Living Past Your Reproductive Years
How many female animals live beyond their reproductive years?
Which animals experience menopause?
Those were my Google searches after reading NPR’s story on the grandmother hypothesis. Because I had never given this fact consideration… at all:
Killer whales, Japanese aphids and Homo sapiens — they’re among the few organisms whose females live on long past the age of reproduction. Since the name of the evolutionary game is survival and reproduction, the phenomenon begs explanation — why live longer than you can reproduce?
Apparently “um” is not an answer.
The hypothesis is that these older women help the younger women have more children. Having a child or multiple children is a lot of work. Having another set of hands around makes parenthood easier.
Which gives grandmothers a clear role: give help and support. So why does society not give equal consideration to women (and, frankly, men) living without children? Aunts make parenthood easier. Fictive kin makes parenthood easier. Friends make parenthood easier. In all these cases, parenthood is easier due to the other women in your life supporting your children.
I am not reducing the role that grandmothers play in the world. The grandmothers who support me are awesome. I just wish researchers would also turn their eye to other women who are not currently raising children who play a vital role in helping and supporting, exploring the aunt hypothesis or the fictive kin hypothesis, too. It really does take a village.
7 comments
Yes. I have grandmother support. But also so much support from friends, both with and without children. And I was that supportive person to friends even before I was a parent myself. It’s true that grandmothers are important but so many play a role.
Huh. I thought the theory of why whales go thru menopause (which results in outliving reproductive years) was that the younger whales reproduced more when the older ones weren’t competing for resources. (Thus, evolution—those younger whales produced more offspring who had that trait and eventually only whales who go thru menopause were left…)
https://www.sciencemag.org/news/2017/01/study-suggests-surprising-reason-killer-whales-go-through-menopause
As someone who is dreading menopause I wish we had not evolved to undergo it…
Um indeed.
I remember hearing about this decades ago, when menopause wasn’t even on my radar, when fertility wasn’t even on my radar. I think whatever I was reading at the time had the same hypothesis, that the wise elders still had something to offer the tribe besides fecundity.
And yes, such consideration should extend to others who may or may not currently contribute to the gene pool. There are many ways to promote the propagation of a species.
I was born in the same town as one grandmother & 18 miles away from the other, but we soon moved far away, & the closest we ever lived to them (or any other relatives) again was about 1.5-2 hours’ drive away. The absence of both my mother (1000 miles away) & MIL (who died before I ever met her) was certainly one reason why we delayed ttc. I knew I wasn’t going to have much help around me, so I’d better be ready for the responsibility. Not that grandmothers are the only ones who can & do offer support, as you point out.
Re: menopause & childless women, there has been some excellent writing on this subject recently from childless not by choice bloggers… to name a few:
Mali at No Kidding in NZ has done an entire series of posts lately on this subject: here’s the latest, with links to her previous posts:
https://nokiddinginnz.blogspot.com/2019/02/a-teaching-moment.html
Berenice at Walk in Our Shoes: https://walkinourshoes.net/blog/2019/1/28/childlessness-and-the-menopause
And an older one from Jody Day at Gateway Women:
http://gateway-women.com/the-childless-menopause/?fbclid=IwAR3HPKXvr8zv4k2AzHumiOzpuYtVoYf–l2Dn9ONbf-TfIvaYhn7locRc20
There are links in some of these pieces to other bloggers’ posts about menopause… I would highly recommend all of them! 🙂
A new wrinkle added to the Kin Selection Theory: https://en.m.wikipedia.org/wiki/Kin_selection
And I have my own theory why we don’t give recognition to all the “village” that is required to raise children. Acknowledging the village means we have to foster the village. And there’s a host of reasons not to do that in our modern era (all of them equaling $$$).
Also, to clarify Working Mom’s observations. It’s not that the younger daughters reproduce more offspring. It’s that the older mothers are caring for everyone in the family, resulting in their younger offspring being more neglected for the sake of the family. Hence higher mortality rates and thus the evolution of menopause.
Now, given this, the question is why we have older adult human males, given most other males die at a young age. I suspect it also has to do with Kin Selection and the unique role human males can play with care of young. But another topic for another time.
“It takes a village” has always seemed so obvious to me, as I’ve talked before about societies that did this before our highly mobile, digitally connected and socially disconnected one. One of my many losses in living a No Kidding life has been that I do not live near any of my nieces and nephews, and haven’t been able to be very involved in their lives as they grow up. And yes, like you I wish there wasn’t just the focus on women, and on grandmothers in particular. To me it is laziness. Stereotyping. Again. Still. Sigh.
I will admit, when I saw the question “why live longer than you can reproduce?” it made me feel all stabby inside, because I know that biology is all about replication and passing on those genes, but it makes me feel super defective when put in those terms. BUT, I do love the recognition of the other women who help with children, who influence children, who may not have children of their own but who can be a positive influence for children or moms nonetheless. I do this through my students, but also my friends’ kids — I don’t have young nieces and nephews as Bryce is an only child and my sister’s stepsons are in their 20s, so I don’t really get to be an “auntie” in the traditional sense, which saddens me. But, I can be a nurturing person in the lives of children I know through other venues. I love that part of this, and appreciate very much your call to recognize the non-grandmothers, the women and men who didn’t reproduce for whatever reason but are still super value to society as a whole and the lives of the next generation(s).