̽��ֱ�� of Cambridge - Andrea Manica

World’s most threatened seabirds visit remote plastic pollution hotspots

jg533 — Tue, 04 Jul 2023 15:00:00 +0000

̽��ֱ��extensive study assessed the movements of 7,137 individual birds from 77 species of petrel, a group of wide-ranging migratory seabirds including the Northern Fulmar and European Storm-petrel, and the Critically Endangered Newell’s Shearwater.

This is the first time that tracking data for so many seabird species has been combined and overlaid onto global maps of plastic distribution in the oceans.

̽��ֱ��results show that plastic pollution threatens marine life on a scale that transcends national boundaries: a quarter of all plastic exposure risk occurs in the high seas. This is largely linked to gyres - large systems of rotating ocean currents - where vast accumulations of plastics form, fed by waste entering the sea from boats, and from many different countries.

Seabirds often mistake small plastic fragments for food, or ingest plastic that has already been eaten by their prey. This can lead to injury, poisoning and starvation, and petrels are particularly vulnerable because they can’t easily regurgitate the plastic. In the breeding season they often inadvertently feed plastic to their chicks.

Plastics can also contain toxic chemicals that can be harmful to seabirds.

Petrels are an understudied but vulnerable group of marine species, which play a key role in oceanic food webs. ̽��ֱ��breadth of their distribution across the whole ocean makes them important ‘sentinel species’ when assessing the risks of plastic pollution in the marine environment.

“Ocean currents cause big swirling collections of plastic rubbish to accumulate far from land, way out of sight and beyond the jurisdiction of any one country. We found that many species of petrel spend considerable amounts of time feeding around these mid-ocean gyres, which puts them at high risk of ingesting plastic debris,” said Lizzie Pearmain, a PhD student at the ̽��ֱ�� of Cambridge’s Department of Zoology and the British Antarctic Survey, and joint corresponding author of the study.

She added: “When petrels eat plastic, it can get stuck in their stomachs and be fed to their chicks. This leaves less space for food, and can cause internal injuries or release toxins.”

Petrels and other species are already threatened with extinction due to climate change, bycatch, competition with fisheries, and invasive species such as mice and rats on their breeding colonies. ̽��ֱ��researchers say exposure to plastics may reduce the birds’ resilience to these other threats.

̽��ֱ��north-east Pacific, South Atlantic, and the south-west Indian oceans have mid-ocean gyres full of plastic waste, where many species of threatened seabird forage.

“Even species with low exposure risk have been found to eat plastic. This shows that plastic levels in the ocean are a problem for seabirds worldwide, even outside of these high exposure areas,” said Dr Bethany Clark, Seabird Science Officer at BirdLife International and joint corresponding author of the study.

She added: “Many petrel species risk exposure to plastic in the waters of several countries and the high seas during their migrations. Due to ocean currents, this plastic debris often ends up far away from its original source. This highlights the need for international cooperation to tackle plastic pollution in the world’s oceans.”

̽��ֱ��study also found that the Mediterranean Sea and the Black Sea together account for over half of petrels’ global plastic exposure risk. However, only four species of petrel forage in these enclosed, busy areas.

̽��ֱ��study was led by a partnership between the ̽��ֱ�� of Cambridge, BirdLife International and the British Antarctic Survey, in collaboration with Fauna & Flora International, the 5 Gyres Institute, and over 200 seabird researchers in 27 countries.

It was published on 4 July in the journal Nature Communications.

To get their results, the researchers overlaid global location data, taken from tracking devices attached to the birds, onto pre-existing maps of marine plastic distribution. This allowed them to identify the areas on the birds’ migration and foraging journeys where they are most likely to encounter plastics.

Species were given an ‘exposure risk score’ to indicate their risk of encountering plastic during their time at sea. A number of already threatened species scored highly, including the Critically Endangered Balearic Shearwater, which breeds in the Mediterranean, and Newell’s Shearwater, endemic to Hawaii.

Another Endangered species, the Hawaiian Petrel also scored high for plastic exposure risk, as did three species classified by the IUCN as Vulnerable: the Yelkouan Shearwater, which breeds in the Mediterranean; Cook’s Petrel, which breeds in New Zealand, and the Spectacled Petrel, which only breeds on an extinct volcano called Inaccessible Island, part of the Tristan da Cunha archipelago, a UK Overseas Territory.

“While the population-level effects of plastic exposure are not yet known for most species, many petrels and other marine species are already in a precarious situation. Continued exposure to potentially dangerous plastics adds to the pressures,” said Professor Andrea Manica at the ̽��ֱ�� of Cambridge’s Department of Zoology, a co-author of the study.

He added: “This study is a big leap forward in understanding the situation, and our results will feed into conservation work to try and address the threats to birds at sea.”

̽��ֱ��research was funded by the Cambridge Conservation Initiative’s Collaborative Fund for Conservation, sponsored by the Prince Albert II of Monaco Foundation, and the Natural Environment Research Council.

Reference

Clark, B.L. et al.: ‘Global assessment of marine plastic exposure risk for oceanic birds.’ Nature Communications, July 2023. DOI: 10.1038/s41467-023-38900-z

Analysis of global tracking data for 77 species of petrel has revealed that a quarter of all plastics potentially encountered in their search for food are in remote international waters – requiring international collaboration to address.

Ocean currents cause big swirling collections of plastic rubbish to accumulate far from land

Lizzie Pearmain

Beth Clark

Northern Fulmar bird in flight

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Licence type:

Attribution

Relocating farmland could turn back clock twenty years on carbon emissions

jg533 — Thu, 10 Mar 2022 10:00:00 +0000

̽��ֱ��reimagined world map of agriculture includes large new farming areas for many major crops around the cornbelt in the mid-western USA, and below the Sahara desert. Huge areas of farmland in Europe and India would be restored to natural habitat.

̽��ֱ��redesign - assuming high-input, mechanised farming - would cut the carbon impact of global croplands by 71%, by allowing land to revert to its natural, forested state. This is the equivalent of capturing 20 years’ worth of our current net CO2 emissions. Trees capture carbon as they grow, and also enable more carbon to be captured by the soil than when crops are grown in it.

In this optimised scenario, the impact of crop production on the world’s biodiversity would be reduced by 87%. This would drastically reduce the extinction risk for many species, for which agriculture is a major threat. ̽��ֱ��researchers say that croplands would quickly revert back to their natural state, often recovering their original carbon stocks and biodiversity within a few decades.

̽��ֱ��redesign would eliminate the need for irrigation altogether, by growing crops in places where rainfall provides all the water they need to grow. Agriculture is currently responsible for around 70% of global freshwater use, and this causes drinking water shortages in many drier parts of the world.

̽��ֱ��researchers used global maps of the current growing areas of 25 major crops, including wheat, barley and soybean, which together account for over three quarters of croplands worldwide. They developed a mathematical model to look at all possible ways to distribute this cropland across the globe, while maintaining overall production levels for each crop. This allowed them to identify the option with the lowest environmental impact.

̽��ֱ��study is published today in the journal Nature Communications Earth & Environment.

“In many places, cropland has replaced natural habitat that contained a lot of carbon and biodiversity – and crops don’t even grow very well there. If we let these places regenerate, and moved production to better suited areas, we would see environmental benefits very quickly,” said Dr Robert Beyer, formerly a researcher in the ̽��ֱ�� of Cambridge’s Department of Zoology, and first author of the study. Beyer is now based at the Potsdam Institute for Climate Impact Research (PIK), Germany.

Previous studies have identified priority areas for ecological restoration, but this is the first to plot the relocation of agricultural land to maximise long-term environmental benefits without compromising food security.

While a complete global relocation of cropland is clearly not a scenario that could currently be put into practice, the scientists say their models highlight places were croplands are currently very unproductive, but have potential to be hotspots for biodiversity and carbon storage.

Taking a pared-back approach and only redistributing croplands within national borders, rather than globally, would still result in significant benefits: global carbon impact would be reduced by 59% and biodiversity impact would be 77% lower than at present.

A third, even more realistic option of only relocating the worst-offending 25% of croplands nationally would result in half of the benefits of optimally moving all croplands.

“It’s currently not realistic to implement this whole redesign. But even if we only relocated a fraction of the world’s cropland, focusing on the places that are least efficient for growing crops, the environmental benefits would be tremendous,” said Beyer.

̽��ֱ��study finds that the optimal distribution of croplands will change very little until the end of the century, irrespective of the specific ways in which the climate may change.

“Optimal cropping locations are no moving target. Areas where environmental footprints would be low, and crop yields high, for the current climate will largely remain optimal in the future,” said Professor Andrea Manica in the Department of Zoology at the ̽��ֱ�� of Cambridge, senior author of the paper.

̽��ֱ��researchers acknowledge that relocating cropland must be done in a way that is acceptable to the people it affects, both economically and socially. They cite examples of set-aside schemes that give farmers financial incentives to retire part of their land for environmental benefit. Financial incentives can also encourage people to farm in better suited locations.

̽��ֱ��model generated alternative global distribution maps depending on the way the land is farmed – ranging from advanced, fully mechanised production with high-yielding crop varieties and optimum fertiliser and pesticide application, through to traditional subsistence-based organic farming. Even redistribution of less intensive farming practices to optimal locations would substantially reduce their carbon and biodiversity impacts.

While other studies show that if we moved towards more plant-based diets we could significantly reduce the environmental impacts of agriculture, the researchers say that in reality diets aren’t changing quickly. Their model assumed that diets will not change, and focused on producing the same food as today but in an optimal way.

Many of the world's croplands are located in areas where they have a huge environmental footprint, having replaced carbon-rich and biodiversity-rich ecosystems, and are a significant drain on local water resources. These locations were chosen for historical reasons, such as their proximity to human settlements, but the researchers say it is now time to grow food in a more optimal way.

This research was funded by the European Research Council.

Reference

Beyer, RM et al: ‘Relocating croplands could drastically reduce the environmental impacts of global food production.’ Nature Communications Earth & Environment, March 2022. DOI: 10.1038/s43247-022-00360-6

Scientists have produced a map showing where the world’s major food crops should be grown to maximise yield and minimise environmental impact. This would capture large amounts of carbon, increase biodiversity, and cut agricultural use of freshwater to zero.

If we moved production to better suited areas, we would see environmental benefits very quickly

Robert Beyer

Wheat fields

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Climate changed the size of our bodies and, to some extent, our brains

jg533 — Thu, 08 Jul 2021 09:21:51 +0000

An interdisciplinary team of researchers, led by the Universities of Cambridge and Tübingen, has gathered measurements of body and brain size for over 300 fossils from the genus Homo found across the globe. By combining this data with a reconstruction of the world’s regional climates over the last million years, they have pinpointed the specific climate experienced by each fossil when it was a living human.

̽��ֱ��study reveals that the average body size of humans has fluctuated significantly over the last million years, with larger bodies evolving in colder regions. Larger size is thought to act as a buffer against colder temperatures: less heat is lost from a body when its mass is large relative to its surface area. ̽��ֱ��results are published today in the journal Nature Communications.

Our species, Homo sapiens, emerged around 300,000 years ago in Africa. ̽��ֱ��genus Homo has existed for much longer, and includes the Neanderthals and other extinct, related species such as Homo habilis and Homo erectus.

A defining trait of the evolution of our genus is a trend of increasing body and brain size; compared to earlier species such as Homo habilis, we are 50% heavier and our brains are three times larger. But the drivers behind such changes remain highly debated.

“Our study indicates that climate - particularly temperature - has been the main driver of changes in body size for the past million years,” said Professor Andrea Manica, a researcher in the ̽��ֱ�� of Cambridge’s Department of Zoology who led the study.

He added: “We can see from people living today that those in warmer climates tend to be smaller, and those living in colder climates tend to be bigger. We now know that the same climatic influences have been at work for the last million years.”

̽��ֱ��researchers also looked at the effect of environmental factors on brain size in the genus Homo, but correlations were generally weak. Brain size tended to be larger when Homo was living in habitats with less vegetation, like open steppes and grasslands, but also in ecologically more stable areas. In combination with archaeological data, the results suggest that people living in these habitats hunted large animals as food - a complex task that might have driven the evolution of larger brains.

“We found that different factors determine brain size and body size – they’re not under the same evolutionary pressures. ̽��ֱ��environment has a much greater influence on our body size than our brain size,” said Dr Manuel Will at the ̽��ֱ�� of Tubingen, Germany, first author of the study.

He added: “There is an indirect environmental influence on brain size in more stable and open areas: the amount of nutrients gained from the environment had to be sufficient to allow for the maintenance and growth of our large and particularly energy-demanding brains.”

This research also suggests that non-environmental factors were more important for driving larger brains than climate, prime candidates being the added cognitive challenges of increasingly complex social lives, more diverse diets, and more sophisticated technology.

̽��ֱ��researchers say there is good evidence that human body and brain size continue to evolve. ̽��ֱ��human physique is still adapting to different temperatures, with on average larger-bodied people living in colder climates today. Brain size in our species appears to have been shrinking since the beginning of the Holocene (around 11,650 years ago). ̽��ֱ��increasing dependence on technology, such as an outsourcing of complex tasks to computers, may cause brains to shrink even more over the next few thousand years.

“It’s fun to speculate about what will happen to body and brain sizes in the future, but we should be careful not to extrapolate too much based on the last million years because so many factors can change,” said Manica.

This research was funded by the European Research Council and the Antarctic Science Platform.

Reference

Will, M et al: ‘Different environmental variables predict body and brain size evolution in Homo.’ Nature Communications, July 2021. DOI: 10.1038/s41467-021-24290-7

̽��ֱ��average body size of humans has fluctuated significantly over the last million years and is strongly linked to temperature. Colder, harsher climates drove the evolution of larger body sizes, while warmer climates led to smaller bodies. Brain size also changed dramatically but did not evolve in tandem with body size.

Our study indicates that climate - particularly temperature - has been the main driver of changes in body size for the past million years.

Andrea Manica

Human fossils illustrating the variation in brain (skulls) and body size (thigh bones) during the Pleistocene.

Yes

Climate change may have driven the emergence of SARS-CoV-2

jg533 — Fri, 05 Feb 2021 12:03:26 +0000

A new study published today in the journal Science of the Total Environment provides the first evidence of a mechanism by which climate change could have played a direct role in the emergence of SARS-CoV-2, the virus that caused the COVID-19 pandemic.

̽��ֱ��study has revealed large-scale changes in the type of vegetation in the southern Chinese province of Yunnan, and adjacent regions in Myanmar and Laos, over the last century. Climatic changes including increases in temperature, sunlight, and atmospheric carbon dioxide - which affect the growth of plants and trees - have changed natural habitats from tropical shrubland to tropical savannah and deciduous woodland. This created a suitable environment for many bat species that predominantly live in forests.

̽��ֱ��number of coronaviruses in an area is closely linked to the number of different bat species present. ̽��ֱ��study found that an additional 40 bat species have moved into the southern Chinese province of Yunnan in the past century, harbouring around 100 more types of bat-borne coronavirus. This ‘global hotspot’ is the region where genetic data suggests SARS-CoV-2 may have arisen.

“Climate change over the last century has made the habitat in the southern Chinese Yunnan province suitable for more bat species,” said Dr Robert Beyer, a researcher in the ̽��ֱ�� of Cambridge’s Department of Zoology and first author of the study, who has recently taken up a European research fellowship at the Potsdam Institute for Climate Impact Research, Germany.

He added: “Understanding how the global distribution of bat species has shifted as a result of climate change may be an important step in reconstructing the origin of the COVID-19 outbreak.”

To get their results, the researchers created a map of the world’s vegetation as it was a century ago, using records of temperature, precipitation, and cloud cover. Then they used information on the vegetation requirements of the world’s bat species to work out the global distribution of each species in the early 1900s. Comparing this to current distributions allowed them to see how bat ‘species richness’, the number of different species, has changed across the globe over the last century due to climate change.

“As climate change altered habitats, species left some areas and moved into others - taking their viruses with them. This not only altered the regions where viruses are present, but most likely allowed for new interactions between animals and viruses, causing more harmful viruses to be transmitted or evolve,” said Beyer.

̽��ֱ��world’s bat population carries around 3,000 different types of coronavirus, with each bat species harbouring an average of 2.7 coronaviruses - most without showing symptoms. An increase in the number of bat species in a particular region, driven by climate change, may increase the likelihood that a coronavirus harmful to humans is present, transmitted, or evolves there.

Most coronaviruses carried by bats cannot jump into humans. But several coronaviruses known to infect humans are very likely to have originated in bats, including three that can cause human fatalities: Middle East Respiratory Syndrome (MERS) CoV, and Severe Acute Respiratory Syndrome (SARS) CoV-1 and CoV-2.

̽��ֱ��region identified by the study as a hotspot for a climate-driven increase in bat species richness is also home to pangolins, which are suggested to have acted as intermediate hosts to SARS-CoV-2. ̽��ֱ��virus is likely to have jumped from bats to these animals, which were then sold at a wildlife market in Wuhan - where the initial human outbreak occurred.

̽��ֱ��researchers echo calls from previous studies that urge policy-makers to acknowledge the role of climate change in outbreaks of viral diseases, and to address climate change as part of COVID-19 economic recovery programmes.

“ ̽��ֱ��COVID-19 pandemic has caused tremendous social and economic damage. Governments must seize the opportunity to reduce health risks from infectious diseases by taking decisive action to mitigate climate change,” said Professor Andrea Manica in the ̽��ֱ�� of Cambridge’s Department of Zoology, who was involved in the study.

“ ̽��ֱ��fact that climate change can accelerate the transmission of wildlife pathogens to humans should be an urgent wake-up call to reduce global emissions,” added Professor Camilo Mora at the ̽��ֱ�� of Hawai‘i at Manoa, who initiated the project.

̽��ֱ��researchers emphasised the need to limit the expansion of urban areas, farmland, and hunting grounds into natural habitat to reduce contact between humans and disease-carrying animals.

̽��ֱ��study showed that over the last century, climate change has also driven increases in the number of bat species in regions around Central Africa, and scattered patches in Central and South America.

This research was supported by the European Research Council.

Reference
Beyer, R.M. et al: ‘Shifts in global bat diversity suggest a possible role of climate change in the emergence of SARS-CoV-1 and SARS-CoV-2.’ Science of the Total Environment, Feb 2021. DOI: 10.1016/j.scitotenv.2021.145413

--------------------------

Hear from other ̽��ֱ�� of Cambridge researchers who are investigating how to reduce the risk of animal viruses jumping to humans.

Global greenhouse gas emissions over the last century have made southern China a hotspot for bat-borne coronaviruses, by driving growth of forest habitat favoured by bats.

Governments must seize the opportunity to reduce health risks from infectious diseases by taking decisive action to mitigate climate change.

Andrea Manica

Shi bai Xiao/ Greenpeace

Forest landscape in Yunnan Province, PRC

Yes

Licence type:

Attribution

Climate change and food demand could shrink species’ habitats by almost a quarter by 2100

jg533 — Fri, 06 Nov 2020 10:06:12 +0000

̽��ֱ��study, published today in the journal Nature Communications, analysed changes in the geographical range of 16,919 species from 1700 to the present day. ̽��ֱ��data were also used to predict future changes up to the year 2100 under 16 different climate and socio-economic scenarios.

A diverse abundance of species underpins essential ecosystem functions from pest regulation to carbon storage. Species’ vulnerability to extinction is strongly impacted by their geographical range size, and devising effective conservation strategies requires a better understanding of how ranges have changed in the past, and how they will change under alternative future scenarios.

“ ̽��ֱ��habitat size of almost all known birds, mammals and amphibians is shrinking, primarily because of land conversion by humans as we continue to expand our agricultural and urban areas,” said Dr Robert Beyer in the ̽��ֱ�� of Cambridge’s Department of Zoology, first author of the report.

Some species are more heavily impacted than others. A worrying 16% of species have lost over half their estimated natural historical range, a figure that could rise to 26% by the end of the century.

Species’ geographical ranges were found to have recently shrunk most significantly in tropical areas. Until around 50 years ago, most agricultural development was in Europe and North America. Since then, large areas of land have been converted for agriculture in the tropics: clearance of rainforest for oil palm plantations in South East Asia, and for pasture land in South America, for example.

As humans move their activities deeper into the tropics, the effect on species ranges is becoming disproportionately larger because of a greater species richness in these areas, and because the natural ranges of these species are smaller to begin with.

“ ̽��ֱ��tropics are biodiversity hotspots with lots of small-range species. If one hectare of tropical forest is converted to agricultural land, a lot more species lose larger proportions of their home than in places like Europe,” said Beyer.

̽��ֱ��results predict that climate change will have an increasing impact on species’ geographical ranges. Rising temperatures and changing rainfall patterns will alter habitats significantly, for example: other studies have predicted that without climate action, large parts of the Amazon may change from canopy rainforest to a savannah-like mix of woodland and open grassland in the next 100 years.

“Species in the Amazon have adapted to living in a tropical rainforest. If climate change causes this ecosystem to change, many of those species won’t be able to survive - or they will at least be pushed into smaller areas of remaining rainforest,” said Beyer.

He added: “We found that the higher the carbon emissions, the worse it gets for most species in terms of habitat loss.”

̽��ֱ��results provide quantitative support for policy measures aiming at limiting the global area of agricultural land – for example by sustainably intensifying food production, encouraging dietary shifts towards eating less meat, and stabilising population growth.

̽��ֱ��conversion of natural vegetation to agricultural and urban land, and the transformation of suitable habitat caused by climate change are major causes of the decline in range sizes, and two of the most important threats to global terrestrial biodiversity.

“Whether these past trends in habitat range losses will reverse, continue, or accelerate will depend on future global carbon emissions and societal choices in the coming years and decades,” Professor Andrea Manica in the ̽��ֱ�� of Cambridge’s Department of Zoology, who led the study.

He added: “While our study quantifies the drastic consequences for species’ ranges if global land use and climate change are left unchecked, they also demonstrate the tremendous potential of timely and concerted policy action for halting - and indeed partially reversing - previous trends in global range contractions. It all depends on what we do next.”

This research was supported by the European Research Council.

Reference
Beyer, R.M. & Manica, A.: ‘Historical and projected future range sizes of the world’s mammals, birds and amphibians.’ Nature Communications, Nov 2020. DOI: 10.1038/s41467-020-19455-9

Mammals, birds and amphibians worldwide have lost on average 18% of their natural habitat range as a result of changes in land use and climate change, a new study has found. In a worst-case scenario this loss could increase to 23% over the next 80 years.

We found that the higher the carbon emissions, the worse it gets for most species in terms of habitat loss.

Robert Beyer

Ulet Ifansasti/ Greenpeace

Baby orangutans in Central Kalimantan. Expansion of oil palm plantations is destroying their forest habitat.

Yes

Licence type:

Attribution-Noncommerical

Shoals of sticklebacks differ in their collective personalities

cjb250 — Wed, 07 Feb 2018 01:34:32 +0000

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 ̽��ֱ�� 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 ̽��ֱ�� 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.

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

Reference
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 ̽��ֱ�� 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.

Jolle Jolles

Stickleback

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution

Baltic hunter-gatherers adopted farming without influence of mass migration, ancient DNA suggests

fpjl2 — Thu, 02 Feb 2017 17:18:30 +0000

New research indicates that Baltic hunter-gatherers were not swamped by migrations of early agriculturalists from the Middle East, as was the case for the rest of central and western Europe. Instead, these people probably acquired knowledge of farming and ceramics by sharing cultures and ideas rather than genes with outside communities.

Scientists extracted ancient DNA from a number of archaeological remains discovered in Latvia and the Ukraine, which were between 5,000 and 8,000 years old. These samples spanned the Neolithic period, which was the dawn of agriculture in Europe, when people moved from a mobile hunter-gatherer lifestyle to a settled way of life based on food production.

We know through previous research that large numbers of early farmers from the Levant (the Near East) – driven by the success of their technological innovations such as crops and pottery – had expanded to the peripheral parts of Europe by the end of the Neolithic and largely replaced hunter-gatherer populations.

However, the new study, published today in the journal Current Biology, shows that the Levantine farmers did not contribute to hunter-gatherers in the Baltic as they did in Central and Western Europe.

̽��ֱ��research team, which includes scientists from the ̽��ֱ�� of Cambridge and Trinity College Dublin, say their findings instead suggest that the Baltic hunter-gatherers learned these skills through communication and cultural exchange with outsiders.

̽��ֱ��findings feed into debates around the ‘Neolithic package’ – the cluster of technologies such as domesticated livestock, cultivated cereals and ceramics, which revolutionised human existence across Europe during the late Stone Age.

Advances in ancient DNA work have revealed that this ‘package’ was spread through Central and Western Europe by migration and interbreeding: the Levant and later Anatolian farmers mixing with and essentially replacing the hunter-gatherers.

But the new work suggests migration was not a ‘universal driver’ across Europe for this way of life. In the Baltic region, archaeology shows that the technologies of the ‘package’ did develop – albeit less rapidly – even though the analyses show that the genetics of these populations remained the same as those of the hunter-gatherers throughout the Neolithic.

Andrea Manica, one of the study’s senior authors from the ̽��ֱ�� of Cambridge, said: “Almost all ancient DNA research up to now has suggested that technologies such as agriculture spread through people migrating and settling in new areas.”

“However, in the Baltic, we find a very different picture, as there are no genetic traces of the farmers from the Levant and Anatolia who transmitted agriculture across the rest of Europe.”

“ ̽��ֱ��findings suggest that indigenous hunter-gatherers adopted Neolithic ways of life through trade and contact, rather than being settled by external communities. Migrations are not the only model for technology acquisition in European prehistory.”

̽��ֱ��researchers analysed eight ancient genomes – six from Latvia and two from Ukraine – that spanned a timeframe of three and a half thousand years (between 8,300 and 4,800 years ago). This enabled them to start plotting the genetic history of Baltic inhabitants during the Neolithic.

DNA was extracted from the petrous area of skulls that had been recovered by archaeologists from some of the region’s richest Stone Age cemeteries. ̽��ֱ��petrous, at the base of the skull, is one of the densest bones in the body, and a prime location for DNA that has suffered the least contamination over millennia.

While the sequenced genomes showed no trace of the Levant farmer influence, one of the Latvian samples did reveal genetic influence from a different external source – one that the scientists say could be a migration from the Pontic Steppe in the east. ̽��ֱ��timing (5-7,000 years ago) fits with previous research estimating the earliest Slavic languages.

Researcher Eppie Jones, from Trinity College Dublin and the ̽��ֱ�� of Cambridge, was the lead author of the study. She said: “There are two major theories on the spread of Indo-European languages, the most widely spoken language family in the world. One is that they came from the Anatolia with the agriculturalists; another that they developed in the Steppes and spread at the start of the Bronze Age.

“That we see no farmer-related genetic input, yet we do find this Steppe-related component, suggests that at least the Balto-Slavic branch of the Indo-European language family originated in the Steppe grasslands of the East, which would bring later migrations of Bronze Age horse riders.”

̽��ֱ��researchers point out that the time scales seen in Baltic archaeology are also very distinct to the rest of Europe, with a much more drawn-out and piecemeal uptake of Neolithic technologies, rather than the complete ‘package’ that arrives with migrations to take most of Europe by storm.

Andrea Manica added: “Our evidence of genetic continuity in the Baltic, coupled with the archaeological record showing a prolonged adoption of Neolithic technologies, would suggest the existence of trade networks with farming communities largely independent of interbreeding.

“It seems the hunter-gatherers of the Baltic likely acquired bits of the Neolithic package slowly over time through a ‘cultural diffusion’ of communication and trade, as there is no sign of the migratory wave that brought farming to the rest of Europe during this time.

“ ̽��ֱ��Baltic hunter-gatherer genome remains remarkably untouched until the great migrations of the Bronze Age sweep in from the East.”

Ancient DNA analyses show that – unlike elsewhere in Europe – farmers from the Near East did not overtake hunter-gatherer populations in the Baltic. The findings also suggest that the Balto-Slavic branch of the Indo-European language family originated in the Steppe grasslands of the East.

̽��ֱ��Baltic hunter-gatherer genome remains remarkably untouched until the great migrations of the Bronze Age sweep in from the East

Andrea Manica

Valters Grivins

̽��ֱ��shores of Lake Burtnieks in Latvia, near where the human remains were discovered from which ancient DNA was extracted for this study.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution

Ancient DNA reveals 'genetic continuity’ between Stone Age and modern populations in East Asia

fpjl2 — Wed, 01 Feb 2017 19:04:57 +0000

Researchers working on ancient DNA extracted from human remains interred almost 8,000 years ago in a cave in the Russian Far East have found that the genetic makeup of certain modern East Asian populations closely resemble that of their hunter-gatherer ancestors.

̽��ֱ��study, published today in the journal Science Advances, is the first to obtain nuclear genome data from ancient mainland East Asia and compare the results to modern populations.

̽��ֱ��findings indicate that there was no major migratory interruption, or “population turnover”, for well over seven millennia. Consequently, some contemporary ethnic groups share a remarkable genetic similarity to Stone Age hunters that once roamed the same region.

̽��ֱ��high “genetic continuity” in East Asia is in stark contrast to most of Western Europe, where sustained migrations of early farmers from the Levant overwhelmed hunter-gatherer populations. This was followed by a wave of horse riders from Central Asia during the Bronze Age. These events were likely driven by the success of emerging technologies such as agriculture and metallurgy

̽��ֱ��new research shows that, at least for part of East Asia, the story differs – with little genetic disruption in populations since the early Neolithic period.

Despite being separated by a vast expanse of history, this has allowed an exceptional genetic proximity between the Ulchi people of the Amur Basin, near where Russia borders China and North Korea, and the ancient hunter-gatherers laid to rest in a cave close to the Ulchi’s native land.

̽��ֱ��researchers suggest that the sheer scale of East Asia and dramatic variations in its climate may have prevented the sweeping influence of Neolithic agriculture and the accompanying migrations that replaced hunter-gatherers across much of Europe. They note that the Ulchi retained their hunter-fisher-gatherer lifestyle until recent times.

“Genetically speaking, the populations across northern East Asia have changed very little for around eight millennia,” said senior author Andrea Manica from the ̽��ֱ�� of Cambridge, who conducted the work with an international team, including colleagues from Ulsan National Institute of Science and Technology in Korea, and Trinity College Dublin and ̽��ֱ�� College Dublin in Ireland.

“Once we accounted for some local intermingling, the Ulchi and the ancient hunter-gatherers appeared to be almost the same population from a genetic point of view, even though there are thousands of years between them.”

̽��ֱ��new study also provides further support for the ‘dual origin’ theory of modern Japanese populations: that they descend from a combination of hunter-gatherers and agriculturalists that eventually brought wet rice farming from southern China. A similar pattern is also found in neighbouring Koreans, who are genetically very close to Japanese.

However, Manica says that much more DNA data from Neolithic China is required to pinpoint the origin of the agriculturalists involved in this mixture.

̽��ֱ��team from Trinity College Dublin were responsible for extracting DNA from the remains, which were found in a cave known as Devil’s Gate. Situated in a mountainous area close to the far eastern coast of Russia that faces northern Japan, the cave was first excavated by a soviet team in 1973.

Along with hundreds of stone and bone tools, the carbonised wood of a former dwelling, and woven wild grass that is one of the earliest examples of a textile, were the incomplete bodies of five humans.

If ancient DNA can be found in sufficiently preserved remains, sequencing it involves sifting through the contamination of millennia. ̽��ֱ��best samples for analysis from Devil’s Gate were obtained from the skulls of two females: one in her early twenties, the other close to fifty. ̽��ֱ��site itself dates back over 9,000 years, but the two women are estimated to have died around 7,700 years ago.

Researchers were able to glean the most from the middle-aged woman. Her DNA revealed she likely had brown eyes and thick, straight hair. She almost certainly lacked the ability to tolerate lactose, but was unlikely to have suffered from ‘alcohol flush’: the skin reaction to alcohol now common across East Asia.

While the Devil’s Gate samples show high genetic affinity to the Ulchi, fishermen from the same area who speak the Tungusic language, they are also close to other Tungusic-speaking populations in present day China, such as the Oroqen and Hezhen.

“These are ethnic groups with traditional societies and deep roots across eastern Russia and China, whose culture, language and populations are rapidly dwindling,” added lead author Veronika Siska, also from Cambridge.

“Our work suggests that these groups form a strong genetic lineage descending directly from the early Neolithic hunter-gatherers who inhabited the same region thousands of years previously.”

In contrast to Western Europeans, new research finds contemporary East Asians are genetically much closer to the ancient hunter-gatherers that lived in the same region eight thousand years previously.

̽��ֱ��Ulchi and the ancient hunter-gatherers appeared to be almost the same population from a genetic point of view, even though there are thousands of years between them

Andrea Manica

Elizaveta Veselovskaya/Yuriy Chernyavskiy

Right: Exterior of Devil’s Gate, the cave in the Primorye region near the far eastern coast of Russia. Left: One of the skulls found in the Devil’s Gate cave from which ancient DNA used in the study was extracted.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes