The mitochondrial lineage U8a reveals a Paleolithic settlement in the Basque country

The mitochondrial lineage U8a reveals a Paleolithic settlement in the Basque country
Ana M González1 , Oscar García2 , José M Larruga1  and Vicente M Cabrera1

Published: 23 May 2006

Background
It is customary, in population genetics studies, to consider Basques as the direct descendants of the Paleolithic Europeans. However, until now there has been no irrefutable genetic proof to support this supposition. Even studies based on mitochondrial DNA (mtDNA), an ideal molecule for constructing datable maternal genealogies, have failed to achieve this. It could be that incoming gene flow has replaced the Basque ancient lineages but it could also be that these lineages have not been detected due to a lack of resolution of the Basque mtDNA genealogies. To assess this possibility we analyzed here the mtDNA of a large sample of autochthonous Basques using mtDNA genomic sequencing for those lineages that could not be unequivocally classified by diagnostic RFLP analysis and control region (HVSI and HVSII) sequencing.
Results
We show that Basques have the most ancestral phylogeny in Europe for the rare mitochondrial subhaplogroup U8a. Divergence times situate the Basque origin of this lineage in the Upper Palaeolithic. Most probably, their primitive founders came from West Asia. The lack of U8a lineages in Africa points to an European and not a North African route of entrance. Phylogeographic analysis suggest that U8a had two expansion periods in Europe, the first, from a south-western area including the Iberian peninsula and Mediterranean France before 30,000 years ago, and the second, from Central Europe around 15,000–10,000 years ago.

Conclusion
It has been demonstrated, for the first time, that Basques show the oldest lineages in Europe for subhaplogroup U8a. Coalescence times for these lineages suggest their presence in the Basque country since the Upper Paleolithic. The European U8 phylogeography is congruent with the supposition that Basques could have participated in demographic re-expansions to repopulate central Europe in the last interglacial periods.

I’ll read this one a bit more thoroughly when the kids calm down.

One response to “The mitochondrial lineage U8a reveals a Paleolithic settlement in the Basque country

  1. This is a classical. If I don’t recall badly most of the known carriers of U8a are Basque. U8a is obviously a sublcade of U8, which also includes U8b, of which rather common haplogroup K is a subclade. U8b(xK) appears to be a West Asian or Mediterranean clade, with cases in Jordan and Italy.

    I link this with the issue of the apparent old age of haplogroup U (whose movement towards Europe possibly happened with Aurignacian) and the high diversity of U6 in Iberia, the highest of all by large. A clade on which we have discussed before: I suspect it to be an Aurignacian or Gravettian founder effect in Iberia, as U8a is among Basques, and to have expanded towards Africa much the same that U8a expanded towards Central Europe, just that in somewhat larger apportion.

    It also makes me wonder about the origins and history of the important haplogroup K, the most common U8 subclade: when did it arrive to Europe (and North Africa), in the Neolithic or in the Paleolithic?

    And makes me wonder as well about why U5 is more common in Eastern than Western Europe, in spite that Eastern Europe was never Aurignacian (so it may have arrived with Gravettian from a Central European source?)

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