Menopause: Whales get it, too

Killer whales: Busy being awesome.

Well… I was reading Scientific American in my never-ending quest to be able to state that I read such a high-brow mag, and I learned that both certain species of whales and the females of the human species live decades past menopause.

And nobody else. Not dogs, not elephants, not fish. Nor sea turtles. Nor ducks. No really, you can keep guessing--- but you’d be wrong. Just humans and two species of whales live decades past menopause.

I have never in my life thought about this fact. First, because I didn’t know it until I read Scientific American (name dropping again) and second because I took it for granted that all animals’ life cycles were similar.

Nope. It all comes down to breeding patterns.

In some societies, the male leaves the group to go mate. The females of that group, then, see lots of males (to whom they are unrelated) over the course of their lives. Which is to say, a female in that group raises her young; her sons leave eventually to seek their reproductive fortunes elsewhere.

However…

“For mammals in which the female leaves the group to mate—or in which breeding happens away from the group—a female will find herself surrounded by an increasing number of males to which she is related (as sons, grandsons and other generations of males stick around). In this scenario, it actually behooves her—and the group—to stop mating (and competing for breeding resources that could increase the fertility of younger females) and help younger females raise her progeny. Other research has shown that having a grandmother around to help out confers extra benefits on younger generations.”

Call it the grandmother effect: We all do better when there’s a grandma around.

“Although contemporary human societies have given rise to all kinds of moving and mating arrangements, the researchers point out that in traditional human forager societies, "female transfer to the husband's family at marriage is more common," and genetic analysis shows an extended human history of "female-biased transfer." For the two whale species, the researchers noted that both are thought to mate outside of their local groups, leading to "an increase in local relatedness with female age."

So, not to overstate the case, but we live longer because, in a best case scenario, we had grandmas that helped our moms raise us to maturity. Same thing with these whales. And we live well past menopause, because we are supposed to help our kids raise their kids. Doing little things like helping forage dinner for the young, or watching the calves while mom and dad get away, take a breather and grab some krill.

And not to overstate overstating the case, but perhaps we just stumbled upon the meaning of life: grandparenting.

To read the full article, visit Scientific American online. To send your grandmother flowers, visit FTD.com.