The Greenlander belonged to a Paleo-Eskimo culture called the Saqqaq by archaeologists. On the basis of his genome, the Saqqaq man’s closest living relatives are the Chukchis, people who live at the easternmost tip of Siberia. His ancestors split apart from Chukchis some 5,500 years ago, according to genetic calculations, implying the Saqqaq people’s ancestors must have traveled across the northern edges of North America until they reached Greenland.
Here is the full article. Call me crazy, but I've long been a (partial) fan of John Bailey's Sailing to Paradise: The Discovery of the Americas by 7000 B.C.