Projects

Population biology in paleontology

How do species change over time—in their abundance, interactions, and potential for extinction, speciation, or fossilization? And how do these changes flow from simple ecological and evolutionary theory? My work in this area includes efforts to model fossil species survivorship with ecological neutral theory (figure at right, from here), ongoing investigation into the role of selection and drift in the rise and fall of species in the fossil record, and new work exploring the implications of individual-based models for the prevalence of ancestors in the fossil record.

Invertebrates in a changing ocean

Another research theme is the role of major events in earth history in the evolution of marine organisms and communities. This includes studies on work on the roles of phylogenetic conservatism and local environment in determining growth rates in bivalves, the history of the Indo-Pacific diversity hotspot in comatulid crinoids and its correspondence with tectonic changes (figure, from here), and ongoing work on skeletal adaptations among bryozoans to deep-time shifts in ocean chemistry.

Crinoid evolutionary history

My research is grounded in the careful study of fossil and living organisms, especially marine invertebrates like the crinoids figured here. Past and ongoing projects include contributions to crinoid physiology and internal morphology, phylogenetics of living and fossil crinoids, crinoid historical biogeography, and descriptions and revisions of crinoid faunas from the Cretaceous of Texas and the Miocene of Europe and Australia.