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NSF DDIG for Zach Marion

Congratulations to Zach Marion & Ben Fitzpatrick. They just found out that Zach’s NSF Dissertation Improvement Grant will be funded (details below)!

Dissertation Research: Evolutionary complexity and diversity of chemical defenses in diurnal and nocturnal fireflies

Predation is a powerful force driving prey evolution. Recent studies have highlighted that defenses against predators are rarely simple but are instead multivariate, with individual components that are better suited for some predators than others, or that are differentially expressed at different stages of ontogeny. Closely related populations or species may employ qualitatively and quantitatively different defense strategies because of chance or from past or ongoing selection. Thus, two key questions are (i) what factors favor particular defensive strategies and (ii) how are these strategies integrated into the phenotype? Chemically mediated defenses in fireflies provide an excellent system in which to evaluate these questions. Although primarily known for their bioluminescent mate signaling, most fireflies produce an impressive array of cardiac steroids that vary qualitatively (e.g., chemical structure) and quantitatively (e.g., concentrations) within and among populations and species. Yet, little is known about firefly chemical diversity, and how it—and integrated defensive phenotypes in general—evolve. Here we consider whether shifts between diurnal and nocturnal activity (and associated loses or gains of bioluminescence) are accompanied by changes in the mode and tempo of evolution of chemical defenses. We propose to quantify the complexity and diversity of chemical defense compounds in several species, and use a phylogenetic comparative framework to estimate rates of change and patterns of convergence and divergence of chemical phenotypes.

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