School of Natural Sciences, Trinity College Dublin, , Dublin 2, Republic of Ireland, Trinity Centre for Biodiversity Research, Trinity College Dublin, , Dublin 2, Republic of Ireland.
Proc Biol Sci. 2014 Apr 16;281(1784):20140298. doi: 10.1098/rspb.2014.0298. Print 2014 Jun 7.
Maximum lifespan in birds and mammals varies strongly with body mass such that large species tend to live longer than smaller species. However, many species live far longer than expected given their body mass. This may reflect interspecific variation in extrinsic mortality, as life-history theory predicts investment in long-term survival is under positive selection when extrinsic mortality is reduced. Here, we investigate how multiple ecological and mode-of-life traits that should reduce extrinsic mortality (including volancy (flight capability), activity period, foraging environment and fossoriality), simultaneously influence lifespan across endotherms. Using novel phylogenetic comparative analyses and to our knowledge, the most species analysed to date (n = 1368), we show that, over and above the effect of body mass, the most important factor enabling longer lifespan is the ability to fly. Within volant species, lifespan depended upon when (day, night, dusk or dawn), but not where (in the air, in trees or on the ground), species are active. However, the opposite was true for non-volant species, where lifespan correlated positively with both arboreality and fossoriality. Our results highlight that when studying the molecular basis behind cellular processes such as those underlying lifespan, it is important to consider the ecological selection pressures that shaped them over evolutionary time.
鸟类和哺乳动物的最大寿命与体重差异很大，因此大型物种的寿命往往比小型物种长。然而，许多物种的寿命远远超过了根据其体重所预期的寿命。这可能反映了种间外在死亡率的变化，因为寿命史理论预测，当外在死亡率降低时，长期生存的投资会受到积极选择。在这里，我们调查了多种应该降低外在死亡率的生态和生活方式特征（包括飞行能力、活动期、觅食环境和穴居性），同时如何影响恒温动物的寿命。使用新颖的系统发育比较分析，据我们所知，这是迄今为止分析物种最多的一次（n = 1368），我们表明，除了体重的影响外，能够延长寿命的最重要因素是飞行能力。在会飞的物种中，寿命取决于物种活动的时间（白天、夜晚、黄昏或黎明），而不是地点（在空中、在树上还是在地上）。然而，对于不会飞的物种来说，情况正好相反，它们的寿命与树栖性和穴居性呈正相关。我们的研究结果强调，在研究细胞过程的分子基础时，如那些与寿命相关的细胞过程，重要的是要考虑塑造它们的生态选择压力。
