There’s a little quirk of evolutionary biology that doesn’t quite fit with Darwin’s theories, that has left scientists a bit baffled, that kind of flies in the face of survival of the fittest. Natural selection suggests that any characteristic that reduces an animal’s chance of passing along its genes will soon be phased out.
That little quirk that doesn’t quite fit is actually called “menopause.” No one really understands why it happens in humans….and orcas. Apes, chimpanzees, even those critters alleged to be our closest cousins, do not experience menopause.
Evo/psychologists and biologists have long captured my irritation with some of their bizarre and dare I say it, downright misogynistic observations, such as suggesting that both human women and orcas have apparently de-evolved, evolved backwards, creating this completely illogical genetic defect that allows us to live long, active, post-reproductive lives, long after our alleged usefulness has expired.
What can I say, women just do things like that, like spontaneously de-evolving just to mess with your head. While human women may be good at it, orcas have taken it to a whole new level. They go through menopause at about 30 years old. Than they can live well past a hundred. So a female orca’s dedication to passing down her genes can be a bit like attention deficit disorder, she’s got about a 15 year window before she simply decides to do other things. What that might be, no one really knows. Women can be mysterious that way.
None of these things were really well-known because we’ve always studied orcas in captivity. Where I live and the water is very cold, we’ve been studying orcas in the wild for about 40 years now. One such orca, affectionately named Granny, is our oldest known living killer whale. No one is quite certain how old she is, but estimates say at least 80. Granny is providing a wealth of data and information, none of which is going to be the least bit useful or helpful if we insist on asking foolish questions like,
“One part of their research is to plug the whales’ vital life statistics – birth rates, death rates and odds of survival – into a Darwinian calculator to see if menopause is a net benefit. It is a biological cost-benefit analysis. The question is whether an older female brings a measurable benefit to her existing family which outweighs the genetic cost of having no more babies.” link here
I’ve been watching orcas for a long time and watching human evolutionary biologists with even more skepticism. It’s somewhat amusing, their latest theories for the alleged usefulness of menopause seem to be revolving around the idea that male orcas, sons, even those well into adulthood, may simply be too stupid to learn how to hunt and fish for themselves, so the female orcas must hang around for a good 70 years to make sure they continue to get fed.
While it is quite possible that is true of evolutionary biologists, I remain unconvinced it is true of orcas.