New study finds skin pigmentation gene is shared across the globe

The first large-scale study of the genetics of skin color in Africans was published in the journal Science on Oct. 12 — identifying new regions of the human genome that are associated with skin color variation in African populations and throughout the world.

According to the study, there are eight genetic variants in humans that can influence skin pigmentation to make it lighter or darker. The variants, which date back over 300,000 years, have been identified not only in Africa, but throughout the world.

Sarah Tishkoff, a geneticist at the University of Pennsylvania who spearheaded the study, has been researching indigenous African populations since the early 2000s. She said she was interested in pursuing this research because many people aren’t aware of the diversity in skin pigmentation in Africa alone.

“This was the first study of indigenous African populations and on what the cause is of differences in skin color in Africa,” Tishkoff said. “We weren’t necessarily expecting that we were going to find totally new genes — that was a big surprise.”

Nicholas Crawford, a postdoctoral researcher at the University of Pennsylvania and a co-author of the new study, also expressed surprise at the findings.

“The fact that we identified genes that are associated with dark pigmentation is pretty brand new to us,” he said. “Up until this study there wasn’t any chief reporting that it was a functional variant and that if you changed it, it would change skin color or pigmentations.”

While this study is very indicative of genetic diversity in skin pigmentation in Africa and around the world, Tishkoff and Crawford were never intending to bring forward conversations surrounding race through their research.

“The focus of our paper was nothing to do with race, it was on biology and the genetics of skin color,” Tishkoff said. “But when you start talking skin color and Africa and genetics, people start thinking about race.”

Mosi Ifatunji, a UNC sociology professor, also said many people often tend to unfairly lump together skin color and race. 

“It wasn’t until the real rise of the enlightenment in the 1700s that we began to look for evidence of discrete populations by observing the body,” he explained. “And that sort of caught on and became the way that we generally wanted to go about marking and identifying discrete populations.”

Ifatunji said when talking about racial groups, we tend to refer to race and skin color synonymously. He said skin color has not ever been entirely indicative of racial classification — not even in the United States.

Race, according to Ifatunji, must at a minimum take into account facial bone structure, hair texture, language, religion and nationality. Skin color is only one potential component of race, and not a very reliable one at that. 

"The public has a particular understanding about race," he said. "And I think it’s unfortunate that our media outlets are more concerned with meeting people where they are on their understanding than it is with providing something that is less colloquial and more — for lack of a better term — accurate."

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