Fincke Ola M
Program in Evolutionary Ecology and Behavior, Department of Biology, The University of Iowa, Iowa City, IA, 52242.
Evolution. 1986 Jul;40(4):791-803. doi: 10.1111/j.1558-5646.1986.tb00539.x.
Major components of male and female lifetime reproductive success (LRS) were quantified for a damselfly that exhibits "scramble competition" for mates. The opportunity for selection on male reproduction was potentially 2.9 times that for females. Differential fertility/clutch and survivorship each accounted for about half of the total variation in female reproductive success. Variation in fertilization efficiency accounted for 7% of the total opportunity for selection on males. Although differences in survivorship and mating efficiency each contributed to about a third of the total opportunity for selection on male reproduction, both components appeared to be influenced by random factors. Survivorship was age-independent, and the mating distributions among males with equal mating opportunities were indistinguishable from those expected if matings were random with respect to male phenotype. Because the proportion of the standarized variance (I) in LRS that was attributed to sexual selection depended on the way the selective episodes were defined, the sample of individuals included in the partitioning analysis, and the degree of sexual selection on mated males that could be detected, my results caution against drawing conclusions about the dynamics of sexual selection on populations based on a superficial comparison of I values.
对一种表现出配偶“争夺竞争”的豆娘，对其雄性和雌性一生繁殖成功率（LRS）的主要组成部分进行了量化。雄性繁殖的选择机会可能是雌性的2.9倍。雌性生育力/窝卵数差异和存活率差异各占雌性繁殖成功率总变异的约一半。受精效率的变异占雄性繁殖选择总机会的7%。虽然存活率和交配效率的差异各占雄性繁殖选择总机会的约三分之一，但这两个组成部分似乎都受随机因素影响。存活率与年龄无关，具有同等交配机会的雄性之间的交配分布与假设交配相对于雄性表型随机时预期的分布没有区别。由于LRS中归因于性选择的标准化方差（I）比例取决于选择性事件的定义方式、划分分析中包含的个体样本以及对已交配雄性可检测到的性选择程度，我的研究结果提醒人们不要基于I值的表面比较就对种群中性选择的动态得出结论。
