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.
Nice synopsis Tim
ReplyDeleteOne thing that struck me in the article is how early in the game we are getting this information for a Palaeoeskimo individual. According to the authors, until the '1000 Genomes' project is complete there are only 8 individual genome sequences reported before "Inuk" the Saqqaq: 1 Yoruba African, 4 Europeans, 1 Han Chinese, and 2 Koreans.
ReplyDeleteUnless they are made the villians in Indiana Jones 5, I can't think of any other Palaeoeskimo story that has garnered so much attention in the mainstream media.
Here is an interesting link for interested readers that may prove insightful in stimulating future research and applied fieldwork in underwater archaeology. The research study shows an ancient link or geentic continuity (mtDNA D1) between a Late Pleistocene female skeleton, dated to 12,000-13,000 BP, discovered in an underwater cave in the Yucatan Peninsula, Mexico. Such interdisciplinary research, namely aDNA studies of human skeletal remains found in underwater archaeological sites, highlights the convergence of both disciplines. Such a parallel study may be extended some day in the distant future here in NL to help solve the puzzle or mystery of why there is a relative paucity of Beo skeletal samples today!
ReplyDeleteTitle:
Late Pleistocene Human Skeleton and mtDNA Link Paleoamericans and Modern Native Americans
(Chatters et al 2014, Science, Vol. 344 (No. 6185), pp. 750-4)
Link:
http://www.sciencemag.org/content/344/6185/750
Here is an interesting link on an ancient DNA study of South American NA mummies which seems to support evidence for a single migration wave into SA. The evidence in SA, as well as perhaps NA, seems to confirm a bottleneck resulting from a founder effect with resulting diversity deriving from drift and selection. The evidence seems to confirm once again the absence of polyphyletic and polymorphic diversity at the level of mtDNA (HVR I-II) and YDNA (STR-SNP), as attested for instance in Central Asia and Western Eurasia. I suspect that future full genome sequencing of autosomal SNP DNA, n(nuclear) DNA and x chromosomes will only merely reinforce these preliminary results. Here is the link:
ReplyDeletehttp://www.nature.com/news/bone-dna-reveals-humanity-s-trek-into-south-america-1.17424
As a final note, preliminary DNA testing of Paleo-American or Paleo-Indian skeletal remains such as the noted Kennewick Man are also revealing the same consistent pattern of genome diversity. The same argument can also apply to the reconstructed genomes of the now extinct Beothuk Indians of Newfoundland, for whom published and forthcoming to-be-published preliminary DNA studies are showing to be Native American with no Western European DNA introgression.
According to Deniekes Blog, the Siberian Chukchi are the closest living relatives of this tested Saqqaq PaleoEskimo or PaleoInuit based on the aDNA analyis of his reconstructed genome. For further details the reader id directed to the link in Denieke's Blog:
ReplyDeletehttp://dienekes.blogspot.ca/2010/02/paleo-eskimo-whole-genome-sequenced.html
On a similar vein or tangent a recent comparative study of Circumpolar mtDNA shows a common shared ancestry for all NeoEskimo or NeoInuit People extrending from Alaska to Greenland, as summarized by the interdisciplinary research team findings:
"Our results yield insight into the maternal population history of the Alaskan North Slope and support the hypothesis that this region served as an ancestral pool for eastward movements to Canada and Greenland, for both the Paleo-Eskimo and Neo-Eskimo populations"
http://dienekes.blogspot.ca/2015/04/mtdna-of-alaskan-eskimos.html
While Paleoindian or Paleoamerican aDNA (ancient DNA) represents a different source for the founding population of the NA (Native American) or First Nations peoples, the Paleoeskimo or Plaeoinuit founding population of the Canadian Arctic do share some shared phylogenetic features (eg., YDNA Q, & mtDNA D4) in common as descending from an anceint Siberian or Beringian population that had contact in Beringia and/or NE Siberia on a very ancient time level. On that note, the recent aDNA (YDNA, mtDNA and at(autosomal) DNA) test results of the noted Kennewick Man, a Paleindian originating from the Columbia River basin, suggest shared ancestry with living NA groups. According to the most recent aDNA evidence his YDNA SNP haplogroup was Q...-M3, mtDNA HVR I X2a..., like the late NL Beo Chief Nonosabasutt-interesting! Here is the article link for the paper as published in Nature for any interested readers who wish to explore further details on the aDNA study, as cited from Deniekes Anthropology Blog (http://dienekes.blogspot.ca/):
ReplyDeletehttp://www.nature.com/nature/journal/vnfv/ncurrent/full/nature14625.html
Supplementary Data (mtDNA, YDNA, and atDNA):
http://www.nature.com/nature/journal/vnfv/ncurrent/extref/nature14625-s1.pdf
Note that the atDNA results for Kennewick Man do not cluster close to Anzick, the latter clustering closer to Central and South American NA groups, suggesting that there may have been a North-South population cline in ancient North America, where the ancestors of the Anzick people migrated southward into Mesoamerica as a founding population, while the root population of Kennewick Man may have been a later incoming Beringian indigneous group autochthonous to the Cordilleran Corridor south of the LGM ice sheets or glaciers, or perhaps a remnant Paleoindian migration group originating from Eastern North America, migrating westward to the Columbia Drainage Basin after the emigration of Anzick kin groups further south. Note also that the autosomal results for Kennewick Man cluster closer to extant Pacific Northwest Amerindian groups and Algonquian groups of NE America (Maritimes), collated as a whole in combination with the YDNA (Q-M3) and mtDNA (X2a-root), seem to confirm an ancient migration route from the Columbia Basin for Proto-Algic (reconstructed proto-ancestor of Proto-Algonquian and Proto-Ritwan (Wiyot & Yurok in California), suggesting ancient continuity or convergence between genetics and linguistics-for the Algonquian language family at least. It would be interesting to see any future YDNA SNP test results on the Maritime Archaic Indian (7000BP) groups to see if they are consistent with YDNA Q-M3, or C3 (common in NL-NS Mi'kmaq).