Urban people have less diverse populations of microbes:
The researchers analyzed bacterial DNA to identify recent cases of horizontal gene transfer (HGT), a process that allows individual cells to mix up their genomes and acquire new functions from other bugs in the microbial community without having to reproduce. The team found that species in the gut frequently exchange genetic material, and that they do it more if they’re living inside people in industrialized or urban societies than if their hosts reside in rural or less developed environments.
“What’s novel and really impressive here” is the team’s use of whole-genome sequencing to study thousands of individual bacterial genomes, says Gladstone Institutes data scientist Katie Pollard, who was not involved in the study. While the results themselves aren’t unexpected given findings from previous work on HGT and industrialization in the context of the human microbiome, “this paper brings it all together and confirms it in a more rigorous way.”Catherine Offord, “Gene Exchange Among Gut Bacteria Is Linked to Industrialization” at The Scientist
It’s not yet clear why there are fewer types of microbes in urban people’ guts or why they favor horizontal gene transfer more often.
But note: At one time, the researchers would be trying to explain it all in terms of Darwinism. That alone shows how much has changed without people really noticing.
The paper is open access.
See also: Horizontal gene transfer: Sorry, Darwin, it’s not your evolution any more