Last common ancestor was 13 million years ago, according to study of chimpanzee mutation rates
Courtesy of Biomedical Primate Research Centre
Human and chimpanzee ancestors may have split into different species millions of years earlier than scientists thought, a new study of chimpanzee mutation rates suggests.
In each generation, chimps’ average mutation rate is one DNA chemical unit changed out of every 83 million, researchers report in the June 13 Science. That mutation rate is nearly identical to the rate previously calculated for humans using similar methods (SN Online: 6/13/11). If the human and chimp mutation rates remained constant throughout evolutionary history, the species would have shared their most recent common ancestor about 13 million years ago.
That estimate is far longer ago than the 6 million to 8 million years surmised based on the fossil record. “It’s a number that people will be shocked, surprised