Do any other animals go through the menopause?
Jane - Do animals go through a menopause a bit like humans do?
Chris Smith put this to veterinary scientist Chris Basu...
Chris B - The menopause, it’s a bit of a conundrum on the surface if you think about it. So, if there’s some kind of benefit to living a long life after the ability to reproduce, how do you actually transfer that benefit on to the next generation? And the and we to that kind of unites the animals that we do know go through the menopause, so people, of course, go through menopause. As far as we know there are only two other species that go through menopause and, surprisingly, it's not an ape, it’s not a primate, the other two are both whales.
Chris S - So elephants don’t.
Chris B - Elephants don’t.
Chris S - They’re very long-lived though, aren’t they?
Chris B - They are and that’s also a question that other people have asked when thinking in the context of why do whales do it, why do people do it, why don’t elephants do it? So the answer to this question is it shows us what we have in common with all these animals and part of it is what’s called ‘the granny effect.’ It’s not called the granny effect after your Nan or anything like that, it’s actually named after a killer whale who was called Granny. Killer whales are one of the species...
Chris S - As you do!
Chris B - Yes, exactly.
Chris S - There’s a story in that - why was it called Granny?
Chris B - Because she was really old, bless her.
Chris S - Okay. It was sort of logical then.
Chris B - People started studying Granny about 40 years ago. She actually died very recently, I think last month, and she was about 100 years old. During the 30 years of research she never had a calf so she was menopausal. But the way that she helped her family group was each year she would take the whales to find out where the best stocks of fish were. So she was helping her immediate family to find the best resources of food and because of that, she improved the health and welfare of her family. So, of course that’s how they get to pass this ability along to the next generation.
Then that goes on to your question: why don’t elephants do this? Well, whales are very family centric and people are very family centric as well. Whereas groups of elephants are not as loyal or rather their groups tend to split off and reform, whereas people and whale family groups tend to stay together very closely.
Chris S - So the fact that the grandma may not be reproducing, but is doing the babysitting and helping with family cohesion means that there’s a strong contribution to the family unit’s success so you breed into evolution.
Chris B - Exactly. She’s passing on the knowledge from her long lifetime. She’s improving the health of the calves, the calves are more likely to survive and then the next generation comes.