The surprising reason why some Latin Americans have light skin

Undercutting the simplistic racial assumptions often made from skin color.


For a long time, individuals have accepted that the variation in skin colors originates from the meeting and mixing of Native Americans, Europeans, and Africans amid colonial times and later. Individuals with lighter skin are thought to have increasingly European ancestry, while those with darker skin are taken to have progressively Native American or African ancestry—and are frequently focused for discrimination.

A new study conducted on almost 6000 people from five Latin American countries undercuts the simplistic racial assumptions often made from skin color.

Scientists discovered a new genetic variant associated with lighter skin found only in Native American and East Asian populations. It suggests that in Latin America, lighter skin can reflect Native American as well as European ancestry.

Scientists analyzed the genome 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). By measuring how much light reflected off participants’ skin, they were able to gauge the levels of the dark pigment melanin. Doing this, they observed genetic varients 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. When they looked for the variant in other populations, they found it only in Native Americans and East Asians.

Nina Jablonski, a biological anthropologist at Pennsylvania State University in University Park said, “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. But, People have been scratching their heads about which variants do this in East Asians. Now, researchers know MFSD12 is one.”

“The ancestors of Native Americans presumably carried that variant over the Bering Strait into the Americas. There was variation [in skin tone] present in Latin America long before Europeans got there.”

Geneticist Andrés Ruiz-Linares of Fudan University in Shanghai, China, chair of CANDELA said, “The larger lesson, is the pitfalls of a Eurocentric view. Our study shows that going beyond Europeans one can find additional genes, even for well-studied traits. Clearly, the bias towards Europeans has led to a restricted view of human diversity.”

Human geneticist Sarah Tishkoff of the University of Pennsylvania Perelman School of Medicine said, “It’s a really important study,” especially because little genetic research has been done on Latin American populations. Most work on skin pigmentation genes has been done on Europeans, where ironically we don’t see a lot of variation. One of the last frontiers has been, ‘What about East Asians and Native Americans?'”

The report is published in the journal Nature Communications.

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