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Cheating birds mimic host nestlings to deceive foster parents

By jg533 from University of Cambridge - Department of Zoology. Published on Oct 02, 2020.

Parasitic purple indigo bird

Working in the savannahs of Zambia, a team of international researchers collected images, sounds and videos over four years to reveal a striking and highly specialised form of mimicry. They focused on a group of finches occurring across much of Africa called the indigobirds and whydahs, of the genus Vidua

Like cuckoos, the 19 different species within this group of finches forego their parental duties and instead lay their eggs in the nests of other birds. Each species of indigobird and whydah chooses to lay its eggs in the nests of a particular species of grassfinch. Their hosts then incubate the foreign eggs, and feed the young alongside their own when they hatch. 

Grassfinches are unusual in having brightly coloured and distinctively patterned nestlings, and nestlings of different grassfinch species have their own unique appearance, begging calls and begging movements. Vidua finches are extremely specialised parasites, with each species mostly exploiting a single host species. 

Nestlings of these ‘brood-parasitic’ Vidua finches were found to mimic the appearance, sounds and movements of their grassfinch host’s chicks, right down to the same elaborately colourful patterns on the inside of their mouths. The study is published in the journal Evolution

“The mimicry is astounding in its intricacy and is highly species-specific,” said Dr Gabriel Jamie, lead author on the paper and a research scientist in the University of Cambridge’s Department of Zoology, and at the FitzPatrick Institute of African Ornithology, University of Cape Town.

He added: “We were able to test for mimicry using statistical models that approximate the vision of birds. Birds process colour and pattern differently to humans so it is important to analyse the mimicry from their perspective rather than just relying on human assessments.”

While the mimicry is very precise, the researchers did find some minor imperfections. These may exist due to insufficient time for more precise mimicry to evolve, or because current levels of mimicry are already good enough to fool the host parents. The researchers think that some imperfections might actually be enhanced versions of the hosts’ signal, forcing it to feed the parasite chick even more than it would its own. 

The mimetic adaptations to different hosts identified in the study may also be critical in the formation of new species, and in preventing species collapse through hybridisation. 

“The mimicry is not only amazing in its own right but may also have important implications for how new species of parasitic finches evolve,” added Professor Claire Spottiswoode, an author of the paper and a research scientist at both the University of Cambridge and Cape Town. 

Vidua nestlings imprint on their hosts, altering their mating and host preferences based on early life experiences. These preferences strongly influence the host environment in which their offspring grow up, and therefore the evolutionary selection pressures they experience from foster parents. When maintained over multiple generations, these selection pressures generate the astounding host-specific mimetic adaptations observed in the study.

Reference
Jamie, G. A, et al: ‘Multimodal mimicry of hosts in a radiation of parasitic finches.’ Evolution, July 2020. DOI:10.1111/evo.14057

 

 

The common cuckoo is known for its deceitful nesting behaviour – by laying eggs in the nests of other bird species, it fools host parents into rearing cuckoo chicks alongside their own. While cuckoos mimic their host’s eggs, new research has revealed that a group of parasitic finch species in Africa have evolved to mimic their host’s chicks - and with astonishing accuracy.

The mimicry is astounding in its intricacy and is highly species-specific.
Gabriel Jamie

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Yes

Provide shady spots to protect butterflies from climate change

By jg533 from University of Cambridge - Department of Zoology. Published on Sep 24, 2020.

Researchers have discovered significant variations in the ability of different UK butterfly species to maintain a suitable body temperature. Species that rely most on finding a suitably shady location to keep cool are at the greatest risk of population decline. 

The Zoologist’s Guide to the Galaxy

By jg533 from University of Cambridge - Department of Zoology. Published on Sep 22, 2020.

In his new book, Dr Arik Kershenbaum draws on his knowledge of life on Earth to argue that aliens probably aren’t as weird as we might expect.

World’s largest-ever DNA sequencing of Viking skeletons reveals they weren’t all Scandinavian

By Anonymous from University of Cambridge - Department of Zoology. Published on Sep 16, 2020.

A mass grave of around 50 headless Vikings from a site in Dorset, UK. Some of these remains were used for DNA analysis.

Now cutting-edge DNA sequencing of more than 400 Viking skeletons from archaeological sites scattered across Europe and Greenland will rewrite the history books as it has shown:

  • Skeletons from famous Viking burial sites in Scotland were actually local people who could have taken on Viking identities and were buried as Vikings.
  • Many Vikings actually had brown hair not blonde hair.
  • Viking identity was not limited to people with Scandinavian genetic ancestry. The study shows the genetic history of Scandinavia was influenced by foreign genes from Asia and Southern Europe before the Viking Age.
  • Early Viking Age raiding parties were an activity for locals and included close family members.
  • The genetic legacy in the UK has left the population with up to six per cent Viking DNA. 

Results of the six-year research project, published in the journal Nature, debunk the modern image of Vikings and was led by Professor Eske Willerslev, a Fellow of St John’s College, University of Cambridge, and director of The Lundbeck Foundation GeoGenetics Centre, University of Copenhagen.

“We have this image of well-connected Vikings mixing with each other, trading and going on raiding parties to fight Kings across Europe because this is what we see on television and read in books – but genetically we have shown for the first time that it wasn’t that kind of world,” said Willerslev, who is also affiliated with Cambridge’s Department of Zoology. “This study changes the perception of who a Viking actually was – no one could have predicted these significant gene flows into Scandinavia from Southern Europe and Asia happened before and during the Viking Age.”

The word Viking comes from the Scandinavian term ‘vikingr’ meaning ‘pirate’. The Viking Age generally refers to the period from AD800, a few years after the earliest recorded raid, until the 1050s, a few years before the Norman Conquest of England in 1066.

The Vikings changed the political and genetic course of Europe and beyond: Cnut the Great became the King of England, Leif Eriksson is believed to have been the first European to reach North America – 500 years before Christopher Columbus - and Olaf Tryggvason is credited with taking Christianity to Norway. Many expeditions involved raiding monasteries and cities along the coastal settlements of Europe, but the goal of trading goods like fur, tusks and seal fat was often the more pragmatic aim.

“We didn’t know genetically what they actually looked like until now,” said Willerslev. “We found genetic differences between different Viking populations within Scandinavia which shows Viking groups in the region were far more isolated than previously believed. Our research even debunks the modern image of Vikings with blonde hair as many had brown hair and were influenced by genetic influx from the outside of Scandinavia.”

The international team sequenced the whole genomes of 442 mostly Viking Age men, women, children and babies from their teeth and petrous bones found in Viking cemeteries. They analysed the DNA from the remains from a boat burial in Estonia and discovered four Viking brothers died the same day. The scientists have also revealed male skeletons from a Viking burial site in Orkney, Scotland, were not actually genetically Vikings despite being buried with swords and other Viking memorabilia.

There wasn’t a word for Scandinavia during the Viking Age - that came later. But the study shows that the Vikings from what is now Norway travelled to Ireland, Scotland, Iceland and Greenland. The Vikings from what is now Denmark travelled to England. And Vikings from what is now Sweden went to the Baltic countries on their all-male ‘raiding parties’.

“We carried out the largest ever DNA analysis of Viking remains to explore how they fit into the genetic picture of Ancient Europeans before the Viking Age,” said co-first author Dr Ashot Margaryan from the University of Copenhagen. “The results were startling and some answer long-standing historical questions and confirm previous assumptions that lacked evidence.

“We determined that a Viking raiding party expedition included close family members as we discovered four brothers in one boat burial in Estonia who died the same day. The rest of the occupants of the boat were genetically similar suggesting that they all likely came from a small town or village somewhere in Sweden.”

DNA from the Viking remains were shotgun sequenced from sites in Greenland, Ukraine, the United Kingdom, Scandinavia, Poland and Russia.

“We found that Vikings weren’t just Scandinavians in their genetic ancestry, as we analysed genetic influences in their DNA from Southern Europe and Asia which has never been contemplated before,” said co-first author Professor Martin Sikora form the University of Copenhagen. “Many Vikings have high levels of non-Scandinavian ancestry, both within and outside Scandinavia, which suggest ongoing gene flow across Europe.”

The team’s analysis also found that genetically Pictish people ‘became’ Vikings without genetically mixing with Scandinavians. The Picts were Celtic-speaking people who lived in what is today eastern and northern Scotland during the Late British Iron Age and Early Medieval periods.

“Individuals with two genetically British parents who had Viking burials were found in Orkney and Norway,” said co-first author Dr Daniel Lawson from the University of Bristol. “This is a different side of the cultural relationship from Viking raiding and pillaging.”

The Viking Age altered the political, cultural and demographic map of Europe in ways that are still evident today in place names, surnames and modern genetics.

“Scandinavian diasporas established trade and settlement stretching from the American continent to the Asian steppe,” said co-author Professor Søren Sindbæk from Moesgaard Museum in Denmark. “They exported ideas, technologies, language, beliefs and practices and developed new socio-political structures. Importantly our results show that ‘Viking’ identity was not limited to people with Scandinavian genetic ancestry. Two Orkney skeletons who were buried with Viking swords in Viking style graves are genetically similar to present-day Irish and Scottish people and could be the earliest Pictish genomes ever studied.”

“This is the first time we can take a detailed look at the evolution of variants under natural selection in the last 2,000 years of European history,” said co-first author Professor Fernando Racimo from the University of Copenhagen. “The Viking genomes allow us to disentangle how selection unfolded before, during and after the Viking movements across Europe, affecting genes associated with important traits like immunity, pigmentation and metabolism. We can also begin to infer the physical appearance of ancient Vikings and compare them to Scandinavians today.”

The genetic legacy of the Viking Age lives on today with six per cent of people of the UK population predicted to have Viking DNA in their genes compared to 10 per cent in Sweden.

“The results change the perception of who a Viking actually was. The history books will need to be updated,” said Willerslev.

Reference:
Ashot Margaryan et al. ‘Population genomics of the Viking world.’ Nature (2020). DOI: 10.1038/s41586-020-2688-8

Adapted from a St John’s College press release.

Invaders, pirates, warriors – the history books taught us that Vikings were brutal predators who travelled by sea from Scandinavia to pillage and raid their way across Europe and beyond.

The results change the perception of who a Viking actually was. The history books will need to be updated
Eske Willerslev
A mass grave of around 50 headless Vikings from a site in Dorset, UK. Some of these remains were used for DNA analysis.

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Yes

Living Planet Report reveals 68% decline in global wildlife populations since 1970

By Anonymous from University of Cambridge - Department of Zoology. Published on Sep 10, 2020.

The WWF’s Living Planet Report 2020 presents a comprehensive overview of the state of our natural world as captured by the Living Planet Index (LPI) of the Zoological Society of London (ZSL). Almost 21,000 populations of over 4,000 vertebrate species were tracked between 1970 and 2016, with contributions from over 125 experts from around the world. 

“The Living Planet Report 2020 underlines how humanity’s increasing destruction of nature is having catastrophic impacts not only on wildlife populations, but on human health and all aspects of our lives,” said Marco Lambertini, Director General of WWF International. 

He added: “In the midst of a global pandemic, it is now more important than ever to take unprecedented and coordinated global action to halt and reverse the loss of biodiversity and wildlife populations across the globe by the end of the decade.” 

The report shows that the main cause of the dramatic decline in species populations on land is habitat loss and degradation, including deforestation, driven by food production. Factors believed to increase the planet’s vulnerability to pandemics, including land-use change and the use and trade of wildlife, are also drivers of the decline. 

Endangered species include the eastern lowland gorilla, whose numbers in the Kahuzi-Biega National Park, Democratic Republic of Congo have seen an estimated 87 percent decline between 1994 and 2015 mostly due to illegal hunting, and the African grey parrot in southwest Ghana, whose numbers fell by up to 99 percent between 1992 and 2014 due to threats posed by trapping for the wild bird trade and habitat loss.

Wildlife populations found in freshwater habitats have suffered a decline of 84 per cent - the starkest average population decline in any biome. For example, the spawning population of the Chinese sturgeon in China’s Yangtze river declined by 97 percent between 1982 and 2015 due to the damming of the waterway.

University of Cambridge zoologists Dr Lynn Dicks and Dr Edgar Turner contributed a summary of global insect decline to the report. They reveal evidence of recent, rapid declines in insect abundance and diversity in some places, but not everywhere. The researchers highlight the importance of long-term monitoring of insect abundance around the world.

Dicks, a Lecturer in Animal Ecology in the University of Cambridge’s Department of Zoology, said: “Most information about insects comes from a small number of countries in the northern hemisphere. There is very little information from large parts of the world such as Africa, South America and Asia, where land use change and agricultural expansion - key drivers of insect decline - are happening fast.” 

She added: “What happens to insects matters a lot to humanity. These small six-legged creatures play central roles in the world’s ecosystems - as waste processors, pollinators, predators, and prey. Without them, humans - and all of nature - could be in a lot of trouble.”

Dr Andrew Terry, ZSL’s Director of Conservation said: “This report is clear evidence of the damage human activity is doing to the natural world. If nothing changes, populations will undoubtedly continue to fall, driving wildlife to extinction and threatening the integrity of the ecosystems on which we all depend. But we also know that conservation works and species can be brought back from the brink. With commitment, investment and expertise, these trends can be reversed.”

Stabilising and reversing the loss of nature caused by humans’ destruction of natural habitats will only be possible if bolder, more ambitious conservation efforts are embraced, and transformational changes made to the way we produce and consume food. Changes include making food production and trade more efficient and ecologically sustainable, reducing waste, and favouring healthier and more environmentally-friendly diets. Implementing these measures together, rather than in isolation, will allow the world to more rapidly alleviate pressures on wildlife habitats. 

The Living Planet Report 2020 launches less than a week before the 75th session of the United Nations General Assembly, when leaders are expected to review the progress made on the Sustainable Development Goals, the Paris Agreement and the Convention on Biological Diversity (CBD). Bringing together world leaders, businesses and civil society, the meeting will develop the post-2020 framework for action for global biodiversity. 

Lambertini said: “With leaders gathering virtually for the UN General Assembly in a few days’ time, this research can help us secure a New Deal for Nature and People which will be key to the long-term survival of wildlife, plant and insect populations and the whole of nature, including humankind.  A New Deal has never been needed more.”

The Living Planet Report is WWF's flagship publication and is produced every two years as a comprehensive study of trends in global biodiversity and the health of the planet. This is the 13th edition.

Adapted from a press release by WWF.

 

Global populations of mammals, birds, amphibians, reptiles and fish have declined by over two-thirds in less than half a century, due in large part to the same environmental destruction that is contributing to the emergence of zoonotic diseases like COVID-19, according to a World Wide Fund for Nature (WWF) report released today.

What happens to insects matters a lot to humanity
Lynn Dicks
'Blue Marble' image of Earth

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Yes

Understand what works when trying to protect monkeys and apes, say scientists

By jg533 from University of Cambridge - Department of Zoology. Published on Aug 26, 2020.

Researcher recording data on a group of habituated chimpanzees (Pan troglodytes verus) in Taï National Park, Ivory Coast.

Primates are the group of mammals that includes monkeys, apes, lemurs – and humans. There is far more research and conservation funding for non-human primates than other animal species, due largely to their charisma and their close relationship with humans. Despite this, about 60 percent of primate species are now threatened with extinction and 75 percent have declining populations.

In a study published today in the journal BioScience, a team of experts in 21 countries examined 13,000 primate studies. They found a severe lack of evidence for the effectiveness of primate conservation measures. 

The team found only 80 primate studies that investigated the effectiveness of conservation measures. In addition, only 12 percent of threatened primates and 14 percent of all known primate species were covered by these intervention studies. The studies focused on large-bodied primates and Old World monkeys, particularly great apes, but left out entire families such as tarsiers and night monkeys. 

Despite the taxonomic biases, the authors also found that primate studies were biased towards specific geographic regions and interventions. Fewer than half of the 162 possible primate conservation activities identified by primate experts were evaluated quantitatively. 

Likewise, almost 80 percent of tested interventions were of unknown effectiveness. This was due to studies lacking quantitative data, difficulties in undertaking post-implementation monitoring of populations or individuals, or implementing several interventions at once. 

“Our findings imply that many primate conservation activities are carried out without demonstrably knowing if they have worked or not in other similar situations. This is alarming, given the urgent need for effective conservation measures for these species. Primate conservationists need to showcase the most effective actions for others to learn from,” said Dr Silviu Petrovan in the University of Cambridge’s Department of Zoology, who co-led the research.

“Whether a species was threatened or not played no role for the scientists in the choice of their studied species. We therefore lack the evidence-based information necessary to effectively protect and manage many vulnerable species,” said Dr Jessica Junker at the German Centre for Integrative Biodiversity Research (iDiv) and the Max Planck Institute for Evolutionary Anthropology (MPI-EVA), who co-led the research with Dr Petrovan.  

The study outlines several reasons for the lack of evidence on what works in primate conservation. These include the pattern of survival and reproduction events typical for members of this taxonomic group, also referred to as life history traits. 

“Primates tend to occur at low densities, have slow life histories, and their tree-dwelling habits make them difficult to count. This requires innovative methods and intense monitoring over long periods, specific knowledge and hard-to-obtain long-term funding,” said Hjalmar Kühl at iDiv, MPI-EVA, senior author of the study. 

The authors say there is another disincentive for primate researchers to conduct evaluations of their primate conservation work: publishing can be extremely time and resource intensive, and difficult to achieve in high impact science journals, especially when the results show that a conservation measure was not effective. 

They propose several measures to improve the evidence-base for primate conservation. These include: raising resources for intervention-effectiveness testing and publication, developing guidelines for primate conservation activities, shifting the research focus to threatened species and understudied regions, and seeking long-term collaborations with stakeholders.

The study was led by researchers from the German Centre for Integrative Biodiversity Research (iDiv), the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) and the University of Cambridge.

Adapted from a press release by the German Centre for Integrative Biodiversity Research (iDiv). 

Reference
Junker, J. & Petrovan, S. O., ‘Severe Lack of Evidence Limits Effective Conservation of the World’s Primates.’ BioScience, 2020. DOI: 10.1093/biosci/biaa082

Despite significant protection efforts, global populations of monkeys and apes are declining dramatically. A new study has found that the effectiveness of protection measures is rarely evaluated, and calls for an evidence-based approach to future conservation efforts to prevent imminent extinctions. 

Our findings imply that many primate conservation activities are carried out without demonstrably knowing if they have worked or not in other similar situations. This is alarming.
Silviu Petrovan
Researcher recording data on a group of habituated chimpanzees (Pan troglodytes verus) in Taï National Park, Ivory Coast.

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Yes

Adding a metre between meals boosts vegetarian appeal – study

By fpjl2 from University of Cambridge - Department of Zoology. Published on Aug 13, 2020.

Meat-heavy diets not only risk our health but that of the planet, as livestock farming on a massive scale destroys habitats and generates greenhouse gases.

Conservationists at the University of Cambridge are investigating ways of “nudging” people towards eating more plants and less meat, to help curb the environmental damage caused by excessive consumption of animal products.

The researchers experimented on customers in the cafeterias of two Cambridge colleges to find out whether the position of vegetarian options influences the uptake of plant-based dining.

They collected and analysed data from 105,143 meal selections over a two-year period, alternating the placement of meat and veg dishes every week, and then changing the pattern to every month.

The size of the study is unprecedented. A previous review of various studies using “choice architecture” to reduce meat intake only reached a combined total of 11,290 observations.    

The researchers found that simply placing veggie before meat in the order of meal options as people entered the serving area did little to boost green eating in one of the colleges.

In the other college, however, the sales of plant-based dishes shot up by a quarter (25.2%) in the weekly analysis, and by almost 40% (39.6) in the monthly comparison.

The difference: almost a metre of added distance between the vegetarian and meat options, with an 85cm gap in the first college compared to a 181cm gap in the second. The findings are published today in the journal Nature Food.

“Reducing meat and dairy consumption is one of the simplest and most impactful choices we can make to protect the climate, environment and other species,” said study lead author Emma Garnett, a conservationist from Cambridge’s Department of Zoology.

“We’ve got to make better choices easier for people. We hope to see these findings used by catering managers and indeed anyone interested in cafeteria and menu design that promotes more climate friendly diets.”

The latest research follows on from work by Garnett and colleagues published last autumn, which showed that adding an extra veggie option in cafeterias cuts meat consumption without denting overall sales.

Livestock and aquacultures behind meat, fish, dairy and eggs are responsible for some 58% of the greenhouse gas created by global food, and take up 83% of farmland despite contributing to just 18% of the world’s calorie intake.

Recently, Cambridge researchers recommended eating less meat to reduce the risk of future pandemics, and the UK’s public sector caterers pledged to cut the amount of meat used in schools and hospitals by 20%.

The experiments were conducted across two colleges – one with 600 students and one with 900 students – where cafeteria customers were presented with vegetarian and meat options in differing orders for weekday lunch and dinner.

College members take a tray, view the meals on offer, and then ask serving staff to dish up their preferred options. Food is purchased by swiping a university card, and the researchers gathered anonymised data on main meal selections only (sandwiches and salads went uncounted).

While the catering managers helped to set the experiments up, the diners remained unaware.

The researchers had expected to see a difference in vegetarian sales through order alone, but it was only in the college with the extra metre – the 181cm gap – between food options that recorded an uptick when arranged “Veg First”.

To confirm the findings, researchers reduced the gap in this cafeteria to just 67cm, and vegetarian sales fell sharply. In fact, with such a small gap, vegetarian dishes fared even worse when put first in line (falling almost 30% compared to “Meat First” days).

“We think the effect of the metre may be down to the additional effort required to seek out meat. If the first bite is with the eye, then many people seem perfectly happy with an appetising veggie option when meat is harder to spot,” said Garnett.

“All cafeterias and restaurants have a design that ‘nudges’ people towards something. So it is sensible to use designs that make the healthiest and most sustainable food options the easiest to pick without thinking about it,” she said.

“We know that information alone is generally not enough to get us to change damaging habits. More research is needed on how to set up our society so that the self-interested default decision is the best one for the climate.”

Garnett’s research has contributed to food policy at the University of Cambridge, where the catering service has worked to reduce the amount of meat it uses.

Last year, University cafeterias (separate from the colleges) announced a 33% reduction in carbon emissions per kilogram of food purchased, and a 28% reduction in land use per kilogram of food purchased.

Researchers have identified the optimal dish positions to help “nudge” diners into picking more planet-friendly meals in cafeterias.

More research is needed on how to set up our society so that the self-interested default decision is the best one for the climate
Emma Garnett
A Cambridge college cafeteria

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The text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright ©University 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

Beyond the pandemic: reduce the risk of animal viruses jumping to humans

By lw355 from University of Cambridge - Department of Zoology. Published on Jul 30, 2020.

Cambridge zoologists Bill Sutherland and Silviu Petrovan warn that we must dramatically change the way we interact with animals to reduce the risk of this happening again.

Vikings had smallpox and may have helped spread the world’s deadliest virus

By Anonymous from University of Cambridge - Department of Zoology. Published on Jul 23, 2020.

Massacred 10th century Vikings found in a mass grave at St John’s College, Oxford

Smallpox spread from person to person via infectious droplets, killed around a third of sufferers and left another third permanently scarred or blind. Around 300 million people died from it in the 20th century alone before it was officially eradicated in 1980 through a global vaccination effort – the first human disease to be wiped out. 

Now an international team of scientists have sequenced the genomes of newly discovered strains of the killer virus after it was extracted from the teeth of Viking skeletons from sites across northern Europe. The findings are published today in the journal Science.

“We already knew Vikings were moving around Europe and beyond, and we now know they had smallpox. Just as people travelling around the world today quickly spread COVID-19, it is likely Vikings spread smallpox. Only back then, they travelled by ship rather than plane,” said Professor Eske Willerslev in the University of Cambridge’s Department of Zoology and St. John’s College, and Director of The Lundbeck Foundation GeoGenetics Centre at the University of Copenhagen, who led the study. 

The team found smallpox - caused by the variola virus - in 11 Viking-era burial sites in Denmark, Norway, Russia, and the UK. They also found it in multiple human remains from Öland, an island off the east coast of Sweden with a long history of trade. 

They were able to reconstruct near-complete variola virus genomes for four of the samples. The genetic structure of this earliest-known smallpox strain is different to the modern smallpox virus eradicated in the 20th century.

“There are multiple ways viruses may diverge and mutate into milder or more dangerous strains. This is a significant insight into the steps the variola virus took in the course of its evolution,” said Dr Barbara Mühlemann, formerly at the Centre for Pathogen Evolution at the University of Cambridge, now based at the Institute of Virology at Charité – Universitätsmedizin Berlin, and one of the first authors of the report.

Historians believe smallpox may have existed since 10,000 BC but until now there was no scientific proof that the virus was present before the 17th century. It is not known how it first infected humans but, like COVID-19, it is believed to be a zoonotic disease - one that originated in an animal. 

Smallpox was eradicated throughout most of Europe and the United States by the beginning of the 20th century but remained endemic throughout Africa, Asia, and South America. The World Health Organisation launched an eradication programme in 1967 that included contact tracing and mass communication campaigns - all public health techniques that countries have been using to control today’s coronavirus pandemic. But it was the global roll-out of a vaccine that ultimately enabled scientists to stop smallpox in its tracks.  

While it is not clear whether these ancient strains of smallpox were fatal, the Vikings must have died with smallpox in their bloodstream for the scientists to detect it up to 1400 years later. It is also highly probable there were epidemics earlier than these findings.

“While written accounts of disease are often ambiguous, our findings push the date of the confirmed existence of smallpox back by a thousand years,” said Dr Terry Jones at the Centre for Pathogen Evolution at the University of Cambridge and the Institute of Virology at Charité – Universitätsmedizin Berlin, and one of the senior authors who led the study.

He added: “To find smallpox so genetically different in Vikings is truly remarkable. No one expected that these smallpox strains existed. It has long been believed that smallpox was in Western and Southern Europe regularly by 600 AD, around the beginning of our samples. We have proved that smallpox was also widespread in Northern Europe. Returning crusaders or other later events have been thought to have first brought smallpox to Europe, but such theories cannot be correct.” 

“Smallpox was eradicated, but another strain could spill over from the animal reservoir tomorrow. What we know in 2020 about viruses and pathogens that affect humans today is just a small snapshot of what has plagued humans historically,” said Willerslev. 

This research is part of a long-term project sequencing 5000 ancient human genomes and their associated pathogens. It was made possible thanks to a scientific collaboration between The Lundbeck Foundation, The Wellcome Trust, The Nordic Foundation, and Illumina Inc. 

Reference

Muhlemann, B. et al. 'Diverse variola virus (smallpox) strains were widespread in northern Europe in the Viking Age. Science, July 2020. DOI: 10.1126/science.aaw8977

Adapted from a press release by St John’s College, Cambridge.

Scientists have discovered extinct strains of smallpox in the teeth of Viking skeletons – proving for the first time that the killer disease plagued humanity for at least 1400 years. 

Just as people travelling around the world today quickly spread COVID-19, it is likely Vikings spread smallpox. Only back then, they travelled by ship rather than plane.
Eske Willerslev
Massacred 10th century Vikings found in a mass grave at St John’s College, Oxford

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Yes

Scientists supercharge shellfish to tackle vitamin deficiency in humans

By ta385 from University of Cambridge - Department of Zoology. Published on Jul 20, 2020.

Oysters

Over two billion people worldwide are nutrient deficient, leading to a wide range of serious health problems. Fortifying food with micronutrients is already an industry standard for enhancing public health but now scientists at Cambridge’s Department of Zoology have teamed up with Cambridge-based company BioBullets to supercharge one of the world’s most healthy and sustainable sources of animal protein: bivalve shellfish such as oysters, clams and mussels.

Dr David Aldridge and PhD student David Willer have produced the world’s first microcapsule specially designed to deliver nutrients to bivalves which are beneficial to human health. These “Vitamin Bullets” – manufactured under patent by Aldridge’s company, BioBullets – are tailored for optimal size, shape, buoyancy and to appeal to shellfish.

This breakthrough, described in a study published today in the journal Frontiers in Nutrition, is particularly valuable because when we eat bivalves, we consume the entire organism including its gut, meaning that we digest the nutrients which the animals consumed towards the end of their lives. This makes bivalve shellfish the ideal target for nutritional fortification.

In their Cambridge laboratory, the scientists trialled Vitamin A and D fortified microcapsules on over 100 oysters to identify the optimal dose. They also established that this should be fed for 8 hours towards the end of “depuration”, the period in which bivalves are held in cleansing tanks after being harvested.

The team found that fortified oysters delivered around 100 times more Vitamin A, and over 150 times more Vitamin D, than natural oysters. Even more importantly, they dramatically outperformed salmon, one of the best natural sources of these vitamins. The fortified oysters provided more than 26 times more Vitamin A and over four times more Vitamin D than salmon. The scientists found that a serving of just two of their supercharged shellfish provided enough Vitamin A and D to meet human Recommended Dietary Allowance (RDAs). 

Vitamin A and D deficiencies pose a particularly serious public health challenge – in Ghana more than 76% of children are Vitamin A deficient, causing widespread mortality and blindness. In India, 85% of the population is Vitamin D deficient, which causes cardiovascular diseases, osteoporosis, and rickets. Even in the US, over 40% of people are Vitamin D deficient.

David Willer said: “We have demonstrated a cheap and effective way to get micronutrients into a sustainable and delicious source of protein. Targeted use of this technology in regions worst affected by nutrient deficiencies, using carefully selected bivalve species and micronutrients, could help improve the health of millions, while also reducing the harm that meat production is doing to the environment”.

David Aldridge said: “We are very excited about BioBullets’ potential. We are now establishing links with some of the world’s biggest seafood manufacturers to drive a step change in the sustainability and nutritional value of the seafood that we consume.”

Bivalves have a higher protein content than beef, are a rich source of omega-3 fatty acids, and have some of the highest levels of key minerals of all animal foods. Nevertheless, the nutrients that they deliver naturally is unlikely to solve global deficiencies. These shellfish are also highly sustainable to farm, having a far lower environmental footprint than animal meat or fish, and lower even than many plant crops such as wheat, soya, and rice. 

Bivalves are a highly affordable food source when produced at large scale and the global market is rapidly expanding. Production in China alone has grown 1000-fold since 1980 and there is great potential to sustainably expand bivalve aquaculture worldwide, with over 1,500,000 km2 available for sustainable low-cost industry development, particularly around the west coast of Africa and India.

The researchers point out that consumers in poorer regions where vitamin deficiencies are most prevalent are more likely to buy slightly more expensive fortified food than to make additional purchases to take supplement pills. They calculate that fortification adds just $0.0056 to the cost of producing a single oyster.

David Willer is supported by the Biotechnology and Biological Sciences Research Council; and David Aldridge is supported by The University of Cambridge, St Catharine’s College and Corpus Christi College.
 

Reference:

D.F. Willer & D.C. Aldridge, ‘Vitamin bullets. Microencapsulated feeds to fortify shellfish and tackle human nutrient deficiencies’, Frontiers in Nutrition (July 2020). DOI: 10.3389/fnut.2020.00102

Cambridge scientists have developed a new way to fortify shellfish to tackle human nutrient deficiencies which cause severe health problems across the world. The team is now working with major seafood manufacturers to further test their microencapsulation technology, or “Vitamin Bullets”. 

Targeted use of this technology in regions worst affected by nutrient deficiencies ... could help improve the health of millions
David Willer
Oysters
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Learn more about the work of David Willer and Dr David Aldridge in this feature.

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