Senescence or selective disappearance? Age trajectories of body mass in wild and captive populations of a small-bodied primate
Senescence or selective disappearance? Age trajectories of body mass in wild and captive populations of a small-bodied primate
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DOI：
10.1098/rspb.2014.0830
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发表时间：
2014-09-22
影响因子：
4.7
通讯作者：
Kraus, Cornelia
中科院分区：
文献类型：
--
作者：
Haemaelaeinen, Anni;Dammhahn, Melanie;Kraus, Cornelia
衰老的经典理论认为外在死亡率（EM）是影响寿命和衰老的主要因素，但大多数功能性衰老的研究都集中在EM低的物种上。这种偏见可能会导致高估的衰老下降的影响，在性能条件依赖性死亡率的人口过程中的类群。为了同时研究功能性衰老（FS）和内在的，外在的和条件依赖的死亡率在自然界中具有高捕食风险的物种中的作用，我们比较了野生和圈养灰鼠狐猴（Microcebus murinus）的体重（BM）的年龄轨迹，使用纵向数据（853个个体，直到成年）。我们在两种情况下都发现了非随机死亡的证据。在圈养条件下，最老的动物表现出衰老的能力，以恢复失去的BM，而没有证据表明FS被发现在野外。总体而言，圈养动物寿命更长，但野生和圈养种群之间观察到相反的性别偏见。我们认为，即使是适度的条件依赖性EM可能会导致在野外可以忽略不计的FS。虽然高EM可能会减少平均寿命，但这种进化过程可能会被长寿，高质量个体的适应性增加所抵消。
Classic theories of ageing consider extrinsic mortality (EM) a major factor in shaping longevity and ageing, yet most studies of functional ageing focus on species with low EM. This bias may cause overestimation of the influence of senescent declines in performance over condition-dependent mortality on demographic processes across taxa. To simultaneously investigate the roles of functional senescence (FS) and intrinsic, extrinsic and condition-dependent mortality in a species with a high predation risk in nature, we compared age trajectories of body mass (BM) in wild and captive grey mouse lemurs (Microcebus murinus) using longitudinal data (853 individuals followed through adulthood). We found evidence of non-random mortality in both settings. In captivity, the oldest animals showed senescence in their ability to regain lost BM, whereas no evidence of FS was found in the wild. Overall, captive animals lived longer, but a reversed sex bias in lifespan was observed between wild and captive populations. We suggest that even moderately condition-dependent EM may lead to negligible FS in the wild. While high EM may act to reduce the average lifespan, this evolutionary process may be counteracted by the increased fitness of the long-lived, high-quality individuals.