Chimp and human lineages may have split twice as long ago as thought | Science News

Support Science Journalism

Science News is a nonprofit.

Support us by subscribing now.


Chimp and human lineages may have split twice as long ago as thought

Last common ancestor was 13 million years ago, according to study of chimpanzee mutation rates

2:23pm, June 12, 2014

FAMILY SPLIT  Chimpanzees have a much slower mutation rate than previously estimated. That could mean that humans and chimps last shared a common ancestor 13 million years ago.

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

This article is only available to Science News subscribers. Already a subscriber? Log in now.
Or subscribe today for full access.

Get Science News headlines by e-mail.

More from Science News

From the Nature Index Paid Content