Priest Nicholas K, Galloway Laura F, Roach Deborah A
Department of Biology, University of Virginia, Charlottesville, Virginia 22904, USA.
Am Nat. 2008 Jan;171(1):10-21. doi: 10.1086/523944.
In many species, increased mating frequency reduces maternal survival and reproduction. In order to understand the evolution of mating frequency, we need to determine the consequences of increased mating frequency for offspring. We conducted an experiment in Drosophila melanogaster in which we manipulated the mating frequency of mothers and examined the survival and fecundity of the mothers and their daughters. We found that mothers with the highest mating frequency had accelerated mortality and more rapid reproductive senescence. On average, they had 50% shorter lives and 30% lower lifetime reproductive success (LRS) than did mothers with the lowest mating frequency. However, mothers with the highest mating frequency produced daughters with 28% greater LRS. This finding implies that frequent mating stimulates cross-generational fitness trade-offs such that maternal fitness is reduced while offspring fitness is enhanced. We evaluate these results using a demographic metric of inclusive fitness. We show that the costs and benefits of mating frequency depend on the growth rate of the population. In an inclusive fitness context, there was no evidence that increased mating frequency results in fitness costs for mothers. These results indicate that cross-generational fitness trade-offs have an important role in sexual selection and life-history evolution.
在许多物种中，交配频率的增加会降低母体的生存和繁殖能力。为了理解交配频率的进化，我们需要确定交配频率增加对后代的影响。我们在黑腹果蝇中进行了一项实验，在实验中我们操纵了母体的交配频率，并研究了母体及其女儿的生存和繁殖力。我们发现，交配频率最高的母体死亡率加速，生殖衰老更快。平均而言，与交配频率最低的母体相比，它们的寿命缩短了50%，终身繁殖成功率（LRS）降低了30%。然而，交配频率最高的母体所生女儿的LRS比其他女儿高28%。这一发现意味着频繁交配会刺激跨代适应性权衡，从而降低母体适应性，同时提高后代适应性。我们使用包容性适应性的人口统计学指标来评估这些结果。我们表明，交配频率的成本和收益取决于种群的增长率。在包容性适应性背景下，没有证据表明交配频率增加会给母体带来适应性成本。这些结果表明，跨代适应性权衡在性选择和生活史进化中具有重要作用。
