My lab studies the ecology and evolution of marine animals, focusing on their larval stages. We seek to understand how dispersal and habitat colonization by planktonic larvae links populations, and to identify factors that limit gene flow, set range limits, and promote speciation in the sea. A combination of molecular and chemical techniques, field studies, and laboratory experiments are employed. We are currently studying population connectivity between estuaries along the northeast Pacific coast, and among islands in the Caribbean.
Most marine invertebrates produce many long-lived, feeding larvae (planktotrophy) or a few short-lived, non-feeding larvae (lecithotrophy). A major goal of evolutionary biology is to understand the selective forces that favor shifts to non-feeding larvae, and the consequences of reduced dispersal following such shifts. Species with short-lived larvae typically show greater adaptation to local conditions and may speciate at a higher rate than planktotrophic taxa, in which dispersing larvae maintain gene flow between distant populations.
I use host-specialized sea slugs as a model system to investigate chemical mediation of larval settlement, the evolution of dispersal strategies, and mechanisms of speciation. Slugs in the suborder Sacoglossa are herbivores that feed on large-celled algae; most are highly specific, feeding only on one host species. This has led to remarkable co-evolution between slugs and algae. Slug larvae settle in response to chemical cues from their host, and adults may sequester functional chloroplasts and defensive chemicals from their algal food. Non-feeding larvae have evolved many times among sacoglossans, and three species produce both feeding and non-feeding larvae, a very rare polymorphism. This group is thus an ideal system for studying processes important to marine ecology and evolution.
Links to major research topics:
REAL-WORLD APPLICATIONS -- Drugs from Slugs