'Dark-Skinned' Cheddar Man Was Just A Wild Guess

A Briton who lived 10,000 years ago had dark brown skin and blue eyes. At least, that’s what dozens of news stories published this month – including our own – stated as fact. But one of the geneticists who performed the research says the conclusion is less certain, and according to others we are not even close to knowing the skin colour of any ancient human.

[...]In November 2017, [Brenna Henn at Stony Brook University, New York] and her colleagues published a paper exploring the genetics of skin pigmentation in populations indigenous to southern Africa – where skin colour varies more than many people appreciate. Just weeks before, a group led by Sarah Tishkoff at the University of Pennsylvania in Philadelphia had published a paper on the genetics of skin pigmentation in people from eastern and southern Africa.

“The conclusions were really the same,” says Henn. “Known skin pigmentation genes, discovered primarily in East Asian and European populations, don’t explain the variation in skin pigmentation in African populations. The idea that there are really only about 15 genes underlying skin pigmentation isn’t correct.”

It now seems likely that many other genes affect skin colour. We don’t know how.

If we are still learning about the link between genes and skin pigmentation in living populations, we can’t yet predict the skin colour of prehistoric people, says Henn.

[...]Henn’s team has tested an older model that aimed to predict skin colour from DNA. When they put it to work among southern African populations, “it literally predicted that people with the darkest skins would have the lightest skin.”