IBE (CSIC-UPF): Genetic signature of natural selection in first Americans

IBE (CSIC-UPF): Genetic signature of natural selection in first Americans

News from IBE (CSIC-UPF)

When 18,000 years ago humans entered America through the Bering Strait they found a totally different climate and food. A recent study published in the journal Proceedings of the National Academy of Sciences USA (PNAS) shows that this migration left traces in the genome of Native Americans, descendants of those early settlers. These are genetic variants that facilitate the digestion of fats, a distinctive feature of adaptation to the Arctic climate and protein-richdiets.

David Comas, a scientist at the IBE (CSIC-UPF) and director of the DCEXS at UPF, who has participated in the research, states: "The environmental and dietary pressures that the first settlers of America encountered marked them genetically.” In fact, this is what in evolutionary biology is known as the founder effect. Namely, from the small group of people who crossed the Strait for the first time, only those who had these mutations survived. "As a result, all the populations that emerged from those early settlers carry the same genetic variants", explains Comas.

The paradox is that Inuit who live in the Arctic Circle still benefit from this biological adaptation, but the Amazonian Indians, who live in a tropical climate, also conserve them. According to Comas, "the fact that current populations contain adaptations of the past is not necessarily negative but can lead to metabolic dysfunctions."

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Reference Article:
Amorim, C.E.; Nunes, K.; Meyer, D.; Comas, D.; Bortolini, M.C.; Salzano, F.M.; Hünemeier, T. 2107. Genetic signature of natural selection in first Americans. Proc Natl Acad Sci U S A. pii: 201620541. doi: 10.1073/pnas.1620541114.