some awkward questions for large companies, and some financial dilemmas for individuals. Genetic Disease Genetic testing is now relatively simple. Geneticists can compare DNA samples from large numbers
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of people, some suffering from a particular illness, and some who are judged to be healthy. Any genetic differences on certain portions of DNA could signify a gene that causes the illness, or makes the illness more likely to occur in combination with other factors, like smoking. This process used to take months or even years, but now anyone worried about their family history can achieve peace of mind, or decide upon preventative treatment, within days. Four main breast cancer genes have been identified in this way. Around one in nine women will be affected by this cancer in their life time, and previously, the presence of a tumour was the only
way to see if a woman was likely to develop it. While every woman over the age of fifty should have regular mammograms, younger women with a family history of breast cancer often face a lifetime of worry. Genetic testing has discovered four genes that make breast cancer more likely. Women carrying the BRCA1 and BRCA2 genes have a 50 to 80% chance of developing breast cancer at some point in their lives. Women carrying the TP53 or PTEN genes are slightly more likely to develop breast cancer than the average woman. Until 2011 however, anyone who has been genetically tested and found to carry these genes, will not have to declare their results when taking
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“People with “high-risk” genes may now have to pay huge premiums for life insurance” out a life insurance policy. Illness Penalty After 2011 it seems likely that insurance companies will raise premiums for people who have had a positive predictive test. Certain illness have faced raised premiums for life insurance. Now, with genetic testing, they can reduce the cost of their policies if they are negative for “high-risk” genes. However there are many ethical issues surrounding this. For years, people with a poor family history of a certain illness have faced raised premiums for life insurance. However, people with “highrisk” genes may now have to pay huge premiums for life insur-
ance, or even be refused a policy altogether.
in order to protect their family financially.
Of course, a woman carrying a gene that makes breast cancer more likely may never have a tumour, and a woman who is negative for all four high-risk genes could develop breast cancer early in her life. It could also be possible that people with a predicted genetic illness who opt for a preventative treatment, such as a mastectomy, will now be rewarded with lower premiums, while people who do not will be refused insurance. This could result in people feeling forced into major invasive surgery for an illness that they may never develop,
What will the next step be? If insurance companies have the right to the results of predictive genetic tests, employers may soon follow. It is possible that people carrying a “highrisk” gene for a certain illness will be unable to find a job, as employers may not wish to financially support people who may become ill in the future. Ultimately it is the right of the individual to decide whether they should undergo a predictive genetic test, but the decision on what to do with the results may soon be taken out of their hands.
“Around one in nine women will be affected by breast cancer in their lifetime” [11]
In focus In focus is a new feature we are introducing next month to give you a chance to show off your talent. We would like to encourage you to send us a photograph with a small piece telling us what it is about, where it was taken, what camera was used and what it means to you. Photographs will be chosen by vote by the Editorial team and will appear here in colour. So be inspired, get snapping and send your entries to our Art Editor Nadège (nl7678@bristol.ac.uk) with a separate word file with your description. Good luck!
“I took this photo one year ago at the Vancouver aq cause they’re so active and playful, Sea otters are a to photograph.” Nadège Laici
“This photograph was taken in a small park in the middle of Bristol, one of my favourite spots in the city.” Emma Clark
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quarium on a rainy day. Beamazing but also very difficult
"”This Leatherback Turtle hatchling was photographed by Claudio, our volunteer coordinator, in Gandoca - Costa Rica. On one of my hatchery shifts, we released two hundred and fifty hatchlings into the Carribean Sea!” Emma Clark ! “I photogrpahed this Green Page Moth hatchling in the garden of Cano Palma Biological Field Station in the coastal rainforest of Costa Rica. They hatched and died within a few days. I was hanging my washing out in the garden when I noticed that the trees were literally swarming with these beautiful moths.” Ariane Whitehead
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Psychology
Psychological Assumptions Sarah Haigh explores the psychology behind experimenter bias and the way our brains process information. When studying psychology there are certain issues which arise. At first, they appear redundant and detract from what the experimenter is trying to say, but after several years of intensive study, these issues begin to nag away at the back of the mind. I am being vague on purpose at this point because I do not want to single out psychology as the only contradicting and philosophically inconsistent subject, but as it is the only one I am studying at degree level, you will have to bear with me.
1963. This interesting finding has led perceptual psychologists like Marr and Nishihara to conclude that edges are one of the main features we look at when building the full representation of the object. The problem is that Marr and Nishihara have jumped from neurons firing in the physical brain, to a mental representation with top-down processing (where the individual looks at the whole picture as a unit, instead of individual features), which the perceiver can manipulate.
I will give an example of how these inconsistencies can slowly nag away at the argument proposed by the experimenters and potentially hinder the scientific understanding. When studying perception there is an issue commonly known as the ‘binding problem’. This is when scientists jump from the biological ‘brain’ to the metaphysical ‘mind’. Biologists talk about the brain in terms of neurons firing when certain stimuli are presented to the perceiver, for example, neurons that fire for edge detection in cats discovered by Hubel and Wiesel
We frequently talk about the ‘mind’s eye’ and generally agree that we can view a video screen of our memories, yet there is no physical evidence that there is a TV screen in our heads that facilitates this operation – so where does this idea come from? From a cognitive perspective, these theories are not to be taken literally but as a result corner psychologists into a dualist argument. Dualism is referring to the physical and the mental world as two separate worlds but the problem arises when we try to connect the two in order to find out how
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they influence one another. Since Psychology is trying to explain human behaviour, this argument can be troubling. And yet these studies illustrate that the physical does affect the mental, establishing a connection. Perhaps then, it is only a matter of time until we discover the reasons for what we call consciousness in a neurological sense, which will resolve the dualist argument. In fact studying the brain itself causes a few contractions because its structure is so complicated. Neuropsychologists wanting to find out which part of the brain serves what function carve up the brain to do so. The problem is that there are 1010 neurons in the brain, each with 103 connections, which means that every part of the brain is communicating with the others, making modulation very difficult indeed. Many studies which have ‘discovered’ the roles played by different parts of the brain have been due to double dissociations in brain damaged patients. These occur when a patient with damage to part A of their brain is unable to do task 1 but is able to do task 2,
MissingLink Link TheThe Missing
“Dualism” - Drawing by Sarah Haigh. tion between smoking and lung cancer but that this was not a causal relationship – there was also a genetic influence. This is an interesting discovery, but the fact that he was supported by ‘R J Reynolds Tobacco Company’ strongly suggests Eysenck may have been biased in his interpretation.
whereas another patient with damage to part B of their brain is able to do task 1 but not task 2. An example is a lesion in the dorsal pathway leads to patient A being unable to reach for objects (the ‘where’ system in our brains), but they are still able to tell what the object is. However, patient B has a lesion in their ventral pathway and as a result they cannot tell what an object is (visual agnosia) but can still reach for objects, i.e. the reverse of what patient A can do. From this, we are able to determine that part A of the brain is responsible for task 2 and part B is responsible for task 1. It may seem like a reasonable assumption but does the fact that the person is brain damaged make their brain fundamentally different from a normally func tioning brain?
It is not to say that the results of these studies aren’t useful – in fact they are incredibly useful for those who have or may potentially have brain damage in these specific areas, but can we really generalise for normally functioning brains? Even when results have been published, there are also publication biases with studies that have shown unusual findings. It is often more interesting to find something unusual rather than to find that nothing significant is happening, even though nonsignificant results can be just as useful as significant findings. The financial support for studies may sometimes also influence how the experimenters interpret their results. In 1985 Eysenck claimed that there was a correla-
The media often have a habit of dramatising scientific studies, for example referring to genetic discoveries as causal and deterministic for certain behavioural traits. In 2004 Yudkin found that a mutation in the dopamine D2 receptor in the brain could make it more difficult for women to give up smoking when using nicotine replacement patches. This was reported by the BBC as ‘Genes could stop women quitting’, which is not what the study was showing. In fact, this headline is determinist (i.e. makes it a fact that these women will never be able to quit smoking and so are less likely to try as a result), and so is not only producing potentially damaging effects for women but is also misrepresenting the study. By no means are these issues exclusive to psychology, but when reading about psychological studies it is worth bearing them in mind. Sometimes there can be other explanations for behavioural tendencies and so analysing the methodology and results in the light of the assumptions or biases on the experimenter’s behalf can help highlight potential problems.
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Psychology
Evolution What’s that? Anna Leon asks: What do people really know about the theory of evolution?
Most of the readers and writers of the Missing Link are students in the life sciences. The field is so huge that I cannot possibly argue that I know anything about the whole of its scope. As a psychologist, I have no clue what palaeontologists learn about (and I would suspect that there are not many palaeontologists that know anything about sex differences in social cognition) but I do know that we all share one common piece of knowledge: it is very basic, simple, well-known, and extremely important. It is the theory of evolution. Studying anything in the life sciences without taking into account evolution is almost pointless, and thinking in terms of phylogeny – how organisms are
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grouped taxonomically – is something we are all trained to do. But what about everyone else? What happens when you leave the Biological Sciences building and enter the realms of the Arts or Engineering departments? And what happens when you leave the University precinct altogether? What do people know about evolution? Well, as you might suspect, the best way to learn that is to simply ask them, and that is what I did. I asked everyone in my family, and amongst my friends (including Facebook contacts) what evolution meant to them. Their answers turned out to be as interesting as the theory itself.
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Misconceptions Let’s start with the basics: what does the theory of evolution say? Although several people blatantly admitted that they had no idea, most of my interviewees gave an acceptable definition of it. They seemed to have a good general idea of the concept of evolution, but this idea was incomplete. Things like natural selection, a common ancestor of all species, gene mutations, changes from one generation to the next, the ability to survive and reproduce, and adaptation to different environments were all mentioned, but not once in a single answer. These answers indicated that people with no training in the life sciences learn about evolution mainly by passively picking up information from a number of sources – popular magazines, maybe the odd Biology class they remember from school – but this does not provide them with a thorough understanding, especially of the role genes play in the evolutionary process. After talking to many people, I saw that the gaps in their knowledge are due to the fact they are learning about evolution without learning how it actually works.
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For example, a major misconception turned out to be that evolution is regarded as a process of “improvement”.
This idea seems to deduce from our knowledge that useful characteristics tend to be passed on, the unfounded thought that evolution is an almost teleological mechanism – that it is a means to a particular, pre-determined end. Many answers I received implied that many people do not realise that evolution is not the result of conscious choice, and interpret “passing on useful traits” as a somehow purposeful choice for better adaptation to the environment. Furthermore, almost all my interviewees believed that useless characteristics will disappear throughout the course of evolution: people overlooked the fact that if something has no disadvantage to survival and reproduction then, theoretically, it has no reason to disappear. It seems that people see evolution as a purposeful process, one that is in some weird sense aware of its own results. What does this mean? Lack of complete scientific knowledge is acceptable, but misinterpretation viewed as knowledge is not. Evolution was not meant to lead to a perfect being, and this will certainly not be the end point either. Seeing a goal in the evolution of our own species is a view that may give rise to eugenics – where humans will be selectively bred to produce the perfect specimen. This was certainly not implied >>
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Psychology
“Lack of complete scientific knowledge is acceptable, but misinterpretation viewed as knowledge is not.” by Darwin – misinterpretation of science can lead to dangerous conclusions, and the worst part of this process is that science is then blamed for those conclusions.
Demographics of knowledge Moving on from what people know, it was interesting to see who knew what: when I started the interviews, I had expected that more mature people would have been less exposed to Darwin’s theory, and would not understand it as well as younger, fresher minds. Surprisingly, age turned out to be a completely irrelevant factor when it came to the state of people’s knowledge. Seventy- and eighty-year-olds gave complete answers to questions for which fifteen-year-olds’ answers made me wince. I am happy to report, however, that having a university degree (or studying for one) was a very good indicator of awareness of the theory. This of course is not to say that university students and graduates are more knowledgeable – many students know absolutely nothing outside their own field, and many people without formal qualifications could make University Challenge finalists look like idiots. Evolution is a tricky subject, in
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that it has sparked a lot of debate, especially when contrasted with religious accounts of the creation of humans. It is one of those things that you might be aware of, but not accept – and, indeed, a few people told me that evolution was only one possibility, and that they would prefer the theory to fit in with the Bible story (it has to be noted here that teleological views of evolution are very likely to be caused by the idea of humans as perfect beings created by God). However, most of the people I asked, including all of those under the age of thirty, said that they believed that the theory of evolution was true because it gives us the best explanation for how we became what we are.
Education required So what do we get out of this all? Yes, some people thought evolution referred to the progress of
technology. And yes, I got a brief account of “Darwing’s” theory. And yes, I also got an account of evolution referring only to humans and not to other species. But overall, my (admittedly) small sample did quite well – evolution is widely known about, very much in the same way that the force of gravity is. But gravity is not socially relevant, whereas evolution may have serious social consequences if misinterpreted. It is obvious that education must involve an account of the theory of evolution as it really is: a theory that explains what happens in nature, and how. A description of a natural process should not include any normative claims about what evolution should lead to, or the implication that by understanding it we can control it – just the importance of understanding what we are, as part, and result of nature.
“Evolution is a tricky subject, in that it has sparked a lot of debate, especially when contrasted with religious accounts of the creation of humans”
The Missing Link
The Glowing Worm 1 unit vodka 1 unit blue Curacao # unit cream Squeeze of lemon Stir all the ingredients together then pour into a large shot glass. Garnish with a mayfly…or not.
Cockatiels and Cocktails Glow Worms, Waitomo, New Zealand – Andy Wakefield explores a starry cave Taking care to avoid being temporarily blinded by one of the many drops of water falling from above, I tilted my head backwards as our guide switched off the lights that had previously illuminated the path leading to the cave. It took a moment or two for my eyes to adjust to the darkness, but as soon as they did they were greeted with what must surely be one of the most magical illuminations in the natural world. It seemed as though I was looking up at the night sky crammed full of neon-blue stars, each twinkling and shimmering silently in the dark. In reality I was gazing at several thousand miniature, glowing but tocks! These elaborate moonings
are the larval displays of a small insect known as a fungus gnat, found in a few caves near the small town of Waitomo in New Zealand.
From these waters hatch adult mayfly, frantically looking for mates. Although their urge to mate is innately massive, they find the temptation of the pretty blue lights just far too alluring and fly straight into the threads of glue-laden silk! As its victim struggles to free itself, the fungus gnat slides slowly yet purposefully within its lube-tube and in the direction of the vibrations, anticipating a feed. It then reels in its unfortunate prey and devours it to satisfy its hunger. Once the capture has been made the gnat eats the silk filaments on which
“I was gazing at several thousand miniature, glowing buttocks!” Each light is produced by phosphorescent chemicals in a specialised compartment that opens from the side of the insect’s intestine. As the matchstick-sized beast lies suspended from the ceiling by silken threads in its transparent tube of mucus, it uses its remarkable light source to fatally attract its prey. Below, invisible in the darkness, a stream was cutting its way through the cave’s soft rock.
the prey was entrapped, to save its supplies of silk; it also switches off its light to save energy. The supply of silk comes from the larva’s mouth and each downward hanging lure may reach up to a metre in length. With as many as several hundred fungus gnat larvae in only one square metre of cave roof, it was no wonder that the display above my head was truly awe-inspiring.
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Interview
The giant sea scorpion An interview with Dr Simon Braddy: Written by Ashley Canning Dr. Simon Braddy, MSc Palaeobiology tutor at the University of Bristol and specialist in arthropod palaeontology, tells Ashley Canning all about the recent discovery of a two and a half metre long scorpion in Germany species Jaekelopterus rhenaniae that lived between 460 and 255 million years ago.
Scorpions are scary enough creatures at their modern proportions. However, a recent discovery has unearthed a giant sea scorpion that could have reached 2.5 m in length! This new discovery was announced on the 21st of November in a paper in the journal Biology Letters and describes a huge eurypterid (commonly known as a sea scorpion) from rocks dated at 390 million years old. The description is based on the finding of a 45 cm long claw in a quarry near Prüm, Germany, by Markus Poschmann – co-author of the paper with Dr Simon Braddy of our very own Earth Sciences department. The claw belongs to an exceptionally large member of the
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Eurypterids are believed to be the marine ancestors of modern arachnids – the scorpions and spiders. It has been known for some time that during the Earth’s history, arthropods, particularly the insects, have grown to phenomenal proportions, such as Meganeura, the dragonfly with a wingspan reaching 70 cm. However, palaeontologists have been unable to resolve the cause of this ancient gigantism. Dr. Braddy tells us more: What was it that interested you about, and ‘got you into’ palaeontology, particularly the arthropods? As a child I was always pas-
sionate about dinosaurs, and this continued right through my undergraduate degree, but it wasn’t until I started my PhD at the University of Manchester that I developed a fascination for these giant creepy crawlies. It was there that I was introduced to the eurypterids (giant sea scorpions) of the same ilk as this new discovery. So just how big was this sea scorpion? The size estimate is based on the discovery of a 45 cm claw. The size of the claw can be used in calculations to scale up to the whole body size of an eurypterid. These calculations gave us a size range, so we decided to use the average of these which turned out to be 246 cm in length.
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“Scorpions are scary enough creatures at their modern proportions. However, a recent discovery has unearthed a giant sea scorpion that could have reached 2.5 m in length! This new discovery was announced on the 21st of November in a paper in the journal Biology Letters and describes a huge eurypterid (commonly known as a sea scorpion) from rocks dated at 390 million years old.” This exceeds the maximum size for any other fossil arthropod.
shallow seas were the perfect environment.
What sort of environment would such a monster have occupied? This find is around 390 million years old, so it is from the Devonian Period. During the Devonian, a succession of rocks known as the Old Red Sandstone were being laid down in Northern Europe in a hot dry environment. Further south, from the Welsh borderlands down to what is now Germany, the rocks show a swampy succession of rivers and lakes and shallow seas. South of this was the open ocean. As mentioned before, Jaekelopterus rhenaniae belongs to a group of giant sea scorpions known as the eurypterids. They lived in marine settings, and the swampy
What role would Jaekelopterus rhenaniae have played in this environment? Eurypterids were the top predators of their day. They would have preyed upon a wide range of other animals, such as the Agnatha, the early jawless armoured fish, as well as other types of marine arthropod, and there is even evidence of cannibalism. There are many theories as to why arthropods evolved such huge size in the past, for example elevated oxygen levels in the atmosphere; could you explain why Jaekelopterus rhenaniae was particularly massive? Yes there are several theories
“I developed a fascination for these giant creepy crawlies.”
about arthropod size being related to increased oxygen levels in the past, in fact this has almost become the fashionable explanation, and it is probable that this was a driving factor for large body size in terrestrial arthropods, but this peak in oxygen levels is during the Carboniferous Period. However, giant arthropods are not limited to the Carboniferous and most are actually marine, for instance, the largest trilobites were from the Ordovician Period a good 140 million years or so before the Carboniferous. The constraints on body size for marine organisms are not the same as those for terrestrial organisms, so the elevated oxygen theory is not as applicable here. There is no single answer as to why Jaekelopterus rhenaniae got so big, but it is likely to be related to competition. There simply was none from vertebrates during the Palaeozoic, and so the eurypterids had ecological space to become large predators.
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Comment Photograph by Nadège Laici
Dr. Arthur Goldsmith
Careers events in Bristol this month CAREERS IN SOCIAL CARE Monday 11 Feb, 5.30-7, Hawthorns Come along to this event and hear about the employers, jobs and roles within this sector. As well as general information you will also hear from a social worker, probation officer and counsellor. Numbers are limited so sign up via the following link: https://www.bris.ac.uk/cas/events CAREERS IN HEALTHCARE Tuesday 12 Feb. 5.15-7.15, Hawthorns This session will focus on speech therapy, occupational therapy, physiotherapy, and careers in NHS Management. Come and meet some of those employed within the above areas and find out how they were recruited, the selection process and what they actually do on a day to day basis. Sign up via: <https://www.bris.ac.uk/cas/events>
Coming soon: The next issue of The Missing Link will feature a brand new and exciting column by a lecturer and researcher from the School of Biological Sciences: Dr Arthur Goldsmith. Familiar to many second and third year biologists form his lectures on evolution and Acquisition of Behaviour, Dr Goldsmith will provide us with an insight to current research, offering his own comments and opinions on the subject. Reading any news section in a science magazine you’ll immediately find there is a lot of controversial and sometimes outright bizarre research going on. A critical commentary of these may turn out to be rather provocative but also highly entertaining. As Dr Goldsmith said: “There’s nothing I love more than having a pop at anyone who seems to be falling into the trap of taking themselves or their research too seriously”. If you’ve ever wondered whether some new ‘discoveries’ make any sense and would like to know what experts have to say on that matter or even if you just want an interesting read, look for the new column in March issue. Agata Staniewicz
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CAREERS IN DEVELOPMENT Tuesday 5 Feb, 5.30-7.30, Hawthorns Come along to this event and hear about this sector. Speakers include Medecine Du Monde, One World Trust and Motivation. Numbers are limited so sign up via the following link: https://www.bris.ac.uk/ cas/events RUNNING YOUR OWN BUSINESS Wednesday 13 Feb, 5.30-7, Hawthorns Come along to this event and hear how to go about it. Sign up via https://www.bris.ac.uk/cas/events INSIGHT INTO MEDIA 16-18 April. Arts Faculty A three day course designed to give you a taste of a variety of careers within the media industry. People currently working in advertising, TV production, PR, radio, publishing and journalism help you discover what their jobs are all about through talks and case studies. You also get a great chance to gain contacts that can lead to work experience placements and further your career in a sector which it is notoriously difficult to get into. This event is oversubscribed every year so it is very important to sign up early. To book go to: http://www.bristol.ac.uk/ careers/insightintomedia/index.asp
The Missing Link
Book Review “Elephantoms: Tracking the Elephant” by Lyall Watson Nowadays, conservation and safari trips to the wilds of Africa take millions to see elephants in one of their native continents. As a child growing up there before the tourist boom, Lyall Watson was able to explore Africa’s beaches and forests without disturbance. His memories of his experiences are lyrically recorded in “Elephantoms”. As a ‘strandloper’, Watson spent his childhood summers living with friends on a beach in the Cape. Looking back on his youth, Watson writes of wordless meetings with Khoi tribeschildren, discoveries of illusive species, and of course, encounters with elephants.
Photograph by Emma Clark
A review by Hannah Welham
“They are models of refinement, nature’s archangels, the oldest and largest land animals, touchstones to our imagination.”
While still a boy, Watson sees a bull elephant up close. The creature is seemingly unaware of its awestruck visitors and the atmosphere is described tangibly as the children watch the animal’s every move. As this happens early on in the book, a flowing narrative depicting a lifelong fascination with the majestic species ensues. Watson has most certainly done his homework and the book overflows with intriguing facts and descriptions that will surely capture the imagination of any naturalist. The behavioural ecology and evolution of the species are portrayed in detail, often based on personal sightings, and are cleverly intertwined with the archaeological, philosophical and religious links held between the elephants and mankind. This refreshingly honest and simple account of a species is a must read for any life scientist. Hannah Welham
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Entertainment
TV and Radio
Researched by Emma Clark
TV highlights: Life In Cold Blood – starts Monday 4 February at 9pm on BBC One
PACIFIC ABYSS BBC1, Three-Parter, Sundays from 20 Janurary, 7pm. NATURAL WORLD: WHITE FALCON, WHITE WOLF BBC2, Friday 1 February, 8pm. Repeated Sunday. NICK BAKER’S WEIRD CREATURES 2 Animal Planet, Wednesdays, from 6 February, 9pm. NATURAL WORLD: SAVED BY DOLPHINS BBC2, Friday 8 February, 8pm. Repeated Sunday. NATURAL WORLD: BADGERS SECRETS OF THE SET BBC2, Friday 15 February, 8pm. Repeated Sunday.
“Sir David Attenborough brings viewers the final chapter of his epic overview of life on Earth as he transforms perceptions of coldblooded animals in this landmark BBC One series Life In Cold Blood.” “Now, using the very latest in filming technology from the BBC’s world-renowned Natural History Unit – including ultra-high-speed, thermal, miniature and on-board cameras – David reveals the surprising and intimate lives of the cold-blooded reptiles and amphibians, discovering the secret of their success. After all, they have ruled the Earth for nearly 200 million years and, today, there are well over 14,000 species.” http://www.bbc.co.uk/pressoffice
Radio highlights: WORLD ON THE MOVE - Begins Tuesday 12 February, 9am (11am thereafter) throughout 2008. BBC Radio 4 92-95FM
NATURAL WORLD: SPACE CHIMP BBC2, Friday 15 February, 8pm. Repeated Sunday SHARED EARTH - Fridays from 15 February, 3pm. BBC Radio 4 92-95FM. [24]
[25] Fact or Fiction: Well which do you think is false? Obviously it’s not the one about the Velociraptor, as we know for a fact that they are pink. We saw them with our own eyes when we traveled back in time, just last Tuesday. Crossword: Across - 1.gecko 3. quagga 7. diploi 9. hawthorn 11. sperm 14. acid 15. arabidopsis 16. elephant 19. genus 20. lungs Down - 2. topo 4. anther 5. christmas 6. ant 8. polymerase 10. freud 12. mind 13. giraffe 17. leon 18. tree
Answers:
• We experience muscular paralysis during REM sleep. • Recent findings suggest that the Velociraptor was actually closer to magenta in colour, than the widely popularised brown. • By law Idaho residents may not fish from a giraffe’s back. • Warm olive oil dropped into the ear sooths earache. • Sigmund Freud was one of 8 children.
Sally Snow and Eloisa Noble
Fact or Fiction? Entertainment The Missing Link
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