A FEW strands of hair was all it took for scientists to reconstruct both physical characteristics and a family tree for a man who lived in Greenland 4,000 years ago.
We know he was likely to have had brown eyes and type A positive blood. He had non-white skin and square front teeth shaped like shovels. These he used to chew up dinners heavily dependent on seal meat.
He had thick, dark hair but might have been unhappy to know he would be prone to early baldness.
All of this was gleaned when scientists used just a few tufts of hair to reconstruct a DNA profile of the man, named “Inuk” by the research team. The scant remains were dug out of the permafrost back in 1986 at Qeqertasussuk on the western edge of Greenland, according to the Danish-led research team which reported their discoveries this morning in the journal Nature.
The hairs are one of the very few examples of ancient human remains left behind by the Saqqaqs, the first humans to occupy Greenland. The freezing permafrost was enough to preserve Inuk’s DNA over the 4,000 years that it lay hidden in the soil with other waste next to a buried reindeer skull.
The team used the latest techniques to recover the DNA and ensure it was not contaminated with modern DNA. This is the first time that a near complete, high-quality genetic blueprint has been recovered from ancient human remains, the authors write.
It has also delivered an astounding avalanche of information about Inuk and the earliest human settlers in the North American Arctic.
The researchers were able to compare small lengths of Inuk’s DNA with modern human DNA to winkle out specific physical characteristics, for example hair and skin colour. The 4,000-year-old DNA told the team Inuk was slightly inbred, to the degree expected should two first cousins mate.
DNA from chromosome 16 told them that Inuk had a “dry type” of earwax, typical of Asian and Native American populations. The team also showed that he possessed both a metabolism and body mass index typical of a person adapted to living in a cold climate.
But the ancient DNA record told them more, settling a long-running dispute over the degree of relatedness between the Saqqaq people and modern Amerindians and Inuit.
Physical characteristics suggested they must be related but the DNA told a different story, one of a previously unknown human migration out of eastern Asia to the New World as many as 5,500 years ago.
Inuk’s DNA showed he was not closely related to Amerindians or Inuit but to Old World Arctic populations, the Koryaks and the Chukchis, the authors write.
This means there must have been a separate migration from Siberia into the New World, independent of the one that brought ancestors of the Inuit.
Effectively, this work shows that ancient DNA “can be used to identify important . . . traits of an individual from an extinct culture”, the authors conclude.