Why does skin wrinkle in water?

Surely you haven't asked yourself many times What is the point of fingers wrinkling when in water?, because it is quite banal information that almost no one cares about.

Still, it is a curious fact, and today I am going to explain it to you briefly.

To begin with, it is interesting to know that humans and primates have nerves in the tips of their fingers that are responsible for carrying out this function, and their job is, ultimately, get a better grip despite the humidity.

This happens because on the skin we have a very thin, external layer of fat called sebum that is responsible for repelling water, making it slip and not penetrate the skin; but this thin layer falls apart if it has been repelling liquid for more than five minutes, so our secondary layer in the dermis begins to absorb tiny amounts of water which produces this small deformation in the fingertips, serving, ultimately and as I mentioned above, as a mechanism that facilitates our interaction with some objects or situations.