The past 25 years of research on seaweed-herbivore interactions have witnessed remarkable advances in our understanding of seaweed defenses, the chemical and morphological mechanisms that seaweeds use to protect themselves from being consumed by their herbivores. In contrast, we have relatively less information on the proximate and ultimate mechanisms sculpting the evolution of herbivore feeding preference and tolerance for seaweed defenses. As an example, there is a mountain of evidence that tropical seaweeds produce greater types and quantities of seaweed chemical defenses than temperate seaweeds. In contrast, there is little direct evidence on whether tropical herbivores have evolved greater feeding preferences for, and juvenile performance on, tropical seaweeds relative to temperate herbivores. Using a cross- disciplinary approach that includes field-sampling, laboratory-based feeding behavior assays, juvenile performance assays, biochemical manipulation and DNA sequencing, the investigator will directly compare the genetically based feeding responses of tropical and temperate populations toward chemically-rich tropical seaweeds. These experiments should lead the investigator to discern whether or not tropical seaweeds and herbivores are evolving in a diffuse co-evolutionary manner. The investigator will also perform selection experiments to assess whether evolving feeding tolerance for a chemically-rich seaweed comes at an energetic cost. The broader impacts include partnering with programs at College of Charleston and an NSF-funded Research Experience for Undergraduates program in order to train at least 10-15 undergraduates across three years. Graduate students will also be trained during the course of the project.
