Figure S3 contains the results of the STRUCTURE analysis (from K=2 top row). The broad results are consistent with similar past analyses, but many populations that were previously not examined in the global context are included. You can probably discern many interesting features with your magnifying glass, but I will limit myself to a handful:
- Greeks from northern Greece (#15) and Cyprus (#9) appear fairly unremarkable in their genetic makeup; indeed most Europeans appear similar in this broad global context
- The small sample of 4 Turks (#38) shows a small membership in "Asian" clusters, although these appear to be mostly of the "Central/South Asian", rather than the "East Asian" variety. This probably makes them similar somewhat to the Adygei from the Caucasus in a previous analysis. This element does not, however, seem to be very important in Near Eastern Semitic populations included in the HGDP panel, so it would be interesting to see how the transition from European to Central/South Asian Caucasoids occurs in Transcaucasia, Iran, and the various -stans.
- CEU Utahns seem to lack the "purple" component altogether (bottom row), and in this they are most similar to Britons and Iberians, perhaps signifying a peculiarity of Western-most populations in Europe.
Table S5 shows the percentage of haplotypes shared between different European regions and the African Yoruba (YRI) sample.
Most European regions are within 0.12% of each other, but Southwest Europe has an elevated percentage of 5.52% of 0.3% higher than the next highest percentage. Thus, the hypothesis of a separate influence in Iberia from Africa that did not pass from east-to-west seems reasonable.
However, the STRUCTURE analysis (see above) does not indicate a substantial presence of the Yoruba (dark green) element anywhere in Europe, consistent with the recent paper of Tishkoff et al. It appears more likely that the similarity is due to a (as of yet unsampled) element common to both populations, perhaps of North African or other intermediate origin.
In conclusion, this is a very interesting paper (of great interest for South Asia and the Americas as well, not covered in my post), as it furthers our understanding of the global distribution of genetic diversity. It would be wonderful to combine such a comprehensive global dataset with the substantial African one of the Tishkoff paper, but unfortunately the different types of markers genotyped make it at present impossible.