Archive for February 10th, 2010

Bald Stone Age Siberians settled in Greenland

Wednesday, February 10th, 2010

DNA testing performed on a 4000-year-old tuft of hair and bone chips embedded in the Greenland permafrost has overturned conventional wisdom on how the Arctic regions were settled and by whom.

The hair and bone are the only human remains ever found of the Saqqaq culture who lived on the coast of Greenland from around 2,500 B.C. until they petered out around 800 B.C.

University of Copenhagen researcher Eske Willerslev led a team that exhaustively analysed the precious Qeqertasussuk find.

Artists impression of Inuk, Saqqaq man who unwittingly donated his hair to science 4000 years agoThey teased out nearly 80 percent of the genetic code and identified 353,151 single variations in DNA that are telltale signs of body characteristics.

“What we can see from the genomic data is a number of traits,” Willerslev told journalists in a teleconference.

“For example, we can see the guy had most likely brown eyes, brown skin, he had shovel-form front teeth and he had dry earwax, which increased the chance of getting infection in the ear,” said Willerslev.

“We can also see that he had a tendency to baldness and because we found quite a lot of hair from this guy we presume he actually died quite young, and we can see he was genetically adapted to cold temperatures, living in the Arctic.”

Previously anthropologists thought Greenland was settled by people whose ancestors had crossed the Bering Strait via the Beringia land bridge 15,000 years ago then moved south, eventually reaching as far as the tip of South America, or from the second New World migration 6,000 to 8,000 years ago by the ancestors of western Native Americans in the Na-Dene language group.

But in fact Inuk’s DNA sequence indicates that Greenland — the Neolithic Saqqaq part of it anyway — seems to have been settled by direct descendants of Siberians who crossed the Bering Strait either by kayak or by walking over winter ice and then kept going east. This is solid evidence of a third New World migration, something that linguistic analysis has only hinted at before.

The technique used to extract DNA from Inuk’s fallen tufts was actually pioneered on mammoth hairs. It’s unlikely that a clean sample of DNA can be extracted from even relatively well-preserved tissues like bone or mummified skin because they’re highly susceptible to fungal and bacterial contamination.

Now that we know enough about the human genome that we can pinpoint things like ancient people’s ear wax problems, there’s a whole new world of historical discoveries to be found in preserved hair.