Posted on 06/14/2013 11:10:52 AM PDT by 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.
Of course! It’s all men’s fault!!!!
This is one of the most ridiculous things I’ve heard lately.
Heeheeeeeee, let me take it a step further.....Bush is a man, therefore, it's Bush's fault!
Chicken, meet egg...
...Egg, chicken.
I have observed that women who continue to have children , continue to have children, even to 50 years old.
Correct me if I’m wrong, but I thought women exited puberty with a set number of eggs and when they are gone, they are gone. And they lose a few every month or so.
“Of course! It’s all men’s fault!!!!”
That’s right ‘cause what we want is:
Faster Cars
Younger Women
Older Whiskey
More Money!
George Bush is a man, so it’s really his fault.
I need a shovel on this one. Can’t leave that laying in the yard. I have to mow the lawn later.
I’d think that “menopause” is a mammalian thing, and without having researched it yet, I’d bet a lot of other mammals go through something similar.
So they suggest we needed extra grandma’s to help raise the kids...
Next they will tell us there was also a need for some extra childless uncles to help raise the kids...
The gay gene explained!
Correct.
I’m still trying to figure out the key question: what is the ADVANTAGE of women running out of eggs sooner? What disadvantage might there be to having surplus eggs? The article appears not to provide even a hypothests for this.
And, the sun rising in the east might be an unintended effect of God's design of the universe!
"Researchers" and "scientists" are becoming politically correct terms for "idiots" and "morons"!
Women didn’t live to see menopause for most of human history. I believe the human body is simply not yet adapted to live as long as we do today
The article appears not to provide even a hypothests for this.
What a complete load of horse sh*t.
Suggestion: Premenopausal women hang around bars at closing time.
Oh, wait...never mind.
So, women stop being able to reproduce after a certain age (the age is variable) how is this not menopause? If they stop generating eggs then why continue all the other processes that go into egg production like the uterine lining etc... Isn't the hormones that control reproduction so doesn't it make sense that the production of estrogen goes down then leading to infertility which makes it sound like their research is backwards.
I get it, it's all men's fault.
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