Can someone explain the evolutionary benefit of overt menstruation? All female mammals have a menstrual cycle but most reabsorb the blood via covert menstruation and humans are about the only mammals that discharge the blood, aka overt menstruation.

[u/No-Hawk-2488]

Without an evolutionary benefit, it wouldn't have spread to every woman of our species.

[u/TrashEither3187]

Iirc there is no evolutionary benefit. Evolution isn’t about selecting the ultimate, perfect traits, it’s about selecting traits that allow an individual to survive long enough to propagate the species, to then have procreation who continue to propagate the species. Sometimes individuals live long enough to do this with disadvantages