Well preserved in Arctic permafrost, the hair belonged to "Inuk," a relatively young member of the now extinct Saqqaq culture, the earliest known inhabitants of Greenland.

The Saqqaq have long presented a puzzle to scientists, according to study co-author Eske Willerslev, an evolutionary biologist at the University of Copenhagen in Denmark.

"Various theories have suggested that they were direct ancestors to the Inuit, or that they were actually Native Americans who penetrated into the High Arctic," Willerslev said. But little has been known about the Saqqaq's genetic history, since archaeological sites have yielded only a few small bits of preserved bone and hair.

The new DNA evidence, presented online today by the journal Nature, shows