Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



ABOUT US
'Fourth strand' of European ancestry originated with hunter-gatherers isolated by Ice Age
by Staff Writers
Cambridge, UK (SPX) Nov 23, 2015


DNA was extracted from the molar teeth of this skeleton, dating from almost 10,000 years ago and found in the Kotias Klde rockshelter in Western Georgia. Image courtesy Eppie Jones. For a larger version of this image please go here.

The first sequencing of ancient genomes extracted from human remains that date back to the Late Upper Palaeolithic period over 13,000 years ago has revealed a previously unknown "fourth strand" of ancient European ancestry.

This new lineage stems from populations of hunter-gatherers that split from western hunter-gatherers shortly after the 'out of Africa' expansion some 45,000 years ago and went on to settle in the Caucasus region, where southern Russia meets Georgia today.

Here these hunter-gatherers largely remained for millennia, becoming increasingly isolated as the Ice Age culminated in the last 'Glacial Maximum' some 25,000 years ago, which they weathered in the relative shelter of the Caucasus mountains until eventual thawing allowed movement and brought them into contact with other populations, likely from further east.

This led to a genetic mixture that resulted in the Yamnaya culture: horse-borne Steppe herders that swept into Western Europe around 5,000 years ago, arguably heralding the start of the Bronze Age and bringing with them metallurgy and animal herding skills, along with the Caucasus hunter-gatherer strand of ancestral DNA - now present in almost all populations from the European continent.

The research was conducted by an international team led by scientists from Cambridge University, Trinity College Dublin and University College Dublin. The findings are published in the journal Nature Communications.

"The question of where the Yamnaya come from has been something of a mystery up to now," said one of the lead senior authors Dr Andrea Manica, from Cambridge's Department of Zoology.

"We can now answer that as we've found that their genetic make-up is a mix of Eastern European hunter-gatherers and a population from this pocket of Caucasus hunter-gatherers who weathered much of the last Ice Age in apparent isolation. This Caucasus pocket is the fourth major strand of ancient European ancestry, one that we were unaware of until now," he said

Professor Daniel Bradley, leader of the Trinity team, said: "This is a major new piece in the human ancestry jigsaw, the influence of which is now present within almost all populations from the European continent and many beyond."

Previously, ancient Eurasian genomes had revealed three ancestral populations that contributed to contemporary Europeans in varying degrees, says Manica.

Following the 'out of Africa' expansion, some hunter-gatherer populations migrated north-west, eventually colonising much of Europe from Spain to Hungary, while other populations settled around the eastern Mediterranean and Levant, where they would develop agriculture around 10,000 years ago. These early farmers then expanded into and colonised Europe.

Finally, at the start of the Bronze Age around 5,000 years ago, there was a wave of migration from central Eurasia into Western Europe - the Yamnaya.

However, the sequencing of ancient DNA recovered from two separate burials in Western Georgia - one over 13,000 years old, the other almost 10,000 years old - has enabled scientists to reveal that the Yamnaya owed half their ancestry to previously unknown and genetically distinct hunter-gatherer sources: the fourth strand.

By reading the DNA, the researchers were able to show that the lineage of this fourth Caucasus hunter-gatherer strand diverged from the western hunter-gatherers just after the expansion of anatomically modern humans into Europe from Africa.

The Caucasus hunter-gatherer genome showed a continued mixture with the ancestors of the early farmers in the Levant area, which Manica says makes sense given the relative proximity. This ends, however, around 25,000 years ago - just before the time of the last glacial maximum, or peak Ice Age.

At this point, Caucasus hunter-gatherer populations shrink as the genes homogenise, a sign of breeding between those with increasingly similar DNA. This doesn't change for thousands of years as these populations remain in apparent isolation in the shelter of the mountains - possibly cut off from other major ancestral populations for as long as 15,000 years - until migrations began again as the Glacial Maximum recedes, and the Yamnaya culture ultimately emerges.

"We knew that the Yamnaya had this big genetic component that we couldn't place, and we can now see it was this ancient lineage hiding in the Caucasus during the last Ice Age," said Manica.

While the Caucasus hunter-gatherer ancestry would eventually be carried west by the Yamnaya, the researchers found it also had a significant influence further east. A similar population must have migrated into South Asia at some point, says Eppie Jones, a PhD student from Trinity College who is the first author of the paper.

"India is a complete mix of Asian and European genetic components. The Caucasus hunter-gatherer ancestry is the best match we've found for the European genetic component found right across modern Indian populations," Jones said. Researchers say this strand of ancestry may have flowed into the region with the bringers of Indo-Aryan languages.

The widespread nature of the Caucasus hunter-gatherer ancestry following its long isolation makes sense geographically, says Professor Ron Pinhasi, a lead senior author from University College Dublin. "The Caucasus region sits almost at a crossroads of the Eurasian landmass, with arguably the most sensible migration routes both west and east in the vicinity."

He added: "The sequencing of genomes from this key region will have a major impact on the fields of palaeogeneomics and human evolution in Eurasia, as it bridges a major geographic gap in our knowledge."

David Lordkipanidze, Director of the Georgian National Museum and co-author of the paper, said: "This is the first sequence from Georgia - I am sure soon we will get more palaeogenetic information from our rich collections of fossils."


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
University of Cambridge
All About Human Beings and How We Got To Be Here






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
ABOUT US
Scientists fill in the gaps of human hunter-gatherer history
Dublin, Ireland (SPX) Nov 20, 2015
An international team led by scientists in Trinity College Dublin, University College Dublin and Cambridge University, has, for the first time, sequenced ancient genomes from the Late Upper Palaeolithic period. In doing so, the team has discovered a new strand of European hunter-gatherer ancestry. Where human genomes are concerned the past is indeed a different country. Most modern populat ... read more


ABOUT US
UN details doubling in weather disasters ahead of climate summit

Hopes fade as Myanmar mine landslide toll tops 100

UN decries Thailand, Vietnam deportations to China

UN peacekeepers must use force where needed: US envoy

ABOUT US
Primordial goo used to improve implants

From nanocrystals to earthquakes, solid materials share similar failure characteristics

UW team refrigerates liquids with a laser for the first time

Network analysis shows systemic risk in mineral markets

ABOUT US
Researchers discover sediment size matters in high-elevation erosion rates

Small landscape changes can mean big freshwater gains

Green campaigner readies to swim the Pacific

Study finds High Plains Aquifer peak use by state, overall usage decline

ABOUT US
Melting Scandinavian ice provides missing link in Europe's final Ice Age story

Climate change could slash polar bear numbers by 2050

Sea ice plays a pivotal role in the Arctic methane cycle

Geophysics could slow Antarctic ice retreat

ABOUT US
South American origins and spread of the Irish potato famine pathogen

High yield crops a step closer in light of photosynthesis discovery

Going native - for the soil

FDA okays GM salmon for sale in the United States

ABOUT US
Hidden earthquakes present challenge to earthquake early-warning systems

Saudi flooding dath toll hits eight

6.8-magnitude quake hits off Solomon Islands: USGS

Deaths, flight delays as heavy rains hit Saudi

ABOUT US
Pope readies for Africa, riskiest trip of his papacy

Corruption hampered troops fighting Boko Haram: Nigeria's Buhari

In Kenya, a digital classroom in a box

Mali jihadist leader denounces peace deal, wants fight against France

ABOUT US
Human brains evolved to be more responsive to environmental influences

'Fourth strand' of European ancestry originated with hunter-gatherers isolated by Ice Age

Scientists fill in the gaps of human hunter-gatherer history

CCNY researchers open 'Golden Window' in deep brain imaging




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement