CNIC: US-Croatian-French Research on the Digestive Anatomy and Physiology of Herbivorous Populations of the Lizard Species,Podarcis sicula

University Of California-Irvine, Irvine CA

Investigators

Abstract

An animal's digestive tract is a dynamic physiological system that supplies nutrients to the body and, to ensure survival, it must respond to changes in diet and environmental conditions. What an animal is capable of digesting, or not digesting, tells us how an animal lives in its environment and how it contributes to nutrient cycling in that environment. Recent studies have shown the value of using experimental evolution to reveal how the digestive tract responds to diet changes over different time scales. In this preliminary study, researchers from the University of California-Irvine and expert international counterparts from the University of Zagreb, in Croatia, and the French Museum National d'Histoire Naturelle in Paris will begin a collaboration to investigate the nutritional physiology of Podarcis sicula, a lizard species that has shown rapid evolution of feeding and digestive tract morphology. Together, the US-Croatian-French team led in the U.S. by Donovan P. German of U.C.-Irvine will examine the results of a manipulative study that transferred breeding pairs of Podarcis sicula from the island of Pod Kopiste to another Croatian island, Pod Mrcaru, which had lacked this species. Interestingly, after 30 generations the transferred pairs became more herbivorous on Pod Mrcaru (~36 years), resulting in marked differences in body morphology compared to the insect-eating parent population from Pod Kopiste. The goal of this new collaboration is to initiate an investigation of the digestive physiology (including digestive enzyme activities and microbial diversity) and the gut structure of P. sicula from Pod Kopiste and Pod Mrcaru to better understand "what it takes to be an herbivore?" and how such changes in an animal's gut can occur so quickly. The broader impacts of this work may include contributions to the medical field of gastroenterology (e.g., what happens when people suddenly become vegetarian?). Thus in the long run, this effort should benefit society by adding to our fundamental knowledge of nutritional physiology and dietary specialization, both, in animal models and potentially in humans. Furthermore, because U.C.-Irvine and Croatian students will be involved in the joint work, broader impacts also include publication and direct outreach by the researchers and these students in schools and other public fora, as well as educational benefits for the U.S. student participants through early career training in scientific techniques and inquiry-based research abroad.