October 18, 2017
Researchers from the University of Pennsylvania conducted the first-ever large-scale study of skin color genetics in Africans, finding that the genetic variations that cause different skin pigments actually far predate any human life as we know it.
What’s more, the eight genetic variations studied are actually present in different populations throughout the world, not confined to one specific race of people.
Studies of genetic variants influencing pigmentation had already yielded familiar results for what causes paler skin, present in a majority of Europeans. That gene, SLC24A5, became widespread only within the last few thousand years – relatively recent compared to other genetic variants.
Dr. Sarah A. Tishkoff, a geneticist at the University of Pennsylvania, led a study of 1,570 Africans from Ethiopia, Tanzania and Botswana. Throughout the research, the mysterious gene variant MFSD12 was discovered to produce a darker skin color.
That gene variant is one of eight that Tishkoff and her colleagues discovered in Africans, all of which far predated the rise of Homo sapiens. One variant arose as long as 900,000 years ago, for example.
Because the genes are so widespread, present in so many populations across the world and preserved for so many thousands of years, Tishkoff asserts the discovery essentially “dispels a biological concept of race,” she told The New York Times.
Tishkoff’s discoveries also complicate a long-held theory among researchers that skin pigmentation is an evolutionary result of exposure to sunlight. The new research would mean that darker-skinned people in regions outside of Africa, like southern India or Australia, didn’t just evolve that way due to sunlight but also inherited the gene variant that creates a darker pigment from Africans.
“They had to be introduced from an African population,” Tishkoff told the Times. This theory also applies to paler-skinned people in other regions – those gene variants also came from Africa.
Learn more and check out the full research article published this month in Science.