Latest by Alpha Unit. Pretty interesting stuff! We have been discussing on here for awhile why human females live on past menopause (or past their age of “usefulness” to put it brutally). No one seems to exactly know why. The latest research, cited by AU below, is about as good an explanation as any that I’ve read.
One good evolutionary reason for menopause is that past a certain age in Paleolithic times, an older woman was quite likely to die during childbirth. Menopause had survival value for females in that it allowed them to survive by shutting off the reproductive organs around the age at which childbirth becomes quite deadly.
On the other hand, these women have already had kids when they were younger, so where’s the evolutionary value (since her genes are already passed on anyway, even though she’s dead)? It may be that in tribes where the women did have go through menopause, the older women simply died. The death of the grandmothers was so harmful to the group that these groups went out.
Some tribes that evolved menopause managed to keep the grandmas around, and thereby failed to go extinct, passing their genes on. Any tribe that goes extinct is evolutionarily useless. This suggests that grandmothers had survival value for the tribe as a whole. And what might that value have been? These questions are very difficult to answer, but it’s fun to play around with them.
It is one of the most bizarre (and annoying) commercials I’ve seen on TV.
The California-based HMO Kaiser Permanente advertises itself with images of post-menopausal females, including a cheerleader, and a singer intoning in the background: “When I grow up, I wanna be an old woman….”
I mean, I hope to be an old woman one day, since the alternative is to drop dead right now. But what is so wonderful about being an old woman? My mom would know, I suppose. But I have the feeling she wouldn’t want me to ask her. If I did, she would probably smile at me and say, “You’ll see.”
What good is an old woman, anyway?
Researchers have been trying to figure this out for decades now. Apparently there shouldn’t be any old women. The Grandmother Hypothesis, mentioned here , is an attempt to explain why human females survive past menopause. Supposedly the older females help nurture their grandchildren, who benefit from their accumulated wisdom and expertise.
But there are skeptics. They point out that these older females use up resources that could be going to the younger generations, offsetting any benefit the younger ones get from having them around.
Maybe what matters isn’t what Grandmother can do for anybody but why she went through menopause in the first place.
Researchers at the Universities of Cambridge and Exeter published an explanation last March. In summary, they say that females go through menopause in order to prevent sexual competition between themselves and the younger females in the family. According to the press release:
In natural fertility populations, women on average have their first baby at 19 years and their last baby at 38 years; in other words, women stop breeding when the next generation starts to breed.
One of the researchers explained that women everywhere experience a rapid decline in fertility after the age of 40, and, on average, stop having children about ten years before the onset of menopause.
It also helps to explain why in some societies (particularly in Africa and Asia), women are required by social law to stop having children when their first grandchild is born.
And why should older females bow out of the competition?
Reproduction is more taxing on the female body, obviously, than on the male body. It’s probably better for babies to be carried by and delivered from younger, fitter female bodies. So my guess is that at the time daughters are in their prime childbearing years, menopause switches on for mothers, knocking them out of the game.
This is probably the way grandmothers really help their grandchildren. Any accumulated wisdom and expertise they bring are just secondary benefits.
Older women manage to bow out of reproduction and yet live on. And nobody seems able to figure out exactly why.
Maybe those old women in the commercial know but aren’t telling.
Could be that they know there’s no reason to be jealous of those younger women being pursued by older men. They know those younger women have something to look forward to: menopause.
As for the older men…what are they going to get that’s nearly as liberating?