Some toothed whales —like humans—go through menopause. And it may help them live longer

Ninety million years of evolution may separate toothed whales from humans, but we may share with them a rare reproductive strategy that allows relatively long life spans. Toothed whales—including belugas, killer whales, and narwhals—can live into their 90s. Humans can live to 100 and beyond. Menopause may be part of the reason for that longevity, the researchers behind a study published today in Nature say. The work, which is the first to comparatively examine menopause across multiple whale species, argues it’s an adaptation that allows females to look out for their offspring for longer while minimizing competition with their daughters—an advantage that allows people and whales alike to stick around well past their birthing years. “It’s a very convincing argument,” says Robin Baird, a biologist at the Cascadia Research Collective who wasn’t involved with the study. “It’s a really nice addition to understanding menopause and how and why it may have evolved.” Menopause—when the menstrual cycle stops and the ability to reproduce ceases—developed independently and at different time points across the five toothed whale species known to exhibit the trait. The fact that it evolved so many times suggests it carries an evolutionary purpose. Yet precisely what that is has long been a subject of debate. One explanation suggests menopause evolved by shortening mothers’ total birth-giving years while their ove...
Source: Science of Aging Knowledge Environment - Category: Geriatrics Source Type: research