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Thread: Skin depigmentation alleles in Native Americans

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    Skin depigmentation alleles in Native Americans



    This is another reporter who seems to have not done his homework. We've known since 2007 that East Asians underwent convergent evolution for depigmentation.

    Didn't know which ones were present in Native Americans, however.


    https://www.sciencemag.org/news/2019...ave-light-skin

    "Now, a new study of the genes of more than 6000 people from five Latin American countries undercuts the simplistic racial assumptions often made from skin color. An international team discovered a new genetic variant associated with lighter skin found only in Native American and East Asian populations. That means that in Latin America, lighter skin can reflect Native American as well as European ancestry."

    "
    Latin America is fertile ground for such studies. People there often have Native American, European, and African ancestors, and because Native American populations are closely related to those from East Asia, researchers can also spot East Asian variants in Latin American genomes. “You get, in one place, the genetic variation from four different continents,” says statistical geneticist Kaustubh Adhikari of University College London.He and Javier Mendoza-Revilla, a geneticist at the Pasteur Institute in Paris, analyzed the genomes of 6357 people from Brazil, Colombia, Chile, Mexico, and Peru, collected by the Consortium for the Analysis of the Diversity and Evolution of Latin America (CANDELA). The consortium also measured how much light reflected off participants’ skin, a way of gauging their levels of the dark pigment melanin. That allowed Adhikari and Mendoza-Revilla to look for genetic variants linked to skin tone.
    One variant was on MFSD12. Tishkoff recently linked reduced expression of this gene with darker skin in Africans. The new MFSD12 variant, however, is associated with lighter skin, and might instead enhance the gene’s expression, Adhikari and Mendoza-Revilla report this week in Nature Communications. When they looked for the variant in other populations, they found it only in Native Americans and East Asians.
    So the new variant sheds light on the genes underlying pale skin in East Asia. People at high latitudes in Europe and East Asia seem to have independently evolved lighter skin to produce vitamin D more efficiently with less sunlight, says Nina Jablonski, a biological anthropologist at Pennsylvania State University in University Park. "

    This is the original Heather L. Norton et al paper. There are global maps for the distribution of the major de-pigmentation genes, minus this new one.
    https://www.researchgate.net/publica...nd_East_Asians

    It's a good review for everyone.

    This is the actual new paper.

    See:


    "A GWAS in Latin Americans highlights the convergent evolution of lighter skin pigmentation in Eurasia"

    "We report a genome-wide association scan in >6,000 Latin Americans for pigmentation of skin and eyes. We found eighteen signals of association at twelve genomic regions. These include one novel locus for skin pigmentation (in 10q26) and three novel loci for eye pigmentation (in 1q32, 20q13 and 22q12). We demonstrate the presence of multiple independent signals of association in the 11q14 and 15q13 regions (comprising the GRM5/TYR and HERC2/OCA2 genes, respectively) and several epistatic interactions among independently associated alleles. Strongest association with skin pigmentation at 19p13 was observed for an Y182H missense variant (common only in East Asians and Native Americans) in MFSD12, a gene recently associated with skin pigmentation in Africans. We show that the frequency of the derived allele at Y182H is significantly correlated with lower solar radiation intensity in East Asia and infer that MFSD12 was under selection in East Asians, probably after their split from Europeans."

    https://www.nature.com/articles/s41467-018-08147-0


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    Good to finally see a study on the skin pigmentation genetic architecture of Native Americans. I was curious about it, especially if they were very similar to the East Asians on it. It seems to me then that by the time ANE contributed heavily to the Paleo-Amerinds the selection for any of the two main light skin alleles of West Eurasians hadn't begun yet.

    But, yes, it's quite disheartening to see a report in a science magazine which presumably ignored that we've known that light skin evolved differently in East Eurasians since several years ago.

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    1 out of 1 members found this post helpful.
    Quote Originally Posted by Ygorcs View Post
    Good to finally see a study on the skin pigmentation genetic architecture of Native Americans. I was curious about it, especially if they were very similar to the East Asians on it. It seems to me then that by the time ANE contributed heavily to the Paleo-Amerinds the selection for any of the two main light skin alleles of West Eurasians hadn't begun yet.

    But, yes, it's quite disheartening to see a report in a science magazine which presumably ignored that we've known that light skin evolved differently in East Eurasians since several years ago.
    The Heather Norton paper from 2007 has some great maps and shows that East Asians have selection on OCA2 which Amerindians don't share, which ties in with your point.

    Those maps also show differences between North Amerindians and Amazonians. Selection on these alleles is very strong and quite fast as human history goes.

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