Peter Breslin, PhD

Staff Researcher, Desert Laboratory on Tumamoc Hill

Peter Breslin started his Ph.D. in Environmental Life Sciences at Arizona State University in 2014 after a 30-year career teaching secondary school. He finished the Ph.D. in 2020. His Ph.D. research involved the evolution, ancestral biogeography, and population viability of a group of cacti called the Mammilloid Clade, composed of plants commonly called "pincushions" and "fishhooks," including the locally common Cochemiea grahamii (formerly in Mammillaria). He has published three greatly revised chapters of his dissertation, in Ecology and Evolution, Taxon, and the American Journal of Botany. He is also the editor of The Cactus and Succulent Journal and the peer-reviewed annual, Haseltonia, published by The Cactus and Succulent Society of America. On Tumamoc Hill, Breslin is a postdoctoral researcher conducting the decadal survey of the saguaro plots set up in 1964 by Rod Hastings and Ray Turner. He hopes to use this extraordinary long-term data set, as well as data from the National Park Service and researchers in Mexico, to make projections about the future of the saguaro over the next 100 to 200 years.


  • PhD in Environmental Life Sciences, Arizona State University, in 2020