Do you tan easily? It could be your Neanderthal DNA

Thousands of years ago when humans met they had sex and had children. From this union of two species we have inherited 2% of our DNA from them.

Some of this DNA has helped with our immunity and has contributed to some modern disease. Studies have shown that human genes involved in skin and hair biology were strongly influenced by Neandertal DNA but it hadn’t been clear how.

Janet Kelso at the Max Planck Institute for Evolutionary Anthropology in Germany wanted to uncover the “influence Neandertal DNA might be having on ordinary variation in people today.”Ms Kelso stated  “We can now show that it is skin  tone, and the ease with which one tans, as well as hair color that are affected,” Kelso says.

The researchers observe multiple different Neandertal alleles contributing to skin and hair tones. What they found somewhat surprising is that some Neandertal alleles are associated with lighter skin tones and others with darker skin tones. The same was true for hair color.

“These findings suggest that Neandertals might have differed in their hair and skin tones, much as people now do” adds Michael Dannemann, first author of the study.

“Skin and hair color, circadian rhythms and mood are all influenced by light exposure,” the researchers wrote. “We speculate that their identification in our analysis suggests that sun exposure may have shaped Neandertal phenotypes and that gene flow into modern humans continues to contribute to variation in these traits today.”

Kelso and her colleagues say they’ll continue to explore Neandertals’ influence on modern-day traits as more data becomes available.