He earned a Ph.D. in Zoology in 1990 at Duke University and did postdoctoral training with Eric Davidson at the California Institute of Technology. As a developmental biologist he has used sea urchins as an experimental model to investigate how ontogeny is controlled by genetic information, cell physiology and environmental conditions. He is an author of numerous refereed journal articles. Over the past decade he has been exploring the idea that evolutionary change in complex systems is progressively constrained by their development.