DNA analysis studies published in Nature and Science showed that humans are part Neanderthals.
When modern humans moved out of Africa into Eurasia about 100,000 years ago, they found Neanderthals already living there. They’ve probably made war with each other, but it’s now certain that they made love: their offspring, the people of Europe and Asia, have 1 to 4 percent Neanderthal DNA.
Despite using different methodologies, both two studies pointed to part of the human genome that affect skin and hair as being part Neanderthal. “The idea is that maybe Neanderthals carried versions of alleles [genetic variants] for these genes that were well-adapted to their environment,” Harvard Medical School’s Sriram Sankararaman, told NBC News.
Geneticist Joshua Akey of University of Washington added, “It’s a pretty fascinating way of adapting to an environment. Instead of resting on your laurels, waiting for an adaptation to appear, you just pick one up from the local population.”
But not all of the Neanderthal DNA is actually good for humans: National Geographic reported that Neanderthal genetic variants have been linked to various diseases including lupus, biliary cirrhosis, Crohn’s disease and type 2 diabetes. Indeed, both teams found that there are long stretches of human DNA that’s completely devoid of Neanderthal sequences, suggesting that some Neanderthal genes were actually bad and therefore got purged out of the human genome over hundreds of generations.