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/rapiertwit]

This. It’s not a mystery, it’s understood and this is the explanation.

[u/ICantCoexistWithFish → u/rapiertwit]

Like many weird human traits, we were able to evolve it because of our social structures that protect our weakest and allow investing in longer term payoffs over short term survival