Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, EH9 3FL, UK.
Nat Ecol Evol. 2017 Nov;1(11):1773-1781. doi: 10.1038/s41559-017-0329-x. Epub 2017 Oct 9.
The unusually long lifespans of humans and the persistence of post-reproductive lifespans in women represent evolutionary puzzles because natural selection cannot directly favour continued living in post-menopausal women or elderly men. Suggested sources of indirect selection require genetic correlations between fitness and survival or reproduction at younger ages, reproduction in the opposite sex, or late-life contributions to offspring or grandoffspring fitness. Here we apply quantitative genetic analyses to data from a historical human population to explicitly test these evolutionary genetic hypotheses. Total genetic selection increased the male post-50 lifespans by 0.138 years per generation; 94% of this arose from indirect selection acting to favour early-life fitness in both sexes. These results argue strongly against life-history models of ageing that depend on trade-offs between reproduction and late-life survival. No source of indirect selection for female post-50 lifespan was detected, deepening the mystery of why female post-reproductive survival persists. This result is probably due to recent changes in the genetic architecture of female lifespan, and it highlights the need for similar quantitative genetic analyses of human populations at other points along demographic transitions.
人类异常长的寿命和女性在绝经后仍能保持生殖寿命，这代表了进化谜题，因为自然选择不能直接有利于绝经后女性或老年男性的继续生存。间接选择的来源可能需要在年轻时与健康和生存或繁殖之间存在遗传相关性、在异性中繁殖，或者在晚年为后代或孙辈的健康做出贡献。在这里，我们应用定量遗传学分析方法来分析历史人类群体的数据，以明确检验这些进化遗传学假说。总遗传选择使男性在 50 岁后的寿命每代增加了 0.138 年；其中 94% 来自间接选择，有利于两性的早期健康。这些结果强烈反对依赖生殖与晚年生存之间权衡的衰老的生活史模型。没有检测到女性在 50 岁后寿命的间接选择来源，这加深了为什么女性在生育后仍能存活的谜团。这一结果可能是由于女性寿命的遗传结构在最近发生了变化，这突出表明需要对处于人口转型其他阶段的人类群体进行类似的定量遗传学分析。
