Evidence in 700 regions of our genome offers the best support yet for human evolution within the past 5,000 to 10,000 years. The genes showing this change govern senses of taste and smell, bone structure, skin color, brain function, and ability to detoxify plant poisons, perhaps signaling the advent of agriculture.

Jonathan Pritchard, a population geneticist at the University of Chicago, found selection occurring in brain genes, including a group governing microcephaly, when disrupted cause infants with unusually small brains. Afforded by a richer diet, successive changes in these genes may have enabled the brain to expand during primate evolution. Rice farming became widespread in China 6000 to 7000 years ago, and agriculture reached Europe from the Near East around the same time.

Rare are skeletons like modern Chinese before that period and modern Europeans before 10,000 years, suggesting a change in bone structure occurred in the two populations, maybe in connection with the shift to agriculture. They found several genes governing embryonic development of bones undergoing selection in East Asians and Europeans.

The selected genes quite differ between racial groups. They reveal 206 regions of the genome under selection in Nigerian Yorubans, 185 regions in Beijing Han and Tokyo Japanese and 188 in Utah French and Europeans. The few genetic overlaps between races could evidence migration or independent evolution.

—Nicholas Wade