My primary research interest focuses on macroevolutionary patterns, particularly origins and diversification patterns, evolution of key character suites, and biogeography. 

I have several projects ongoing. One of my long-standing interests has to do with neogastropod phylogeny, particularly that of the Columbellidae. This incredible diversity of this marine group makes them a good model system for investigating evolutionary changes in anatomy and ecology. 

Shell of Euplica turturina, a common Indo Pacific columbellid species.

As a gastropod anatomist, I also occasionally work on snails that don't live in water... Like succineid land snails! More details on those later, but here's a Catinella on the left.

I am also embarking into molecular phylogenetics and biogeography, with two projects. The first is a study of phylogeographic patterns in benthic marine organisms of the Hawaiian Islands. Marine organisms in Hawaii are often assumed to be panmictic throughout the islands. This is however likely not be true for species with little or no dispersal ability, and the degree of gene flow occurring between benthic marine populations is an important  consideration for developing conservation strategies. This project seeks to identify common patterns of gene flow throughout the islands, as well as the degree of connectivity between the Hawaiian Islands and nominally conspecific populations in other areas of the Pacific. At present we are focusing on investigating population structure in nondispersing marine snails, using mitochondrial and nuclear gene sequences. The picture at left is Peristernia chlorostoma, a nondispersing fasciolariid species native to the Hawaiian Islands, and in contrast the micrograph at right shows the protoconch and early teleoconch of Euplica varians, a columbellid species with long range larval dispersal.

The second project is a study of the evolution of small body size, using columbellid phylogenies and anatomical data. Columbellids are a diverse group of 400 or more small species (many of 10 to 20 mm shell length), including one or more clades of species that reach no more than 4 mm in shell length, for instance the adult Seminella pictured at left. A question that few researchers have been able to address is how anatomy changes in the evolution of taxa with very small adult sizes. Small body size can be achieved through one or both of two evolutionary shifts: proportional dwarfism (downsizing the entire body plan), or loss or reduction of body parts (often resulting in paedomorphosis). Columbellids are known to display reduction in size or total absence of some organs, and also vary in somatic cell sizes in some organs.  Resolving the evolutionary changes that have occurred in the evolution of small columbellids will illustrate how this process may have occurred in the origins of many major molluscan taxa, as well as other animal groups.

Last updated 27 January 2005