Tuesday, January 8, 2008
Using DNA To Figure Out Ancient Migration
Greenland DNA could hold key to migration mysteries: researchers Tue Dec 18, 2:34 PM ET COPENHAGEN (AFP) - Danish researchers are to sieve through human and skeletal remains on Greenland in a quest to explain an enduring enigma over the island's settlement over thousands of years, one of the scientists said Tuesday. "We want to track down how the settlement actually happened," Niels Lynnerup, a researcher at Copenhagen University's forensic medicine department, told AFP. The island, today a semi-autonomous Danish territory, had been colonised at least 3,000 years ago by Arctic Inuit people, who were then forced to leave, apparently because plunging temperatures eventually made the place uninhabitable. Then came the Norwegian Viking, Erik the Red, who is popularly but wrongly credited with founding the first settlement on Greenland around the 11th century. The Viking settlement lasted until about the 15th century when it strangely petered out. One possible explanation for this is that Greenland, like the rest of northern Europe, experienced a "Little Ice Age" that sent the beleaguered Norse settlers searching for a warmer climate. The Inuits living in Greenland today can be traced back to ancestors of the so-called Thule culture, who first arrived around the 13th century and for a time shared the island with the Norsemen, but contacts between the two communities are believed to have been rare or even hostile. The Thule had a way of life based on the kayak and seal hunting that enabled them to brave the bitter Little Ice Age and remain on the island to this day. "We're trying to ascertain from DNA whether there is a link between some of the very first settlers with today's Inuits and discover how the different waves of colonisation related to each other," Lynnerup said. The team wants to explain how a tiny Norse population managed to survive on the perimeter of the Greenland icesheet 500 years and whether it ever interbred with the Thule Inuit. "We want to see whether there are Thule genes in the European culture and Norse genes in today's Inuit cultures, to see if they met," Lynnerup said. If so, it would mark the first time since humans first migrated from Africa to Asia around 50,000 years ago that two such genetically diverse peoples interacted, he said. To do this, the researchers hope to tease out DNA that has been preserved in human remains and cross-match any genetic link between individuals. Greenland is the perfect laboratory for doing this, as the different waves of migrants to the island had remained relatively isolated -- which would make cross-matching relatively ease -- and the deep cold may helped preserve vital DNA in human remains that were buried for centuries.