Disease Genes In Human Came From Neanderthals
Genes that influence various diseases in humans at present are from interbreeding with Neanderthals, according to a new study.
Neanderthals passed on variants of genes that influences diseases like type 2 diabetes, Crohn's disease and also smoking addiction.
The study revealed that the species Homo sapiens mated with them after leaving Africa. Prior to this study it was unclear what Neanderthal DNA did to human health.
Statistically, between 2 percent and 4 percent of the genetic blueprint of present-day non-Africans are from Neanderthals.
Researchers screened genomes of more than thousand modern humans and identified regions that carried the Neanderthal versions of different genes.
The Neanderthal ancestry has been discovered in regions of the genome that were linked to the regulation of skin pigmentation.
"We found evidence that Neanderthal skin genes made Europeans and East Asians more evolutionarily fit," said Benjamin Vernot, from the University of Washington, co-author of a separate study in Science journal, according to BBC.
The research also noted that Genes for keratin filaments - a fibrous protein that lends toughness to skin, hair and nails resembled Neanderthal DNA. They also suggested it might have helped provide the newcomers with thicker insulation when subjected to cold conditions.
"It's tempting to think that Neanderthals were already adapted to the non-African environment and provided this genetic benefit to (modern) humans," said Prof David Reich, from Harvard Medical School, co-author of the paper in Nature.
"We find that there are large regions of the genome where most modern humans carry little or no Neanderthal ancestry," Mr. Sriram Sankararaman, lead researcher of the study told BBC News.
"This reduction in Neanderthal ancestry was probably due to selection against genes that were bad - deleterious - for us." The findings of the report are published in the journal Nature.