Neanderthal Origin of the Haplotypes Carrying the Functional Variant Val92Met in the MC1R in Modern Humans
Qiliang Ding et al.
Skin color is one of the most visible and important phenotypes of modern humans. Melanocyte-stimulating hormone and its receptor played an important role in regulating skin color. In this paper, we present evidence of Neanderthal introgression encompassing the melanocyte-stimulating hormone receptor gene MC1R. The haplotypes from Neanderthal introgression diverged with the Altai Neanderthal 103.3 KYA, which postdates the anatomically modern human – Neanderthal divergence. We further discovered that all of the putative Neanderthal introgressive haplotypes carry the Val92Met variant, a loss-of-function variant in MC1R that is associated with multiple dermatological traits including skin color and photoaging. Frequency of this Neanderthal introgression is low in Europeans (~5%), moderate in continental East Asians (~30%), and high in Taiwanese aborigines (60-70%). Since the putative Neanderthal introgressive haplotypes carry a loss-of-function variant that could alter the function of MC1R and is associated with multiple traits related to skin color, we speculate that the Neanderthal introgression may have played an important role in the local adaptation of Eurasians to sunlight intensity.
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3 comments:
"we speculate that the Neanderthal introgression may have played an important role in the local adaptation of Eurasians to sunlight intensity".
That, in itself is not surprising. What is surprising is this:
"Frequency of this Neanderthal introgression is low in Europeans (~5%), moderate in continental East Asians (~30%), and high in Taiwanese aborigines (60-70%)".
Difficult to make sense of that.
If Neanderthals had 600,000 years of cold adaptation including - if they moved inland away from seafood - a need for lighter skin for vitamin D then I think this should always have been expected.
It looks like fairly random drift to me. Note that the Japanese have the supposedly Neanderthal variant at only Northern European level, and the Cambodians have the supposedly Neanderthal variant at only South Asian/Southwest Asian/Southern European level. I cannot envision a scenario by which the Japanese and the Cambodians would have either a much lower level of Neanderthal introgression than Taiwan aborigines and other East Asians or have experienced significantly different selective pressures.
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