Data from: The physical environment mediates male harm and its effect on selection in females

Recent experiments indicate that male preferential harassment of high-quality females reduces the variance in female fitness, thereby weakening natural selection through females and hampering adaptation and purging. We propose that this phenomenon, which results from a combination of male choice and male-induced harm, should be mediated by the physical environment in which intersexual interactions occur. Using Drosophila melanogaster, we examined intersexual interactions in small and simple (standard fly vials) versus slightly more realistic (small cages with spatial structure) environments. We show that in these more realistic environments, sexual interactions are less frequent, are no longer biased towards high-quality females, and that overall male harm is reduced. Next, we examine the selective advantage of high- over low-quality females while manipulating the opportunity for male choice. Male choice weakens the viability advantage of high-quality females in the simple environment, consistent with previous work, but strengthens selection on females in the more realistic environment. Laboratory studies in simple environments have strongly shaped our understanding of sexual conflict but may provide biased insight. Our results suggest that the physical environment plays a key role in the evolutionary consequences of sexual interactions and ultimately the alignment of natural and sexual selection.

近期实验研究表明，雄性对优质雌性的选择性骚扰会降低雌性适合度的方差，进而削弱作用于雌性的自然选择，并阻碍适应性进化与净化选择。我们提出，这种由雄性选择与雄性诱导伤害共同导致的现象，应当受雌雄间相互作用发生的物理环境所调控。本研究以黑腹果蝇（Drosophila melanogaster）为实验对象，对比考察了小型简易环境（标准果蝇培养管）与稍具生态真实性的空间结构小型笼养环境中的雌雄间相互作用。我们发现，在这类更具生态真实性的环境中，性相互作用的发生频率更低，不再偏向优质雌性，且整体的雄性诱导伤害水平有所下降。随后，我们在操控雄性选择机会的前提下，考察了优质雌性相较于低质雌性的选择优势。研究结果显示，与既往研究一致，在简易环境中雄性选择会削弱优质雌性的生存优势；但在更具生态真实性的环境中，雄性选择反而会强化作用于雌性的自然选择。尽管基于简易环境的实验室研究极大地塑造了我们对性冲突的认知，但这类研究可能会带来带有偏差的结论。本研究结果表明，物理环境在性相互作用的进化后果中发挥着关键作用，并最终影响自然选择与性选择的协同一致。