Collaborative Research: RUI: Evolution of color variation in Hawaiian damselflies: causal links for an ecological selection hypothesis

James Madison University, Harrisonburg VA

Investigators

Abstract

Colors of male and female animals can be strikingly different, a condition usually explained by the advantages provided in attracting mates. However, the sexes may vary over a wide spectrum, from very different in color to identical, and in some species one sex can vary across typically male or female colors. This study tests whether colorful pigments function not as a visual mating signal, but rather as antioxidant protection against damaging effects of UV radiation. The researchers extend their past research documenting the spectacular variation in color in endemic Hawaiian damselflies, including the discovery that sexual and population variation in color is correlated with each sex's solar exposure, which varies substantially across different island habitats. Undergraduate students at both RUI institutions will assist in research and in developing curricular materials and an exhibition that explores color in nature, both scientifically and artistically. This project contributes to our understanding of genotype to phenotype mapping and tests a novel hypothesis about pigmentation and antioxidant function. The researchers will (1) identify how body color is correlated with UV exposure, which varies with sex and species-specific microhabitats; (2) test whether sexual selection can explain the habitat and color correlations; (3) connect color variation with survivorship in different habitats, and (4) identify pigment chemical identity and confirm its antioxidant function across many species of the radiation. A direct test of the pigment's antioxidant function provides a new perspective on the causes of variation between species and sexes, and sets the stage for future studies on color variation, including its genetic basis, its role in crypsis, and the role of selection on color vs. gene flow in species diversification.