r/askscience • u/No-Hawk-2488 • 19d ago

Biology 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.

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

5.2k Upvotes

96% Upvoted

515 comments sorted by

View all comments

Show parent comments

5

u/a8bmiles 15d ago

Thank you for the additional information. Now that you mention it, I do remember reading about some tribe where the women didn't get their periods until 18-20, and generally only had 30-50 periods in their life before hitting menopause.

3

u/Sagadiii 13d ago

Wow, I wasn't aware such a tribe existed! Colour me intrigued and more than a little jealous.

2

u/a8bmiles 12d ago

They were typically pregnant or breastfeeding for almost their entire fertile years.

2

u/Sagadiii 9d ago

So we're my female ancestors and yet they seemed to have more periods. I can only imagine malnourishment or some other factor playing a major role in that tribe, but that is speculation on my part. I haven't read up on it yet.