His bachelor’s degree is in biology in environmental science from the University of Iowa, and his doctorate is from UCLA. Between his undergraduate and graduate coursework, Dr. Gaddis served in the Peace Corps in Mauritania, teaching and coordinating environmental education programs and girl’s mentoring centers throughout the country. Dr. Gaddis works on a range of topics integrating ecological, genetic, and geographic tools to trace the effects of climate, environment, and landscape on the contemporary and historic movement patterns in plant and animal species.