Evolution of gut bacteria tracks splits in primate species

Microbes may have played a role in making us, us. A new study shows similar patterns in the evolution of gut bacteria and the primates they live in, suggesting that germs and apes could have helped shaped one another.

For at least 10 million years, bacteria have been handed down from the common ancestor of humans and African apes. As apes split into separate species, so did the microbes inside them, researchers report July 22 in Science. Now, relationships between gut bacterial species mirror the family tree of gorillas, humans, bonobos and chimpanzees.

Germs are a piece of our history, says evolutionary biologist Andrew Moeller who led the study while at both the University of Texas at Austin and the University of California, Berkeley. “Just like genes we’ve inherited from our ancestors,” he says, “we've inherited some of our bacteria from our ancestors as