Scientists have reconstructed the genome of an ancient human from a tuft of hair that had been preserved in the Arctic permafrost for 4,000 years.
Genetic analysis of the thick, dark hairs revealed that they belonged to a young man with dark skin, brown eyes and shovel-shaped teeth, whose metabolism and build were well adapted to life in a cold climate.
The DNA encased in his frozen locks also revealed his blood group (A+), his risk of developing certain diseases, that he faced a high likelihood of going bald, and perhaps most improbably, the dry consistency of his earwax. Other tests on the hair suggest the man survived on a marine diet of seals and seabirds.
“Because we found quite a lot of hair from this guy, we presume he died quite young,” said Eske Willerslev, who led the study at the Centre of Excellence in GeoGenetics at the Natural History Museum in Copenhagen.
“He’s genetically adapted to living in the Arctic, although it was not that many generations ago that his ancestors came to the New World,” he added.
The work, a tour de force of modern genetic technology, is the first to piece together an almost complete genome of an ancient human. The feat is exceptional because DNA degrades over time, making it difficult to read and reassemble into a meaningful genome.
The hairs were recovered from the permafrost in the Qeqertasussuk region of Greenland and are from an individual the scientists have named “Inuk”, meaning man or human in Greenlandic.
Inuk was part of the Saqqaq culture, the first known people to inhabit Greenland. The origins of the culture are hotly debated by scientists, though most believe the Saqqaq’s ancestors were migrants from neighbouring populations, such as the Na-Dene of North America or the Inuit of the New World Arctic.
Detailed analysis of Inuk’s genome allowed the scientists to compare his genome with that of several surrounding populations. To their surprise, they found that Inuk was most closely related to three Old World Arctic populations, the Nganasans, Koryaks and Chukchis of far eastern Siberia.
The discovery suggests that there was a wave of migration from Siberia into the New World some 5,500 years ago that was independent of those that gave rise to modern Native Americans and the Inuit.