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David Attenborough Building Synergy Project

From Department of Zoology. Published on Mar 16, 2018.

Conservationists gather to mark International Women's Day

By ed515 from University of Cambridge - Department of Zoology. Published on Mar 09, 2018.

The event, jointly organised by the Museum and the Cambridge Conservation Forum’s Women in Conservation Leadership Network, was held to mark International Women’s Day and included a keynote lecture by Professor Rebecca Kilner from Cambridge’s Department of Zoology.

Kilner said; “Events like this are important for showing the next generation that anyone with a spark for science can work in science subjects. They are designed to excite and encourage young people to pursue their interests - and not to be held back by their gender, race or background.”

The Museum welcomed over 100 visitors to the event, which included ‘meet the scientist’ stalls, a poster exhibition, and a sneak-peek at the newly refurbished Whale Hall.

More than 30 women working in different scientific fields took part, from organisations including the United Nations’ Environment World Conservation Monitoring Centre, the RSPB and the International Union for the Conservation of Nature. They were joined by staff and volunteers from the museum, and Cambridge postgraduate students.

Dr Rosalyn Wade, the Museum’s Interpretation and Learning Officer, helped to coordinate the event. She said; “A key role for the Museum is engaging with the public and raising awareness of work in biological and environmental sciences.

“It’s important to raise awareness of the different kinds of careers available in scientific fields. A number of our visitors were GCSE and A-Level students, and it was a great opportunity for them to see the range of roles that might be available to them in the future.

“We also had lots of new mums who are thinking about a career change and were interested to learn more about different areas. It was great to see such a diverse range of people.”

The Museum has undergone a massive redevelopment, and will officially re-open to the public on 23 June.

Scientists from around the world gathered at the Museum of Zoology yesterday to celebrate and promote the work of women in conservation.

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Annual Equalities and Wellbeing Lecture 2018

From Department of Zoology. Published on Mar 08, 2018.

Regulation of DNA replication during early embryogenesis

From Department of Zoology. Published on Mar 05, 2018.

Ancient genome study identifies traces of indigenous “Taíno” in present-day Caribbean populations

By tdk25 from University of Cambridge - Department of Zoology. Published on Feb 19, 2018.

Researchers were able to use the tooth of a woman found in a cave on the island of Eleuthera in the Bahamas to sequence the first complete ancient human genome from the Caribbean. The woman lived at some point between the 8th and 10th centuries, at least 500 years before Columbus made landfall in the Bahamas.

The results provide unprecedented insights into the genetic makeup of the Taíno – a label commonly used to describe the indigenous people of that region. This includes the first clear evidence that there has been some degree of continuity between the indigenous peoples of the Caribbean and contemporary communities living in the region today.

Such a link had previously been suggested by other studies based on modern DNA. None of these, however, was able to draw on an ancient genome. The new research finally provides concrete proof that indigenous ancestry in the region has survived to the present day.

Comparing the ancient Bahamian genome to those of contemporary Puerto Ricans, the researchers found that they were more closely related to the ancient Taíno than any other indigenous group in the Americas. However, they argue that this characteristic is unlikely to be exclusive to Puerto Ricans alone and are convinced that future studies will reveal similar genetic legacies in other Caribbean communities.

The findings are likely to be especially significant for people in the Caribbean and elsewhere who have long claimed indigenous Taíno heritage, despite some historical narratives that inaccurately brand them “extinct”. Such misrepresentations have been heavily criticised by historians and archaeologists, as well as by descendant communities themselves, but until now they lacked clear genetic evidence to support their case.

The study was carried out by an international team of researchers led by Dr Hannes Schroeder and Professor Eske Willerslev of Cambridge's Department of Zoology within the framework of the ERC Synergy project NEXUS1492. The findings are published in the journal Proceedings of the National Academy of Sciences (PNAS).

Schroeder, from the University of Copenhagen who carried out the research as part of the NEXUS1492 project, said: “It’s a fascinating finding. Many history books will tell you that the indigenous population of the Caribbean was all but wiped out, but people who self-identify as Taíno have always argued for continuity. Now we know they were right all along: there has been some form of genetic continuity in the Caribbean.”

Willerslev, who has dual posts at St John’s College, University of Cambridge, and the University of Copenhagen, said: “It has always been clear that people in the Caribbean have Native American ancestry, but because the region has such a complex history of migration, it was difficult to prove whether this was specifically indigenous to the Caribbean, until now.”

The researchers were also able to trace the genetic origins of the indigenous Caribbean islanders, showing that they were most closely related to Arawakan-speaking groups who live in parts of northern South America today. This suggests that the origins of at least some the people who migrated to the Caribbean can be traced back to the Amazon and Orinoco Basins, where the Arawakan languages developed.

The Caribbean was one of the last parts of the Americas to be populated by humans starting around 8,000 years ago. By the time of European colonization, the islands were a complex patchwork of different societies and cultures. The “Taíno” culture was dominant in the Greater, and parts of the Lesser Antilles, as well as the Bahamas, where the people were known as Lucayans.

To trace the genetic origins of the Lucayans the researchers compared the ancient Bahamian genome with previously published genome-wide datasets for over 40 present-day  indigenous groups from the Americas. In addition, they looked for traces of indigenous Caribbean ancestry in present-day populations by comparing the ancient genome with those of 104 contemporary Puerto Ricans included in the 1000 Genomes Project. The 10-15% of Native American ancestry in this group was shown to be closely related to the ancient Bahamian genome.

Jorge Estevez, a Taíno descendant who works at the National Museum of the American Indian in New York and assisted the project team, said that as a boy growing up in the United States, he was told stories about his Taíno ancestors at home, but at school was taught that the same ancestors had died out. “I wish my grandmother were alive today so that I could confirm to her what she already knew,” he added. “It shows that the true story is one of assimilation, certainly, but not total extinction. I am genuinely grateful to the researchers. Although this may have been a matter of scientific inquiry for them, to us, the descendants, it is truly liberating and uplifting.”

Although indigenous Caribbean communities were island-based, the researchers found very little genomic evidence of isolation or inbreeding in the ancient genome. This reinforces earlier genetic research led by Willerslev, which suggests that early human communities developed surprisingly extensive social networks, long before the term had digital connotations. It also echoes ongoing work by researchers at the Faculty of Archaeology in Leiden and others indicating the connectedness of indigenous Caribbean communities. 

Professor Corinne Hofman from Leiden University and PI of the NEXUS1492 project, said: "Archaeological evidence has always suggested that large numbers of people who settled the Caribbean originated in South America, and that they maintained social networks that extended far beyond the local scale. Historically, it has been difficult to back this up with ancient DNA because of poor preservation, but this study demonstrates that it is possible to obtain ancient genomes from the Caribbean and that opens up fascinating new possibilities for research."

A thousand-year-old tooth has provided genetic evidence that the so-called “Taíno”, the first indigenous Americans to feel the full impact of European colonisation after Columbus arrived in the New World, still have living descendants in the Caribbean today.

It has always been clear that people in the Caribbean have Native American ancestry, but it was difficult to prove whether this was specifically indigenous to the Caribbean, until now.
Eske Willerslev
First encounter. Columbus landing in the New World

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Shoals of sticklebacks differ in their collective personalities

By cjb250 from University of Cambridge - Department of Zoology. Published on Feb 07, 2018.

For centuries, scientists and non-scientists alike have been fascinated by the beautiful and often complex collective behaviour of animal groups, such as the highly synchronised movements of flocks of birds and schools of fish. Often, those spectacular collective patterns emerge from individual group members using simple rules in their interactions, without requiring global knowledge of their group.

In recent years it has also become apparent that, across the animal kingdom, individual animals often differ considerably and consistently in their behaviour, with some individuals being bolder, more active, or more social than others.

New research conducted at the University of Cambridge’s Department of Zoology suggests that observations of different groups of schooling fish could provide important insights into how the make-up of groups can drive collective behaviour and performance.

In the study, published today in the journal Proceedings of the Royal Society B, the researchers created random groups of wild-caught stickleback fish and subjected them repeatedly to a range of environments that included open spaces, plant cover, and patches of food.

Dr Jolle Jolles, lead author of the study, now based at the Max Planck Institute for Ornithology, said: “By filming the schooling fish from above and tracking the groups’ movements in detail, we found that the randomly composed shoals showed profound differences in their collective behaviour that persisted across different ecological contexts. Some groups were consistently faster, better coordinated, more cohesive, and showed clearer leadership structure than others.

“That such differences existed among the groups is remarkable as individuals were randomly grouped with others that were of similar age and size and with which they had very limited previous social contact.”

This research shows for the first time that, even among animals where group membership changes frequently over time and individuals are not very strongly related to each other, such as schooling fish or flocking birds, stable differences can emerge in the collective performance of animal groups.

Such behavioural variability among groups may directly affect the survival and reproductive success of the individuals within them and influence how they associate with one another. Ultimately these findings may therefore help understand the selective pressures that have shaped social behaviour.

Dr Andrea Manica, co-author of the paper from the University of Cambridge, added: “Our research reveals that the collective performance of groups is strongly driven by their composition, suggesting that consistent behavioural differences among groups could be a widespread phenomenon in animal societies.”

These research findings provide important new insights that may help explain and predict the performance of social groups, which could be beneficial in building human teams or constructing automated robot swarms.

The research was supported by the Biotechnology and Biological Sciences Research Council.

Jolles, JW et al. Repeatable group differences in the collective behaviour of stickleback shoals across ecological contexts. Proceedings of the Royal Society B; 7 Feb 2018; DOI: 10.1098/rspb.2017.2629

Research from the University of Cambridge has revealed that, among schooling fish, groups can have different collective personalities, with some shoals sticking closer together, being better coordinated, and showing clearer leadership than others.


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Launch of Cambridge ZooCasts

From Department of Zoology. Published on Feb 05, 2018.

Think of honeybees as ‘livestock’ not wildlife, argue experts

By fpjl2 from University of Cambridge - Department of Zoology. Published on Jan 25, 2018.

The ‘die-off’ events occurring in honeybee colonies that are bred and farmed like livestock must not be confused with the conservation crisis of dramatic declines in thousands of wild pollinator species, say Cambridge researchers.

Writing in the journal Science, the conservationists argue there is a “lack of distinction” in public understanding – fuelled by misguided charity campaigns and media reports – between an agricultural problem and an urgent biodiversity issue.

In fact, they say domesticated honeybees actually contribute to wild bee declines through resource competition and spread of disease, with so-called environmental initiatives promoting honeybee-keeping in cities or, worse, protected areas far from agriculture, only likely to exacerbate the loss of wild pollinators.

“The crisis in global pollinator decline has been associated with one species above all, the western honeybee. Yet this is one of the few pollinator species that is continually replenished through breeding and agriculture,” said co-author Dr Jonas Geldmann from Cambridge University’s Department of Zoology.

“Saving the honeybee does not help wildlife. Western honeybees are a commercially managed species that can actually have negative effects on their immediate environment through the massive numbers in which they are introduced.

“Levels of wild pollinators, such as species of solitary bumblebee, moth and hoverfly, continue to decline at an alarming rate. Currently, up to 50% of all European bee species are threatened with extinction,” Geldmann said.  

Honeybees are vital for many crops – as are wild pollinators, with some assessments suggesting wild species provide up to half the needed “pollinator services” for the three-quarters of globally important crops that require pollination.

However, generating honeybee colonies for crop pollination is problematic. Major flowering crops such as fruits and oilseed rape bloom for a period of days or weeks, whereas honeybees are active for nine to twelve months and travel up to 10km from their hives.

This results in massive “spillover” from farmed honeybees into the landscape, potentially out-competing wild pollinators. A recent study by the co-author of today’s Science article, Dr Juan P. González-Varo, showed honeybee levels in woodlands of southern Spain to be eight times higher after orange tree crops finish blooming.

“Keeping honeybees is an extractive activity. It removes pollen and nectar from the environment, which are natural resources needed by many wild species of bee and other pollinators,” said González-Varo, also from Cambridge’s Zoology Department.

“Honeybees are artificially-bred agricultural animals similar to livestock such as pigs and cows. Except this livestock can roam beyond any enclosures to disrupt local ecosystems through competition and disease.”

As with other intensively farmed animals, overcrowding and homogenous diets have depressed bee immune systems and sent pathogen rates soaring in commercial hives. Diseases are transferred to wild species when bees feed from the same flowers, similar to germs passing between humans through a shared coffee cup.

This puts added pressure on endangered wild European bee species such as the great yellow bumblebee, which was once found across the UK but has lost 80% of its range in the last half century, and is now limited to coastal areas of Scotland.

Both wild and cultivated pollinators are afflicted by pesticides such as neonicotinoids, as well as other anthropogenic effects – from loss of hedgerows to climate change – which drive the much-publicised die-offs among farmed bees and the decline in wild pollinator species over the last few decades.

“Honeybee colony die-offs are likely to be a ‘canary in the coalmine’ that is mirrored by many wild pollinator species. The attention on honeybees may help raise awareness, but action must also be directed towards our threatened species,” said Geldmann.

“The past decade has seen an explosion in research on honeybee loss and the dangers posed to crops. Yet little research has been done to understand wild native pollinator declines, including the potential negative role of managed honeybees.”

Geldmann and González-Varo recommend policies to limit the impact of managed honeybees, including hive size limits, the moving of colonies to track the bloom of different crops, and greater controls on managed hives in protected areas.

“Honeybees may be necessary for crop pollination, but beekeeping is an agrarian activity that should not be confused with wildlife conservation,” they write. 

Contrary to public perception, die-offs in honeybee colonies are an agricultural not a conservation issue, argue Cambridge researchers, who say that manged honeybees may contribute to the genuine biodiversity crisis of Europe’s declining wild pollinators.

Honeybees are artificially-bred agricultural animals similar to livestock such as pigs and cows
Juan P. González-Varo
Commercial honeybee hives in the Teide National Park, Tenerife, Spain.

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Are insects a credible food source?

From Department of Zoology. Published on Jan 22, 2018.

Bolivian biodiversity hotspot on road to deforestation

From Department of Zoology. Published on Jan 15, 2018.

Direct genetic evidence of founding population reveals story of first Native Americans

By tdk25 from University of Cambridge - Department of Zoology. Published on Jan 03, 2018.

The data, which came from archaeological finds in Alaska, also points to the existence of a previously unknown Native American population, whom academics have named “Ancient Beringians”.

The findings are being published in the journal Nature and present possible answers to a series of long-standing questions about how the Americas were first populated.

It is widely accepted that the earliest settlers crossed from what is now Russia into Alaska via an ancient land bridge spanning the Bering Strait which was submerged at the end of the last Ice Age. Issues such as whether there was one founding group or several, when they arrived, and what happened next, are the subject of extensive debate, however.

In the new study, an international team of researchers led by academics from the Universities of Cambridge and Copenhagen sequenced the full genome of an infant – a girl named Xach'itee'aanenh t'eede gay, or Sunrise Child-girl, by the local Native community - whose remains were found at the Upward Sun River archaeological site in Alaska in 2013.

To their surprise, they found that although the child had lived around 11,500 years ago, long after people first arrived in the region, her genetic information did not match either of the two recognised branches of early Native Americans, which are referred to as Northern and Southern. Instead, she appeared to have belonged to an entirely distinct Native American population, which they called Ancient Beringians.

Further analyses then revealed that the Ancient Beringians were an offshoot of the same ancestor population as the Northern and Southern Native American groups, but that they separated from that population earlier in its history. This timeline allowed the researchers to construct a picture of how and when the continent might have been settled by a common, founding population of ancestral Native Americans, that gradually divided into these different sub-groupings.

The study was led by Professor Eske Willerslev, who holds positions both at St John’s College, University of Cambridge, and the University of Copenhagen in Denmark.

“The Ancient Beringians diversified from other Native Americans before any ancient or living Native American population sequenced to date. It’s basically a relict population of an ancestral group which was common to all Native Americans, so the sequenced genetic data gave us enormous potential in terms of answering questions relating to the early peopling of the Americas,” he said. 

“We were able to show that people probably entered Alaska before 20,000 years ago. It’s the first time that we have had direct genomic evidence that all Native Americans can be traced back to one source population, via a single, founding migration event.”

The study compared data from the Upward Sun River remains with both ancient genomes, and those of numerous present-day populations. This allowed the researchers first to establish that the Ancient Beringian group was more closely related to early Native Americans than their Asian and Eurasian ancestors, and then to determine the precise nature of that relationship and how, over time, they split into distinct populations.

Until now, the existence of two separate Northern and Southern branches of early Native Americans has divided academic opinion regarding how the continent was populated. Researchers have disagreed over whether these two branches split after humans entered Alaska, or whether they represent separate migrations.

The Upward Sun River genome shows that Ancient Beringians were isolated from the common, ancestral Native American population, both before the Northern and Southern divide, and after the ancestral source population was itself isolated from other groups in Asia. The researchers say that this means it is likely there was one wave of migration into the Americas, with all subdivisions taking place thereafter.

According to the researchers’ timeline, the ancestral population first emerged as a separate group around 36,000 years ago, probably somewhere in northeast Asia. Constant contact with Asian populations continued until around 25,000 years ago, when the gene flow between the two groups ceased. This cessation was probably caused by brutal changes in the climate, which isolated the Native American ancestors. “It therefore probably indicates the point when people first started moving into Alaska,” Willerslev said.

Around the same time, there was a level of genetic exchange with an ancient North Eurasian population. Previous research by Willerslev has shown that a relatively specific, localised level of contact between this group, and East Asians, led to the emergence of a distinctive ancestral Native American population.

Ancient Beringians themselves then separated from the ancestral group earlier than either the Northern or Southern branches around 20,000 years ago. Genetic contact continued with their Native American cousins, however, at least until the Upward Sun River girl was born in Alaska around 8,500 years later.

The geographical proximity required for ongoing contact of this sort led the researchers to conclude that the initial migration into the Americas had probably already taken place when the Ancient Beringians broke away from the main ancestral line. José Víctor Moreno-Mayar, from the University of Copenhagen, said: “It looks as though this Ancient Beringian population was up there, in Alaska, from 20,000 years ago until 11,500 years ago, but they were already distinct from the wider Native American group.”

Finally, the researchers established that the Northern and Southern Native American branches only split between 17,000 and 14,000 years ago which, based on the wider evidence, indicates that they must have already been on the American continent south of the glacial ice.

The divide probably occurred after their ancestors had passed through, or around, the Laurentide and Cordilleran ice sheets – two vast glaciers which covered what is now Canada and parts of the northern United States, but began to thaw at around this time.

The continued existence of this ice sheet across much of the north of the continent would have isolated the southbound travellers from the Ancient Beringians in Alaska, who were eventually replaced or absorbed by other Native American populations. Although modern populations in both Alaska and northern Canada belong to the Northern Native American branch, the analysis shows that these derive from a later “back” migration north, long after the initial migration events.

“One significant aspect of this research is that some people have claimed the presence of humans in the Americas dates back earlier – to 30,000 years, 40,000 years, or even more,” Willerslev added. “We cannot prove that those claims are not true, but what we are saying, is that if they are correct, they could not possibly have been the direct ancestors to contemporary Native Americans.”


Willerslev, E, et al. Terminal Pleistocene Alaskan genome reveals first founding population of Native Americans. Nature. 3 Jan 2018. DOI: 10.1038/nature25173

Direct genetic traces of the earliest Native Americans have been identified for the first time in a new study. The genetic evidence suggests that people may have entered the continent in a single migratory wave, perhaps arriving more than 20,000 years ago.

It’s the first time that we have had direct genomic evidence that all Native Americans can be traced back to one source population, via a single, founding migration event
Eske Willerslev
Excavations at the Upward Sun River archaeological site in Alaska. The new study shows that the remains found there belonged to members of a previously unknown Native American population, whom academics have named “Ancient Beringians”.

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Political instability and weak governance lead to loss of species, study finds

By fpjl2 from University of Cambridge - Department of Zoology. Published on Dec 20, 2017.

A vast new study of changes in global wildlife over almost three decades has found that low levels of effective national governance are the strongest predictor of declining species numbers – more so than economic growth, climate change or even surges in human population.   

The findings, published in the journal Nature, also show that protected conservation areas do maintain wildlife diversity, but only when situated in countries that are reasonably stable politically with sturdy legal and social structures.

The research used the fate of waterbird species since 1990 as a bellwether for broad biodiversity trends, as their wetland habitats are among the most diverse as well as the most endangered on Earth.

An international team of scientists and conservation experts led by the University of Cambridge analysed over 2.4 million annual count records of 461 waterbird species across almost 26,000 different survey sites around the world.

The researchers used this giant dataset to model localised species changes in nations and regions.  Results were compared to the Worldwide Governance Indicators, which measure everything from violence rates and rule of law to political corruption, as well as data such as gross domestic product (GDP) and conservation performance.

The team discovered that waterbird decline was greater in regions of the world where governance is, on average, less effective: such as Western and Central Asia, South America and sub-Saharan Africa.

The healthiest overall species quotas were seen in continental Europe, although even here the levels of key species were found to have nosedived.

This is the first time that effectiveness of national governance and levels of socio-political stability have been identified as the most significant global indicator of biodiversity and species loss.   

“Although the global coverage of protected areas continues to increase, our findings suggest that ineffective governance could undermine the benefits of these biodiversity conservation efforts,” says Cambridge’s Dr Tatsuya Amano, who led the study at the University’s Department of Zoology and Centre for the Study of Existential Risk.

“We now know that governance and political stability is a vital consideration when developing future environmental policies and practices.”

For the latest study, Amano worked with Cambridge colleagues as well as researchers from the universities of Bath, UK, and Santa Clara, US, and conservation organisations Wetlands International and the National Audubon Society.

The lack of global-level data on changes to the natural world limits our understanding of the “biodiversity crisis”, say the study’s authors. However, they say there are advantages to focusing on waterbirds when trying to gauge these patterns.

Waterbirds are a diverse group of animals, from ducks and heron to flamingos and pelicans. Their wetland habitats cover some 1.3 billion hectares of the planet – from coast to freshwater and even highland – and provide crucial “ecosystem services”. Wetlands have also been degraded more than any other form of ecosystem.

In addition, waterbirds have a long history of population monitoring. The annual global census run by Wetlands International has involved more than 15,000 volunteers over the last 50 years, and the National Audubon Society’s annual Christmas bird count dates back to 1900.

“Our study shows that waterbird monitoring can provide useful lessons about what we need to do to halt the loss of biodiversity,” said co-author Szabolcs Nagy, Coordinator of the African-Eurasian Waterbird Census at Wetlands International.

Compared to all the “anthropogenic impacts” tested by the researchers, national governance was the most significant. ”Ineffective governance is often associated with lack of environmental enforcement and investment, leading to habitat loss,” says Amano.

The study also uncovered a relationship between the speed of GDP growth and biodiversity: the faster GDP per capita was growing, the greater the decline in waterbird species.

Diversity on a localised level was worst affected on average in South America, with a 0.95% annual loss equating to a 21% decline across the region over 25 years. Amano was also surprised to find severe species loss across inland areas of western and central Asia.  

The researchers point out that poor water management and dam construction in parts of Asia and South America have caused wetlands to permanently dry out in counties such as Iran and Argentina – even in areas designated as protected.

Impotent hunting regulations can also explain species loss under ineffective governance. “Political instability can weaken legal enforcement, and consequently promote unsuitable, often illegal, killing even in protected areas,” says Amano.

In fact, the researchers found that protected conservation areas simply did not benefit biodiversity if they were located in nations with weak governance.

Recent Cambridge research involving Amano suggests that grassroots initiatives led by local and indigenous groups can be more effective than governments at protecting ecosystems – one possible conservation approach for regions suffering from political instability.   

Amano, T et al. Successful conservation of global waterbird populations depends on effective governance. Nature; 20 December 2017; DOI: 10.1038/nature25139

Big data study of global biodiversity shows ineffective national governance is a better indicator of species decline than any other measure of “anthropogenic impact”. Even protected conservation areas make little difference in countries that struggle with socio-political stability.

We now know that governance and political stability is a vital consideration when developing future environmental policies and practices
Tatsuya Amano
Black-tailed godwit (Limosa limosa), a waterbird with habitats ranging from the Russian far-east to Europe, Africa, and Australasia.

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Birds learn from each other’s ‘disgust’, enabling insects to evolve bright colours

By fpjl2 from University of Cambridge - Department of Zoology. Published on Dec 18, 2017.

Many animals have evolved to stand out. Bright colours may be easy to spot, but they warn predators off by signalling toxicity or foul taste.

Yet if every individual predator has to eat colourful prey to learn this unappetising lesson, it’s a puzzle how conspicuous colours had the chance to evolve as a defensive strategy. 

Now, a new study using the great tit species as a “model predator” has shown that if one bird observes another being repulsed by a new type of prey, then both birds learn the lesson to stay away.

By filming a great tit having a terrible dining experience with conspicuous prey, then showing it on a television to other tits before tracking their meal selection, researchers found that birds acquired a better idea of which prey to avoid: those that stand out.   

The team behind the study, published in the journal Nature Ecology & Evolution, say the ability of great tits to learn what to avoid through observing others is an example of “social transmission” of information.

The scientists scaled up data from their experiments through mathematical modelling to reveal a tipping point: where social transmission has occurred sufficiently in a predator species for its potential prey to stand a better chance with bright colours over camouflage.  

“Our study demonstrates that the social behaviour of predators needs to be considered to understand the evolution of their prey,” said lead author Dr Rose Thorogood, from the University of Cambridge’s Department of Zoology.

“Without social transmission taking place in predator species such as great tits, it becomes extremely difficult for conspicuously coloured prey to outlast and outcompete alternative prey, even if they are distasteful or toxic.

“There is mounting evidence that learning by observing others occurs throughout the animal kingdom. Species ranging from fruit flies to trout can learn about food using social transmission.

“We suspect our findings apply over a wide range of predators and prey. Social information may have evolutionary consequences right across ecological communities.”    

Thorogood (also based at the Helsinki Institute of Life Science) and colleagues from the University of Jyväskylä and University of Zürich captured wild great tits in the Finnish winter. At Konnevesi Research Station, they trained the birds to open white paper packages with pieces of almond inside as artificial prey.    

The birds were given access to aviaries covered in white paper dotted with small black crosses. These crosses were also marked on some of the paper packages: the camouflaged prey.

One bird was filmed unwrapping a package stamped with a square instead of a cross: the conspicuous prey. As such, its contents were unpalatable – an almond soaked with bitter-tasting fluid.

The bird’s reaction was played on a TV in front of some great tits but not others (a control group). When foraging in the cross-covered aviaries containing both cross and square packages, the birds exposed to the video were quicker to select their first item, and 32% less likely to choose the ‘conspicuous’ square prey.    

“Just as we might learn to avoid certain foods by seeing a facial expression of disgust, observing another individual headshake and wipe its beak encouraged the great tits to avoid that type of prey,” said Thorogood.

“By modelling the social spread of information from our experimental data, we worked out that predator avoidance of more vividly conspicuous species would become enough for them to survive, spread, and evolve.”

Great tits – a close relation of North America’s chickadee – make a good study species as they are “generalist insectivores” that forage in flocks, and are known to spread other forms of information through observation.

Famously, species of tit learned how to pierce milk bottle lids and siphon the cream during the middle of last century – a phenomenon that spread rapidly through flocks across the UK.

Something great tits don’t eat, however, is a seven-spotted ladybird. “One of the most common ladybird species is bright red, and goes untouched by great tits. Other insects that are camouflaged, such as the brown larch ladybird or green winter moth caterpillar, are fed on by great tits and their young,” said Thorogood.

“The seven-spotted ladybird is so easy to see that if every predator had to eat one before they discovered its foul taste, it would have struggled to survive and reproduce.

“We think it may be the social information of their unpalatable nature spreading through predator species such as great tits that makes the paradox of conspicuous insects such as seven-spotted ladybirds possible.”      

A new study of TV-watching great tits reveals how they learn through observation. Social interactions within a predator species can have “evolutionary consequences” for potential prey – such as the conspicuous warning colours of insects like ladybirds.

We suspect our findings apply over a wide range of predators and prey. Social information may have evolutionary consequences right across ecological communities
Rose Thorogood

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Meerkat morning weights

From Department of Zoology. Published on Dec 01, 2017.

Does the presence of helpers affect maternal investment in cooperative breeders?

From Department of Zoology. Published on Nov 24, 2017.

In case you missed it...

From Department of Zoology. Published on Nov 22, 2017.

Ancient fish scales and vertebrate teeth share an embryonic origin

By fpjl2 from University of Cambridge - Department of Zoology. Published on Nov 20, 2017.

In biology, one long-running debate has teeth: whether ancient fish scales moved into the mouth with the origin of jaws, or if the tooth had its own evolutionary inception.

Recent studies on species such as zebrafish showed scales and teeth developing from distinctly different clusters of cells in fish embryos, pouring cold water on ‘teeth from scales’ theories.

However, while most fish in the sea have bones, one ancient lineage – sharks, skates and rays – possess skeletons made entirely of cartilage.

These cartilaginous fish retain some primitive characteristics that have been lost in their bony counterparts, including small spiky scales embedded in their skin called ‘dermal denticles’ that bear a striking resemblance to jagged teeth.  

Now, researchers at the University of Cambridge have used fluorescent markers to track cell development in the embryo of a cartilaginous fish – a little skate in this case – and found that these thorny scales are in fact created from the same type of cells as teeth: neural crest cells.

The findings, published in the journal PNAS, support the theory that, in the depths of early evolution, these ‘denticle’ scales were carried into the emerging mouths of jawed vertebrates to form teeth. Jawed vertebrates now make up 99% of all living vertebrates, from fish to mammals.

“The scales of most fish that live today are very different from the ancient scales of early vertebrates,” says study author Dr Andrew Gillis from Cambridge’s Department of Zoology and the Marine Biological Laboratory in Woods Hole.

“Primitive scales were much more tooth-like in structure, but have been retained in only a few living lineages, including that of cartilaginous fishes such as skates and sharks.

“Stroke a shark and you’ll find it feels rougher than other fish, as shark skin is covered entirely in dermal denticles. There’s evidence that shark skin was actually used as sandpaper as early as the Bronze Age,” says Gillis.

“By labelling the different types of cells in the embryos of skate, we were able to trace their fates. We show that, unlike most fish, the denticle scales of sharks and skate develop from neural crest cells, just like teeth.

“Neural crest cells are central to the process of tooth development in mammals. Our findings suggest a deep evolutionary relationship between these primitive fish scales and the teeth of vertebrates.

“Early jawless vertebrates were filter feeders – sucking in small prey items from the water. It was the advent of both jaws and teeth that allowed vertebrates to begin processing larger and more complex prey.”

The very name of these scales, dermal denticles, alludes to the fact that they are formed of dentine: a hard calcified tissue that makes up the majority of a tooth, sitting underneath the enamel.  

The jagged dermal denticles on sharks and skate – and, quite possibly, vertebrate teeth – are remnants of the earliest mineralised skeleton of vertebrates: superficial armour plating. 

This armour would have perhaps peaked some 400 million years ago in now-extinct jawless vertebrate species, as protection against predation by ferocious sea scorpions, or even their early jawed kin. 

The Cambridge scientists hypothesise that these early armour plates were multi-layered: consisting of a foundation of bone and an outer layer of dentine – with the different layers deriving from different types of cells in unborn embryos.

These layers were then variously retained, reduced or lost in different vertebrate linages over the course of evolution. “This ancient dermal skeleton has undergone considerable reductions and modifications through time,” says Gillis.

“The sharks and skate have lost the bony under-layer, while most fish have lost the tooth-like dentine outer layer. A few species, such as the bichir, a popular fish in home aquariums, have retained aspects of both layers of this ancient external skeleton.”

Latest findings support the theory that teeth in the animal kingdom evolved from the jagged scales of ancient fish, the remnants of which can be seen today embedded in the skin of sharks and skate. 

This ancient dermal skeleton has undergone considerable reductions and modifications through time
Andrew Gillis
Dermal denticles on the tail of the Little Skate, as used in the latest research.

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2017 Marsh Book of the Year prize awarded to Tim Clutton-Brock

From Department of Zoology. Published on Nov 06, 2017.

Teaching and the Museum of Zoology

From Department of Zoology. Published on Oct 30, 2017.

New evidence shows that domestication of dogs has changed their skull shapes

From Department of Zoology. Published on Oct 18, 2017.

New Deputy Head of Department (Teaching)

From Department of Zoology. Published on Oct 17, 2017.

The David Attenborough Building sign is up

From Department of Zoology. Published on Oct 13, 2017.

Conservationists’ eco-footprints suggest education alone won’t change behaviour

By fpjl2 from University of Cambridge - Department of Zoology. Published on Oct 10, 2017.

Conservationists work to save the planet, and few are as knowledgeable when it comes to the environmental pressures of the Anthropocene.

However, the first wide-ranging study to compare the environmental footprint of conservationists to those of others – medics and economists, in this case – has found that, while conservationists behave in a marginally ‘greener’ manner, the differences are surprisingly modest.

Researchers say their findings add to increasing evidence that education and knowledge has little impact on individual behavior when it comes to major issues such as the environment and personal health.

Conservation scientists from the universities of Cambridge, UK, and Vermont, US, gathered data on a range of lifestyle choices – from bottled water use to air travel, meat consumption and family size – for 734 participants across the three groupings.

They found that fellow conservationists recycled more and ate less meat than either economists or medics, were similar to the other groups in how they travelled to work, but owned more cats and dogs.

The combined footprint score of the conservationists was roughly 16% less than that of economists, and 7% lower than the medics.

Nevertheless the average conservationist in the study’s sample took nine flights a year (half for work; half personal), ate meat or fish five times a week, and purchased very few offsets to their personal carbon emissions.

In fact, researchers found little correlation between the extent of environmental knowledge and environmentally-friendly behavior.

Moreover, greener action in one aspect of a person’s life did not predict it in any others – regardless of occupation. So a positive and relatively simple habit such as recycling did not appear to act as a “gateway” to more committed behaviour change.   

The team suggest that overall improvements might be most effectively achieved through tailored interventions: targeting higher-impact behaviors such as meat consumption and flying through government regulation and by incentivising alternatives. 

“While it may be hard to accept, we have to start acknowledging that increased education alone is perhaps not the panacea we would hope,” said lead author Andrew Balmford, Professor of Conservation Science at the University of Cambridge.

“Structural changes are key. For example, providing more affordable public transport, or removing subsidies for beef and lamb production. Just look at the effect of improved collection schemes on the uptake of recycling.

“The idea of ‘nudging’ – encouraging particular choices through changes in how cafes are laid out or travel tickets are sold, for instance – might have untapped potential to help us lower our footprint,” Balmford said.  

“As conservationists we must do a great deal more to lead by example. Obvious starting points include changing the ways we interact, so that attending frequent international meetings is no longer regarded as essential to making scientific progress. For many of us flying is probably the largest contributor to our personal emissions.”

The study’s four authors offer their own mea culpa: pointing out that, between them, they have seven children, took 31 flights in 2016, and ate an average of two meat meals in the week before submitting their study – now published – to the journal Biological Conservation.

“I don’t think conservationists are hypocrites, I think that we are human – meaning that some decisions are rational, and others, we rationalise,” said study co-author Brendan Fisher from the University of Vermont’s Gund Institute for Environment and Rubenstein School of Environment and Natural Resources.  

“Our results show that conservationists pick and choose from a buffet of pro-environmental behaviours the same as everyone else. We might eat less meat and compost more, but we fly more – and many of us still commute significant distances in gas cars.”

For the study, researchers distributed surveys on environmental behavior through conservation, economics and biomedical organisations to targeted newsletters, mailing lists and social media groups.

Of the self-selecting respondents, there were 300 conservationists, 207 economists and 227 medics from across the UK and US.

The participants were also asked a series of factual questions on environmental issues – from atmospheric change to species extinction – and ways to most effectively lower carbon footprints.

“Interestingly, conservationists scored no better than economists on environmental knowledge and awareness of pro-environmental actions,” said Balmford.

Overall footprint scores were higher for males, US nationals, economists, and people with higher degrees and larger incomes, but were unrelated to environmental knowledge.

Fisher says the study supports the idea that ‘values’ are a key driver of behaviour. Across the professions, attaching a high value to the environment was consistently associated with a lower footprint: fewer personal flights and less food waste, for example.

“It doesn’t matter if you are a medic, economist, or conservationist, our study shows that one of the most significant drivers of your behaviour is how much you value the environment,” Fisher said. 

“Economists who care about the environment behave as well as conservationists.”

A new study shows that even those presumably best informed on the environment find it hard to consistently “walk the walk”, prompting scientists to question whether relying solely on information campaigns will ever be enough.  

While it may be hard to accept, we have to start acknowledging that increased education alone is perhaps not the panacea we would hope
Andrew Balmford

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Prehistoric humans are likely to have formed mating networks to avoid inbreeding

By tdk25 from University of Cambridge - Department of Zoology. Published on Oct 05, 2017.

The study, reported in the journal Science, examined genetic information from the remains of anatomically modern humans who lived during the Upper Palaeolithic, a period when modern humans from Africa first colonised western Eurasia. The results suggest that people deliberately sought partners beyond their immediate family, and that they were probably connected to a wider network of groups from within which mates were chosen, in order to avoid becoming inbred.

This suggests that our distant ancestors are likely to have been aware of the dangers of inbreeding, and purposely avoided it at a surprisingly early stage in prehistory.

The symbolism, complexity and time invested in the objects and jewellery found buried with the remains also suggests that it is possible that they developed rules, ceremonies and rituals to accompany the exchange of mates between groups, which perhaps foreshadowed modern marriage ceremonies, and may have been similar to those still practised by hunter-gatherer communities in parts of the world today.

The study’s authors also hint that the early development of more complex mating systems may at least partly explain why anatomically modern humans proved successful while other species, such as Neanderthals, did not. However, more ancient genomic information from both early humans and Neanderthals is needed to test this idea.

The research was carried out by an international team of academics, led by the University of Cambridge, UK, and the University of Copenhagen, Denmark. They sequenced the genomes of four individuals from Sunghir, a famous Upper Palaeolithic site in Russia, which is believed to have been inhabited about 34,000 years ago.

The human fossils buried at Sunghir represent a rare and highly valuable source of information because, very unusually for finds from this period, the people buried there appear to have lived at the same time and were buried together. To the researchers’ surprise, however, these individuals were not closely related in genetic terms; at the very most, they were second cousins. This is true even in the case of two children who were buried head-to-head in the same grave.

Professor Eske Willerslev, a Fellow at St John’s College, Cambridge, Prince Philip Professor of Ecology and Evolution in the Department of Zoology, and a Professor at the University of Copenhagen, was the senior author on the study. “What this means is that even people in the Upper Palaeolithic, who were living in tiny groups, understood the importance of avoiding inbreeding,” he said. “The data that we have suggest that it was being purposely avoided.”

“This means that they must have developed a system for this purpose. If small hunter–gatherer bands were mixing at random, we would see much greater evidence of inbreeding than we have here.”

Early humans and other hominins such as Neanderthals appear to have lived in small family units. The small population size made inbreeding likely, but among anatomically modern humans it eventually ceased to be commonplace; when this happened, however, is unclear.

“Small family bands are likely to have interconnected with larger networks, facilitating the exchange of people between groups in order to maintain diversity,” Professor Martin Sikora, from the Centre for GeoGenetics at the University of Copenhagen, said.

Sunghir contains the burials of one adult male and two younger individuals, accompanied by the symbolically-modified incomplete remains of another adult, as well as a spectacular array of grave goods. The researchers were able to sequence the complete genomes of the four individuals, all of whom were probably living on the site at the same time. These data were compared with information from a large number of both modern and ancient human genomes.

They found that the four individuals studied were genetically no closer than second cousins, while an adult femur filled with red ochre found in the children’s’ grave would have belonged to an individual no closer than great-great grandfather of the boys. “This goes against what many would have predicted,” Willerslev said. “I think many researchers had assumed that the people of Sunghir were very closely related, especially the two youngsters from the same grave.”

The people at Sunghir may have been part of a network similar to that of modern day hunter-gatherers, such as Aboriginal Australians and some historical Native American societies. Like their Upper Palaeolithic ancestors, these people live in fairly small groups of around 25 people, but they are also less directly connected to a larger community of perhaps 200 people, within which there are rules governing with whom individuals can form partnerships.

“Most non-human primate societies are organised around single-sex kin where one of the sexes remains resident and the other migrates to another group, minimising inbreeding,” Professor Marta Mirazón Lahr, from the Leverhulme Centre for Human Evolutionary Studies at the University of Cambridge, said. “At some point, early human societies changed their mating system into one in which a large number of the individuals that form small hunter-gatherer units are non-kin. The results from Sunghir show that Upper Palaeolithic human groups could use sophisticated cultural systems to sustain very small group sizes by embedding them in a wide social network of other groups.”

By comparison, genomic sequencing of a Neanderthal individual from the Altai Mountains who lived around 50,000 years ago indicates that inbreeding was not avoided. This leads the researchers to speculate that an early, systematic approach to preventing inbreeding may have helped anatomically modern humans to thrive, compared with other hominins.

This should be treated with caution, however: “We don’t know why the Altai Neanderthal groups were inbred,” Sikora said. “Maybe they were isolated and that was the only option; or maybe they really did fail to develop an available network of connections. We will need more genomic data of diverse Neanderthal populations to be sure.”

Willerslev also highlights a possible link with the unusual sophistication of the ornaments and cultural objects found at Sunghir. Group-specific cultural expressions may have been used to establish distinctions between bands of early humans, providing a means of identifying who to mate with and who to avoid as partners.

“The ornamentation is incredible and there is no evidence of anything like that with Neanderthals and other archaic humans,” Willerslev added. “When you put the evidence together, it seems to be speaking to us about the really big questions; what made these people who they were as a species, and who we are as a result.”

The research paper, Ancient genomes show social and reproductive behaviour of early Upper Paleolithic foragers, is published in the October 5 issue of Science

Early humans seem to have recognised the dangers of inbreeding at least 34,000 years ago, and developed surprisingly sophisticated social and mating networks to avoid it, new research has found.

When you put the evidence together, it seems to be speaking to us about the really big questions; what made these people who they were as a species, and who we are as a result
Eske Willerslev
Detail of one of the burials from Sunghir, in Russia.

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