Update: Per the supplementary material, the sample sizes for Finland, Slovakia, and Ukraine are only 1 each, and 6 for Russia.
Nature advance online publication 31 August 2008 | doi:10.1038/nature07331; Received 30 May 2008; Accepted 12 August 2008; Published online 31 August 2008Also of interest, from the gnxp post:
Genes mirror geography within Europe
John Novembre et al.
Understanding the genetic structure of human populations is of fundamental interest to medical, forensic and anthropological sciences. Advances in high-throughput genotyping technology have markedly improved our understanding of global patterns of human genetic variation and suggest the potential to use large samples to uncover variation among closely spaced populations1, 2, 3, 4, 5. Here we characterize genetic variation in a sample of 3,000 European individuals genotyped at over half a million variable DNA sites in the human genome. Despite low average levels of genetic differentiation among Europeans, we find a close correspondence between genetic and geographic distances; indeed, a geographical map of Europe arises naturally as an efficient two-dimensional summary of genetic variation in Europeans. The results emphasize that when mapping the genetic basis of a disease phenotype, spurious associations can arise if genetic structure is not properly accounted for. In addition, the results are relevant to the prospects of genetic ancestry testing6; an individual's DNA can be used to infer their geographic origin with surprising accuracy—often to within a few hundred kilometres.
These authors also develop a model that does reasonably well at predicting the country of origin of an individual based on genetics alone.
[ . . .]
The method the authors develop for predicting an individual's country of origin from genetics are only a beginning for this kind of application of genetic data. They note that the SNP chip used in the study only includes common variation, while rare variants are likely to be much more geographically restricted (and thus more informative in this kind of analysis). The limits to the resolution of these sorts of methods are likely to be very fine indeed; the authors note that, even with this panel, they're able to distinguish with some confidence individuals that are from the German, Italian, and French-speaking parts of Switzerland. With full resequencing data, it's likely that even the precise village of origin of an individual will be predictable from genetics alone.