A portion, also known as region, of Neanderthal DNA related to sunlight adaption was selected and enriched in East Asians, a study published in Molecular Biology and Evolution found.

The researchers identified evidence of the accumulation of a Neanderthal DNA region on chromosome 3 containing 18 genes, several of which are related to UV-light adaptation - including the Hyal2 gene.

In all, the genomic region was found in some 49 percent of of Japanese and 66 percent of those in Southern Chinese.

The geographic range of the Neanderthal genomic region indicates that UV-light mutations were lost when modern humans first left Africa roughly 80,000 years ago, and later reintroduced by Neanderthals to Eurasians, the researchers said.

"Overall, it is still very controversial whether there is more Neanderthal DNA contributions to Asians than Europeans, as we have evidence to argue against this," co-author Li Jin, a geneticist from Fudan University in China. "Although in the case of the Hyal2 variant, it did indeed have a higher frequency in Asians."

The study comes nine months after German researchers used the remains of a toe bone discovered in a Siberian cave to complete the first high-quality sequencing of a Neanderthal genome, which they promptly made available on the Internet.

This work has fueled research around the world on the ancient human ancestors.

In November, for example, scientists pointed to updated genome sequences from Neanderthals as well as one belonging to another ancient group known as Denisovans as evidence that the two interbred with humans and each other much more liberally than previously believed. What's more, the scientists, speaking at the Royal Society in London, said the evidence suggests another, previously unknown human ancestor from Asia was apparently in on the action.