Thursday, September 21, 2006
Identifying genes underlying skin pigmentation differences among human populations:
There are many posts about skin color in the GNXP archives. This should not surprise. The fact that SLC24A5 was positively selected for in Europeans and correlates with light skin, but remains ancestral in both Africans and East Asians, while the Arg163Gln variant of MC1R seems under selection in East Asians, but under relaxed selection or possibly diversifying selection in Europeans suggests that different genetic strategies are scaling the same phenotypic fitness landscape. Additionally, two different strategies suggests to me that gene flow has been low enough so that one best case strategy (i.e., the highest fitness peak in a large admixing population) isn't automatically selected across Eurasia across the common genetic background. You know what they say, selection is stochastic....