Razib's post at Discover
's GNXP, "Icelanders descended from Native Americans?"
, surprised me. It really
Although most mtDNA lineages observed in contemporary Icelanders can be traced to neighboring populations in the British Isles and Scandinavia, one may have a more distant origin. This lineage belongs to haplogroup C1, one of a handful that was involved in the settlement of the Americas around 14,000 years ago. Contrary to an initial assumption that this lineage was a recent arrival, preliminary genealogical analyses revealed that the C1 lineage was present in the Icelandic mtDNA pool at least 300 years ago. This raised the intriguing possibility that the Icelandic C1 lineage could be traced to Viking voyages to the Americas that commenced in the 10th century. In an attempt to shed further light on the entry date of the C1 lineage into the Icelandic mtDNA pool and its geographical origin, we used the deCODE Genetics genealogical database to identify additional matrilineal ancestors that carry the C1 lineage and then sequenced the complete mtDNA genome of 11 contemporary C1 carriers from four different matrilines. Our results indicate a latest possible arrival date in Iceland of just prior to 1700 and a likely arrival date centuries earlier. Most surprisingly, we demonstrate that the Icelandic C1 lineage does not belong to any of the four known Native American (C1b, C1c, and C1d) or Asian (C1a) subclades of haplogroup C1. Rather, it is presently the only known member of a new subclade, C1e. While a Native American origin seems most likely for C1e, an Asian or European origin cannot be ruled out.
The paper trail, the famously well-kept genealogical records of Iceland, go back only to the very beginning of the 18th century. Could the woman with these rare subclade have predated this time, substantially? It's possible.
Because of Iceland’s Lutheran Christian heritage the maternal lineage here could be traced back to 1700. This does not mean that the first woman in the line that we know of was born like Athena from the head of her father; rather, the records were not kept well enough to continue unbroken back to the medieval era. We do know that the first permanent Norse settler in Iceland arrived in 874, and, that very few immigrants from Scandinavia added diversity to the gene pool after ~1000. Iceland is a small and poor island, so quickly reached its Malthusian maximum. How else to explain that Icelanders made a secondary migration to Greenland?Vinland
The most obvious explanation for the existence of the subclade of the C1 lineage is that it arrived recently. Without knowing anything else that is what you’d have assumed. But as noted above the individuals who carry it have been traced back to a common ancestor in the early 18th century; these are native Icelanders, at least if native means anything substantive. An second point which rejects recent injection of this lineage into the gene pool: the Icelanders are their own special branch of C1, C1e. The phylogenetic tree of C1 below illustrates the relationship of the branches to each other. Since the font is so small, I added in clarifying labels (from top to bottom it’s C1a to C1e, with further clades such as C1d1):
[. . .]
If the Greenland and ancient European hypotheses are rejected, what we have is a woman who entered the Icelandic society from an extinct lineage of Native Americans, probably from the northeast (or perhaps her Greenland Norse mother was of this line). What the Norse would have termed Markland. It is tempting to point to the Norse settlement at L’Anse aux Meadows in Newfoundland. Perhaps the Europeans had enslaved a native woman, and taken her back to their homeland when they decamped? But more likely to me is the probability that the Norse brought back more than lumber from Markland, since their voyages spanned centuries.
is the most famous of the three territories chronicled by the Vikings, a territory that seems to encompass the Gulf of St. Lawrence basin (Atlantic Canada and eastern Québec), but with the main nucleus at'L'Anse aux Meadows
in northern Newfoundland. If a woman of First Nations background did come to contribute her genes to the Icelandic gene pool--perhaps via Greenland?--she may have come from this area, with its relatively clement weather and denser populations. The extinct Beothuk people
of the island of Newfoundland may well have been genetically unique, owing to the very small population size. How likely is it, however, that a representative of a First Nations group in perennial conflict with the Vikings would have lived long enough to produce a child of mixed background, and that this child, in turn, would be accepted into an ethnocentric Viking community?
The other two territories in North America chronicled by the Vikings were Helluland
(likely Nunavut's Baffin Island, facing Greenland from across the Davis Strait) and Markland
. At the time of the Viking visits these two regions were populated by two groups: the Dorset culture
that predated the modern Inuit seems to have been present only in what is now Nunavut and northernmost Labrador, with the Innu
predominating in the rest of the territory. Markland seems to have received multiple visits by Greenlanders who established temporary communities and cut down timber for use in Greenland. Did the greater and more sustained presence of Greenlanders in Labrador lead to at least one successful intermarriage between a Viking male and an Innu (or Dorset) female that left descendants? Razib's conclusion makes a fair amount of sense to me