I am a family doctor but I am also a natural generalist. I thought about graduate school but was dating a zoologist who was one of the three world experts on honeybee behavior and I thought that I really did not care to get that in depth in ANYTHING. So I'm a rural family practice doc, do obstetrics and my patients range from birth to 104 currently. I learn stuff all the time.
Being curious about everything, I have wondered why women go through menopause and have collected bits of evidence. Then one day, a theory popped into my head. It's as if all the little pieces suddenly rearrange and form a picture.
Here are some of the bits that contributed:
Women go through menopause but men don't. Why?
Women often gain weight after menopause.
Women often complain of decreased libido after menopause.
An 80 year old man has more estrogen than an 80 year old woman because estrogen is a byproduct of testosterone.
Type II diabetes is common in postmenopausal women.
Type II diabetes is not caused by weight gain but by our bodies making a protein called amylase which is deposited in the Islet cells of the Pancreas until the person no longer makes enough insulin and suddenly has diabetes, which gets worse over time. They keep making the amylase.
Postmenopausal women survive famines best.
There is more type II diabetes in Hispanic, Inuit, Native American and African folks than other ethnic groups.
Women multitask more easily than men and are less linear thinkers. In studies where people watch a video and have to describe it, men describe what happened, in general, more linearly while women, in general, notice all sorts of details and gestalt.
People in Africa who have one gene for sickle cell anemia resist malaria better than those with none, so sickle cell sticks around. What's the advantage of menopause?
Ok, so it's either Intelligent Design or evolution. Why?
My theory is that women are the brains of the tribe. They go through menopause so they can stop having babies and attend to the needs of the tribe. They gain weight and maybe get diabetes in order to survive the next famine. If a guy survives into his 80s then he can still reproduce, and perhaps that used to be good for the tribe. Women, however, have to stay alive in order to teach and raise the next generation, so they don't go chasing the mammoths.
My thought is that someday men may evolve more highly and have their hormones stop when they get old enough. This is a thought that pleases me and really offends my 16 year old son. Oh, well, he just can't think straight with all that damn testosterone.
rootbeer277 says re Why women go through menopause: This is called the Grandmother hypothesis. Would you mind if I changed the title to this?
dang, I didn't come up with it first. See wikipedia. And here.