The history, interactions, and relationships of the taxa that we study are the threads that unite the various temporal and spatial scales of our research. This approach requires that we employ a wide variety of techniques, including paleontological, geological, and biogeographical data, along with comparative morphology, developmental biology, long-term experimental manipulations, phylogenetic studies, and molecular techniques.

My systematic work features the Patellogastropoda, a basal group of gastropod molluscs that figure prominently in ecological studies of rocky shores around the world. We use phylogenetic hypotheses to understand adaptation and evolution in patellacean faunas around the world and through time. I also remain interested in the role of substrates in determining and augmenting community composition. Some effort in our lab is also directed at understanding the evolutionary history of California land snail taxa as well. I also investigate relationships amongst higher molluscan taxa including subclades within the Gastropoda, the "conchiferian" groups, and the phyletic position of the Mollusca on the Tree of Life.

A recurrent theme in many of these studies is the role of heterochrony, especially in the evolution of morphology, life history strategies, and reproductive systems in molluscs. This work focuses on the intersections of phylogeny and development using different developmental data sets and tools and comparisons across levels of organization and the phylogenetic hierarchy.

Research topics selected by my graduate students are often outside my own areas of interest, but share a phylogenetic framework, include fossil as well as living organisms as study taxa, and are concerned with the nearshore marine environment.