Black and white, they've coexisted as early as 900,000 years ago.
Nicholas Crawford and Sarah Tishkoff at the University of Pennsylvania in Philadelphia took around 1500 DNA samples from ethnically and genetically diverse volunteers living in Ethiopia, Tanzania and Botswana. They've also measure participants' skin pigmentation.
With this, researchers were able to accumulate eight sites in the human genome particularly associated with skin pigmentation's level. That's about 30 per cent variation from volunteers' skin pigmentation!
Also, there a genetic variant associated with both pale and dark skin were found. Seven of the former emerged at least 270,000 years ago, with four of these emerging more than 900,000 years ago. This means that while it is thought that Homo sapiens arose in Africa about 300,000 years ago, dark skin tones may have evolved from paler genetic variants! (WTF!)
“They (geneticists) thought [MC1R] shows that there has been selection for dark skin in Africa and therefore there’s no variation,” says Tishkoff.
“I think the most interesting observation is that some ancestral light skin alleles are shared between the San and archaic hominins such as Neanderthals and Denisovans,” says Carles Lalueza-Fox at the Institute of Evolutionary Biology in Barcelona, Spain. “This suggests a shared, common ancestry for this trait before the split of these three hominin lineages.”
“People have thought it was just light skin that has been evolving,” says Tishkoff. “I think dark skin continues to evolve as well.”
“There are racists who want to associate skin pigmentation with intellectual traits or traits dealing with moral behaviour,” says Nina Jablonski at Pennsylvania State University. But “variants associated with whiter skin actually came from Africa,” says Tishkoff.
If this doesn't stop you from being racist and a spoiled white supremacist, I don't know what will.
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