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Puss Moth Caterpillar on The One Show

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

Sir Jim Smith - knighted in 2017 New Years Honours

From Department of Zoology. Published on Jan 03, 2017.

Malcolm Burrows’ research featured on QI

From Department of Zoology. Published on Jan 03, 2017.

Professor Robert Hinde 1923-2016

From Department of Zoology. Published on Jan 03, 2017.

Languages still a major barrier to global science, new research finds

By fpjl2 from University of Cambridge - Department of Zoology. Published on Dec 29, 2016.

English is now considered the common language, or 'lingua franca', of global science. All major scientific journals seemingly publish in English, despite the fact that their pages contain research from across the globe.

However, a new study suggests that over a third of new scientific reports are published in languages other than English, which can result in these findings being overlooked - contributing to biases in our understanding.

As well as the international community missing important science, language hinders new findings getting through to practitioners in the field say researchers from the University of Cambridge.

They argue that whenever science is only published in one language, including solely in English, barriers to the transfer of knowledge are created.

The Cambridge researchers call on scientific journals to publish basic summaries of a study's key findings in multiple languages, and universities and funding bodies to encourage translations as part of their 'outreach' evaluation criteria.

"While we recognise the importance of a lingua franca, and the contribution of English to science, the scientific community should not assume that all important information is published in English," says Dr Tatsuya Amano from Cambridge's Department of Zoology.

"Language barriers continue to impede the global compilation and application of scientific knowledge."

The researchers point out an imbalance in knowledge transfer in countries where English is not the mother tongue: "much scientific knowledge that has originated there and elsewhere is available only in English and not in their local languages."

This is a particular problem in subjects where both local expertise and implementation is vital - such as environmental sciences.

As part of the study, published today in the journal PLOS Biology, those in charge of Spain's protected natural areas were surveyed. Over half the respondents identified language as an obstacle to using the latest science for habitat management.

The Cambridge team also conducted a litmus test of language use in science. They surveyed the web platform Google Scholar - one of the largest public repositories of scientific documents - in a total of 16 languages for studies relating to biodiversity conservation published during a single year, 2014.

Of the over 75,000 documents, including journal articles, books and theses, some 35.6% were not in English. Of these, the majority was in Spanish (12.6%) or Portuguese (10.3%). Simplified Chinese made up 6%, and 3% were in French.

The researchers also found thousands of newly published conservation science documents in other languages, including several hundred each in Italian, German, Japanese, Korean and Swedish.

Random sampling showed that, on average, only around half of non-English documents also included titles or abstracts in English. This means that around 13,000 documents on conservation science published in 2014 are unsearchable using English keywords.

This can result in sweeps of current scientific knowledge - known as 'systematic reviews' - being biased towards evidence published in English, say the researchers. This, in turn, may lead to over-representation of results considered positive or 'statistically significant', and these are more likely to appear in English language journals deemed 'high-impact'.

In addition, information on areas specific to countries where English is not the mother tongue can be overlooked when searching only in English.

For environmental science, this means important knowledge relating to local species, habitats and ecosystems - but also applies to diseases and medical sciences. For example, documents reporting the infection of pigs with avian flu in China initially went unnoticed by international communities, including the WHO and the UN, due to publication in Chinese-language journals.

"Scientific knowledge generated in the field by non-native English speakers is inevitably under-represented, particularly in the dominant English-language academic journals. This potentially renders local and indigenous knowledge unavailable in English," says lead author Amano.

"The real problem of language barriers in science is that few people have tried to solve it. Native English speakers tend to assume that all the important information is available in English. But this is not true, as we show in our study.

"On the other hand, non-native English speakers, like myself, tend to think carrying out research in English is the first priority, often ending up ignoring non-English science and its communication.

"I believe the scientific community needs to start seriously tackling this issue."

Amano and colleagues say that, when conducting systematic reviews or developing databases at a global scale, speakers of a wide range of languages should be included in the discussion: "at least Spanish, Portuguese, Chinese and French, which, in theory, cover the vast majority of non-English scientific documents."

The website conservationevidence.com, a repository for conservation science developed at Cambridge by some of the authors, has also established an international panel to extract the best non-English language papers, including Portuguese, Spanish and Chinese.

"Journals, funders, authors and institutions should be encouraged to supply translations of a summary of a scientific publication - regardless of the language it is originally published in," says Amano. The authors of the new study have provided a summary in Spanish, Portuguese, Chinese and French as well as Japanese.

"While outreach activities have recently been advocated in science, it is rare for such activities to involve communication across language barriers."

The researchers suggest efforts to translate should be evaluated in a similar way to other outreach activities such as public engagement, particularly if the science covers issues at a global scale or regions where English is not the mother tongue.

Adds Amano: "We should see this as an opportunity as well as a challenge. Overcoming language barriers can help us achieve less biased knowledge and enhance the application of science globally."

Over a third of new conservation science documents published annually are in non-English languages, despite assumption of English as scientific ‘lingua franca’. Researchers find examples of important science missed at international level, and practitioners struggling to access new knowledge, as a result of language barriers.

Language barriers continue to impede the global compilation and application of scientific knowledge
Tatsuya Amano
Atypical welcome

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Road planning 'trade off' could boost food production while helping protect tropical forests

By fpjl2 from University of Cambridge - Department of Zoology. Published on Dec 15, 2016.

Conservation scientists have used layers of data on biodiversity, climate, transport and crop yields to construct a colour-coded mapping system that shows where new road-building projects should go to be most beneficial for food production, at the same time as being least destructive to the environment.

The hope is that this "trade-off" strategy might guide governments, investors and developers to focus on road expansions that make the most difference for current agricultural areas, rather than projects that threaten to open up significant natural habitats for conversion to farmland.

As a proof of concept, scientists applied their technique to a specific sub-region: the Greater Mekong in Southeast Asia - one of the most biologically important parts of the planet, and a place that has lost almost a third of its tropical forest since the 1970s.

They found a number of current road proposals in Vietnam, Laos, Myanmar and Cambodia have potential for massive habitat conversion with little benefit for populations and food security. They also found areas where new roads could increase food production and connectivity with limited environmental cost.

Researchers from the University of Cambridge, UK, the Kunming Institute of Botany and the World Agroforestry Centre in China say their study, published today in PLOS Biology, is an attempt to explore a more "conciliatory approach" in the hope of starting greater dialogue between developers and conservation experts.

They call on organisations such as the newly established Asian Infrastructure Investment Bank as well as Asian Development Bank to use such analyses when considering investment in future road expansion projects in the Mekong region - an area undergoing rapid development.

"It is estimated that by 2050 we will build 25 million km of new road lanes, the majority of which will be in the developing world," says Andrew Balmford, Professor of Conservation Science at Cambridge.

"Conservationists can to appear to oppose nearly all new infrastructure, while developers and their financial backers are often fairly mute on the environmental impact of their proposals. This can lead to a breakdown in communication."

"The Mekong region is home to some of the world's most valuable tropical forests. It's also a region in which a lot of roads are going to be built, and blanket opposition by the conservation community is unlikely to stop this," says Prof Jianchu Xu from the Kunming Institute of Botany in China.

"Studies like ours help pinpoint the projects we should oppose most loudly, while transparently showing the reasons why and providing alternatives where environmental costs are lower and development benefits are greater.

"Conservationists need to be active voices in infrastructure development, and I think these approaches have the potential to change the tone of the conversation."

The Greater Mekong encompasses Vietnam, Laos, Cambodia, Thailand, Myanmar and the Yunnan Province of China. It is home to around 20,000 plant species, 2000 types of land vertebrates and 850 species of freshwater fish. Much of this biodiversity is found nowhere else on the planet.

The saola, for example, is a mammal resembling a small antelope that was only discovered in 1992, and is so rare it is known as the "Asian unicorn". The region's vast forests also act as critical carbon 'sinks', absorbing greenhouse gases.

The Greater Mekong is also home to over 320 million people, and habitat loss has been accelerating. Between 1973 and 2009, an estimated 31% of the region's natural forest disappeared. Alongside this there is widespread poverty; food insecurity and malnutrition remain major challenges.

The researchers created the new framework for road planning in the Mekong by analysing various data sources: including crop yield gaps across the region, travel times between population hubs, range maps for birds and mammals, and biomass carbon stocks in soil and vegetation.

By combining this data into composite layers, the team were able to map them over the region and reduce the results to a simple green-to-purple colour scale comparing food production benefits to environmental costs.

In areas such as Myanmar's Ayeyarwady Delta, new roads could substantially boost food production through improved transport links for getting produce to market, lowering waste and increasing access to new technologies. This would come at a relatively limited environmental cost, as much of the area has been converted to agriculture, yet crop yields remain low.

However, researchers warn that planned projects in other areas with extensive forests, such as in northern Laos and western Yunnan in China, could devastate vital ecosystems with little gain for food production.

"If new roads are deployed strategically, and deliberately target already-cleared areas with poor transport connectivity, this could attract agricultural growth that might otherwise spread elsewhere," says Prof Xu.

For Balmford, this is perhaps the crux of the argument, and something he has long been vocal about: "By increasing the crop yield of current agricultural networks, there is hope that food needs can be met while containing the expansion of farming and so sparing natural habitats from destruction. The location of infrastructure, and roads in particular, will play a major role in this."

However, the researchers caution that the channeling of roads into less damaging, more rewarding areas will have to go hand-in-hand with strengthening protection for globally significant habitats such as the remaining forests of the Mekong.

Scientists hope a new approach to planning road infrastructure that could increase crop yield in the Greater Mekong region while limiting environmental destruction will open dialogues between developers and the conservation community.

Conservationists can to appear to oppose nearly all new infrastructure, while developers and their financial backers are often fairly mute on the environmental impact of their proposals. This can lead to a breakdown in communication
Andrew Balmford
A highway cuts across the Yunnan Province of Southwest China, part of the Greater Mekong.

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Larger brain size linked to longer life in deer

By mjg209 from University of Cambridge - Department of Zoology. Published on Dec 14, 2016.

The study, published in the Royal Society Open Science journal, shows that female red deer with larger brains live longer and have more surviving offspring than those with smaller brains. Brain size is heritable and is passed down through the generations. This is the first extensive study of individual differences in brain size in wild mammals and draws on data comparing seven generations of deer. 

Across species of mammals, brain size varies widely. This is thought to be a consequence of specific differences in the benefits and costs of a larger brain. Mammals with larger brains may, for example, have greater cognitive abilities that enable them to adapt better to environmental changes or they may have longer lifespans. But there may also be disadvantages: for instance, larger brains require more energy, so individuals that possess them may show reduced fertility.  

The researchers, based at the University of Cambridge's Zoology Department and Edinburgh University's Institute of Evolutionary Biology, wanted to test if they could find more direct genetic or non-genetic evidence of the costs and benefits of large brain size by comparing the longevity and survival of individuals of the same species with different sized brains. Using the skulls of 1,314 wild red deer whose life histories and breeding success had been monitored in the course of a long-term study on the Isle of Rum, they found that females with larger endocranial volumes lived longer and produced more surviving offspring in the course of their lives. 

Lead author Dr Corina Logan, a Gates Cambridge Scholar and Leverhulme Early Career Research Fellow in Cambridge's Department of Zoology, says: "The reasons for the association between brain size and longevity are not known, but other studies have suggested that larger brains are a consequence of the longer-lived species having longer developmental periods in which the brain can grow. These hypotheses were generated from cross-species correlations; however, testing such hypotheses requires investigations at the within-species level, which is what we did."

Dr Logan adds: "We found that some of the cross-species predictions about brain size held for female red deer, and that none of the predictions were supported in male red deer. This indicates that each sex likely experiences its own set of trade-offs with regard to brain size.”

The study also showed that females' relative endocranial volume is smaller than that of males, despite evidence of selection for larger brains in females.

"We think this is likely due to sex differences in the costs and benefits related to larger brains," adds Dr Logan. "We don’t know what kinds of trade-offs each sex might encounter, but we assume there must be variables that constrain brain size that are sex specific, which is why we see selection in females, but not males."

Professor Tim Clutton-Brock, who set up the Rum Red Deer study with Fiona Guinness in 1972 and initiated the work on brain size, points out that the reason that this kind of study has not been conducted before is that it requires long term records of a large number of individuals across multiple generations and data of this kind are still rare in wild animals.

Reference
C.J. Logan, R. Stanley, A.M. Thompson, T.H. Clutton-Brock. Endocranial volume is heritable and is associated with longevity and fitness in a wild mammal. Royal Society Open Science; 14 Dec 2016; 10.1098/rsos.160622

The size of a female animals' brain may determine whether they live longer and have more healthy offspring, according to new research led by the University of Cambridge. 

We found that some of the cross-species predictions about brain size held for female red deer, and that none of the predictions were supported in male red deer. This indicates that each sex likely experiences its own set of trade-offs with regard to brain size.
Corina Logan
Deer skulls

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Francis Crick: A Singular Approach to Scientific Discovery

From Department of Zoology. Published on Dec 06, 2016.

Nature Ecology and Evolution paper from Prof Jenny Clack and NERC consortium

From Department of Zoology. Published on Dec 06, 2016.

Congratulations to the winners of the Graduate Poster Competition 2016

From Department of Zoology. Published on Nov 22, 2016.

Elephant poaching costs African economies US $25 million per year in lost tourism revenue

By fpjl2 from University of Cambridge - Department of Zoology. Published on Nov 01, 2016.

The current elephant poaching crisis costs African countries around USD $25 million annually in lost tourism revenue, according to a new study published in the journal Nature Communications. Comparing this lost revenue with the cost of halting declines in elephant populations due to poaching, the study determines that investment in elephant conservation is economically favorable across the majority of African elephants’ range.

The research, undertaken by scientists from World Wildlife Fund (WWF), the University of Vermont, and the University of Cambridge, represents the first continent-wide assessment of the economic losses that the current elephant poaching surge is inflicting on nature-based tourism economies in Africa.

“While there have always been strong moral and ethical reasons for conserving elephants, not everyone shares this viewpoint.  Our research now shows that investing in elephant conservation is actually smart economic policy for many African countries,” said Dr. Robin Naidoo, lead wildlife scientist at WWF and lead author on the study.

Poachers kill between 20,000-30,000 African elephants each year for the illegal ivory trade, funded by global organized crime syndicates and fueled largely by demand in China and elsewhere in Asia. In just the past ten years, Africa’s elephants have declined by more than 20 percent.

"We know that within parks, tourism suffers when elephant poaching ramps up. This work provides a first estimate of the scale of that loss, and shows pretty convincingly that stronger conservation efforts usually make sound economic sense even when looking at just this one benefit stream," said study co-author Professor Andrew Balmford, from the University of Cambridge’s Department of Zoology.

The research shows that tourism revenue lost to the current poaching crisis exceeds the anti-poaching costs necessary to stop the decline of elephants in east, southern, and west Africa. Rates of return on elephant conservation in these regions are positive, signaling strong economic incentive for countries to protect elephant populations.

“The average rate of return on elephant conservation in east, west, and south Africa compares favorably with rates of return on investments in areas like education, food security and electricity,” said Dr. Brendan Fisher, an economist at University of Vermont’s Gund Institute for Ecological Economics. “For example, for every dollar invested in protecting elephants in East Africa, you get about $1.78 back. That's a great deal.”

However, for countries in central Africa, the study finds that elephant-based tourism cannot currently be expected to contribute substantially to elephant conservation. In these remote, forested areas where tourism levels are lower and elephants are typically more difficult to see, different mechanisms will be necessary to halt elephant declines.

Taken from a WWF press release. 

New research shows investing in elephant conservation is smart economic policy for many African countries. 

We know that within parks, tourism suffers when elephant poaching ramps up. This work provides a first estimate of the scale of that loss
Andrew Balmford
A male savannah elephant uses his trunk to eat inTarangire National Park, Tanzania.

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Eureka Moments film

From Department of Zoology. Published on Oct 26, 2016.

150th Anniversary photograph album

From Department of Zoology. Published on Oct 03, 2016.

Whale skeleton rebuilt at Cambridge University museum

From Department of Zoology. Published on Sep 29, 2016.

Unprecedented study of Aboriginal Australians points to one shared Out of Africa migration for modern humans

By tdk25 from University of Cambridge - Department of Zoology. Published on Sep 21, 2016.

The first major genomic study of Aboriginal Australians ever undertaken has confirmed that all present-day non-African populations are descended from the same single wave of migrants, who left Africa around 72,000 years ago.

Researchers sequenced the complete genetic information of 83 Aboriginal Australians, as well as 25 Papuans from New Guinea, to produce a host of significant new findings about the origins of modern human populations. Their work is published alongside several other related papers in the journal Nature.

The study, by an international team of academics, was carried out in close collaboration with elders and leaders from various Aboriginal Australian communities – some of whom are co-authors on the paper – as well as with various other organisations representing the participating groups.

Alongside the prevailing conclusion, that the overwhelming majority of the genomes of non-Africans alive today stem from one ancestral group of migrants who left Africa together, there are several other standout findings. These include:

  • Compelling evidence that Aboriginal Australians are descended directly from the first people to inhabit Australia – which is still the subject of periodic political dispute.
  • Evidence of an uncharacterised – and perhaps unknown – early human species which interbred with anatomically modern humans as they migrated through Asia.
  • Evidence that a mysterious dispersal from the northeastern part of Australia roughly 4,000 years ago contributed to the cultural links between Aboriginal groups today. These internal migrants defined the way in which people spoke and thought, but then disappeared from most of the continent, in a manner which the researchers describe as “ghost-like”.

The study’s senior authors are from the University of Cambridge, the Wellcome Trust Sanger Institute, the Universities of Copenhagen, Bern and Griffith University Australia. Within Cambridge, members of the Leverhulme Centre for Evolutionary Studies also contributed to the research, in particular by helping to place the genetic data which the team gathered in the field within the context of wider evidence about early human population and migration patterns.

 

 

Professor Eske Willerslev, who holds posts at St John’s College, University of Cambridge, the Sanger Institute and the University of Copenhagen, initiated and led the research. He said: “The study addresses a number of fundamental questions about human evolution – how many times did we leave Africa, when was Australia populated, and what is the diversity of people in and outside Australia?”

“Technologically and politically, it has not really been possible to answer those questions until now. We found evidence that there was only really one wave of humans who gave rise to all present-day non-Africans, including Australians.”

Anatomically modern humans are known to have left Africa approximately 72,000 years ago, eventually spreading across Asia and Europe. Outside Africa, Australia has one of the longest histories of continuous human occupation, dating back about 50,000 years.

Some researchers believe that this deep history indicates that Papuans and Australians stemmed from an earlier migration than the ancestors of Eurasian peoples; others that they split from Eurasian progenitors within Africa itself, and left the continent in a separate wave.

Until the present study, however, the only genetic evidence for Aboriginal Australians, which is needed to investigate these theories, came from one tuft of hair (taken from a long-since deceased individual), and two unidentified cell lines.

The new research dramatically improves that picture. Working closely with community elders, representative organisations and the ethical board of Griffith University, Willerslev and colleagues obtained permission to sequence dozens of Aboriginal Australian genomes, using DNA extracted from saliva.

This was compared with existing genetic information about other populations. The researchers modelled the likely genetic impact of different human dispersals from Africa and towards Australia, looking for patterns that best matched the data they had acquired. Dr Marta Mirazon Lahr and Professor Robert Foley, both from the Leverhulme Centre, assisted in particular by analysing the likely correspondences between this newly-acquired genetic evidence and a wider framework of existing archaeological and anthropological evidence about early human population movements.

 

 

Dr Manjinder Sandhu, a senior author from the Sanger Institute and University of Cambridge, said: “Our results suggest that, rather than having left in a separate wave, most of the genomes of Papuans and Aboriginal Australians can be traced back to a single ‘Out of Africa’ event which led to modern worldwide populations. There may have been other migrations, but the evidence so far points to one exit event.”

The Papuan and Australian ancestors did, however, diverge early from the rest, around 58,000 years ago. By comparison, European and Asian ancestral groups only become distinct in the genetic record around 42,000 years ago.

The study then traces the Papuan and Australian groups’ progress. Around 50,000 years ago they reached “Sahul” – a prehistoric supercontinent that originally united New Guinea, Australia and Tasmania, until these regions were separated by rising sea levels approximately 10,000 years ago.

The researchers charted several further “divergences” in which various parts of the population broke off and became genetically isolated from others. Interestingly, Papuans and Aboriginal Australians appear to have diverged about 37,000 years ago – long before they became physically separated by water. The cause is unclear, but one reason may be the early flooding of the Carpentaria basin, which left Australia connected to New Guinea by a strip of land that may have been unfavourable for human habitation.

Once in Australia, the ancestors of today’s Aboriginal communities remained almost completely isolated from the rest of the world’s population until just a few thousand years ago, when they came into contact with some Asian populations, followed by European travellers in the 18th Century.

Indeed, by 31,000 years ago, most Aboriginal communities were genetically isolated from each other. This divergence was most likely caused by environmental barriers; in particular the evolution of an almost impassable central desert as the Australian continent dried out.

 

 

Assistant Professor Anna-Sapfo Malaspinas, from the Universities of Copenhagen and Bern, and a lead author, said: “The genetic diversity among Aboriginal Australians is amazing. Because the continent has been populated for such a long time, we find that groups from south-western Australia are genetically more different from north-eastern Australia, than, for example, Native Americans are from Siberians.”

Two other major findings also emerged. First, the researchers were able to reappraise traces of DNA which come from an ancient, extinct human species and are found in Aboriginal Australians. These have traditionally been attributed to encounters with Denisovans – a group known from DNA samples found in Siberia.

In fact, the new study suggests that they were from a different, as-yet uncharacterised, species. “We don’t know who these people were, but they were a distant relative of Denisovans, and the Papuan/Australian ancestors probably encountered them close to Sahul,” Willerslev said.

Finally, the research also offers an intriguing new perspective on how Aboriginal culture itself developed, raising the possibility of a mysterious, internal migration 4,000 years ago.

About 90% of Aboriginal communities today speak languages belonging to the “Pama-Nyungan” linguistic family. The study finds that all of these people are  descendants of the founding population which diverged from the Papuans 37,000 years ago, then diverged further into genetically isolated communities.

This, however, throws up a long-established paradox. Language experts are adamant that Pama-Nyungan languages are much younger, dating back 4,000 years, and coinciding with the appearance of new stone technologies in the archaeological record.

Scientists have long puzzled over how – if these communities were completely isolated from each other and the rest of the world – they ended up sharing a language family that is much younger? The traditional answer has been that there was a second migration into Australia 4,000 years ago, by people speaking this language.

But the new research finds no evidence of this. Instead, the team uncovered signs of a tiny gene flow, indicating a small population movement from north-east Australia across the continent, potentially at the time the Pama-Nyungan language and new stone tool technologies appeared.

These intrepid travellers, who must have braved forbidding environmental barriers, were small in number, but had a significant, sweeping impact on the continent’s culture. Mysteriously, however, the genetic evidence for them then disappears. In short, their influential language and culture survived – but they, as a distinctive group, did not.

“It’s a really weird scenario,” Willerslev said. “A few immigrants appear in different villages and communities around Australia. They change the way people speak and think; then they disappear, like ghosts. And people just carry on living in isolation the same way they always have. This may have happened for religious or cultural reasons that we can only speculate about. But in genetic terms, we have never seen anything like it before.”

The paper, A Genomic History of Aboriginal Australia, is published in Nature. doi:10.1038/nature18299.

Inset images: Professor Eske Willerslev talking to Aboriginal elders in the Kalgoorlie area in southwestern Australia in 2012. (Photo credit: Preben Hjort, Mayday Film). / Map showing main findings from the paper. Credit: St John's College, Cambridge.

The first significant investigation into the genomics of Aboriginal Australians has uncovered several major findings about early human populations. These include evidence of a single “Out of Africa” migration event, and of a previously unidentified, “ghost-like” population spread which provided a basis for the modern Aboriginal cultural landscape.

We found evidence that there was only really one wave of humans who gave rise to all present-day non-Africans, including Australians
Eske Willerslev
Aubrey Lynch, elder from the Wongatha Aboriginal language group, who participated in the study.

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Why mole rats are more flexible than we previously thought

By sjr81 from University of Cambridge - Department of Zoology. Published on Aug 30, 2016.

Mole rats, including the naked mole rat, live in underground colonies. The majority of rodents in the colonies are ‘workers’, with only one female (the ‘queen’) and one male responsible for breeding. All individuals cooperate by digging large underground tunnel systems to forage for food, and if a large food source is found, it is shared with the entire colony. ‘Queens’ and reproductive males remain in this role for their entire life after they have achieved this position. When a ‘queen’ dies, the strongest and largest helper is probably the prime candidate for inheriting the breeding position.

Early studies suggested that non-reproducing mole rats can be divided into non-workers, infrequent workers and frequent workers, and that most individuals stay members of distinct castes for their entire lives. Individual mole rats would focus on a particular task, such as digging, nest building or colony defence, throughout their lives.

Now, however, in a study published in Proceedings of the National Academy of Sciences, researchers from the Department of Zoology at the University of Cambridge have shown that in Damaraland mole rats, the contributions of individuals to cooperative activities change with age and that individual differences in behaviour that appeared to be a consequence of differences in caste are, in fact, age-related changes in behaviour. Whether variation in behaviour between naked mole rats is also a consequence of similar age-related changes is not known – but this seems likely.

Dr Markus Zöttl, first author of the study, explains: “In some ants, aphids and termites, individuals are born into castes that fulfil certain roles, such as soldiers or workers. Initially, everyone thought that this was only found in social invertebrates, like ants and bees, but in the eighties, the discovery of the social behaviour of mole rats challenged this view. Social mole rats were thought to be unique among vertebrates, in that they also had castes. To understand this fully, what we needed was long-term data on many mole rats over extended periods of their lives.”

To study mole rat development in more detail, a team at Cambridge led by Professor Tim Clutton-Brock from the Department of Zoology built a laboratory in the Kalahari Desert, where Damaraland mole rats are native, and established multiple colonies of mole rats in artificial tunnel systems. Over three years, they followed the lives of several hundred individuals to document how the behaviour of individuals changes as they age. All individuals were weighed and observed regularly to document their behavioural changes.

The researchers found that individual mole rats play different roles as they grow and get older.  Rather than being specialists, mole rats are generalists that participate in more or fewer community duties at different stages of their lives. Instead of behaving like ants or termites, where individuals are members of a caste and specialise in doing certain activities, all mole rats are involved in a range of different activities, and their contributions to cooperative activities increases with age.

“As Damaraland mole rats do not have castes, this may mean that castes are only found in social invertebrates and have not evolved in any vertebrates,” adds Dr Zöttl. “Mole rat social organisation probably has more in common with the societies of other cooperative mammals, such as meerkats and wild dogs, than with those of social insects.”

The research was funded by European Research Council.

One of the most interesting facts about mole rats – that, as with ants and termites, individuals specialise in particular tasks throughout their lives – turns out to be wrong. Instead, a new study led by the University of Cambridge shows that individuals perform different roles at different ages and that age rather than caste membership accounts for contrasts in their behaviour.

Mole rat social organisation probably has more in common with the societies of other cooperative mammals, such as meerkats and wild dogs.
Markus Zöttl

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Textbook story of how humans populated America is “biologically unviable”, study finds

By tdk25 from University of Cambridge - Department of Zoology. Published on Aug 10, 2016.

The established theory about how Ice Age peoples first reached the present-day United States has been challenged by an unprecedented study which concludes that their supposed entry route was “biologically unviable”.

The first people to reach the Americas crossed via an ancient land bridge between Siberia and Alaska but then, according to conventional wisdom, had to wait until two huge ice sheets that covered what is now Canada started to recede, creating the so-called “ice-free corridor” which enabled them to move south.

In a new study published in the journal Nature, however, an international team of researchers used ancient DNA extracted from a crucial pinch-point within this corridor to investigate how its ecosystem evolved as the glaciers began to retreat. They created a comprehensive picture showing how and when different flora and fauna emerged and the once ice-covered landscape became a viable passageway. No prehistoric reconstruction project like it has ever been attempted before.

The researchers conclude that while people may well have travelled this corridor after about 12,600 years ago, it would have been impassable earlier than that, as the corridor lacked crucial resources, such as wood for fuel and tools, and game animals which were essential to the hunter-gatherer lifestyle.

If this is true, then it means that the first Americans, who were present south of the ice sheets long before 12,600 years ago, must have made the journey south by another route. The study’s authors suggest that they probably migrated along the Pacific coast.

Who these people were is still widely disputed. Archaeologists agree, however, that early inhabitants of the modern-day contiguous United States included the so-called “Clovis” culture, which first appear in the archaeological record over 13,000 years ago. And the new study argues that the ice-free corridor would have been completely impassable at that time.

The research was led by Professor Eske Willerslev, an evolutionary geneticist in the Department of Zoology and Fellow of St John’s College, University of Cambridge, who also holds posts at the Centre for GeoGenetics, University of Copenhagen, and the Wellcome Sanger Institute in Cambridge.

“The bottom line is that even though the physical corridor was open by 13,000 years ago, it was several hundred years before it was possible to use it,” Willerslev said.

“That means that the first people entering what is now the US, Central and South America must have taken a different route. Whether you believe these people were Clovis, or someone else, they simply could not have come through the corridor, as long claimed.”

Mikkel Winther Pedersen, a PhD student at the Centre for GeoGenetics, University of Copenhagen, who conducted the molecular analysis, added: “The ice-free corridor was long considered the principal entry route for the first Americans. Our results reveal that it simply opened up too late for that to have been possible.”

The corridor is thought to have been about 1,500 kilometres long, and emerged east of the Rocky Mountains 13,000 years ago in present-day western Canada, as two great ice sheets – the Cordilleran and Laurentide, retreated.

On paper, this fits well with the argument that Clovis people were the first to disperse across the Americas. The first evidence for this culture, which is named after distinctive stone tools found near Clovis, New Mexico, also dates from roughly the same time, although many archaeologists now believe that other people arrived earlier.

“What nobody has looked at is when the corridor became biologically viable,” Willerslev said. “When could they actually have survived the long and difficult journey through it?”

The conclusion reached by Willerslev and his colleagues is that the journey would have been impossible until about 12,600 years ago. Their research focused on a “bottleneck”, one of the last parts of the corridor to become ice-free, and now partly covered by Charlie Lake in British Columbia, and Spring Lake, Alberta – both part of Canada’s Peace River drainage basin.

The team gathered evidence including radiocarbon dates, pollen, macrofossils and DNA taken from lake sediment cores, which they obtained standing on the frozen lake surface during the winter season. Willerslev’s own PhD, 13 years ago, demonstrated that it is possible to extract ancient plant and mammalian DNA from sediments, as it contains preserved molecular fossils from substances such as tissue, urine, and faeces.

Having acquired the DNA, the group then applied a technique termed “shotgun sequencing”. “Instead of looking for specific pieces of DNA from individual species, we basically sequenced everything in there, from bacteria to animals,” Willerslev said. “It’s amazing what you can get out of this. We found evidence of fish, eagles, mammals and plants. It shows how effective this approach can be to reconstruct past environments.”

This approach allowed the team to see, with remarkable precision, how the bottleneck’s ecosystem developed. Crucially, it showed that before about 12,600 years ago, there were no plants, nor animals, in the corridor, meaning that humans passing through it would not have had the resources that were essential for their survival.

Around 12,600 years ago, steppe vegetation started to appear, followed quickly by animals such as bison, woolly mammoth, jackrabbits and voles. Importantly 11,500 years ago, the researchers identified a transition to a “parkland ecosystem” – a landscape densely populated by trees, as well as moose, elk and bald-headed eagles, which would have offered crucial resources for migrating humans.

Somewhere in between, the lakes in the area were populated by fish, including several identifiable species such as pike and perch. Finally, about 10,000 years ago, the area transitioned again, this time into boreal forest, characterised by spruce and pine.

The fact that Clovis was clearly present south of the corridor before 12,600 years ago means that they could not have travelled through it. David Meltzer, an archaeologist at Southern Methodist University and a co-author on the study, said: “There is compelling evidence that Clovis was preceded by an earlier and possibly separate population, but either way, the first people to reach the Americas in Ice Age times would have found the corridor itself impassable.”

“Most likely, you would say that the evidence points to their having travelled down the Pacific Coast,” Willerslev added. “That now seems the most likely scenario.”

The paper Postglacial viability and colonization in North America's ice-free corridor is published in the journal Nature on 10. August 2016. DOI: 10.1038/nature19085

​Inset images: Map outlining the opening of the human migration routes in North America revealed by the results presented in this study. / Mikkel W. Pedersen and colleague preparing for coring of the lake sediments. All images provided by Mikkel Winther Pedersen, Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen.

Using ancient DNA, researchers have created a unique picture of how a prehistoric migration route evolved over thousands of years – revealing that it could not have been used by the first people to enter the Americas, as traditionally thought.

The first people entering what is now the US, Central and South America must have taken a different route to the one that has long been claimed
Eske Willerslev
The fieldwork was conducted during the winter because the frozen lake surface provided the researchers with a solid (but freezing) platform for drilling into the sediment

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Yes

‘Red gene’ in birds and turtles suggests dinosaurs had bird-like colour vision

By fpjl2 from University of Cambridge - Department of Zoology. Published on Aug 03, 2016.

Earlier this year, scientists used zebra finches to pinpoint the gene that enables birds to produce and display the colour red.

Now, a new study shows the same ‘red gene’ is also found in turtles, which share an ancient common ancestor with birds. Both share a common ancestor with dinosaurs.  

The gene, called CYP2J19, allows birds and turtles to convert the yellow pigments in their diets into red, which they then use to heighten colour vision in the red spectrum through droplets of red oil in their retinas.

Birds and turtles are the only existing tetrapods, or land vertebrates, to have these red retinal oil droplets. In some birds and a few turtle species, red pigment produced by the gene is also used for external display: red beaks and feathers, or the red neck patches and rims of shells seen in species such as the painted turtle.

The scientists mined the genetic data of various bird and reptile species to reconstruct an evolutionary history of the CYP2J19 gene, and found that it dated back hundreds of millions of years in the ancient archelosaur genetic line - the ancestral lineage of turtles, birds and dinosaurs.

The findings, published today in the journal Proceedings of the Royal Society B, provide evidence that the ‘red gene’ originated around 250 million years ago, predating the split of the turtle lineage from the archosaur line, and runs right the way through turtle and bird evolution.  

Scientists say that, as dinosaurs split from this lineage after turtles, and were closely related to birds, this strongly suggests that they would have carried the CYP2J19 gene, and had the enhanced ‘red vision’ from the red retinal oil.

This may have even resulted in some dinosaurs producing bright red pigment for display purposes as well as colour vision, as seen in some birds and turtles today, although researchers say this is more speculative.  

“These findings are evidence that the red gene originated in the archelosaur lineage to produce red for colour vision, and was much later independently deployed in both birds and turtles to be displayed in the red feathers and shells of some species, going from seeing red to being red,” says senior author Dr Nick Mundy, from the University of Cambridge’s Department of Zoology.  

“This external redness was often sexually selected as an ‘honest signal’ of genuine high quality in a mate,” he says.

The previous research in zebra finches showed a possible link between red beaks and the ability to break down toxins in the body, suggesting external redness signals physiological quality, and there is some evidence that colouration in red-eared terrapins is also linked to honest signalling. 

“The excellent red spectrum vision provided by the CYP2J19 gene would help female birds and turtles pick the brightest red males,” says Hanlu Twyman, the PhD student who is lead author on the work.

The structure of retinas in the eye includes cone-shaped photoreceptor cells. Unlike mammals, avian and turtle retinal cones contain a range of brightly-coloured oil droplets, including green, yellow and red.

These oil droplets function in a similar way to filters on a camera lens. “By filtering the incoming light, the oil droplets lead to greater separation of the range of wavelengths that each cone responds to, creating much better colour sensitivity,” explains Mundy.

“Humans can distinguish between some shades of red such as scarlet and crimson. However, birds and turtles can see a host of intermediate reds between these two shades, for example. Our work suggests that dinosaurs would have also had this ability to see a wide spectrum of redness,” he says.

Over hundreds of millennia of evolution, the CYP2J19 gene was independently deployed to generate the red pigments in the external displays of some bird species and a few turtle species. The scientists say their data indicate that co-option of CYP2J19 for red colouration in dinosaurs would also have been possible.

The ancestral lineage that led to scaly lizards and snakes split from the archosaur line before turtles, and, as the findings suggest, before the origin of the red gene. These reptiles either lack retinal oil droplets, or have yellow and green but not red.    

However, the crocodilian lineage split from the archelosaur line after turtles, yet crocodiles appear to have lost the CYP2J19 gene, and have no oil droplets of any colour in their retinal cones.

Mundy says there is some evidence that oil droplets were lost from the retinas of species that were nocturnal for long periods of their genetic past, and that this hypothesis fits for mammals and snakes, and may also be the case with crocodiles.   

A gene for red colour vision that originated in the reptile lineage around 250m years ago has resulted in the bright red bird feathers and ‘painted’ turtles we see today, and may be evidence that dinosaurs could see as many shades of red as birds - and perhaps even displayed more red than we might think.

The excellent red spectrum vision provided by the CYP2J19 gene would help female birds and turtles pick the brightest red males
Hanlu Twyman
A Painted Turtle

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Yes

How humans and wild birds collaborate to get precious resources of honey and wax

By amb206 from University of Cambridge - Department of Zoology. Published on Jul 22, 2016.

Humans have trained a range of species to help them find food: examples are dogs, falcons and cormorants. These animals are domesticated or taught to cooperate by their owners. Human-animal collaboration in the wild is much rarer. But it has long been known that, in many parts of Africa, people and a species of wax-eating bird called the greater honeyguide work together to find wild bees’ nests which provide a valuable resource to them both.

Honeyguides give a special call to attract people’s attention, then fly from tree to tree to indicate the direction of a bees’ nest. We humans are useful collaborators to honeyguides because of our ability to subdue stinging bees with smoke and chop open their nest, providing wax for the honeyguide and honey for ourselves.

Experiments carried out in the Mozambican bush now show that this unique human-animal relationship has an extra dimension: not only do honeyguides use calls to solicit human partners, but humans use specialised calls to recruit birds’ assistance. Research in the Niassa National Reserve reveals that by using specialised calls to communicate and cooperate with each other, people and wild birds can significantly increase their chances of locating vital sources of calorie-laden food. 

In a paper (Reciprocal signaling in honeyguide-human mutualism) published in Science today (22 July 2016), evolutionary biologist Dr Claire Spottiswoode (University of Cambridge and University of Cape Town) and co-authors (conservationists Keith Begg and Dr Colleen Begg of the Niassa Carnivore Project) reveal that honeyguides are able to respond adaptively to specialised signals given by people seeking their collaboration, resulting in two-way communication between humans and wild birds.

This reciprocal relationship plays out in the wild and occurs without any conventional kind of ‘training’ or coercion. “What’s remarkable about the honeyguide-human relationship is that it involves free-living wild animals whose interactions with humans have probably evolved through natural selection, probably over the course of hundreds of thousands of years,” says Spottiswoode, a specialist in bird behavioural ecology in Africa.

“Thanks to the work in Kenya of Hussein Isack, who electrified me as an 11-year-old when I heard him speak in Cape Town, we’ve long known that people can increase their rate of finding bees’ nests by collaborating with honeyguides, sometimes following them for over a kilometre. Keith and Colleen Begg, who do wonderful conservation work in northern Mozambique, alerted me to the Yao people’s traditional practice of using a distinctive call which they believe helps them to recruit honeyguides. This was instantly intriguing – could these calls really be a mode of communication between humans and a wild animal?”

With the help of honey-hunters from the local Yao community, Spottiswoode carried out controlled experiments in Mozambique’s Niassa National Reserve to test whether the birds were able to distinguish the call from other human sounds, and so to respond to it appropriately. The ‘honey-hunting call’ made by honey-hunters, and passed from generation to generation, is a loud trill followed by a short grunt: ‘brrr-hm’.

To discover whether honeyguides associate ‘brrr-hm’ with a specific meaning , Spottiswoode made recordings of this call and two kinds of ‘control’ sounds : arbitrary words called out by the honey-hunters and the calls of another bird species. When these sounds were played back in the wild during experimental honey-hunting trips, birds were much more likely respond to the ‘brrr-hm’ call made to attract them than they were to either of the other sounds.

“The traditional ‘brrr-hm’ call increased the probability of being guided by a honeyguide from 33% to 66%, and the overall probability of being shown a bees’ nest from 16% to 54% compared to the control sounds. In other words, the ‘brrr-hm’ call more than tripled the chances of a successful interaction, yielding honey for the humans and wax for the bird,” says Spottiswoode.

“Intriguingly, people in other parts of Africa use very different sounds for the same purpose – for example, our colleague Brian Wood’s work has shown that Hadza honey-hunters in Tanzania make a melodious whistling sound to recruit honeyguides. We’d love to know whether honeyguides have learnt this language-like variation in human signals across Africa, allowing them to recognise good collaborators among the local people living alongside them.” 

The greater honeyguide is widely found in sub-Saharan Africa, where its unassuming brown plumage belies its complex interactions with other species. Its interactions with humans to obtain food are mutually beneficial, but to obtain care for its young it is a brutal exploiter of other birds.  

“Like a cuckoo, it lays its eggs in the nests of other birds, and its chick hatches equipped with sharp hooks at the tips of its beak. Only a few days old, the young honeyguide uses these built-in weapons to kill its foster siblings as soon as they hatch,” says Spottiswoode. “So the greater honeyguide is a master of deception and exploitation as well as cooperation – a proper Jekyll and Hyde of the bird world.”

Human cooperation is crucial to honeyguides because bees’ nests are often hidden in inaccessible crevices high up in trees – and honeybees sting ferociously. Therefore the honeyguide waits while an expert human undertakes the dangerous tasks of subduing the bees (by smoking them out using a flaming bundle of twigs and leaves hoisted high into the tree) and extracting the honey from within, usually by felling the entire tree. There is no competition for the prize: the honey-hunters harvest the honey and honeyguides devour the wax combs left behind.

Co-author Dr Colleen Begg adds: “The Niassa National Reserve is as much about people as it is about wildlife, and this is really exemplified by these human-honeyguide interactions that have been forged over thousands of years of coexistence. While many people consider wilderness not to have people in it, at Niassa people are an essential part of the landscape.”

This foraging partnership was recorded in print as early as 1588, when a Portuguese missionary in what is now Mozambique observed a small brown bird slipping into his church to nibble his wax candles. He described how this bird had another remarkable habit: it led men to bees’ nests by calling and flying from tree to tree. Once the nest was located, he wrote in his account of life on the eastern African coast in the 17th century, Ethiopia Oriental, the men harvested the honey and the bird fed on the wax.

“What João dos Santos described was what we now call a mutualism between species. Mutualisms are crucial everywhere in nature, but to our knowledge, the only comparable foraging partnership between wild animals and our own species involves free-living dolphins who chase schools of mullet into fishermen’s nets and in so doing manage to catch more for themselves. It would be fascinating to know whether dolphins respond to special calls made by fishermen, as Pliny the Elder asserted nearly two thousand years ago,” says Spottiswoode.

 

“Back in Africa, we’re fascinated by the evolution of the honeyguide-human mutualism and, as a next step, we want to test whether young honeyguides learn to recognise local human signals, creating a mosaic of honeyguide cultural variation that reflects that of their human partners. Sadly, the mutualism has already vanished from many parts of Africa. The world is a richer place for wildernesses like Niassa where this astonishing example of human-animal cooperation still thrives.”

The project was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) in the UK and the DST-NRF Centre of Excellence at the FitzPatrick Institute in South Africa.

For further information on this and other projects go to www.africancuckoos.com and www.niassalion.org

Inset images: Yao honey-hunter Orlando Yassene harvests honeycombs from a wild bees’ nest in the Niassa National Reserve, Mozambique (Claire Spottiswoode); Yao honey-hunter Orlando Yassene holds a female greater honeyguide temporarily captured for research in the Niassa National Reserve, Mozambique (Claire Spottiswoode); Yao honey-hunter Orlando Yassene chops open a bees’ nest in a felled tree in the Niassa National Reserve, Mozambique (Claire Spottiswoode); Yao honey-hunter Orlando Yassene holds a wax comb (honeyguide food) from a wild bees’ nest harvested in the Niassa National Reserve, Mozambique (Claire Spottiswoode); Claire Spottiswoode interviewing honey-hunter Issufo "Kambunga" Jaime (Mbumba Marufo).

By following honeyguides, a species of bird, people in Africa are able to locate bees’ nests to harvest honey.  Research now reveals that humans use special calls to solicit the help of honeyguides and that honeyguides actively recruit appropriate human partners. This relationship is a rare example of cooperation between humans and free-living animals.

What’s remarkable about the honeyguide-human relationship is that it involves free-living wild animals whose interactions with humans have probably evolved through natural selection, probably over the course of hundreds of thousands of years.
Claire Spottiswoode
Yao honey-hunter Orlando Yassene holds a male greater honeyguide temporarily captured for research in the Niassa National Reserve, Mozambique.

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Yes

A billion-year history of movement, from bacteria to Olympic athletes

From Department of Zoology. Published on Jul 19, 2016.

Sir Quentin Blake reveals new artwork at Cambridge's Museum of Zoology

From Department of Zoology. Published on Jul 12, 2016.

Darwin’s 'true century' was delayed until animal biographies illuminated social evolution

By fpjl2 from University of Cambridge - Department of Zoology. Published on Jun 14, 2016.

All animals live in a form of society, and the structures of these societies have been as important for the course of evolution as their physical environment because they steer the drive to reproduce, says Professor Tim Clutton-Brock, author of the first major synthesis of mammalian social behaviour.

While Darwin initially recognised the importance of social behaviour in his 1871 masterpiece The Descent of Man, biologists focused on anatomy rather than behaviour for many decades. In his new book Mammal Societies, Clutton-Brock argues that the “true century of Darwin was delayed for nearly 100 years” as a consequence.

Field studies of animal behaviour began with the ringing of birds in the 1930s. But it was the arrival of cheap air travel in the 1960s that fuelled behavioural fieldwork of mammals, says Clutton-Brock, as it enabled scientists to conduct long-term studies of natural populations of the larger, long-lived mammals in Africa and Asia – from gorillas to big cats.

Pioneers such as Jane Goodall and Dian Fossey, both of whom studied at Cambridge under famed zoologist Robert Hinde (as did Clutton-Brock) set up primate field studies in the 1960s and 70s which continue today.

These researchers and others began to follow animal communities over entire lives and then generations, recording a detailed ‘life history’ of each animal. In doing so, they revealed how foraging strategies affect group dynamics, how reproductive behaviour creates breeding systems, and how these create networks of kinship and sociality.  

This shifted how scientists viewed wild animals: as individuals with personality traits that hold positions – some fluid, some stable – in often complex hierarchies. These societies influence who gets to breed, who gets to survive, and consequently how animals evolve.

“Darwin’s message was that selection works through differences in breeding success between individuals, not between species or populations, and the success of individuals is determined by their position in the societies they live in,” says Clutton-Brock, one of the world’s leading behavioural ecologists from Cambridge’s Zoology Department.

“That’s why it is important to be able to recognise and follow individuals. If you see a field full of rabbits, for example, you can’t tell sex, age, kinship, dominance – all of which is crucial to understanding what they are doing. This only comes alive once you follow individuals over significant periods of their lives. Long-term studies can get at questions that nothing else can answer.”

Long-term studies also allowed the wider public to identify with individual animals. The killing of studied animals – such as Digit the gorilla from Fossey’s study, or the recent hunting of Cecil the lion – provoked outcry, which in turn raised awareness of the need for conservation.    

Clutton-Brock has worked on Kalahari meerkats for the last twenty years, and the lives of his study animals were featured in the popular TV series ‘Meerkat Manor’. When a dominant female, Flower, succumbed to snakebite in 2007, fans of the show grieved publicly on internet forums. Clutton-Brock wrote a book that told the true story of Flower’s life from birth to death – the first complete biography of a wild animal.

Now, across twenty chapters in Mammal Societies, he brings together decades of accrued knowledge from observations and experiments on social behaviour right across the field, much of which is the result of the thousands of animal life histories collected from long-term studies over the last fifty years.

While there have been reviews of social organisation for birds and ants, this is the first synthesis of sociality across mammals. The new book is set to become a milestone in the literature of evolution, covering social behaviour from baboons to bears, zebra to squirrels, and ending in the most successful mammal society of all: ours.

For Clutton-Brock, part of the excitement of pulling back to view such an extraordinary sweep of social behaviour is the generalities that start to appear. For example, much of the book is divided between the sexes.

“When viewing the whole scope of behaviour, what emerges is that females are distributed in relation to food, which they process into offspring, and males are adapted to adjust themselves to the distribution of females – or, more precisely, to the distribution of unfertilised ova that they can turn into babies,” he says.

Behaviours examined in the book range from extremes of competition, such as infanticide committed by baboons to increase their own breeding prospects, and hyena cubs, born with a full set of sharp teeth, who will sometimes kill their own siblings. But also extremes of cooperation: female meerkats helping each other through birth; male chimpanzees caring for orphaned juveniles.

The final chapters focus on human social progress, from our hominin ancestors’ journey through the polygynous breeding societies still seen in the great apes, to the unique cooperation with strangers and kin alike that defines us as a species.

If you want to put human society and evolution in perspective, says Clutton-Brock, it is the other mammals which provide it, and generalisations drawn from across mammalian social behaviour feed into our understanding of humanity.

“Though modern humans are mostly monogamous, we carry the legacy of past polygyny, as our ancestors lived in societies where a single male dominates several females. In polygynous mammals such as red deer, males only breed for a short time, as competition is so fierce and often brutal. This may relate to the shorter lifespan and larger bodies we see in men,” he explains.

Clutton-Brock has led a study of red deer on the Isle of Rum for over forty years which often feature on the BBC’s Spring and AutumnWatch, as well as the famous meerkats, and his studies have trained large numbers of young biologists in fieldwork. 

The meerkat project has taken a dozen interns each year (“I don’t take anyone for less than a year”) for the last twenty years. Many go on to do PhDs, starting field studies of their own. Clutton-Brock admits he had to learn the hard way. “I did my PhD on forest monkeys – what a disaster. The animals were a hundred feet above you eating leaves, and urinated in your face as you watched them from below.”

Mammal Societies, a project that has taken some ten years to complete, ends with the mammal that has come to dominate the planet. Clutton-Brock offers suggestions to arguably the central question of human evolution: ‘Why us?’

“Many of the characteristics of higher primates may have facilitated the evolution of our own unusual traits,” he says. “They live in complex societies with many competitors and rely on support from other individuals to breed and protect their offspring. The difficult social decisions they have to take has probably played an important role in the evolution of our large brains and understanding of cause and effect.” 

The book closes with a warning to our species: that controlling population growth and preventing environmental destruction requires cooperation on a global scale – a feat no animal has managed. “This would be a novel development in mammals, and it remains to be seen whether humans are able to meet this challenge.”     


Inset images: babysitting meerkats, credit - Kalahari Meerkat Project. Red Deer, credit - Mick Lobb.

Over the last fifty years, long-term studies following individual animals over entire lifespans have allowed insight into the evolutionary influence of social behaviour – finally fulfilling the holistic approach to evolution first suggested by Darwin, argues the author of a new milestone work on mammal societies.

If you see a field full of rabbits, for example, you can’t tell sex, age, kinship, dominance – all of which is crucial to understanding what they are doing. This only comes alive once you follow individuals over significant periods of their lives
Tim Clutton-Brock
Members of a chacma baboon troop, studied as part of the long-term Tsaobis Baboon Project.

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Yes

Tim Clutton-Brock's latest book 'Mammal Societies' is published

From Department of Zoology. Published on May 31, 2016.

Raising the Whale: defining zoology at Cambridge

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Baboons queue for food - report by Alecia Carter

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Crawling with Life: Flower drawings from the Henry Rogers Broughton Bequest

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