Gapp concentrates on comparative endocrinology of reptiles, with a focus on the action and evolution of gastrointestinal and pancreatic hormones. He has written and reviewed manuscripts for notable journals including The Journal of Comparative Endocrinology and Physiological Zoology, and he has received research grants from the National Institutes of Health and the National Science Foundation. His research focuses primarily on turtles and alligators, examining factors controlling insulin and gastrin release and looking particularly at seasonal aspects of pancreatic hormone release in turtles. His recent identification of "diabetes" in a local population of snapping turtles may provide an interesting model to pursue the study of this serious metabolic disease that affects a significant portion of the American population.
