Killer whale menopause evolved from mother-daughter conflict

Killer whale Shawn McCready.jpg

From Cosmos Magazine, January 13, 2017 (Image: Shawn McCready via Flickr)

Menopause is an evolutionary anomaly. Only in three species – humans, orcas and short-finned pilot whales – does female reproduction grind to a halt part-way through life.

For orcas (Orcinus orca), a new study published in Current Biology shows that menopause isn’t just a quirk of nature, but a reproductive strategy that specifically evolved to match their social structure. Read more…

Reproductive quirks (part 2): Why did menstruation evolve?

As I’ve noted previously, humans are strange beasts and our reproductive biology illustrates this well. Menstruation and menopause are both rare in the animal kingdom. Of all mammals, only us, our primate relatives and elephant shrews menstruate. Menopause is even harder to come by — killer whales are our only sisters in hot-flushes, apparently.

This begs the question: why? How did each of these reproductive quirks evolve in humans?

I’ve written two pieces for The Conversation about the evolutionary theories that try to explain where menopause and menstruation come from. The first, about menopause, can be found here. The second, on why women menstruate, has also now been published. 

Reproductive quirks (part 1): Why did menopause evolve?

my grandmother
Women go through menopause when they still have a third of their life ahead of them (Photo credit: paul goyette)

Humans are oddballs in the animal kingdom for many reasons, but one of the quirkiest things is how we reproduce. Or, more to the point, how our bodies behave when we aren’t reproducing. Menstruation and menopause are both very rare. Of all mammals, only us, our primate relatives and elephant shrews menstruate. Menopause is even harder to come by — killer whales are our only sisters in hot-flushes, apparently.

I’ve written two pieces for The Conversation about the evolutionary theories that try to explain where menopause and menstruation come from. The first, about menopause, is out today. Check it out!