Maklakov Alexei A, Hall Matthew D, Simpson Stephen J, Dessmann Josephine, Clissold Fiona J, Zajitschek Felix, Lailvaux Simon P, Raubenheimer David, Bonduriansky Russell, Brooks Robert C
Evolution & Ecology Research Centre and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Kensington, Sydney 2052, NSW, Australia.
Aging Cell. 2009 Jun;8(3):324-30. doi: 10.1111/j.1474-9726.2009.00479.x. Epub 2009 Apr 9.
Evolutionary theories of aging predict that fitness-related traits, including reproductive performance, will senesce because the strength of selection declines with age. Sexual selection theory predicts, however, that male reproductive performance (especially sexual advertisement) will increase with age. In both bodies of theory, diet should mediate age-dependent changes in reproductive performance. In this study, we show that the sexes exhibit dramatic, qualitative differences in age-dependent reproductive performance trajectories and patterns of reproductive ageing in the cricket Teleogryllus commodus. In females, fecundity peaked early in adulthood and then declined. In contrast, male sexual advertisement increased across the natural lifespan and only declined well beyond the maximum field lifespan. These sex differences were robust to deviations from sex-specific dietary requirements. Our results demonstrate that sexual selection can be at least as important as sex-dependent mortality in shaping the signal of reproductive ageing.
衰老的进化理论预测，与适应性相关的特征，包括繁殖性能，将会衰老，因为选择的强度会随着年龄的增长而下降。然而，性选择理论预测，雄性的繁殖性能（尤其是性展示）会随着年龄的增长而提高。在这两种理论中，饮食都应该调节繁殖性能中与年龄相关的变化。在本研究中，我们表明，在普通长角蝗中，雄性和雌性在与年龄相关的繁殖性能轨迹和生殖衰老模式上表现出巨大的、质的差异。在雌性中，繁殖力在成年早期达到峰值，然后下降。相比之下，雄性的性展示在整个自然寿命期间都在增加，并且直到远远超过最大野外寿命时才下降。这些性别差异对于偏离特定性别的饮食需求具有很强的抵抗力。我们的结果表明，在塑造生殖衰老信号方面，性选择至少与性别依赖性死亡率同样重要。
