Data from: Local adaptation to developmental density does not lead to higher mating success in Drosophila melanogaster

In this study, we investigate the effect of local adaptation to developmental density on male mating success in laboratory populations of Drosophila melanogaster. Mating success is known to be influenced by body condition which can in turn be influenced by local adaptation. We test the hypothesis that males adapted to a given environment have higher mating success when assayed in that environment. We used males selected for adaptation to high larval density and their controls which are reared at low larval density. We grew assay males in low and high densities while the focal females (raised at low larval density) used for the experiment belonged to the common ancestor of selected and control populations. We considered selected males grown at high density and control males grown at low density as “adapted”. Similarly we considered selected males grown at low density and control males grown at high density as “non-adapted”. Selected male belonging to a given treatment (larval density) was made to compete with control male of the same treatment for mating with ancestral female. We quantified components of reproductive fitness: mating latency, copulation duration, mating success and number of progeny sired by the “adapted” and “non-adapted” males. The results show that local adaptation does not lead to higher mating success in populations adapted to their own larval rearing environment.

本研究以黑腹果蝇（Drosophila melanogaster）的实验室种群为对象，探究发育密度的局部适应对雄性交配成功率的影响。已知交配成功率受身体状态影响，而身体状态又可受到局部适应的调控。本研究验证的假说为：适应特定环境的雄性，在该环境中进行交配检测时，将拥有更高的交配成功率。本研究使用了经过高幼虫密度适应选育的雄性果蝇，以及以低幼虫密度饲养的对照组雄性果蝇。我们将用于交配检测的雄性果蝇分别以低、高两种幼虫密度饲养；本实验所用的目标雌果蝇（均以低幼虫密度饲养）均来自选育种群与对照组种群的共同祖先。我们将高幼虫密度下饲养的选育雄性，与低幼虫密度下饲养的对照组雄性归为"适应组"；同理，将低幼虫密度下饲养的选育雄性与高幼虫密度下饲养的对照组雄性归为"非适应组"。将来自某一处理组（幼虫密度）的选育雄性，与同处理组的对照组雄性进行交配竞争，以争夺与祖先雌果蝇的交配机会。我们量化了繁殖适合度的多项指标：交配潜伏期、交配时长、交配成功率，以及"适应组"与"非适应组"雄性所产下的子代数量。实验结果表明，在适应自身幼虫饲养环境的种群中，局部适应并未提升雄性的交配成功率。