Palaeoeskimo DNA: A Haircut Makes the Man

Four thousand years ago, a man in Greenland got a haircut and because of that, the whole world knows more about him today than he knew about himself. Mats of his hair were preserved in permafrost for millenia. Eventually they were collected by archaeologists and studied by a team of geneticists. They published their results in Nature last week in an article called Ancient Human Genome Sequence of an Extinct Palaeo-Eskimo. Roughly 80% of this Saqqaq Palaeoeskimo man's genome was recovered from his hair. Interestingly, the site of this haircut was Qeqertasussuk in Greenland, which I've blogged about before, because its the source of the stunningly preserved wood and baleen handles that I had such fun reproducing a few weeks ago.

Archaeological research during the last half of the 20th Century backed up what the Inuit have been saying all along, that they were not the first people to live in the Arctic - that the Tunit were there before them. Archaeologists call the Tunit "Palaeoeskimos" and their sites and artifacts confirm that there were people living in the Arctic for several thousand years before the Inuit arrived. The Palaeoeskimo used a completely different toolkit and lived in a different way than the Inuit and their immediate ancestors, the Thule, who populated the Eastern Arctic sometime within the last 1000 years.

Genetic research is beginning to fill in even more of the story. Culturally, there is no continuity between the Palaeoeskimo and the Thule (Tunit and Inuit), but there doesn't appear to have been any genetic continuity either. The Palaeoeskimo people are as extinct as their culture. There was a fascinating paper published in 2005 that suggests that the Palaeoeskimo bloodline may have continued into the the 20th century with the enigmatic Sadlermuit people of Southhampton Island(*), but the new analysis of the Saqqaq hair gives us a glimpse at the very earliest times in this ancient and vanished branch of our family tree. The DNA in the Sadlermuit study came from skeletal remains, whereas the new research reported in Nature is based on hair samples and provides a much more detailed reconstruction of a Palaeoeskimo genome. Given the fact that the Palaeoeskimo are extinct, its an important accomplishment that the researchers have been able to recover any DNA at all.

The new research offers fascinating details of one Palaeoeskimo man. There are genes there that tell the researchers that he was dark skinned, with brown eyes, shovel shaped incisors, dry earwax, A+ blood, and a predisposition to heart disease and early hairloss. He was lactose and gluten intolerant, cold adapted with a high BMI and percentage of body fat and unable to taste "bitter". (source .pdf of the image on the right) He's not related to the Inuit living in Greenland today, but he does have ancestors amongst 3 living groups on the Siberian side of the Bering Straits. According to the genome, the split between the Saqqaq Palaeoeskimo people and their Siberian relatives took place sometime between 6400 and 4400 years ago, which corresponds nicely with the oldest dates for Palaeoeskimo sites in the Arctic. There are even some very personal details about the man's family, like the fact that his parents were probably first cousins, or similarily close relatives.

Everything in the article and its supporting information fits with what we thought we knew about the Palaeoeskimo from decades of archaeological research. But that doesn't mean that it doesn't contain new information or make it any less remarkable. Take the timing and origin of the Palaeoeskimo migration into the Eastern Arctic from the Bering Straits, for example. Through the painstaking excavation of dozens, probably hundreds, of Palaeoeskimo sites from one end of the Arctic to the other and the careful analysis of tens of thousands of artifacts and hundreds of radiocarbon samples, archaeologists came to the same conclusion that was contained in a single exceptionally well-preserved haircut; that the Palaeoeskimos migrated eastward into the Arctic sometime before 4500 years ago from the Bering Straits. Archaeologists working in the North have known about this seperate migration into North America for decades, but if you follow the reporting of this story online, the evidence contained in the hair is far more convincing to most people than all those decades of previous research.

Additional online references can be found here:
http://www.ancientgenome.dk/

* Hayes et al. Molecular Archaeology of the Dorset, Thule, and Sadlermiut: Ancestor-Descendant Relationships in Eastern North Amercian Arctic Prehistory. in Contributions to the Study of the Dorset Palaeo-Eskimos.

Photo Credits:
1,3-5: From Nature and the Saqqaq Genome Project
2: Tim Rast

Photo Captions:
1: Cover of Nature, Feb 11, 2010
2: Elfshot reproductions of Saqqaq tools from the Qeqertasussuk site, Greenland
3: From Hair to DNA
4: From Genotype to Phenotype
5: Artist's reconstruction of the Saqqaq man, nicknamed "Inuk". by Nuka Godfredsen.