Switching to an agricultural-based lifestyle has left its mark on human DNA, according to an international team of researchers.
As GenomeWeb reported yesterday, the team led by Harvard Medical School's David Reich studied genome-wide SNP patterns in hundreds of ancient Eurasian samples — including from Anatolian Neolithic farmers — for signs of admixture and selection. As Reich and his team report in Nature this week, they found signals of selection at loci linked to diet, pigmentation, immunity, and height.
For instance, they noted that a certain SLC22A4 gene variant became advantageous upon the introduction of farming. As Carl Zimmer notes at the New York Times, this gene encodes a cell-surface protein that draws in the amino acid ergothioneine, and the variant increases the absorption of ergothioneine, which is present in crops like wheat only at low levels. This variant then would increase the chances of survival.
But, Zimmer adds, that advantage came with a downside as that region of the genome has also been linked to digestive disorders such as irritable bowel syndrome.
Reich and his team also said that changes in skin color and height genes in Europeans could also be tied to the advent of agriculture.
Reich and his colleagues are gathering additional ancient European genes to dive deeper into these effects of natural selection, Zimmer adds.
"I think in the future we can do this everywhere in the world, not just in Europe," Reich tells him.