For nearly 10 years, scientists believed that Neanderthal genes are present in modern-day Europeans, Asians and their descendants. However, a recent study has revealed that an unexpectedly large amount of Neanderthal ancestry in modern populations of Africans. The study also suggests that most of the DNA came from Europeans migrating to Africa nearly 20,000 years ago.
According to anthropologists from Max Planck Institute for Science and Human History, it is an important discovery as it was known gene flow of Neanderthals have existed in all modern humans, but knowing that it exists inside and outside Africa is a 'novel and elegant finding'. Furthermore, the recent work has also put light on the mysterious disparity of why the East Africans appear to have more Neanderthal ancestry than Europeans.
Members of Homo Sapiens spread from Africa into Eurasia nearly 70,000 years ago and that it when they mingled with the Neanderthals. Researchers had already known that later back-migrants of Europeans had introduced some parts of Neanderthal DNA into the African populations, but previous work suggested that it was just a smidgen. On the contrary, modern Europeans and East Asians supposedly inherited nearly two per cent of their DNA from Neanderthals.
However, even though assumptions said that Africans have negligible DNA of the early humans, in order to get more reliable numbers, Princeton University evolutionary biologist Joshua Akey reportedly compared the genome of a Neanderthal from Russia's Altai region in Siberia which was sequenced in 2013 with the world that includes five Africans subpopulations. After getting the genomes, the researchers then calculated the probability that each stretch of DNA was inherited from a Neanderthal ancestor.
Researchers also found that on average, African individuals have significantly more Neanderthal DNA than previously thought which was about 17 megabases or 0.3 per cent of their genome. Furthermore, it has also been found the Neanderthal DNA is responsible for boosting immune function and protection against ultraviolet radiation.