We should expect to see this throughout the world, as the climate crisis intensifies. We should expect to see this especially in intelligent or social species. Game theory predicts that, from the point of view of parents, when the population is expanding it is better to have sons and when the population is shrinking it is better to have daughters. A son might have a lot of children when times are good and zero children when times are bad. A daughter is likely to always have some children, and therefore is a safer bet when things are bad. This shifts the incentives for parents. When population is falling, parents have an incentive to care less about their sons, and to invest more resources in their daughters.
That much is known.
We can also speculate that if daughters are now receiving more investment as children, they are better positioned to go higher in society as they become adults. A general shift in political power, throughout social species, should be expected, as the climate crisis threatens more and more species with extinction.
This might extent to even those species in zoos, as their population usually is not allowed to expand.
This like most evolutionary psychology seems like one of those “anything goes” explanations that simply seems like a plausible explanation, but can just as easily be offered to explain falsehoods.
The problem with it is that one can invent a scenario that never happened and asked for an explanation and similar such plausible explanations can be proffered for it, but there's really no way to actually verify and test them.
It can just as easily be explained with “It is a simple fluke that will repeat itself in another 70 years.”.
I know of the hypothesis, but it doesn't address the problem that it's an unfalsifiable explanation.
It's observing an event, formulating an explanation for it that sounds plausible enough, but the explanation is unfalsifiable, and a number of other explanations that are just as plausible and unfalsifiable can be proffered.
I think you might be confusing a few different things. I originally wrote "Game theory predicts" because this has been worked out with some rigor in game theory. You should never assume that anything in game theory necessarily applies to real life. At best, game theory models give us a starting point for other lines of inquiry. That's the whole of the claim, not that this is real, but only that there is a game theory model where this works well.
That makes no sense to me because for every child a daughter has, someone's son had a child. It has to balance out unless someone invents monkey mitosis.
It doesn't. In a species with 50/50 split between male and female, the number of males is almost irrelevant to population growth. Take rabbits. If you kill at birth 90% of the males, the population growth won't slow as the limit is the number of babies per-female. The 10% of males that survive simply father more kids via more females. Males can do that. Females cannot. Going one step further, killing all those males increases the resources available to the females. Ironically, culling those males can cause a population to grow faster than if they lived.
> In a species with 50/50 split between male and female, the number of males is almost irrelevant to population growth.
The split between male and female isn't relevant to this. Unless the males are needed to raise the children, the number of males is irrelevant to population growth.
But the average benefit of having a son remains equal to the average benefit of having a daughter; that's why the ratio stays at 50/50.
In nature, males can impregnate many females and do not have to necessarily be around to rear their many offspring. So it is advantageous to have many females that can procreate with less males to increase the population size at a higher rate than more males and less females to mate with.
Indications from genetic research are that humans may have about twice as many female ancestors as male according to some theory about discrepancy in the "time to most recent common ancestor" for mitochondrial DNA (extrapolating for female ancestors) and the nonrecombining portion of the Y chromosome (extrapolating for male ancestors).
I think the presence discrepancy is reasonably well accepted.
The guys weren't cutting it any more. They were not delivering on the expectations of the group (growing it). Life became too harsh and stressful for them, they are not even mating any more, since the offspring couldn't be fed, so they stop breading with the females. Still: Everyone is disappointed and the males know it, too... affecting their behavior which gets less dominant/aggressive. The females are now in focus, since they procreated more reliably (on average, the old alpha, that had a lot of offspring, is likely dead by now). The shift to a female leader means the population is in trouble and in decline. A crisis manager(female) gets installed.
Note that typically older males mate with (much) younger females: It's no coincidence, that she is that much younger than her male counter parts: She is angry about her mating partners that they have stopped mating (with her). Older females have offspring. The old alpha male, which is dead, has a lot of offspring. The external life conditions just became too harsh, this is not a happy setup. There are 2 strategies, but one is to react on external circumstances (stop procreating), instead of blindly going ahead and having to stem the bill later (starving babies). Apes are intelligent enough for the first, but there are furious women now (including "her").
That much is known.
We can also speculate that if daughters are now receiving more investment as children, they are better positioned to go higher in society as they become adults. A general shift in political power, throughout social species, should be expected, as the climate crisis threatens more and more species with extinction.
This might extent to even those species in zoos, as their population usually is not allowed to expand.