Human, Chimp Ancestors May Have Mated, DNA Suggests

Early human ancestors and chimpanzee ancestors may have mated and produced offspring, according to a new DNA study. The study suggests that the human and chimp lineages initially split off from a single ape species about ten million years ago. Later, early chimps and early human ancestors may have begun interbreeding, creating hybrids—and complicating and prolonging the evolutionary separation of the two lineages.

The second and final split occurred some four million years after the first one, the report proposes.

"One thing that emerges [from the data] is a reestimate of the date when humans and chimps last exchanged genes," said David Reich, a professor at Harvard Medical School's Department of Genetics in Boston.

"Our data strongly suggest that [the last gene exchange] occurred more recently than 6.3 million years ago and probably more recently than 5.4 million years ago," said Reich, senior author of the study, to be published tomorrow in the journal Nature.

"This paper is very interesting, because it provides a hypothesis that is outside of the currently accepted dogma," said Kateryna Makova, a professor at Pennsylvania State University's Center for Comparative Genomics and Bioinformatics who is unaffiliated with the study.

Human, Chimp Ancestors May Have Mated, DNA Suggests