Tatar Marc, Carey James R, Vaupel James W
Graduate Group in Ecology, University of California, Davis, California, 95616.
Department of Entomology, University of California, Davis, California, 95616.
Evolution. 1993 Oct;47(5):1302-1312. doi: 10.1111/j.1558-5646.1993.tb02156.x.
Age-specific mortality is measured to characterize the costs of reproduction in the beetle Callosobruchus maculatus, providing explicit details of the timing, duration, magnitude, and acceleration of mortality. We experimentally manipulated reproductive effort in four cohorts of 200 individually housed females by controlling exposure to males and to an artificial oviposition substrate. We demonstrate that (1) early reproduction produces long-term increases in age-specific mortality; (2) egg-laying effort affects the onset of age-specific mortality but not its shape or rate of change; and (3) mating with subsequent reproduction increases the rate of change in age-specific mortality relative to virgins. Accelerated senescence is defined demographically as an increase in the rate of change of age-specific mortality. Our results challenge the hypothesis that reproductive effort accelerates senescence but provides evidence that mating itself may have this effect.
通过测量特定年龄死亡率来描述黄斑豆象繁殖的成本，提供了死亡率的时间、持续时间、幅度和加速情况的明确细节。我们通过控制雌性个体与雄性以及人工产卵基质的接触，对四个由200只单独饲养的雌性组成的队列的繁殖努力进行了实验性操纵。我们证明：（1）早期繁殖会导致特定年龄死亡率的长期增加；（2）产卵努力会影响特定年龄死亡率的起始，但不影响其形状或变化速率；（3）与后续繁殖的交配相对于未交配的雌性会增加特定年龄死亡率的变化速率。加速衰老在人口统计学上被定义为特定年龄死亡率变化速率的增加。我们的结果挑战了繁殖努力会加速衰老的假设，但提供了证据表明交配本身可能具有这种作用。
