The appendix is routinely removed, especially after in becomes inflamed, but the surgery could be a mistake, say researchers from Midwestern University who have researched its function across a range of different mammals.
They have discovered that the appendix has evolved in 30 different groups that have a more advanced immune system, and especially have higher concentrations of lymphoid (immune) tissue in the cecum, a sac that is between the small and large intestines.
It seems to play a vital role as a secondary immune organ, and is a ‘safe house’ for good gut bacteria.
The appendix hasn’t disappeared in any species, which suggests it’s far from useless, and has evolved along with other parts of the intestine, say the researchers.
(Source: Comptes Rendus Palevol, 2017; 16: 39)