Ecological models in paleobiology


How do species change over time—in their abundance, competitive ability, and potential for extinction, speciation, or fossilization—and can these changes be predicted? One strand of my reseach uses ecological theory to address this question in the fossil record. This includes efforts to model fossil species survivorship with ecological neutral theory (figure at right, from here), ongoing investigation into the role of stochastic and deterministic forces in the rise and fall of species occupancy in fossil assemblages, and new work exploring the implications of individual-based models for ancestry in the fossil record.

Organisms in a changing ocean


Another research theme is the role of major events in earth history in facilitating or limiting the evolution of marine organisms. This has ranged from work on phylogenetic conservatism and local environment in predicting growth rates in bivalves, to ongoing work on evolutionary responses among bryozoans to a deep-time shift in ocean chemistry favoring aragonitic skeletons, to an attempt to trace the history of the Indo-Pacific diversity hotspot in comatulid crinoids and its correspondence with tectonic changes (figure, from here).

Crinoid evolutionary history


I try to ground my research questions in a careful study of marine organisms, especially the crinoids and their fossil representatives. 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.