However, according to new research published in the Journal of Anatomy, this “small anatomical structure of a few centimetres in size, located in the abdomen and attached to the colon” could contribute to an increase in mammals’ lifespans.

According to researchers, the appendix appeared 80 million years ago in mammals.

Since then,”over the course of evolution, [it] has developed independently multiple times in several mammalian lineages, with no obvious correlation with diet, social life, or the environment,” reports France’s National Institute of Health and Medical Research, Inserm.

While the function of this organ is still not clearly defined, it would seem that its presence is linked to an increase in mammalian longevity, reports the study, conducted by Inserm researcher Eric Ogier-Denis and his colleague Michel Laurin of the French Museum of Natural History.

The scientists analysed data from 258 mammals. Of these, 219 had no appendix and 39 did.

They focused on the theoretical maximum longevity of the animals, namely “the theoretical lifespan of mammals, established based on their weight.” They also looked at “actual maximum longevity of the various species considered.”

According to the researchers, the presence of the appendix “enables the development of a selective ‘bacterial sanctuary’ that reduces mortality from infectious diarrhoea by promoting rapid recolonisation of bacterial species that are essential to the host.”

So, for a mammal, having an appendix could reduce the risk of death and therefore promote a longer lifespan.

So, what if you’ve had your appendix removed after suffering from appendicitis?

According to researchers, it doesn’t affect how long you live: “appendicitis at a young age is clearly beneficial by strengthening the education of the immune system and enabling it to fight any subsequent infection more effectively.”