MSc. Student University of Toronto Fergus, Ontario, Canada
Sexual selection creates and maintains elaborate phenotypes despite costs imposed by natural selection1. This creates a trade-off that exists between natural and sexual selection whereby organisms can display traits that decrease survivorship if they sufficiently improve reproductive success1. Sexually selected ornaments used to signal attractiveness to potential mates, can be subject to this trade-off2,3. Typically, males display ornaments, and in many species, the more elaborate and showy the ornaments, the greater his mating success2. In dragonflies, many males display melanized wing ornaments where males with darker ornaments have higher reproductive success4. However, in a warming climate, male dragonflies that rely on dark pigments like melanin, which absorbs solar radiation, may be at particular risk of overheating as temperatures rise5,6 . Through manipulative field experiments of Leucorrhinia intacta and observations of naturally ornamented Celithemis elisa, I will assess how these two competing selection pressures acting on an organism can alter phenotypic variation. I will specifically investigate the question: how does variation in melanin ornamentation affect dragonfly mating success and thermoregulatory behaviour in varying weather conditions? My research will measure costs of climate change (time spent away from the mating arena) associated with sexual selection (wing ornamentation) of wild dragonflies. The trade-off between sexual and natural selection is an idea that has existed since Darwin first described these phenomenaand my research findings will add to our understanding of how this trade-off is influenced by climate change.
