The evolutionary consequences of phenotypic plasticity are debated. For example, reproductive barriers between incipient species can depend on the social environment, but most evidence for this comes from studies focusing on the effects of experiencing heterospecific individuals of the opposite sex. In Drosophila melanogaster, males are well known to invest strategically in ejaculate components and show different courtship behavior when reared in the presence of male competitors. It is unknown whether such plasticity in response to same-sex social experience influences sexual isolation, so we tested this using African and cosmopolitan lines, which show partial sexual isolation. Males were housed in social isolation, with homopopulation, or with heteropopulation male partners. We then measured their mating success, latency, and duration, their paternity share, and female remating success. Isolated males copulated for a shorter duration than males housed with any male partners. However, we found no difference in any measure between homopopulation or heteropopulation treatments. Our findings suggest that the male intrasexual competitive social environment does not strongly influence sexual isolation in D. melanogaster, and that plastic effects on reproductive isolation may be influenced more strongly by the experience of social isolation than by the composition of individuals within different social environments.

中文翻译：

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D. melanogaster男性对同性竞争者的反应会影响性隔离吗？

对表型可塑性的进化影响进行了辩论。例如，初期物种之间的生殖障碍可能取决于社会环境，但大多数证据来自侧重于经历异性异性个体影响的研究。在果蝇中，雄性有战略性地投资于射精成分，并且在雄性竞争者的面前饲养时表现出不同的求爱行为。未知这种对同性社会经历的可塑性是否会影响性隔离，因此我们使用非洲和世界主义的线来测试这一点，这表明部分性隔离。男性被安置在社会隔离，同居或异居的男性伴侣中。然后，我们测量了它们的交配成功率，潜伏期和持续时间，他们的亲子关系和女性成功的婚姻。隔离的雄性的交配时间短于与任何雄性伴侣同房的雄性。但是，我们发现同族或异族治疗之间的任何测量均无差异。我们的研究结果表明，男性的性生活竞争性社会环境不会强烈影响黑腹果蝇中的性隔离，并且对生殖隔离的可塑性影响可能受社会隔离经验的影响比受不同社会环境中个体组成的影响更大。