Data from: The effect of sexual selection on adaptation and extinction under increasing temperatures

Strong sexual selection has been reported to both enhance and hinder the
adaptive capacity and persistence of populations when exposed to novel
environments. Consequently, how sexual selection influences population
adaption and persistence under stress remains widely debated. Here we
present two empirical investigations of the fitness consequences of sexual
selection on populations of the Indian meal moth, Plodia interpunctella,
exposed to stable or gradually increasing temperatures. When faced with
increasing temperatures strong sexual selection was associated with both
increased fecundity and offspring survival compared to populations
experiencing weak sexual selection, suggesting sexual selection acts to
drive adaptive evolution by favouring beneficial alleles. Strong sexual
selection did not, however, delay extinction when the temperature became
excessively high. By manipulating individuals’ mating opportunities during
fitness assays we were able to assess the effect of multiple mating
independently from the effect of population-level sexual selection, and
found that polyandry has a positive effect on both fecundity and offspring
survival under increasing temperatures in those populations evolving with
weak sexual selection. Within stable temperatures there were some benefits
from strong sexual selection but these were not consistent across the
entire experiment, possibly reflecting changing costs and benefits of
sexual selection under stabilising and directional selection. These
results indicate that sexual selection can provide a buffer against
climate change and increase adaptation rates within a continuously
changing environment. These positive effects of sexual selection may
however be too small to protect populations and delay extinction when
environmental changes are relatively rapid.