More thought? Well, we can’t have THAT, can we? ;->
Other posts have addressed the obvious error about life expectancy, and done so quite well. (See the other threads on this subject.) What nobody seems to have addressed is Cecil’s reference to “menopause” in other mammals. HUH???!!!
Only humans and Old World (Asia and Africa) primates menstruate. NO OTHER MAMMALS EVEN MENSTRUATE*. So what’s up with this “menopause” in rabbits business?
Combine this with the fact that, once the life-expectancy error is corrected, human females live something like 15 to 20 years after their last child is born. Humans are tribal; a child who’s survived past the intensive mothering years (about the first 4) stands a pretty good chance (well, almost as good as his/her peers) of making it to adulthood due to access to tribal resources.
Toss in the fact that if a woman who remains fertile throughout life has even one child who survives to reproduce, she’s got an evolutionary advantage over any woman who does NOT remain fertile throughout life. I think we are left with an incomplete answer (Cecil’s) to a still-interesting question. Obviously, there is some evolutionary advantage to menopause. Obviously, that advantage isn’t the advantage to the woman pausing, because she’s no longer passing along genes. Logically, the advantage would apply to the people who are NOW passing along her genes–i.e., her own children and their children. And it must be a strong advantage, or why would menopause be universal?
I think the Granny Effect is far from discredited by Cecil’s opinion–or UM’s Craig Packer’s paper, for that matter. I’d need a bit more convincing.
–P. Rhiannon Griffith
*And I’d sure like to hear a little more about what’s up with THAT. If there was a biological phenomenon that impacted as heavily on men’s lives as menstruation does on women’s, and was only existent in Old World primates (including humans)–wouldn’t there be, like, Ph.D programs in it? Have you tried finding solid data on this? Trust me. There’s not much out there. On behalf of my gender, harrumph! ;->
“Obviously, there is some evolutionary advantage to menopause. Obviously, that advantage isn’t the advantage to the woman pausing, because she’s no longer passing along genes. Logically, the advantage would apply to the people who are NOW passing along her genes–i.e., her own children and their children. And it must be a strong advantage, or why would menopause be universal?”
Great point, and was what I was getting at. I believe that everything today is the result of natural selection in the previous 35 million years.
The only way for menopause to be “passed on” would be for it to benefit those who are actaully passing their genes on to future generations, not the actual woman experiencing menopuase.
But I don’t have the answer - just the question - which is why I said it requires more thought
Welcome to the SDMB, and thank thee for posting thy comment.
Please include a link to Cecil’s column if it’s on the straight dope web site.
To include a link, it can be as simple as including the web page location in thy post (make sure there is a space before and after the text of the URL).
Not necessarily. It could be passed on because it is not a detriment to those with the genes. That is, if it only kicks in around the time that fertility is down anyway, and health is getting poorer, and then the woman dies, then menopause may not in any way make their offspring more likely to survive, but may not be causing fewer offspring. Thus, it would be neutral, and therefore passed on.
