The evolution of the anus may have driven the body plan of all advanced animals, including humans MattLphotography / Alamy
The anus is a wildly successful innovation, but how did it evolve? A genetic analysis suggests it probably began as an opening used to release sperm that later fused with the gut – an example of evolution repurposing structures.
“Once a hole is there, you can use it for other things,” says at Friedrich Schiller University Jena in Germany.
It is thought that early animals evolved…
Article amended on 1 April 2025
We corrected Andreas Hejnol's affiliation.
