News and Information
2012 News
Dr Ken Joysey
The Department received with sadness the news of the death of Dr Ken Joysey on 25th November 2012. Ken Joysey spent most of his scientific career in the University Museum of Zoology , and was Director of the Museum from 1970 until his retirement in 1995.
An appreciation of his life and contribution to the Department can be found here:
John Gurdon wins Nobel Prize
The Department is delighted to congratulate Sir John Gurdon on the award of this year's Nobel prize for medicine, announced on 8th October 2012.
The prize is awarded for John's work demonstrating that mature cells can be reprogrammed to become pluripotent. John showed in 1962 that single frog nuclei transplanted into enucleated eggs could give rise to an entire animal.
John shares the prize with Shinya Yamanaka, who discovered more than 40 years later that intact mature cells in mice could be reprogrammed to become immature stem cells.
John is of course a member of this Department. He worked in the labs just above the whale for six years before moving to what is now the Gurdon Institute.
Further information can be found at http://www.nobelprize.org/nobel_prizes/medicine/laureates/2012/press.html
Courtship in Drosophila melanogaster
A new paper published in Current Biology this week by several members of the department looks at substrate-borne vibratory communication during courtship in Drosophila melanogaster.
Courtship in Drosophila melanogaster has become an iconic example of an innate and interactive series of behaviors. The female signals her acceptance of copulation by becoming immobile in response to a male's display of stereotyped actions. The male and female communicate via vision, air-borne sounds, and pheromones, but what triggers the female's immobility is undetermined. Here, we describe an overlooked and important component of Drosophila courtship. Video recordings and laser vibrometry show that the male abdomen shakes ("quivers"), generating substrate-borne vibrations at about six pulses per second. We present evidence that the female becomes receptive and stops walking because she senses these vibrations, rather than as a response to air-borne songs produced by the male fluttering the wings. We also present evidence that the neural circuits expressing the sex-determination genes fruitless and doublesex [8] drive quivering behavior. These abdominal quivers and associated vibrations, as well as their effect on female receptivity, are conserved in other Drosophila species. Substrate-borne vibrations are an ancient form of communication that is widespread in animals. Our findings in Drosophila open a door to study the neuromuscular circuitry responsible for these signals and the sensory systems needed for their reception.
Fabre et al., Substrate-Borne Vibratory Communication during Courtship in Drosophila melanogaster, Current Biology (2012), http://dx.doi.org/10.1016/j.cub.2012.09.042
Good news for a change
News about the environment can seem like one long litany of loss, but is nature’s continued decline inevitable? Certainly not, argues Andrew Balmford in his book Wild Hope, published by University of Chicago Press, which instead explores the successful side of conservation. From the floodplain of Assam to the mountains of western Ecuador Andrew discovers remarkable creatures and places, meets the heroes and foot soldiers who are working to save them and learns about innovative approaches and incentives being used to effect real change.
“In conservation, we immerse ourselves in the bad news”, says Andrew. “We document it, we cleverly investigate its causes and consequences, and we find ever more compelling ways to communicate it to the outside world.”
Yet most people hearing that message still don’t translate it into action. “Faced with an unending barrage of bad news, they see no hope for turning things around. This book is about challenging that sense of hopelessness, by unearthing and celebrating initiatives around the world where people are succeeding in stemming the tide.”
“A very important book by a very knowledgeable author”
Robert May
“Humane, intelligent and inspirational”
William Foster
Andrew is talking about Wild Hope at
Topping and Company books in Ely at 7pm on Tue 2 October
The Institute of Continuing Education at Madingley at 7pm on Mon 8 October
The Royal Society at 6.30pm on Mon 10 December
You can also download podcasts about Wild Hope from The Guardian Science Weekly and Cambridge 105
Research raises doubts about whether modern humans and Neanderthals interbred
New research raises questions about the theory that modern humans and Neanderthals at some point interbred, known as hybridisation. The findings of a study by researchers at the University of Cambridge suggests that common ancestry, not hybridisation, better explains the average 1-4 per cent DNA that those of European and Asian descent (Eurasians) share with Neanderthals. It was published today, 13 August, in the journal PNAS.
In the last two years, a number of studies have suggested that modern humans and Neanderthals had at some point interbred. Genetic evidence shows that on average Eurasians and Neanderthals share between 1-4 per cent of their DNA. In contrast, Africans have almost none of the Neanderthal genome. The previous studies concluded that these differences could be explained by hybridisation which occurred as modern humans exited Africa and bred with the Neanderthals who already inhabited Europe.
However, a new study funded by the BBSRC and the Leverhulme Trust has provided an alternative explanation for the genetic similarities. The scientists found that common ancestry, without any hybridisation, explains the genetic similarities between Neanderthals and modern humans. In other words, the DNA that Neanderthal and modern humans share can all be attributed to their common origin, without any recent influx of Neanderthal DNA into modern humans.
Dr Andrea Manica, from the Department, who led the study said: "Our work shows clearly that the patterns currently seen in the Neanderthal genome are not exceptional, and are in line with our expectations of what we would see without hybridisation. So, if any hybridisation happened – it's difficult to conclusively prove it never happened – then it would have been minimal and much less than what people are claiming now."
http://www.bbc.co.uk/news/science-environment-19250778
Solving the riddle of horse domestication
Domestic horses likely arose from the western Eurasian steppe-the area of present day Ukraine and West Kazakhstan-and repeatedly interbred with wild horses as the herds spread, a study suggests. Researchers have long debated the early history of horse domestication: Archeological evidence suggests that horses were domesticated in the western Eurasian steppe, whereas genetic evidence from modern mares points to multiple domestication events across a wide geographic area. Vera Warmuth from the department and colleagues modeled the origin and spread of horse domestication using genetic data from more than 300 horses across northern Eurasia. The authors reconstruct the demographic history of Equus ferus, the extinct wild progenitor of domestic horses, and suggest that E. ferus expanded out of eastern Eurasia approximately 160,000 years ago. Further analysis suggested to the authors that horse domestication originated in the western Eurasian steppe approximately 6,000 years ago, and that domesticated herds were repeatedly restocked with wild horses as they spread across Eurasia. The findings confirm horse domestication's origins in western Eurasia, and provide evidence for widespread incorporation of wild horses into domestic herds, thereby uniting disparate evidence from previous studies and resolving conflicting interpretations, according to the authors.
L'Oréal UNESCO For Women in Science Award
Many congratulations to Claire Spottiswoode, who has been awarded one of this year's four L'Oreal "Women in Science" Fellowships for her work on the genetics of mimicry in Cuckoo eggs. The four outstanding female scientists, who are all working on postdoctoral studies, were each awarded fellowships of £15,000 to spend on whatever they may need to continue their research, from buying scientific equipment to paying for childcare or travel.
They were selected by a jury of eminent scientists, chaired by Professor Dame Athene Donald (DBE, FRS), Professor of Physics and Gender Equality Champion at the University of Cambridge and FWIS Laureate.
Claire is in interested in the genetic underpinnings of coevolution, the process by which two or more species reciprocally influence one another’s evolution. Claire studies brood parasitic birds, such as cuckoos, which are cheats that lay their eggs in other birds' nests. Cuckoos and other brood parasites lay eggs that beautifully mimic those of their chosen host, to trick host parents into accepting the parasitic egg as one of their own . This research project will attempt to solve a century-old evolutionary puzzle: how do individual females of the same brood parasitic species lay eggs that mimic those of their specialist host, despite interbreeding with males raised by other hosts? Claire hopes to locate the genes involved in mimicry of different host species, by exploiting powerful new genomic methods in combination with breeding experiments on captive Cuckoo Finches that she will study in Zambia.
Avian flu viruses which are transmissible between humans could evolve in nature
It might be possible for human-to-human airborne transmissible avian H5N1 influenza viruses to evolve in nature, new research has found. The findings, from research led by Professor Derek Smith and Dr Colin Russell from the Department, were published last month in the journal Science.
Currently, avian H5N1 influenza, also known as bird flu, can be transmitted from birds to humans, but not (or only very rarely) from human to human. However, two recent papers by Herfst, Fouchier and colleagues in Science and Imai, Kawaoka and colleagues in Nature reveal that potentially with as few as five mutations (amino acid substitutions), or four mutations plus reassortment, avian H5N1 can become airborne transmissible between mammals, and thus potentially among humans. However, until now, it was not known whether these mutations might evolve in nature.
The researcher group first analysed all of the surveillance data available on avian H5N1 influenza viruses from the last 15 years, focusing on birds and humans. They discovered that two of the five mutations seen in the experimental viruses (from the Fouchier and Kawaoka labs) had occurred in numerous existing avian flu strains. Additionally, they found that a number of the viruses had both of the mutations.
Colin Russell, Royal Society University Research Fellow at the University of Cambridge, said: “Viruses that have two of these mutations are already common in birds, meaning that there are viruses that might have to acquire only three additional mutations in a human to become airborne transmissible. The next key question is ‘is three a lot, or a little?’ ”
The scientists explored this key question using a mathematical model of how viruses replicate and evolve within a mammalian host and assessed the influence of various factors on whether the remaining three mutations could evolve in a single host or in a short chain of transmission between hosts.
“With the information we have, it is impossible to say what the exact risk is of the virus becoming airborne transmissible among humans. However, the results suggest that the remaining three mutations could evolve in a single human host, making a virus evolving in nature a potentially serious threat,” said Derek Smith, Professor of Infectious Disease Informatics at the University of Cambridge. “We now know that it is in the realm of possibility that these viruses can evolve in nature, and what needs to be done to assess the risk more accurately of these mutations evolving in nature.”
The research was funded by multiple sources including the European Commission through framework 7 grants EMPERIE and ANTIGONE, the Royal Society, the Human Frontiers Science Program, the Wellcome Trust, and the National Institutes of Health.
Further information and an interview with Derek Smith and Colin Russell
Novel 3D reconstruction of fossil reveals how limb movement evolved in the first land animals
Research published in the journal Nature reveals for the first time how a famous extinct animal, the early four-legged vertebrate (tetrapod) called Ichthyostega, moved on land.
The study, conducted by Dr. Stephanie E Pierce and Professor John R Hutchinson from the Royal Veterinary College and Professor Jennifer A Clack from the Department of Zoology, examined limb mobility in the 360 million year old fossil tetrapod by reconstructing the first ever three-dimensional computer model of its skeleton.
Lead author Dr. Pierce says: "It took almost three years of hard work on difficult fossil material, but we are finally able to see how the skeleton of Ichthyostega fits together and might have moved in three-dimensions. This is very exciting, as it allows us to examine how ancient vertebrates made the monumental transition from swimming to walking."
To test how the limbs of Ichthyostega moved, the team micro-computed tomography (CT) scanned dozens of fossil specimens and digitally separated the bones from surrounding rock. Each bone was then carefully put back together like a jigsaw puzzle in animation software and painstakingly manipulated to estimate each joint's maximal range of motion.
Professor Clack says: "Our reconstruction demonstrates that the old idea, often seen in popular books and museum displays, of Ichthyostega looking and walking like a large salamander, with four sturdy legs, is incorrect."
By comparing their data to five living animals (salamander, crocodile, platypus, seal, and otter), the researchers found that the shoulder and hip joints in Ichthyostega were unusually restricted in their motions, meaning the animal could not have used a conventional 'walking' step. In particular, the study uncovered that the limbs in Ichthyostega were incapable of rotating along their long-axis - a limb motion critical to locomotion in living land animals.
Professor Hutchinson commented: "Remarkably, earlier fishes (called tetrapodomorphs) had the ability to rotate their fins, so it seems that just as vertebrates were experimenting with terrestrial movement, the limbs became confined to mainly back-and-forth and up-and-down motions. It wasn't until tetrapods became more competent on land that they recovered the ability to rotate their limbs around their long axis."
According to the study, a limited capacity to rotate the limbs implies that some of the earliest land animals could not walk well on all four legs. In particular, manipulation of the 3D model demonstrates that land locomotion in Ichthyostega-like animals would probably have involved synchronized motions of the front legs, with the hind legs barely being able to reach the ground and probably playing a more minor supportive role along with the tail.
Dr. Pierce adds: "These early tetrapods probably moved in a similar way to living mudskipper fishes in which the front fins/legs are used like crutches to haul the body up and forward. As early tetrapods were still mostly aquatic, this type of movement may have helped to stabilize the body during their first tentative forays onto land."
The next step, the researchers say, is to combine their models of limb motion with similar models of the rest of the skeleton as well as muscles, to make much more sophisticated biomechanical analyses of just how these animals did or did not move, and how well they were able to do it. When did the ability to run, for example, first evolve? The approach used in this study, combining modern 3D imaging tools and computer modelling along with knowledge of the rules of animal movement, may answer such big questions.
An explanatory webpage has been set up by the researchers and can be seen here: http://www.rvc.ac.uk/sml/Research/Stories/TetrapodLimbMotion.cfm
The study was funded by the Natural Environment Research Council.
Butterfly genome reveals a promiscuous past
An international collaborative study to map the genome of a South American butterfly has identified the secret behind its mimetic nature.
The genome sequence of the Postman butterfly, Heliconius melpomene, was used as a reference to study species that live together in the Peruvian Amazon. Several of these share bright wing patterns in order to reinforce a warning signal that they are bad to eat - dissuading predators from attack.
Sequence data showed that those species with similar wing patterns shared a similar genetic signal, precisely in those narrow regions of the genome responsible for controlling patterns. This is a result of hybrid exchange of genes between three co-mimic species, which has allowed them to copy each other's wing patterns.
Dr Chris Jiggins from the Department said, "These butterflies, in order to better survive in the wild, have taken successful survival techniques from other butterflies and have incorporated them into their own genetic code. This is significant as it has occurred in a natural adaptive radiation, suggesting an important role for hybrids in the origins of biodiversity."
The phenomenon, known as adaptive introgression, involves different species sharing genetic material and has been considered very rare, especially in animals. Although many species can interbreed in the wild, the resulting hybrids are often infertile and considered an evolutionary dead-end. However, occasionally hybrids might introduce useful genetic material that can help populations adapt to changing conditions. This source of novelty might be more effective than having to wait for a mutation to occur in order to yield a similar result. In the case of butterflies, the effects can be clearly seen on their wings.
Dr Kanchon Dasmahapatra, who worked with Professor James Mallet at University College London added, "What we show is that one butterfly species can gain its protective colour pattern genes ready-made from a different species by hybridizing (or interbreeding) with it. A much faster process than having to evolve one's colour patterns from scratch."
The butterfly genus Heliconius is found in the tropical and sub-tropical regions of the Americas, from the Amazon basin to Texas and has been studied by scientists since the Victorian era.
Dr Jiggins added: "The genus Heliconius has been the subject of evolutionary studies since Darwin's time, and the original formulation of mimicry theory. We are especially interested in them because their convergent wing patterns offer an opportunity to study the repeatability of evolutionary change."
The sequencing of a butterfly genome also offers some remarkable insights into the biology of these charismatic insects. Butterflies are thought to be more visual in their communication as compared to night-flying moths. Surprisingly, in work done by Adriana Briscoe at the University of California, analysis carried out at the University of California by Adriana Briscoe showed that they have an even greater array of genes involved in chemical communication as compared to moths.
Owen McMillan of the Smithsonian Tropical Research Institute in Panama said: "We are accustomed to thinking of butterflies as brightly coloured, primarily visual insects, but the presence of such a rich array of olfactory receptors and chemosensory genes, suggests that smell and taste are also vital."
The study heralds a new era in genome biology, in which genome sequencing has become available to small groups of researchers for their own organism of choice. In this case academics from 9 labs across the globe each contributed to a pool of funding that permitted the sequencing effort, without any major grant funding.
Dr Jiggins added, "I think it's been a great privilege to work with all these people across the world, and especially our collaborators in Latin America, who are all equally excited about these butterflies."
Larks Ascending
The Critically Endangered Raso lark (Alauda razae) lives on a single desert island of 7 km2 in the Cape Verdes off West Africa. Happily, the birds have undergone a remarkable boom over the past decade, according to a paper published online this week in Animal Conservation. Since 2004, the world population of the birds has skyrocketed from 65 to 1490—including a tripling in numbers last year alone—according to a team led by ornithologist Michael Brooke of the Department of Zoology, University of Cambridge. "It's unprecedented among birds," Brooke says. The increase correlates with greater rainfall, which probably boosts the number of insects available to eat.
When the population was at its nadir in 2004, there were just 20 females, and about 45 males. This sex ratio bias arose because of consistently higher female mortality. Since then, the annual visits, also involving Tom Flower and Justin Welbergen of the Department of Zoology, have recorded not only a growing population but also a return to equal number of males and females. This happened because the young fledglings pumped into the population were equally likely to be male or female.
Andy Symes of BirdLife International, who has reviewed the conservation status of the lark, calls the finding "fantastic news." But he cautions that the population could easily fall if the island dries out again. Both he and Brooke recommend that a second population be established on a nearby island to help ensure that the species isn't wiped out by an unlucky event such as severe drought, disease, or new predators.
Pilkington Teaching Prize 2012
The Department is delighted to announce that Torsten Krude has been awarded one of this years Pilkington Teaching Prizes, in recognition of excellence in teaching at the University.
The Pilkington Prizes were inaugurated and endowed by Sir Alistair Pilkington, to acknowledge excellence in teaching; they are funded from the Cambridge Foundation Fund for Teaching Prizes.
The Head of Department, Professor Michael Akam, writes "Torsten has for many years introduced our students to the molecular biology of the cell nucleus. His lectures, setting the tone for the NST 1B Cell and Developmental Biology course at the beginning of the second year, receive an outstandingly positive response from the students. To accompany these lectures he presents practical classes that provide the students with an introduction to sophisticated molecular techniques. These are equally popular."
Poster Competition Successes 2012
The Graduate School of Life Sciences Poster and Images competition
Image Competition: Second prize to Paola Cognigni for her image "A view into a fly's backside". Image
Impact Poster competition: Second prize to Gerit Linneweber for his poster "Insects impact on us!"
Departmental Seminar Day Poster Competition
Winner: Jiggins Lab - Butterfly Genetics Group Poster
Demise of large animals such as woolly mammoth and giant sloths caused by both man and climate change
Past waves of extinctions, which removed some of the world's largest animals, were caused by both people and climate change, according to new research from the members of the Department.
By examining extinctions during the late Quaternary period (from 700,000 year ago until present day), but primarily focusing on the last 100,000 years, scientists have been able to assess the relative importance of different factors in causing the extinctions of many of the world's terrestrial megafauna, animals 44 kg or larger. These extinctions included mammoths in North America and Eurasia as well as mastodons and giant sloths in the Americas, the woolly rhino in Europe, giant kangaroos and wombats in Australia, and the moas (giant flightless birds) in New Zealand.
The researchers used data from an Antarctic ice core, which gives one of the longest running records of changes in the earth's climate, covering the last several hundred thousand years. They also compiled information on the arrival of modern humans from Africa on five different landmasses (North America, South America, most of Eurasia, Australia and New Zealand). By conducting a statistical analysis using both the climatic information and the timing of arrival of modern humans, they were able to determine whether the pattern of extinctions across landmasses was best explained by climate change, the arrival of modern humans, or both. They concluded that it was a combination of both the arrival of man (probably through hunting or habitat alteration) as well as climate change which caused the extinctions.
The authors believe that the research provides insights into the consequences of pressures on megafauna living today, including tigers, polar bears, elephants and rhinos. Graham Prescott, currently a PhD student in the department and co-author on the paper, highlighted how their research may inform us about the current plight facing large animals: "Our research suggests that a combination of human pressure and climate change was able to cause the extinctions of many large animals in the past. Many large, charismatic animals today are threatened by both hunting pressure and changes in climate; if we do not take action to address these issues we may see further extinctions. And in contrast to the people who first encountered these megafauna, people today are fully aware of the consequences of our actions; this gives us hope that we can prevent future extinctions, but will make it all the worse if we do not."
David Williams, currently a PhD student in the department and co-author on the paper, added: "The loss of these animals has been a zoological puzzle since the time of Charles Darwin and Alfred Russel Wallace. At that time, many people didn't believe that human-caused extinctions were possible, but Wallace argued otherwise. We have now shown, 100 years later, that he was right, and that humans, combined with climate change have been affecting other species for tens of thousands of years and continue to do so. Hopefully, now though, we are in a position to do something about it."
Professor Rhys Green, an author on the paper from the Department and the Royal Society for the Protection of Birds (RSPB) said: "Most previous studies have argued that the extinction of mammoths and other megafauna is linked separately to either human pressure or climatic change. Our work indicates that they had their devastating effect working together. This previous combination of unusual patterns of climate change and direct human pressure from hunting and habitat destruction is similar to those to which we are subjecting nature to today and what happened before should be taken as a warning. The key difference this time is that the climate change is not caused by fluctuations in the earth's rotation axis but to warming caused by fossil fuel burning and deforestation by humans - a double whammy of our own making. We should learn the lesson and act urgently to moderate both types of impact."
The paper ‘Quantitative global analysis of the role of climate and people in explaining late Quaternary megafaunal extinctions’ was published in the 05 March 2012 edition of PNAS.
Part II Zoology Open Day
2nd Year Natural Science, Medic and Vet Students are invited to come along to the Museum of Zoology on Monday 12th March to talk to course and module organisers about taking their Part II year in the Zoology Department.
Optimal foraging in C.elegans
Dr Birgitta Olofsson and colleagues have published a paper looking at neuronal and molecular substrates for optimal foraging in Caenorhabditis elegans.
Variation in food quality and abundance requires animals to decide whether to stay on a poor food patch or leave in search of better food. An important question in behavioral ecology asks when is it optimal for an animal to leave a food patch it is depleting. Although optimal foraging is central to evolutionary success, the neural and molecular mechanisms underlying it are poorly understood.
They investigate the neuronal basis for adaptive food-leaving behavior in response to resource depletion in Caenorhabditis elegans, and identify several of the signaling pathways involved. The ASE neurons, previously implicated in salt chemoattraction, promote food-leaving behavior via a cGMP pathway as food becomes limited. High ambient O(2) promotes food-leaving via the O(2)-sensing neurons AQR, PQR, and URX. Ectopic activation of these neurons using channelrhodopsin is sufficient to induce high food-leaving behavior. In contrast, the neuropeptide receptor NPR-1, which regulates social behavior on food, acts in the ASE neurons, the nociceptive ASH neurons, and in the RMG interneuron to repress food-leaving. Finally, we show that neuroendocrine signaling by TGF-β/DAF-7 and neuronal insulin signaling are necessary for adaptive food-leaving behavior. They suggest that animals integrate information about their nutritional state with ambient oxygen and gustatory stimuli to formulate optimal foraging strategies.
Milward K, Busch KE, Murphy RJ, de Bono M, Olofsson B. Neuronal and molecular substrates for optimal foraging in Caenorhabditis elegans. Proc Natl Acad Sci U S A. 2011 Dec 20;108(51):20672-7. Epub 2011 Dec 1.