Monday, October 17, 2011

Pigmentation genetics of Europeans


The maps below are based on three genome-wide SNPs showing high correlation with blue and green eyes and/or fair hair in Europeans. The results obviously suggest that there's an increase in hair and eye blondism from south to north in Europe, with clear peaks east of the Baltic Sea. The three SNPs are rs1667394 (HERC2 gene), rs12913832 (OCA2 gene), and rs12896399 (SLC24A4 gene).





Indeed, I'm a bit taken aback by the very high rate of suggested blondism among the Belorussians and Mordvinians (second highest dot in Russia). This might have something to do with sampling bias. Perhaps most of the 12 Belorussians and 16 Mordvinians used here came from fairer than average communities within their respective nations? I have no idea. In any case, I don't think the picture is too far from reality, because multiple sampling sites from the same general biogeographic zones, but several hundred kilometers apart, are showing very similar results. This can't be a coincidence.

It's also interesting to note that the East Baltic peak in blondism genotypes correlates closely with the North + East European genome-wide ancestral component in my latest ADMIXTURE experiment (see here). Perhaps this is where natural selection for these traits was most extreme due to very specific environmental pressures, like lack of sunlight? Maybe this is also where these traits spread from, either gradually or during one or several major migrations? Someone should look into that. Meantime, I'll try and update this post with new maps as more samples come in.

7 comments:

  1. Population Erzya and Moksha are around the north-Caucasoid populations of Eastern Europe. Scientifically proven that some of the most Erzya light pigmentation of the peoples of Eastern Europe. The results of your analysis confirm the research of anthropologists.

    ReplyDelete
  2. INDEX OF PIGMENTATION

    http://4.bp.blogspot.com/_mlcDtA_ehB8/TEn2di83MNI/AAAAAAAAASM/-RR2GtOJ-5w/s1600/pigmentation-index.png

    ReplyDelete
  3. SNPEDIA says allele associated with Fair hair in rs12896399 is G, not T.
    Perhaps snpedia is wrong... or the image above...

    ReplyDelete
  4. Right, so the allele associated with fair hair would be most common in the Near East not Northern Europe.

    Yeah, makes sense.

    ReplyDelete
    Replies
    1. Of course it does not make sense and that's not what im suggesting.
      I just saw a inaccuracy between information provided by snpedia and information written on map above. Someone made a mistake on typing the correct allele and would be nice to find what's the correct one.

      Delete
    2. You can also update this excellent analysis with the KITLG gene (rs12821256) associated with blonde hair on europeans:https://www.nature.com/articles/ng.3019#f1
      It was identified some years after you posted this article.

      Delete

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