Department of Biology, University of Padova, via U. Bassi 58/B, 35131 Padova, Italy.
Evolution. 2012 Feb;66(2):532-43. doi: 10.1111/j.1558-5646.2011.01455.x. Epub 2011 Sep 29.
Sexual harassment is a common outcome of sexual conflict over mating rate. A large number of studies have identified several direct costs to females of sexual harassment including energy expenditure and reduced foraging ability. However, the fitness consequences of sexual harassment for descendants have rarely been investigated. Here, we manipulated the level of sexual harassment and mating rate in two groups of female guppies, Poecilia reticulata, a live-bearing fish in which sexual conflict over mating rate is particularly pronounced. Each female was allowed to interact with three males for one day (low sexual harassment, LSH) or for eight days (high sexual harassment, HSH) during each breeding cycle throughout their life. Female lifetime fecundity did not differ between the groups, but we found a strong effect on offspring fitness. HSH females produced (1) daughters with smaller bodies and (2) sons with shorter gonopodia, which were less attractive to females and less successful in coercive matings than their LSH counterparts. Although these results may be influenced by the indirect effects of sex ratio differences between treatments, they suggest that sexual harassment and elevated mating rate can have negative cross-generational fitness effects and more profound evolutionary consequences than currently thought.
性骚扰是交配率性冲突的常见结果。大量研究已经确定了女性遭受性骚扰的一些直接代价，包括能量消耗和觅食能力降低。然而，性骚扰对后代的适应度后果很少被研究。在这里，我们在两组雌性孔雀鱼（Poecilia reticulata）中操纵性骚扰和交配率的水平，这是一种胎生鱼，其中交配率的性冲突特别明显。在每个繁殖周期中，每个雌性鱼都可以与三只雄性鱼互动一天（低性骚扰，LSH）或八天（高性骚扰，HSH）。两组之间的女性终生繁殖力没有差异，但我们发现对后代的适应度有很大的影响。HSH 雌性产生（1）体型较小的女儿，（2）具有较短生殖肢的儿子，这些儿子对雌性的吸引力较小，在强制交配中比 LSH 雌性的后代更不成功。尽管这些结果可能受到处理之间性别比例差异的间接影响，但它们表明性骚扰和提高的交配率可能对跨代适应度产生负面影响，并且比目前认为的更具有深远的进化后果。
