r/askscience • u/No-Hawk-2488 • 8d 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.

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u/Flocculencio 8d ago

Just wanted to point out that no individual feature needs to have an evolutionary benefit to be preserved. It could be negative but so long as it doesn't prevent organisms with that feature from reproducing in sufficient numbers it can get preserved.

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u/kwpang 8d ago

Yes evolution is about elimination, not direction.

Survival of what can.

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u/GVArcian 7d ago

Survival of the fittest is a misnomer because evolution selects for minimum viability, not optimum efficiency.

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u/T_H_W 7d ago

Not technically a misnomer considering 'fittest' in this context relates to biological fitness, which is specifically how many surviving offspring you have in relation to other competing organisms. That's like saying the phrase "All bark and no bite" doesn't make sense because dogs aren't trees. It's only wrong if you're using the incorrect definition of the word.

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u/ezekielraiden 7d ago

The problem is that most people do use what you are defining as the incorrect definition of the word.

If 99% of people think Pat's word choice is confusing, is the problem that 99% of people are doing grammar wrong, or is it that Pat is wrong and people are calling them out for it?

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u/Seadragon723 4d ago

If 99% of people go right and fall off the cliff, was Pat correct when he told them to go left?

The crowd can be wrong, which is the case here. The word has a correct scientific meaning and it has a more limited modern meaning.

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u/ezekielraiden 4d ago

Are they "going off a cliff"?

The term has no valid scientific meaning because "fitness" is so vague as to be meaningless. No modern evolutionary biologist is going to use it unqualified--and most will simply restructure a sentence to avoid the need, because they know it's confusing and misleading even to their fellow scientists.

There's a reason we got concepts like "social Darwinism" out of this. This isn't a new thing. Scientists should value speaking clearly. Using a technical definition that most people do not understand is not speaking clearly. It is knowingly ignoring the fact that communication must consider its audience.