A clump of hair that lay frozen in the Greenland tundra for 4,000 years has yielded DNA from the earliest Arctic residents, and offers clues to their origins.

Researchers have long wondered who those rugged settlers were, and where they came from. Were they part of a massive migration that swept through all of North America, or were they a separate tribe that eventually gave rise to Greenland’s present-day Eskimos?

Until now, no ancient human remains had been found in that harsh climate to allow researchers to study the genetics of those “Paleo-Eskimos.” But the new discovery sheds some light on the people, and suggests that neither of the earlier theories is correct; in fact, they were a distinct tribe that journeyed all the way from Siberia to Greenland, but didn’t stick around to populate the frozen north.

The trove of information came from an unassuming source. The ancient clump of hair looks like something you’d sweep off a barbershop floor. “It’s kind of brown, got a bit of dirt in it, a bit of twigs, but … it looks [in] remarkably good condition,” says biologist Thomas Gilbert of the University of Copenhagen.

University of Copenhagen researchers had spent months in Greenland trying to find human remains, with no success. They then learned of this hair sample, which was discovered in the 1980s in Disko Bay, in western Greenland, and was being kept in a museum collection [NPR].

Gilbert’s team was able to isolate the sample’s mitochondrial DNA, which is passed down from mother to child and therefore offers a genetic marker of maternal lineage. When they compared the DNA from the hair to DNA from other populations, they realized that the Paleo-Eskimos were not genetically similar to Native Americans, but they did have much in common with residents of the westernmost Aleutian Islands and Siberia. According to the research team’s report in Science, subscription required, this suggests that the ancient Eskimos migrated from East Asia via the Bering Strait land bridge.

But Greenland’s modern Eskimos aren’t genetically similar to those early residents either, indicating that they couldn’t last in that icy environment. Lead author Gilbert and colleagues suggest that past ancient Eskimo populations succumbed to periods of climate cooling. “Obviously it’s an extremely tough environment up there, and it may be that the environments got so harsh that the populations got smaller and smaller and collapsed,” he said [National Geographic News].

Image: Bjarne Grønnow

May 30th, 2008 5:54 PM Tags: archaeology, Arctic, DNA, human migration, mitochondrial DNA
by Eliza Strickland in Human Origins | 2 comments | RSS feed | Trackback >