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
An illustration of green bacteria floating above neutral-colored intestinal villi

Register for free to listen to this article
Listen with Speechify
0:00
13:00
Share

ABOVE: © SHUTTERSTOCK.COM,
NOBEASTSOFIERCE

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 ...

Interested in reading more?

Become a Member of

The Scientist Logo
Receive full access to digital editions of The Scientist, as well as TS Digest, feature stories, more than 35 years of archives, and much more!
Already a member? Login Here

Related Topics

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.

    View Full Profile

Published In

July 2021

Bacteria-Guided Evolution

Animals' adaptive changes may be influenced by microbes within

Share
February 2026

A Stubborn Gene, a Failed Experiment, and a New Path

When experiments refuse to cooperate, you try again and again. For Rafael Najmanovich, the setbacks ultimately pushed him in a new direction.

View this Issue
Human-Relevant In Vitro Models Enable Predictive Drug Discovery

Advancing Drug Discovery with Complex Human In Vitro Models

Stemcell Technologies
Redefining Immunology Through Advanced Technologies

Redefining Immunology Through Advanced Technologies

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Beckman Coulter Logo
Conceptual multicolored vector image of cancer research, depicting various biomedical approaches to cancer therapy

Maximizing Cancer Research Model Systems

bioxcell

Products

Sino Biological Logo

Sino Biological Pioneers Life Sciences Innovation with High-Quality Bioreagents on Inside Business Today with Bill and Guiliana Rancic

Sino Biological Logo

Sino Biological Expands Research Reagent Portfolio to Support Global Nipah Virus Vaccine and Diagnostic Development

Beckman Coulter

Beckman Coulter Life Sciences Partners with Automata to Accelerate AI-Ready Laboratory Automation

Refeyn logo

Refeyn named in the Sunday Times 100 Tech list of the UK’s fastest-growing technology companies