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

Abstract

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 , 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.

Testing for local adaptation in adult male and female fitness among populations evolved under different mate competition regimes

“…; Yun et al. ). Our two alternative polygamy treatments differ in the extent of male harm (Yun et al.…”

“…Previous experiments using a single fly population have shown that mating interactions are more frequent, and male harm is more severe, when assayed in the simpler environment (Yun et al. ). Thus, we suspect the two polygamy treatments differ with respect to the codependence of male and female fitness and hence the importance of sexual conflict.…”

“…Our two alternative polygamy treatments differ in the extent of male harm (Yun et al. ), providing an opportunity to test whether reciprocal local adaptation between monogamous and polygamous populations is more likely when the polygamous population has evolved under conditions where we expect sexual conflict to be strong versus weak.…”

The “unguarded-X” and the genetic architecture of lifespan: Inbreeding results in a potentially maladaptive sex-specific reduction of female lifespan inDrosophila melanogaster

“…In any case, interpretation of our results in the mixed sexes group is complex and inherently speculative, especially concerning that a recent study has shown that female harm and male–male competition is exacerbated in standard fly vials with respect to more natural environments (Yun et al. ). Taking all of the above into account, we suggest results from the same sex and isolation treatments may actually provide a much clearer test of the UXh prediction than mixed sexes groups.…”

No evidence for short‐term purging benefits of sexual selection in inbred red flour beetle populations

“…Interestingly, recent studies show that the effects of sexual selection on dynamics of deleterious and beneficial genetic variants in populations may be strongly mediated by the physical structure of the environment in which mate competition and mating interactions occur (Singh et al . , Yun et al ., , ), adding another layer of complexity to the relationship between sexual selection and population performance.…”