The Inside Guide: The Gut Microbiome’s Role in Host Evolution

Bacteria that live in the digestive tracts of animals may influence the adaptive trajectories of their hosts.

Written byCatherine Offord
| 13 min read
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A few minutes from the University of Pennsylvania campus in Philadelphia sits a small peach orchard that’s home to some unusual experiments. Contrary to first appearances, the subjects of the experiments are not the peach trees themselves, each of which is protected by a two-meter-cubed tent of fine mesh material. Instead, researchers are interested in the hundreds of tiny fruit flies living on the trees and the even tinier bacteria living inside the insects’ guts.

The setup was designed with a deceptively simple question in mind: Do the microbes in an animal’s digestive tract help shape their host’s evolution? Evolutionary biologist Seth Rudman says that it would make sense if they did. “Microbiomes [can have] a huge effect on host fitness, and hence could have a huge effect on adaptive trajectories of populations,” says Rudman, who helped construct part of the site in 2017 while a ...

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Meet the Author

  • After undergraduate research with spiders at the University of Oxford and graduate research with ants at Princeton University, Catherine left arthropods and academia to become a science journalist. She has worked in various guises at The Scientist since 2016. As Senior Editor, she wrote articles for the online and print publications, and edited the magazine’s Notebook, Careers, and Bio Business sections. She reports on subjects ranging from cellular and molecular biology to research misconduct and science policy. Find more of her work at her website.

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Published In

July 2021

Bacteria-Guided Evolution

Animals' adaptive changes may be influenced by microbes within

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