Data from: Male cognitive performance declines in the absence of sexual selection

Sexual selection is responsible for the evolution of male ornaments and armaments, but its role in the evolution of cognition—the ability to process, retain and use information—is largely unexplored. Because successful courtship is likely to involve processing information in complex, competitive sexual environments, we hypothesized that sexual selection contributes to the evolution and maintenance of cognitive abilities in males. To test this, we removed mate choice and mate competition from experimental populations of Drosophila melanogaster by enforcing monogamy for over 100 generations. Males evolved under monogamy became less proficient than polygamous control males at relatively complex cognitive tasks. When faced with one receptive and several unreceptive females, polygamous males quickly focused on receptive females, whereas monogamous males continued to direct substantial courtship effort towards unreceptive females. As a result, monogamous males were less successful in this complex setting, despite being as quick to mate as their polygamous counterparts with only one receptive female. This diminished ability to use past information was not limited to the courtship context: monogamous males (but not females) also showed reduced aversive olfactory learning ability. Our results provide direct experimental evidence that the intensity of sexual selection is an important factor in the evolution of male cognitive ability.Latency to copulation data w/ one femaleThe time to copulation in seconds for males from different experimental populations when paired with one virgin, receptive femaledryad_SS_exp1.txtLatency to copulation data w/ multiple femalesLatency to copulation for males from different experimental populations when placed with one virgin and either one unreceptive (unreceptive=0) or five unreceptive (unreceptive=1) females.dryad_SS_exp2.txtCompetitive mating success dataCounts of ebony and wild type offspring for competitive mating assays with experimentally-evolved populationsdryad_competitive.txtAversive learning data for males and femalesAversive learning data for flies from experimentally-evolved populations, with the number of flies going each direction (MCH vs OCT) indicated along with the CS+ (under CSplus variable)dryad_SSlines_learning.txtTime series data for male courtshipMinute-by-minute courtship for males from experimentally-evolved populations. Fly is either actively courting (courting=1) or not courting (courting=0). If courting, the fly is either courting the receptive female (target=1) or one of the unreceptive females (target=0).dryad_haystack.tx