What DNA Says About Aryan Invasion Theory -2

[G.Subramaniam]

The A variant is derived, while the G is ancestral. That is, a mutation from G → A occurred at some point in the past, and A increased in frequency in a subset of the world’s populations. When did the increase in frequency occur? It seems fairly recently, Voight et. al. picked up a signature of selection around SLC24A5 though it is nearly fixed in Europeans and so is not an ideal target for their methods (which tend to be best at detecting partial sweeps). This would imply a time scale of less than 10,000 years. Another researcher has reported that the SNPs around SLC24A5 imply a selective event as recent as 5,800 years before the present! I’ve heard from people looking at the frequencies on other populations besides Europeans that a) it is extant at high frequencies across North Africa and Western Asia and <img src='http://www.india-forum.com/forums/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='B)' /> there is a signature of selection.

There is of course one population which I’ve talked about in regards to SLC24A5 already, and that’s South Asians. It seems that about 1/3 of the variation in skin color within this group can be explained by polymorphism on this gene; that’s around the same range as the between-group difference for Africans and Europeans.