Researchers have a clearer picture of Neanderthal evolution than ever before; and it's helping them determine how and where certain traits developed.
Scientists recently determined that humans and Neanderthals occasionally interbred; they made this discovery by revealing that "accumulation of elements of Neanderthal DNA" is found in about five percent of all humans, a Molecular Biology and Evolution (Oxford University Press) news release reported.
Researchers found evidence of Neanderthal DNA in Chromosome 3, which contains 18 genes. A number of the genes, such as the Hyal2 gene, are associated with UV-light adaptation.
This gene was especially prevalent in East Asians; 49 percent of Japanese individuals and 66 percent of southern Chinese were believed to have been enriched with the gene.
The researchers said "geographic distribution of the Neanderthal genomic region" suggests that humans lost their adaptation to UV-light when they left Africa in ancient days; but Eurasians may have reproduced with Neanderthals, reintroducing the trait.
"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," Li Jin, a researcher in the study, said. "Although in the case of the Hyal2 variant, it did indeed have a higher frequency in Asians."
Between 5,000 and 45,000 years ago there was a steady increase in Neanderthal population size. This suggests a population expansions event occurred at some point.
"This Asian-specific Neanderthal evolutionary event is also consistent with previous reports of higher levels of Neanderthal ancestry in East Asians than in Europeans," the news release reported.
The research was published in Molecular Biology and Evolution.
Recent unrelated studies have found Neanderthals may been more advanced than we had previously believed.
Neanderthal bones were found buried in graves in Europe, and the remains looked as if they had been protected from recently after their dearth until the present day, a New York University news release reported.
"While we cannot know if this practice was part of a ritual or merely pragmatic, the discovery reduces the behavioral distance between them and us." William Rendu, the study's lead author and a researcher at the Center for International Research in the Humanities and Social Sciences (CIRHUS) in New York City, said.
