The evolution of menopause in toothed whales

• 成果类型: Article
• 署名作者: Ellis, Samuel; Franks, Daniel W.; Nielsen, Mia Lybkaer Kronborg; Weiss, Michael N.; Croft, Darren P.
• 署名单位: University of Exeter; University of York - UK
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6301
• DOI: 10.1038/s41586-024-07159-9
• 发表日期: 2024-03-21
• 关键词: postreproductive life-span; reproductive conflict; population; longevity; selection; humans; kin; patterns; allocare

摘要

Understanding how and why menopause has evolved is a long-standing challenge across disciplines. Females can typically maximize their reproductive success by reproducing for the whole of their adult life. In humans, however, women cease reproduction several decades before the end of their natural lifespan1,2. Although progress has been made in understanding the adaptive value of menopause in humans3,4, the generality of these findings remains unclear. Toothed whales are the only mammal taxon in which menopause has evolved several times5, providing a unique opportunity to test the theories of how and why menopause evolves in a comparative context. Here, we assemble and analyse a comparative database to test competing evolutionary hypotheses. We find that menopause evolved in toothed whales by females extending their lifespan without increasing their reproductive lifespan, as predicted by the 'live-long' hypotheses. We further show that menopause results in females increasing their opportunity for intergenerational help by increasing their lifespan overlap with their grandoffspring and offspring without increasing their reproductive overlap with their daughters. Our results provide an informative comparison for the evolution of human life history and demonstrate that the same pathway that led to menopause in humans can also explain the evolution of menopause in toothed whales. A comparative analysis tests competing evolutionary hypotheses in toothed whales in which menopause has evolved many times as females extended their overall lifespan but not their reproductive lifespan, increasing their opportunity for intergenerational help without increasing intergenerational reproductive competition.