The appendix may not be useless after all. The worm-shaped structure found near the junction of the small and large intestines evolved 32 times among mammals, according to a new study. The finding adds weight to the idea that the appendix helps protect our beneficial gut bacteria when a serious infection strikes.
Now get ready and see how stuff happens …
What’s more, careful anatomical study of other mammals has revealed that species as diverse as beavers, koalas, and porcupines also have a structure jutting off of their guts in exactly the same place as our appendix—in other words, the feature is much more common among mammals than once thought.
let me repeat this – in other words, the feature (appendix) is much more common among mammals than once thought.
https://www.sciencemag.org/news/2013/02/appendix-evolved-more-30-times