Ryan Harrigan Ph.D.
Associate Adjunct Professor, IoES; Associate Researcher, CTR
Center for Tropical Research
UCLA Institute of the Environment and Sustainability
La Kretz Hall, Suite 300
Los Angeles, CA 90095-1496
My main research interests include the evolutionary biology and ecology of species and species complexes. Separate and yet not mutually exclusive evolutionary forces often contribute to the complex phylogenetic relationships we are witness to across the globe. These include events such as hybridization and introgression between closely related taxa, past and current speciation events, and incomplete lineage sorting. My research focuses on these biological phenomena, and how they help to shape the current patterns and genetic relationships among organisms. Particularly interesting to me are cases where additional anthropogenic forces are likely contributing to already complex natural processes. Such is the case in North American waterfowl, for instance, where a commercially and recreationally valuable species complex has been subjected to both natural and artificial influences, resulting in the patterns of phylogeography and distribution we see today. My current work is focused on how anthropogenic stressors have affected the spread of recently introduced, multi-host pathogens, and how migrant bird populations have been affected by such introductions.