Asynchrony of senescence among phenotypic traits in a wild mammal population.
Asynchrony of senescence among phenotypic traits in a wild mammal population.
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DOI：
10.1016/j.exger.2015.08.003
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发表时间：
2015-11
影响因子：
3.9
通讯作者：
Nussey DH
中科院分区：
文献类型：
--
作者：
Hayward AD;Moorad J;Regan CE;Berenos C;Pilkington JG;Pemberton JM;Nussey DH
在不同的生理系统和表型特征中，寿命变化与衰老变化的耦合程度是衰老学的中心问题。它的基础是更深层次的生物学问题，即衰老是否是一个同步过程，或者同步水平是否取决于物种或环境背景。了解自然选择如何在生理系统和表型性状之间形成衰老的同步模式，需要在自然条件下对许多表型进行纵向研究。在这里，我们研究的模式与年龄相关的变化在成年后期的野生种群的Soay羊（Ovis aries），已受到基于个人的监测三十年。我们研究了20种不同的表型性状的男性和女性，包括生命率（生存和繁殖力），产妇生殖性能（后代出生体重，出生日期和生存），男性发情行为，家庭范围的措施，寄生虫负担，体重。我们最初量化了每个性状的年龄相关变化，控制了环境中的年度变化，个体差异和选择性消失效应。然后，我们标准化了我们的年龄特异性特征均值，并测试了年龄轨迹是否可以根据性别或特征类型进行有意义的分组。虽然大多数特征在晚年表现出与年龄相关的下降，但我们发现性别内部和性别之间的性别差异都达到了惊人的水平。特别值得注意的是，女性生殖力和生殖性能下降，随着年龄的增长，但男性每年的繁殖成功没有。我们还发现，虽然家庭范围的大小和质量下降，随着年龄的女性，家庭范围的大小增加，随着年龄的男性。我们的研究结果强调了自然条件下表型衰老的复杂性，沿着来自其他野生种群和实验室模型的新数据，表明进化生物学中长期存在的假说，即与健康相关的性状应该以同步的方式衰老，是有严重缺陷的。在20个表型性状中衰老模式的惊人差异性在性别之间生殖衰老的意外差异野生哺乳动物的测距行为中衰老的第一个证据挑战衰老同步的进化假说
The degree to which changes in lifespan are coupled to changes in senescence in different physiological systems and phenotypic traits is a central question in biogerontology. It is underpinned by deeper biological questions about whether or not senescence is a synchronised process, or whether levels of synchrony depend on species or environmental context. Understanding how natural selection shapes patterns of synchrony in senescence across physiological systems and phenotypic traits demands the longitudinal study of many phenotypes under natural conditions. Here, we examine the patterns of age-related variation in late adulthood in a wild population of Soay sheep (Ovis aries) that have been the subject of individual-based monitoring for thirty years. We examined twenty different phenotypic traits in both males and females, encompassing vital rates (survival and fecundity), maternal reproductive performance (offspring birth weight, birth date and survival), male rutting behaviour, home range measures, parasite burdens, and body mass. We initially quantified age-related variation in each trait having controlled for annual variation in the environment, among-individual variation and selective disappearance effects. We then standardised our age-specific trait means and tested whether age trajectories could be meaningfully grouped according to sex or the type of trait. Whilst most traits showed age-related declines in later life, we found striking levels of asynchrony both within and between the sexes. Of particular note, female fecundity and reproductive performance declined with age, but male annual reproductive success did not. We also discovered that whilst home range size and quality decline with age in females, home range size increases with age in males. Our findings highlight the complexity of phenotypic ageing under natural conditions and, along with emerging data from other wild populations and laboratory models, suggest that the long-standing hypothesis within evolutionary biology that fitness-related traits should senesce in a synchronous manner is seriously flawed. Striking asynchrony in senescence patterns across 20 phenotypic traits Unexpected differences in reproductive senescence between sexes First evidence for senescence in ranging behaviour in wild mammal Challenges evolutionary hypothesis of synchrony of senescence