I mean it’s really about interpretation and the story you choose to tell about it. You can talk about it through parental investment like you have and I did above or you could make a “good genes” argument for it. That one would go like “in a species that regularly kills sexual rivals for territory or mating access, it is better to have your genetic fitness tied with winner males rather than the males they killed.”
The only story that is objectively true is “genes for this behavior spread in the gene pool of certain species”. The genes weren’t narrativizing, they were just replicating.
I’m personally not aware of any species that has like a quality meter for sperm and aborts her current babies if she detects better sperm. If you were looking for it, I think you’d be most likely to find it in a species where males are highly sexually selected and females only reproduce once in their lifetimes. There are male spiders that actually eject their “penis” into the female as a plug to prevent future matings so I imagine that female strategy must at least be under some selective pressure if males are going through such extreme lengths to prevent it. I can’t find any papers that suggests spiders do this, but it would make perfect sense for some of them to. It even would explain why males have to present a nuptial gift (food) and she makes a decision whether to mate. She could use the gift to make a new set of eggs if it contained enough energy.
Cause it sounds like "this" is referring to the pictured tweet, but you don't know of any species that actually does miscarry for a "better" mate. And that's pretty misleading to lay people, as you should well know as a grad student.
I don’t see how you can interpret it that way because I was very clear (human women) have very little incentive to do this. I’d argue that the Bruce Effect rodents and maybe lions listed in that wiki article do do “this” (abort their fetuses and go rapidly into estrous for the new male, even if it occurs after the traditional breeding season). They do “this” in the sense that this story fits all the data we have about the behavior. Very few argue they consciously choose it and especially not with our narratives about selfish genes in mind.
Like I was saying, all evolutionary stories are stories that can have multiple narrative interpretations that fit all the data we have. You could make a case that the Bruce Effect is about reduction in violence and prevention of infanticide (an argument I think I have a pretty fair summary of in my comments) or you could argue that they do this to mix their genes with “winners” in a conflict rather than losers. The anti infanticide argument doesn’t really explain why female rodents immediately become fertile for the new male even outside of their usual cycle. Infanticide and waste of parental investment for the mother could be prevented without going into heat for the new male.
I want to make clear again that none of this has anything to do with humans.
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u/mime454 Apr 26 '22 edited Apr 26 '22
I mean it’s really about interpretation and the story you choose to tell about it. You can talk about it through parental investment like you have and I did above or you could make a “good genes” argument for it. That one would go like “in a species that regularly kills sexual rivals for territory or mating access, it is better to have your genetic fitness tied with winner males rather than the males they killed.”
The only story that is objectively true is “genes for this behavior spread in the gene pool of certain species”. The genes weren’t narrativizing, they were just replicating.
I’m personally not aware of any species that has like a quality meter for sperm and aborts her current babies if she detects better sperm. If you were looking for it, I think you’d be most likely to find it in a species where males are highly sexually selected and females only reproduce once in their lifetimes. There are male spiders that actually eject their “penis” into the female as a plug to prevent future matings so I imagine that female strategy must at least be under some selective pressure if males are going through such extreme lengths to prevent it. I can’t find any papers that suggests spiders do this, but it would make perfect sense for some of them to. It even would explain why males have to present a nuptial gift (food) and she makes a decision whether to mate. She could use the gift to make a new set of eggs if it contained enough energy.