Agriculture's impact on human evolution clarified

March 9, 2006

University of Chicago, Illinois biologists Dr. Benjamin Voight, Dr. Sridhar Kudaravalli, Dr. Xiaoquan Wen and Dr. Jonathan Pritchard have identified regions of human DNA showing the strongest marks of natural selection within the last 5,000 to 15,000 years.

They found that many recent genetic changes are related to the development of agriculture. In particular, the genes for digestion of milk into adulthood occurred only after some level of domestication of animals. Most mammals drink milk only in infancy.

The work may shed light on the genetic factors involved in various human medical conditions, including high blood pressure and alcoholism.

The Chicago finding also contradicts the tacit assumption of much social science that human evolution "ground to a halt" in the distant past. Even evolutionary psychologists have tempered their claims based upon this assumption.

The study is based upon DNA changes found in three populations examined by the HapMap project: Africans, East Asians and Europeans.

The study has been published in PLOS-Biology.