Much of the study of how people transitioned away from a lifestyle based mostly on food collected from the wild to one based on cultivated crops has focused on Europe, where the shift to agriculture, or “Neolithic transition,” concluded thousands of years ago. Based largely on genetic studies, the prevailing view is that the transition occurred mainly by population replacement rather than cultural change, said first author Shyamalika Gopalan, a graduate student at the time of the work advised by Brenna Henn, associate professor of anthropology at the University of California, Davis.
The team, led by Henn and Barry Hewlett at Washington State University, Vancouver, collected DNA samples from five groups of people in the southwest highlands: the hunter-gatherer Chabu; the Majang, who practice small-scale cultivation of crops; and the Shekkacho, Bench and Sheko, who practice more intensive farming. The goals were to assess both the genetic ancestry of the different groups and demographic trends in the recent past.