Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QG, UK.
Science. 2012 Sep 14;337(6100):1313. doi: 10.1126/science.1224198.
Prolonged life after reproduction is difficult to explain evolutionarily unless it arises as a physiological side effect of increased longevity or it benefits related individuals (i.e., increases inclusive fitness). There is little evidence that postreproductive life spans are adaptive in nonhuman animals. By using multigenerational records for two killer whale (Orcinus orca) populations in which females can live for decades after their final parturition, we show that postreproductive mothers increase the survival of offspring, particularly their older male offspring. This finding may explain why female killer whales have evolved the longest postreproductive life span of all nonhuman animals.
除非延长生殖后的寿命是由寿命延长的生理副作用引起的，或者对相关个体（即增加包容性适合度）有益，否则从进化的角度来看，延长生殖后的寿命是很难解释的。几乎没有证据表明，在非人类动物中，生殖后的寿命是适应性的。通过使用两个虎鲸（Orcinus orca）种群的多代记录，其中雌性在最后一次分娩后可以活几十年，我们表明，生殖后的母亲会增加后代的存活率，特别是它们年长的雄性后代。这一发现可能解释了为什么雌性虎鲸的生殖后寿命是所有非人类动物中最长的。
