The human appendix is a vestigial structure: its original function (digestion of raw vegetable substances) has been lost for a long time.
A vestigial structure is, in evolutionary evolutionary biology, an anatomical structure of the organism of a species whose initial function has been totally or partially lost during evolution.
The uselessness of the vestigial organs remains debated. It is not clear whether these organs are merely relics of old functional organs or whether they have a role, even a discrete one, in the functioning of the organism. From a scientific point of view, it is moreover difficult to declare certain organs as useless, a lack of knowledge being able to be at the origin of a non-comprehension of the role of the organ. Some creationists seize this idea because, according to them, God has given each organism its organs for a specific reason and use.
S.R. Scadding (evolutionist) stated: "As our knowledge has increased, the list of vestigial structures has decreased. Wiedersheim could record about 100 in humans, recent authors usually describe 4 or 5. Even this short list of vestigial structures in humans is debatable. "
On the other hand, one can legitimately think that the acquisition or the conservation of a second function in these vestigial organs is an index of an adaptation of the species and, consequently, of their evolution.
