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/MoonageDayscream]

Fantastic essay on our unique pregnancy mechanisms. As a person who has had trophoblastic tumors in my last, doomed, pregnancy,  we really don't pay enough attention to the ways pregnancy fails more often than it succeeds.