Icelandic C1 distinct from Amerindian and Asian subclades

A new subclade of mtDNA haplogroup C1 found in icelanders: Evidence of pre-columbian contact?

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. Am J Phys Anthropol, 2010.

The logic and evidence behind the authors' assertion that "a Native American origin seems most likely" is wanting; I find it much more likely C1 entered Iceland via Europe. Scientists will need to look elsewhere to explain Björk.

The 11 mutations that differentiate the Icelandic C1 sequences from the C1 root are in the upper range of mutation counts that differentiate the other C1 sequences from the root. [. . .]

A simple [polite way of saying retarded] argument in favor of a Native American origin of C1e is the fact that three of the four previously characterized C1 subclades are associated with these groups and the vast majority of C1 sequences in the literature have been sampled from individuals of Native American ancestry. [. . .]

The German sequence (Pfeiffer et al., 2001) represents a perfect match to the Icelandic C1e for the short HVS1 fragment spanning sites 16024–16365. This raises the intriguing, but perhaps unlikely, hypothesis that C1e is a European-specific subclade of C1, following the precedent of the European and Native American subclades of mtDNA haplogroup X2 (Brown et al., 1998; Reidla et al., 2003). However, given the dense sampling of mtDNA variation in European populations, it is clear that C1e is exceedingly rare, a fact that weighs against a hypothesis of antiquity in Europe.

The frequency of C1 in a sample of 1538 Icelandic mtDNA sequences was 0.26%. Coincidentally, another abstract that recently appeared in PubMed is that of a Russian publication reporting:

The role of natural selection in the evolution of human populations from Northeastern Eurasia was studied. Selection for the regions-specific haplogroup C was demonstrated.