A long-standing question in evolution is whether strong mate competition and mate selection influences the evolution of species. This question remains unresolved because species accumulate over deep timescales, and previous studies have revealed ambiguous results. In contrast to studies across species, studies across populations show clear links between mate selection and rapid evolution, and show correlations between male mating signals and the associated female preferences. Missing in the literature is a study that tests these population-level findings in a species-level context, specifically, one that correlates differentiation in male mating signals and female perception. If changes in female perception are met with changes in male signal, the project will support a novel finding: that similar mechanisms are at work across species as across populations. This also suggests that sexual signals may be constrained by female physiology, and that changes in female physiology allow for changes in male signal diversity. Results from this project will be disseminated at international meetings, undergraduates will be actively involved in this research, and outcomes of this project will contribute to the development of novel biomedical reporter enzymes that create different colors of bioluminescence.
Bioluminescent, mate-signaling ostracod crustaceans offer a unique system to understand how closely sexual signals associate with their intended receivers. The researchers will first measure bioluminescent emission spectra from males of 26 species of ostracod crustaceans collected from the Caribbean Sea. Next, they will measure female perceptual spectra from 10 species using a visual physiology technique that determines the absorption of specific wavelengths of light through single photoreceptor cells in the eye. The researchers will then determine the amount of overlap of male sexual trait spectra (the color of the bioluminescence) and the female perceptual spectra. If population genetic theory holds, and preference is determined by perception, we expect covariation between male signals and female physiology.
