Study: Men Caused Menopause by Selecting Younger Mates

UPI ^ | June 14, 2013 | Kristen Butler

[nickcarraway]

Menopause has bewildered evolutionary biologists, as females in virtually every other species remain fertile until they die. Now a team of Canadian researchers has shown that human menopause might be an unintended effect of men preferring to mate with younger women.

While conventional thinking has held that menopause prevents older women from continuing to reproduce, in fact, the researchers' new theory says it is the lack of reproduction that gave rise to menopause.

The prevailing "grandmother theory" held that women evolved to become infertile after a certain age to allow them to assist with rearing grandchildren, thus improving the survival of kin.

But Rama Singh, Richard Morton, and Jonathan Stone of McMaster University in Hamilton, Ontario, say that theory does not add up from an evolutionary perspective.

"How do you evolve infertility? It is contrary to the whole notion of natural selection. Natural selection selects for fertility, for reproduction -- not for stopping it," Singh said.

Computer models suggest that competition among men of all ages for younger women left older females with a diminished chance of reproducing. Over time, human males stacked the Darwinian deck against continued fertility in older women.

"This theory says if women were reproducing all along, and there were no preference against older women, women would be reproducing like men are for their whole lives," Singh said.

Menopause, however, is not only lost fertility, but an increased risk of illness and death that arises with the hormonal changes. Singh says the new research, published in the journal PLOS Computational Biology, suggests that if menopause developed over time, it could also be reversed.

The models aren't necessarily conclusive, however, as they assume male-driven sexual selection and an overwhelming male preference for younger women. The study also doesn't account for the dangers of pregnancy and childbirth in older women. Further, it isn't known if the only other species to undergo menopause -- captive chimps and certain whales -- lost their fertility due to male-driven selection.

[SunkenCiv]

Thanks BroJoeK.

[Bigg Red]

Thia hypothesis just does not make sense.

[SunkenCiv]

I agree.

[1010RD]

You need to ping the ‘scientist’ Singh. He doesn’t understand the theory where ‘environment’ plays Deus ex Machina and not the other way around. If men prefer younger women then evolutionary theory would indicate that the environment gave men that urge, no? Men didn’t choose it, but were bred for it because having that trait, ‘going for the young gal’, meant better reproductive success across all generations.

His premise is stupid and sexist and most likely political as he doesn’t understand the Theory of Evolution, but does get feminism. Despite his misapplication, his theory that menopause is caused my men’s preference for younger women fits just as well as the grandma hypothesis. The progeny are served just as well under either one. That’s the inherent tautology of the Theory of Evolution: if we have it, it’s because we need it.