NSF PRFB FY 2023: The evolutionary drivers of iridescence

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Iridescence has captured the human mind for hundreds of years, yet its role in animals is still mostly unknown. This research aims to resolve some of the mystery of this animal coloring by understanding how it works as an anti-predator defense. To do so, the fellow will use a combination of approaches, including filming predator-prey battles between birds and butterflies, altering the temperature while butterflies develop, and studying the evolutionary history of iridescence. This research will add to our understanding of the past and future of one of the natural world’s most interesting traits. These beautiful animals provide an excellent opportunity for public education. Using videos from the bird-butterfly experiments, the fellow will create an exhibit at the Smithsonian Museum to connect the visitor experience with scientific facts. To elucidate the evolutionary role and pattern of iridescence in butterflies, the project will explore three aims: 1) The fellow will video record interactions between insectivorous birds and experimentally modified Morpho butterflies to determine whether iridescence dissuades predator attack by warning predators of the difficulty of capture, or makes butterflies difficult to capture as a result of a visual illusion. 2) Using different temperature regimes on Morpho pupae, the fellow will test the developmental plasticity of iridescence to determine how variable environments affect iridescence quality in adult butterflies. 3) Using a comparative phylogenetic approach and phylogenetically-informed models, the fellow will investigate whether iridescence is constrained to certain lineages, constrained to certain regions in the world, or concentrated in areas with higher insectivorous bird diversity. This work will lead to a predictive model of the phylogenetic and biogeographic distribution of the iridescence trait and how this might shift in response to a changing climate. Additionally, the multi-component nature of this project will provide many training and co-authorship opportunities for students and researchers at the Smithsonian Tropical Research Institute based on their area of interest. The fellow plans to offer an R carpentry course at the host institution, in addition to curating a museum exhibit to maximize scientific outreach. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.