When Does Gene Flow Stop? A Mechanistic Approach to the Formation of Phylogeographic Breaks in Nature by Iris Holmes A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Ecology and Evolutionary Biology in the University of Michigan 2020 Doctoral Committee: Assistant Professor Alison Davis Rabosky, Chair Research Professor Liliana Cortés Ortiz Professor Patrick Schloss Associate Professor Stephen Smith Iris A. Holmes
[email protected] ORCID iD: 0000-0001-6150-6150 © Iris A. Holmes 2020 Dedication I dedicate this thesis to Michael Grundler, who is always there. ii Acknowledgements The research in this dissertation was supported by funding from the University of Michigan, including the Department of Ecology and Evolutionary Biology, the Museum of Zoology, and the Rackham Graduate School. It was also supported by grants from the Bureau of Land Management, and the STEPS Institute for Innovation in Environmental Research at the University of California. The research in my dissertation was greatly facilitated by the National Science Foundation Graduate Research Fellowship, the Rackham Predoctoral Fellowship, and the Rackham Graduate School Anna Olcott Smith Women in Science Award. I would like to thank my adviser, Alison Davis Rabosky, for her care and attention in developing both my strengths and weaknesses as a scientist. I would also like to thank the rest of my committee, Patrick Schloss, Stephen Smith, and Liliana Cortez Ortiz, for their help and support in completing my dissertation. In addition, I have had the privilege to work with excellent coauthors on the manuscripts in this dissertation, including Maggie Grundler, William Mautz, Ivan Monagan Jr, and Mike Westphal.