̽��ֱ�� of Cambridge - ancient DNA

Ancient DNA reveals reason for high MS and Alzheimer's rates in Europe

jg533 — Wed, 10 Jan 2024 16:06:31 +0000

Researchers have created the world’s largest ancient human gene bank, and used it to map the historical spread of genes – and diseases – over time as populations migrated.

‘Bone biographies’ reveal life and times of medieval England’s common people

fpjl2 — Fri, 01 Dec 2023 08:57:28 +0000

Researchers have given medieval Cambridge residents the ‘Richard III treatment’ to reveal the hard-knock lives of those who lived in the city during the ̽��ֱ��'s earliest years.

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

Anonymous — Wed, 16 Sep 2020 15:00:00 +0000

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. ̽��ֱ��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.
̽��ֱ��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, ̽��ֱ�� of Cambridge, and director of ̽��ֱ��Lundbeck Foundation GeoGenetics Centre, ̽��ֱ�� 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.”

̽��ֱ��word Viking comes from the Scandinavian term ‘vikingr’ meaning ‘pirate’. ̽��ֱ��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.

̽��ֱ��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.”

̽��ֱ��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. ̽��ֱ��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. ̽��ֱ��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 ̽��ֱ�� of Copenhagen. “ ̽��ֱ��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. ̽��ֱ��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 ̽��ֱ�� of Copenhagen. “Many Vikings have high levels of non-Scandinavian ancestry, both within and outside Scandinavia, which suggest ongoing gene flow across Europe.”

̽��ֱ��team’s analysis also found that genetically Pictish people ‘became’ Vikings without genetically mixing with Scandinavians. ̽��ֱ��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 ̽��ֱ�� of Bristol. “This is a different side of the cultural relationship from Viking raiding and pillaging.”

̽��ֱ��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 ̽��ֱ�� of Copenhagen. “ ̽��ֱ��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.”

̽��ֱ��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.

“ ̽��ֱ��results change the perception of who a Viking actually was. ̽��ֱ��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.

̽��ֱ��results change the perception of who a Viking actually was. ̽��ֱ��history books will need to be updated

Eske Willerslev

Dorset County Council/Oxford Archaeology

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

̽��ֱ��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

‘Game-changing’ research could solve evolution mysteries

Anonymous — Wed, 11 Sep 2019 17:00:00 +0000

Researchers identified an almost complete set of proteins, a proteome, in the dental enamel of the rhino and the genetic information discovered is one million years older than the oldest DNA sequenced from a 700,000-year-old horse.

The findings by scientists from the ̽��ֱ�� of Copenhagen and St John’s College, ̽��ֱ�� of Cambridge, are published in Nature. They mark a breakthrough in the field of ancient biomolecular studies and could solve some of the biggest mysteries of animal and human biology by allowing scientists to accurately reconstruct evolution from further back in time than ever before.

Professor Enrico Cappellini, a specialist in Palaeoproteomics at the Globe Institute, ̽��ֱ�� of Copenhagen, and first author on the paper, said: “For 20 years ancient DNA has been used to address questions about the evolution of extinct species, adaptation and human migration but it has limitations. Now for the first time we have retrieved ancient genetic information which allows us to reconstruct molecular evolution way beyond the usual time limit of DNA preservation.

DNA data that genetically tracks human evolution only covers the last 400,000 years. But the lineages that led to modern humans and to the chimp – the living species genetically closest to humans – branched apart around six to seven million years ago which means scientists currently have no genetic information for more than 90 per cent of the evolutionary path that led to modern humans.

Scientists also don’t know what the genetic links are between us and extinct species such as Homo erectus – the oldest known species of human to have had modern human-like body proportions – because everything that is currently known is almost exclusively based on anatomical information, not genetic information.

Researchers have now used ancient protein sequencing – based on ground-breaking technology called mass spectrometry – to retrieve genetic information from the tooth of a 1.77 million year old Stephanorhinus – an extinct rhinoceros which lived in Eurasia during the Pleistocene. Researchers took samples of dental enamel from the ancient fossil which was discovered in Dmanisi, Georgia, and used mass spectrometry to sequence the ancient protein and retrieved genetic information previously unobtainable using DNA testing.
Tooth enamel is the hardest material present in mammals. In this study researchers discovered the set of proteins it contains lasts longer than DNA and is more genetically informative than collagen, the only other protein so far retrieved from fossils older than one million years.

Professor Jesper V. Olsen, head of the Mass Spectrometry for Quantitative Proteomics Group at the Novo Nordisk Foundation Center for Protein Research, ̽��ֱ�� of Copenhagen, and co-corresponding author on the paper, said: “Mass spectrometry-based protein sequencing will enable us to retrieve reliable and rich genetic information from mammal fossils that are millions of years old, rather than just thousands of years old. It is the only technology able to provide the robustness and accuracy needed to sequence tiny amounts of protein this old.”

Professor Cappellini added: “Dental enamel is extremely abundant and it is incredibly durable, which is why a high proportion of fossil records are teeth.

“We have been able to find a way to retrieve genetic information that is more informative and older than any other source before, and it’s from a source that is abundant in the fossil records so the potential of the application of this approach is extensive.”

Lead author Professor Eske Willerslev, who holds positions at St John’s College, ̽��ֱ�� of Cambridge, and is director of The Lundbeck Foundation Centre for GeoGenetics, Globe Institute, Faculty of Health and Medical Sciences, at the ̽��ֱ�� of Copenhagen, said: “This research is a game-changer that opens up a lot of options for further evolutionary study in terms of humans as well as mammals. It will revolutionise the methods of investigating evolution based on molecular markers and it will open a complete new field of ancient biomolecular studies.”

This rearranging of the evolutionary lineage of a single species may seem like a small adjustment but identifying changes in numerous extinct mammals and humans could lead to massive shifts in our understanding of the way the world has evolved.

̽��ֱ��team of scientists is already implementing the findings in their current research. ̽��ֱ��discovery could enable scientists across the globe to collect the genetic data of ancient fossils and to build a bigger, more accurate picture of the evolution of hundreds of species including our own.

Reference:
Enrico Cappellini et al. 'Early Pleistocene enamel proteome from Dmanisi resolves Stephanorhinus phylogeny.' Nature (2019). DOI: 10.1038/s41586-019-1555-y

Originally published by St John's College, Cambridge

An evolution revolution has begun after scientists extracted genetic information from a 1.7 million-year-old rhino tooth – the largest and oldest genetic data to ever be recorded.

This new analysis of ancient proteins from dental enamel will start an exciting new chapter in the study of molecular evolution.

Enrico Cappellini

Mirian Kiladze, Georgian National Museum

Stephanorhinus skull from Dmanisi

Yes

DNA from 31,000-year-old milk teeth leads to discovery of new group of ancient Siberians

hll43 — Wed, 05 Jun 2019 17:00:00 +0000

̽��ֱ��finding was part of a wider study which also discovered 10,000-year-old human remains in another site in Siberia are genetically related to Native Americans – the first time such close genetic links have been discovered outside of the US.

̽��ֱ��international team of scientists, led by Professor Eske Willerslev who holds positions at St John’s College, ̽��ֱ�� of Cambridge, and is director of ̽��ֱ��Lundbeck Foundation Centre for GeoGenetics at the ̽��ֱ�� of Copenhagen, have named the new people group the ‘Ancient North Siberians’ and described their existence as ‘a significant part of human history’.

̽��ֱ��DNA was recovered from the only human remains discovered from the era – two tiny milk teeth – that were found in a large archaeological site found in Russia near the Yana River. ̽��ֱ��site, known as Yana Rhinoceros Horn Site (RHS), was found in 2001 and features more than 2,500 artefacts of animal bones and ivory along with stone tools and evidence of human habitation.

̽��ֱ��discovery is published as part of a wider study in Nature and shows the Ancient North Siberians endured extreme conditions in the region 31,000 years ago and survived by hunting woolly mammoths, woolly rhinoceroses, and bison.

Professor Willerslev said: “These people were a significant part of human history, they diversified almost at the same time as the ancestors of modern-day Asians and Europeans and it’s likely that at one point they occupied large regions of the northern hemisphere.”

Dr Martin Sikora, of ̽��ֱ��Lundbeck Foundation Centre for GeoGenetics and first author of the study, added: “They adapted to extreme environments very quickly, and were highly mobile. These findings have changed a lot of what we thought we knew about the population history of northeastern Siberia but also what we know about the history of human migration as a whole.”

Researchers estimate that the population numbers at the site would have been around 40 people with a wider population of around 500. Genetic analysis of the milk teeth revealed the two individuals sequenced showed no evidence of inbreeding which was occurring in the declining Neanderthal populations at the time.

̽��ֱ��complex population dynamics during this period and genetic comparisons to other people groups, both ancient and recent, are documented as part of the wider study which analysed 34 samples of human genomes found in ancient archaeological sites across northern Siberia and central Russia.

Professor Laurent Excoffier from the ̽��ֱ�� of Bern, Switzerland, said: “Remarkably, the Ancient North Siberians people are more closely related to Europeans than Asians and seem to have migrated all the way from Western Eurasia soon after the divergence between Europeans and Asians.”

Scientists found the Ancient North Siberians generated the mosaic genetic make-up of contemporary people who inhabit a vast area across northern Eurasia and the Americas – providing the ‘missing link’ of understanding the genetics of Native American ancestry.

It is widely accepted that humans first made their way to the Americas from Siberia into Alaska via a land bridge spanning the Bering Strait which was submerged at the end of the last Ice Age. ̽��ֱ��researchers were able to pinpoint some of these ancestors as Asian people groups who mixed with the Ancient North Siberians.

Professor David Meltzer, Southern Methodist ̽��ֱ��, Dallas, one of the paper’s authors, explained: “We gained important insight into population isolation and admixture that took place during the depths of the Last Glacial Maximum – the coldest and harshest time of the Ice Age - and ultimately the ancestry of the peoples who would emerge from that time as the ancestors of the indigenous people of the Americas.”

This discovery was based on the DNA analysis of a 10,000-year-old male remains found at a site near the Kolyma River in Siberia. ̽��ֱ��individual derives his ancestry from a mixture of Ancient North Siberian DNA and East Asian DNA, which is very similar to that found in Native Americans. It is the first time human remains this closely related to the Native American populations have been discovered outside of the US.

Professor Willerslev added: “ ̽��ֱ��remains are genetically very close to the ancestors of Paleo-Siberian speakers and close to the ancestors of Native Americans. It is an important piece in the puzzle of understanding the ancestry of Native Americans as you can see the Kolyma signature in the Native Americans and Paleo-Siberians. This individual is the missing link of Native American ancestry.”

Reference:
Martin Sikora et al. ' ̽��ֱ��population history of northeastern Siberia since the Pleistocene.' Nature (2019). DOI: 10.1038/s41586-019-1279-z

Originally published on the St John's College website.

Two children’s milk teeth buried deep in a remote archaeological site in north eastern Siberia have revealed a previously unknown group of people lived there during the last Ice Age.

This individual is the missing link of Native American ancestry

Eske Willerslev

Russian Academy of Sciences

̽��ֱ��two 31,000-year-old milk teeth found at the Yana Rhinoceros Horn Site in Russia which led to the discovery of a new group of ancient Siberians

Yes

Ancient DNA analysis unlocks secrets of Ice Age tribes in the Americas

Anonymous — Fri, 09 Nov 2018 09:05:01 +0000

̽��ֱ��results have been published in the journal Science as part of a wide-ranging international study, led by the ̽��ֱ�� of Cambridge, which genetically analysed the DNA of a series of well-known and controversial ancient remains across North and South America.

̽��ֱ��research also discovered clues of a puzzling Australasian genetic signal in the 10,400-year-old Lagoa Santa remains from Brazil revealing a previously unknown group of early South Americans – but the Australasian link left no genetic trace in North America.

Additionally, a legal battle over a 10,600-year-old ancient skeleton – called the ‘Spirit Cave Mummy’ – has ended after advanced DNA sequencing found it was related to a Native American tribe. ̽��ֱ��researchers were able to dismiss a longstanding theory that a group called Paleoamericans existed in North America before Native Americans. ̽��ֱ��Paleoamerican hypothesis was first proposed in the 19^th century, but this new study disproves that theory.

“Spirit Cave and Lagoa Santa were very controversial because they were identified as so-called ‘Paleoamericans’ based on craniometry – it was determined that the shape of their skulls was different to current day Native Americans,” said Professor Eske Willeslev, who holds positions at the Universities of Cambridge and Copenhagen, and led the study. “Our study proves that Spirit Cave and Lagoa Santa were actually genetically closer to contemporary Native Americans than to any other ancient or contemporary group sequenced to date.”

̽��ֱ��scientific and cultural significance of the Spirit Cave remains, which were found in 1940 in a small rocky alcove in the Great Basin Desert, was not properly understood for 50 years. ̽��ֱ��preserved remains of the man in his forties were initially believed to be between 1,500 and 2000 years old but during the 1990s new textile and hair testing dated the skeleton at 10,600 years old.

̽��ֱ��Fallon Paiute-Shoshone Tribe, a group of Native Americans based in Nevada near Spirit Cave, claimed cultural affiliation with the skeleton and requested immediate repatriation of the remains.

Their request was refused and the tribe sued the US government, a lawsuit that pitted tribal leaders against anthropologists, who argued the remains provided invaluable insights into North America’s earliest inhabitants and should continue to be displayed in a museum.

̽��ֱ��deadlock continued for 20 years until the tribe agreed that Professor Willeslev could carry out genome sequencing on DNA extracted from the Spirit Cave for the first time.

“I assured the tribe that my group would not do the DNA testing unless they gave permission and it was agreed that if Spirit Cave was genetically a Native American the mummy would be repatriated to the tribe,” said Professor Willeslev, who is a Fellow of St John’s College.

̽��ֱ��team extracted DNA from the inside of the skull proving that the skeleton was an ancestor of present-day Native Americans. Spirit Cave was returned to the tribe in 2016 and there was a private reburial ceremony earlier this year. ̽��ֱ��tribe were kept informed throughout the two-year project and two members visited the lab in Copenhagen to meet the scientists and they were present when all of the DNA sampling was taken.

̽��ֱ��genome of the Spirit Cave skeleton has wider significance because it not only settled the legal and cultural dispute between the tribe and the Government, it also helped reveal how ancient humans moved and settled across the Americas. ̽��ֱ��scientists were able to track the movement of populations from Alaska to as far south as Patagonia. They often separated from each other and took their chances travelling in small pockets of isolated groups.

Dr David Meltzer, from the Department of Anthropology, Southern Methodist ̽��ֱ��, Dallas, said: “A striking thing about the analysis of Spirit Cave and Lagoa Santa is their close genetic similarity which implies their ancestral population travelled through the continent at astonishing speed. That’s something we’ve suspected due to the archaeological findings, but it’s fascinating to have it confirmed by the genetics. These findings imply that the first peoples were highly skilled at moving rapidly across an utterly unfamiliar and empty landscape. They had a whole continent to themselves and they were travelling great distances at speed.”

̽��ֱ��study also revealed surprising traces of Australasian ancestry in ancient South American Native Americans but no Australasian genetic link was found in North American Native Americans.

Dr Victor Moreno-Mayar, from the Centre for GeoGenetics, ̽��ֱ�� of Copenhagen and first author of the study, said: “We discovered the Australasian signal was absent in Native Americans prior to the Spirit Cave and Lagoa Santa population split which means groups carrying this genetic signal were either already present in South America when Native Americans reached the region, or Australasian groups arrived later. That this signal has not been previously documented in North America implies that an earlier group possessing it had disappeared or a later arriving group passed through North America without leaving any genetic trace.”

Dr Peter de Barros Damgaard, from the Centre for GeoGenetics, ̽��ֱ�� of Copenhagen, explained why scientists remain puzzled but optimistic about the Australasian ancestry signal in South America. He explained: “If we assume that the migratory route that brought this Australasian ancestry to South America went through North America, either the carriers of the genetic signal came in as a structured population and went straight to South America where they later mixed with new incoming groups, or they entered later. At the moment we cannot resolve which of these might be correct, leaving us facing extraordinary evidence of an extraordinary chapter in human history! But we will solve this puzzle.”

̽��ֱ��population history during the millennia that followed initial settlement was far more complex than previously thought. ̽��ֱ��peopling of the Americas had been simplified as a series of north to south population splits with little to no interaction between groups after their establishment.

̽��ֱ��new genomic analysis presented in the study has shown that around 8,000 years ago, Native Americans were on the move again, but this time from Mesoamerica into both North and South America.

Researchers found traces of this movement in the genomes of all present-day indigenous populations in South America for which genomic data is available to date.

Dr Moreno-Mayar added: “ ̽��ֱ��older genomes in our study not only taught us about the first inhabitants in South America but also served as a baseline for identifying a second stream of genetic ancestry, which arrived from Mesoamerica in recent millennia and that is not evident from the archaeological record. These Mesoamerican peoples mixed with the descendants of the earliest South Americans and gave rise to most contemporary groups in the region.”

Reference:
J. Victor Moreno-Mayar et al. 'Early human dispersals within the Americas.' Science (2018). DOI: 10.1126/science.aav2621

Adapted from a St John's College press release.

Inset image: Skulls and other human remains from P.W. Lund's Collection from Lagoa Santa, Brazil. Kept in the Natural History Museum of Denmark. Credit: Natural History Museum of Denmark

Scientists have sequenced 15 ancient genomes spanning from Alaska to Patagonia and were able to track the movements of the first humans as they spread across the Americas at “astonishing” speed during the last Ice Age, and also how they interacted with each other in the following millennia.

Our study proves that Spirit Cave and Lagoa Santa were actually genetically closer to contemporary Native Americans than to any other ancient or contemporary group sequenced to date

Eske Willeslev

Linus Mørk, Magus Film

Professor Eske Willerslev with Donna and Joey, two members of the Fallon Paiute-Shoshone tribe.

Yes

Lost Norse of Greenland fuelled the medieval ivory trade, ancient walrus DNA suggests

fpjl2 — Tue, 07 Aug 2018 23:53:31 +0000

̽��ֱ��Icelandic Sagas tell of Erik the Red: exiled for murder in the late 10th century he fled to southwest Greenland, establishing its first Norse settlement.

̽��ֱ��colony took root, and by the mid-12th century there were two major settlements with a population of thousands. Greenland even gained its own bishop.

By the end of the 15th century, however, the Norse of Greenland had vanished – leaving only abandoned ruins and an enduring mystery.

Past theories as to why these communities collapsed include a change in climate and a hubristic adherence to failing farming techniques.

Some have suggested that trading commodities with Europe – most notably walrus tusks – may have been vital to sustaining the Greenlanders. Ornate items including crucifixes and chess pieces were fashioned from walrus ivory by craftsmen of the age. However, the source of this ivory has never been empirically established.

Now, researchers from the universities of Cambridge and Oslo have studied ancient DNA from offcuts of tusks and skulls, most found on the sites of former ivory workshops across Europe, in order to trace the origin of the animals used in the medieval trade.

In doing so they have discovered an evolutionary split in the walrus, and revealed that the Greenland colonies may have had a “near monopoly” on the supply of ivory to Western Europe for over two hundred years.

For the latest study, published today in the journal Proceedings of the Royal Society B, the research team analysed walrus samples found in several medieval trading centres – Trondheim, Bergen, Oslo, Dublin, London, Schleswig and Sigtuna – mostly dating between 900 and 1400 CE.

̽��ֱ��DNA showed that, during the last Ice Age, the Atlantic walrus divided into two ancestral lines, which researchers term “eastern” and “western”. Walruses of the eastern lineage are widespread across much of the Arctic, including Scandinavia. Those of the western, however, are unique to the waters between western Greenland and Canada.

Finds from the early years of the ivory trade were mostly from the eastern lineage. Yet as demand grew from the 12th century onwards, the research team discovered that Europe’s ivory supply shifted almost exclusively to tusks from the western lineage.

They say that ivory from western linage walruses must have been supplied by the Norse Greenlanders – by hunting and perhaps also by trade with the indigenous peoples of Arctic North America.

“ ̽��ֱ��results suggest that by the 1100s Greenland had become the main supplier of walrus ivory to Western Europe – a near monopoly even,” said Dr James H. Barrett, study co-author from the ̽��ֱ�� of Cambridge’s Department of Archaeology.

“ ̽��ֱ��change in the ivory trade coincides with the flourishing of the Norse settlements on Greenland. ̽��ֱ��populations grew and elaborate churches were constructed.

“Later Icelandic accounts suggest that in the 1120s, Greenlanders used walrus ivory to secure the right to their own bishopric from the king of Norway. Tusks were also used to pay tithes to the church,” said Barrett.

He points out that the 11th to 13th centuries were a time of demographic and economic boom in Europe, with growing demand from urban centres and the elite served by transporting commodities from increasingly distant sources.

“ ̽��ֱ��demands for luxury goods produced from ivory may have helped the far-flung Norse communities in Greenland survive for centuries,” said Barrett.

Co-author Dr Sanne Boessenkool of the ̽��ֱ�� of Oslo said: “We knew from the start that analysing ancient DNA would have the potential for new historical insights, but the findings proved to be particularly spectacular.”

̽��ֱ��new study tells us less about the end of the Greenland colonies, say Barrett and colleagues. However, they note that it is hard to find evidence of walrus ivory imports to Europe that date after 1400.

Elephant ivory eventually became the material of choice for Europe’s artisans. “Changing tastes could have led to a decline in the walrus ivory market of the Middle Ages,” said Barrett.

Ivory exports from Greenland could have stalled for other reasons: over-hunting can cause walrus populations to abandon their coastal “haulouts”; the “Little Ice Age” – a sustained period of lower temperatures – began in the 14th century; the Black Death ravaged Europe.

"Whatever caused the cessation of Europe’s trade in walrus ivory, it must have been significant for the end of the Norse Greenlanders,” said Barrett. “An overreliance on a single commodity, the very thing which gave the society its initial resilience, may have also contained the seeds of its vulnerability.”

̽��ֱ��heyday of the walrus ivory trade saw the material used for exquisitely carved items during Europe’s Romanesque art period. ̽��ֱ��church produced much of this, with major ivory workshops in ecclesiastical centres such as Canterbury, UK.

Ivory games were also popular. ̽��ֱ��Viking board game hnefatafl was often played with walrus ivory pieces, as was chess, with the famous Lewis chessmen among the most stunning examples of Norse carved ivory.

Tusks were exported still attached to the walrus skull and snout, which formed a neat protective package that was broken up at workshops for ivory removal. These remains allowed the study to take place, as DNA extraction from carved artefacts would be far too damaging.

Co-author Dr Bastiaan Star of the ̽��ֱ�� of Oslo said: “Until now, there was no quantitative data to support the story about walrus ivory from Greenland. Walruses could have been hunted in the north of Russia, and perhaps even in Arctic Norway at that time. Our research now proves beyond doubt that much of the ivory traded to Europe during the Middle Ages really did come from Greenland”.

̽��ֱ��research was funded by the Leverhulme Trust, Nansenfondet and the Research Council of Norway.

New DNA analysis reveals that, before their mysterious disappearance, the Norse colonies of Greenland had a “near monopoly” on Europe’s walrus ivory supply. An overreliance on this trade may have contributed to Norse Greenland’s collapse when the medieval market declined.

̽��ֱ��very thing which gave the society its initial resilience, may have also contained the seeds of its vulnerability

James Barrett

Left: James H. Barrett. Right: Museum of Archaeology and Anthropology

Left: Upper jaw bones of a walrus, with tusks removed. Right: an elaborately-carved ecclesiastical walrus ivory plaque.

Yes

First Peoples: two ancient ancestries ‘reconverged’ with settling of South America

fpjl2 — Thu, 31 May 2018 18:01:52 +0000

Recent research has suggested that the first people to enter the Americas split into two ancestral branches, the northern and southern, and that the “southern branch” gave rise to all populations in Central and South America.

Now, a study shows for the first time that, deep in their genetic history, the majority – if not all – of the Indigenous peoples of the southern continent retain at least some DNA from the “northern branch”: the direct ancestors of many Native communities living today in the Canadian east.

̽��ֱ��latest findings, published today in the journal Science, reveal that, while these two populations may have remained separate for millennia – long enough for distinct genetic ancestries to emerge – they came back together before or during the expansion of people into South America.

̽��ֱ��new analyses of 91 ancient genomes from sites in California and Canada also provide further evidence that the first peoples separated into two populations between 18,000 and 15,000 years ago. This would have been during or after migrating across the now-submerged land bridge from Siberia along the coast.

Ancient genomes from sites in Southwest Ontario show that, after the split, Indigenous ancestors representing the northern branch migrated eastwards to the great lakes region. This population may have followed the retreating glacial edges as the Ice Age began to thaw, say researchers.

̽��ֱ��study also adds to evidence that the prehistoric people associated with Clovis culture – named for 13,000-year-old stone tools found near Clovis, New Mexico, and once believed to be ancestral to all Native Americans – originated from ancient peoples representing the southern branch.

This southern population likely continued down the Pacific coast, inhabiting islands along the way. Ancient DNA from the Californian Channel Islands shows that initial populations were closely related to the Clovis people.

Yet contemporary Central and South American genomes reveal a “reconvergence” of these two branches deep in time. ̽��ֱ��scientific team, led by the universities of Cambridge, UK, and Illinois Urbana-Champaign, US, say there must have been one or a number of “admixture” events between the two populations around 13,000 years ago.

They say that the blending of lineages occurred either in North America prior to expansion south, or as people migrated ever deeper into the southern continent, most likely following the western coast down.

“It was previously thought that South Americans, and indeed most Native Americans, derived from one ancestry related to the Clovis people,” said Dr Toomas Kivisild, co-senior author of the study from Cambridge’s Department of Archaeology.

“We now find that all native populations in North, Central and South America also draw genetic ancestry from a northern branch most closely related to Indigenous peoples of eastern Canada. This cannot be explained by activity in the last few thousand years. It is something altogether more ancient,” he said.

Dr Ripan S. Malhi, co-senior author from Illinois Urbana-Champaign, said: “Working in partnership with Indigenous communities, we can now learn more about the intricacies of ancestral histories in the Americas through advances in paleogenomic technologies. We are starting to see that previous models of ancient populations were unrealistically simple.”

Present day Central and South American populations analysed in the study were found to have a genetic contribution from the northern branch ranging between 42% to as high as 71% of the genome.

Surprisingly, the highest proportion of northern branch genetics in South America was found way down in southern Chile, in the same area as the Monte Verde archeological site – one of the oldest known human settlements in the Americas (over 14,500 years old).

“It’s certainly an intriguing finding, although currently circumstantial – we don’t have ancient DNA to corroborate how early this northern ancestral branch arrived,” said Dr Christiana Scheib, first author of the study, who conducted the work while at the ̽��ֱ�� of Cambridge.

“It could be evidence for a vanguard population from the northern branch deep in the southern continent that became isolated for a long time – preserving a genetic continuity.

“Prior to 13,000 years ago, expansion into the tip of South America would have been difficult due to massive ice sheets blocking the way. However, the area in Chile where the Monte Verde site is located was not covered in ice at this time,” she said.

“In populations living today across both continents we see much higher genetic proportions of the southern, Clovis-related branch. Perhaps they had some technology or cultural practice that allowed for faster expansion. This may have pushed the northern branch to the edges of the landmass, as well as leading to admixture encounters.”

While consultation efforts varied in this study from community-based partnerships to more limited engagement, the researchers argue that more must be done to include Indigenous communities in ancient DNA studies in the Americas.

̽��ֱ��researchers say that genomic analysis of ancient people can have adverse consequences for linked Indigenous communities. Engagement work can help avoid unintended harm to the community and ensure that Indigenous peoples have a voice in research.

“ ̽��ֱ��lab-based science should only be a part of the research. We need to work with Indigenous communities in a more holistic way,” added Schieb, who has recently joined the ̽��ֱ�� of Tartu’s Institute of Genomics, where Kivisild also holds an affiliation.

“From the analysis of a single tooth, paleogenomics research can now offer information on ancient diet and disease as well as migration. By developing partnerships that incorporate ideas from Native communities, we can potentially generate results that are of direct interest and use to the Indigenous peoples involved,” she said.

New research using ancient DNA finds that a population split after people first arrived in North America was maintained for millennia before mixing again before or during the expansion of humans into the southern continent.

̽��ֱ��lab-based science should only be a part of the research. We need to work with Indigenous communities in a more holistic way

Dr Christiana Scheib

Scheib/Kivisild/Mahli

Two of the four possible combinations of ancient admixture highlighted by the researchers.

Yes