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Community => Recreation Commons => Our researchers have made a breakthrough! => Topic started by: Buster's Uncle on September 17, 2014, 08:15:54 pm

Title: Genetic history of modern Europeans a tangled tale, research finds
Post by: Buster's Uncle on September 17, 2014, 08:15:54 pm

Genetic history of modern Europeans a tangled tale, research finds
Reuters
By Will Dunham  44 minutes ago


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Members of Russian ensemble perform a traditional Cossack's dance with swords during the opening ceremony of the 3rd Krasnoyarsk Asian-Pacific International musical festival in the Siberian city of Krasnoyarsk, in this file photo taken June 29, 2012. REUTERS/Ilya Naymushin/Files



WASHINGTON (Reuters) - The genetic origins of modern Europeans may be more complicated than previously thought.

Ancient people from Siberia who were related to the first humans to enter the Americas during the Ice Age also mingled with prehistoric populations in Europe and left their mark on the DNA of today's Europeans, scientists said on Wednesday.

Their study, published in the journal Nature, is the latest to use sophisticated genetic research to clarify the ancestry of modern populations.

Experts had thought today's Europeans descended from two other groups of people.

The first were primitive hunter-gatherers from western Europe who had lived on the continent since it was first colonized by our species more than 40,000 years ago. The second were farmers who migrated into Europe from a region spanning parts of Syria, Turkey and Iraq around 7,000 years ago.


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Zoya Lipnyagova carries a bucket at her house farm in the village of Kluchi, in Krasnoyarsk region, Siberia, in this file photo taken August 19, 2014. REUTERS/Ilya Naymushin/Files


The new study revealed the role of hunter-gatherers from the Siberian region who the scientists called "ancient north Eurasians."

The scientists sequenced the genomes of a farmer who had lived in Germany about 7,000 years ago and eight hunter-gatherers who had lived in Luxembourg and Sweden about 8,000 years ago. They then compared those findings with the genomes of 2,345 people living today to decipher European ancestry.

"Our study does indeed show that European origins were more complex than previously imagined," said Iosif Lazaridis, a postdoctoral research fellow at Harvard Medical School.

"It seems that Europeans - who are often considered one group today - actually have a complex history with at least three groups admixing in different proportions in their history," Lazaridis added.

Almost all Europeans were found to have ancestry from all three of those ancient groups. The ancient north Eurasians contributed up to 20 percent of the genetics of Europeans, although this was the smallest proportion among the three ancestral groups.


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A Lithuanian man drives a city resident in a Velomobile outside the cathedral in Vilnius in this file photo taken August 6, 2004. REUTERS/Liutauras Strimaitis


People in northern Europe, especially the Baltic states, have the highest proportion of western European hunter-gatherer ancestry, with up to 50 percent of the DNA of Lithuanians coming from this group.

Southern Europeans had more of their genetic ancestry from the ancient farmers, with up to 90 percent of the DNA of Sardinians tracing back to these early European immigrants.

These farmers who came from the Near East brought new capabilities to Europe, domesticating animals including pigs and cows, growing crops including types of wheat, barley, peas and lentils and using obsidian sickles for harvest.

Another of the researchers, Johannes Krause, a geneticist at the University of Tübingen and co-director of the Max Planck Institute for History and the Sciences in Germany, said the ancient north Eurasians "connect all modern Europeans and Native Americans."

The findings show they not only mixed with prehistoric Europeans but also were related to the people who trekked more than 15,000 years ago across the frozen land bridge that once linked Siberia to Alaska and spread into the Americas.

(Reporting by Will Dunham; Editing by Cynthia Osterman)


http://news.yahoo.com/genetic-history-modern-europeans-tangled-tale-research-finds-181744008.html (http://news.yahoo.com/genetic-history-modern-europeans-tangled-tale-research-finds-181744008.html)

Title: Modern Europeans descended from three groups
Post by: Buster's Uncle on September 18, 2014, 02:42:02 am

Modern Europeans descended from three groups
AFP
4 hours ago


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Researchers exhume human remains dating back to about - 500 BC during excavation works on August 14, 2014 in eastern France (AFP Photo/Fred Marvaux)



Paris (AFP) - Modern Europeans are descended from three major groups of ancient humans, not two as was previously thought, according to a gene analysis published on Wednesday.

Until now, the mainstream theory was that Europeans descended from early farmers who moved into Europe from the Middle East about 7,500 years ago, and local hunter-gatherers they interbred with.

But a DNA analysis in the journal Nature says there was a third group in the mix: people from northern Eurasia.

The finding means that North Eurasians -- who inhabited a vast swathe of land stretching across much of Russia and northern Asia -- contributed to the gene pool both in Europe and North America.

Their influence on the Americas were borne out in previous studies which showed that North Eurasians crossed to modern-day Alaska more than 15,000 years ago via an "ice bridge" that connected islands in the Bering Strait at the time.

"What we find is unambiguous evidence that people in Europe have all three of these ancestries," said David Reich of Harvard Medical School, who led the study with Johannes Krause at Germany's University of Tuebingen.

The 100-strong team of scientists drew on a vast collection of resources.

They unravelled DNA teased from nine ancient skeletons found in Sweden, Luxembourg and Germany. The remains were those of eight hunter-gatherers who lived about 8,000 years ago, before the advent of agriculture, and one farmer from about 7,000 years ago.

"There was a sharp genetic transition between the (era of) hunter-gatherers and the farmers, reflecting a major movement of new people into Europe from the Near East," said Reich.

The genomes were overlaid with the genetic codes of 2,300 present-day people living all over the world.

"The ancient North Eurasian ancestry is proportionally the smallest component everywhere in Europe, never more than 20 percent, but we find it in nearly every European group we've studied and also in the Caucasus and Near East," said Iosif Lazaridis, one of the Harvard team.

Northern Europeans have relatively more hunter-gatherer ancestry -- up to about 50 percent in Lithuanians -- whereas southern Europeans have more farmer ancestry, he added.


http://news.yahoo.com/modern-europeans-descended-three-groups-213146979.html (http://news.yahoo.com/modern-europeans-descended-three-groups-213146979.html)