Molecular Biosciences

Research Summary: 

I seek to understand the mechanisms behind the evolutionary origin of new anatomical features and faunas. The philosophy that underlies all of my empirical work is derived from the conviction that progress in the study of evolutionary biology results from linking research across diverse temporal, phylogenetic, and structural scales. The Origin of Novel Faunas and Anatomical Systems: Much of today's vertebrate diversity was defined by ecological and evolutionary shifts that happened during two critical intervals in the history of the Earth: the Devonian and the Triassic. These periods serve as the focal point for my research because they witness the origin of both new ecosystems and new anatomical designs. My expeditionary research supplies new fossils and a paleoenvironmental context to understand the origin of faunas, whereas our morphological, functional, and developmental studies yield hypotheses on anatomical transformations.

Over the past fifteen years, I have developed expeditionary research programs in Canada, Africa, the continental United States, Asia, and Greenland. These expeditions have led to new insights on the origin of major groups of vertebrates (mammals, frogs, crocodiles, tetrapods, and sarcopterygian fish). Future studies on the origins of pterosaurs, rhizodontid fish, dinosaurs, and salamanders will rely heavily on fossils discovered over the past five years. Examples include the newly discovered adult fin and juvenile skeleton of the fish, Sauripterus. These fossils are providing evidence on the ways that appendage function and skeletal development shifted during the evolutionary radiation of lobe-finned fish. Indeed, this evolutionary radiation is temporally linked to the origin of new freshwater environments. Consequently, the analysis of Sauripterus will place comparative studies of fin structure, development and function in a phylogenetic and paleoenvironmental context.