Aaaah, that's cool! That makes sense.
It's amazing what you can explain with evolution. I wonder how much of it is real and how much of it is, "well, it sounds like it makes sense."
But this definitely makes sense.
I'm not sure how you could explain "career woman" tho, who chooses not to have kids. Tho I'm sure there's like a civilizational advantage to that behavior (aside from the obvious "economic" ones).
I suppose an argument could be made that, people prefer other people who share similar genes, so a powerful woman who rises in the business world, can then favor those with whom she shares genes (and increase their reproductive fitness, if not her own directly), thereby increasing the survivability of their offspring. The same could be said for a man, however. I don't think that makes a difference. In a sense, those who eschew their direct line to accrue worldly power may end up benefiting their "genes" in a different way to those who reproduce conventionally.
Not to take a negative slant at all, but humorously, a sort of post-modernist "deconstructed" nepotism, I suppose, haha!
What was Fukuyama's argument in end of history, again? I don't know, but I suppose at some point you get an "end of evolution" where civilization takes over and there's no obvious "reproductive fitness" any more to explain behaviors, it's more like "civilizational fitness". But, looking at the above, it seems that our genes may run rings around such suppositions already! Our clever genes! So very selfish!
One note in your link: I saw It also fails to explain the detrimental effects of losing ovarian follicular activity but I disagree, I think that physical decline provides opportunities for relatives to provide care, which likely increases social bonds, and enhances the Grandmother's "genetic nurturing" Effect. So if we assume the original hypothesis is true, physical decline would be a development that supports and enhances that effect, and so likely to occur. A truly noble sacrifice, on the part of the Grandmother, and all at the hands of the selfish genes, haha!