Ancient DNA reveals a hidden history of human adaptation

Humans may be just as vulnerable to environmental change as other animals, according to our new research analysing genetic data from more than a thousand people who lived across Europe and Asia over the past 45,000 years.

We found traces of more than 50 “hard sweeps” in which a rare genetic variant rapidly swept through a population – most likely after a change in conditions in which those lacking the variant died out. The most striking sweep occurred among early Anatolian farming people, in a genetic region associated with the immune system called MHC-III.

Hard sweeps have often been seen in other species, but until now there has been little sign of them in humans. The traces of the hard sweeps had been hidden by frequent mixing between populations over the past 8,000 years.