No Stone Age Unturned -- Coombs 2005 (308): 4 -- sciencenow:
Stoneking and his team compared Mlabri DNA with that from neighboring tribes. Astonishingly, all of the Mlabri mitochondrial DNA turned out to be identical--a total lack of variation that hasn't been found in any other human population. As hunter-gatherer societies are thought to have less genetic diversity, the lack of variation suggests that the Mlabri descended from a hunter-gatherer culture. However, unlike other hunter–gatherer groups, the Mlabri share genetic information with neighboring agricultural hill tribes as well as other agricultural groups in Southeast Asia.
The results, published this month in the journal Public Library of Science, Biology, demonstrate that "hunter-gatherers have changed and evolved, particularly in response to interactions with agricultural groups," says Stoneking.
Humans evolved as they transition from foraging, to agriculture, and back to hunter/gatherer. Evolutionary hypotheses tested.