Jessie L. Williamson, a research associate at the Museum of Southwestern Biology at UNM, is the recipient of the 2024 Tom L. Popejoy Dissertation Prize, which will be awarded during UNM’s fall graduate commencement ceremony on Dec. 12.

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Jessie L. Williamson named 2024 recipient of Tom L. Popejoy Dissertation Prize.

Williamson is a National Science Foundation postdoctoral research fellow in biology and a Rose Fellow at the Cornell Lab of Ornithology and Museum of Vertebrates, as well as a member of the Department of Ecology and Evolutionary Biology at Cornell University.

She is an integrative ornithologist who studies how elevation affects the migration, physiology and genomic divergence of birds.

She received a master’s and Ph.D. in biology from UNM, earning her doctorate in 2022. The title of her dissertation is “The role of elevation in the migration, physiology, and genomic diversification of birds.” 

Williamson explained her dissertation research by providing the context around her research topic. She said that elevational gradients cause profound eco-climatic variation over short distances, which underpins spatial patterns of diversity, diversification, seasonal movement, and species resilience in the face of projected climate change. Partial pressure of oxygen, in particular, is a severe challenge that organisms face at high elevations. Due partly to specialization on partial pressure of oxygen, most bird species in the Neotropics have narrow elevational ranges. However, a small fraction are elevational generalists that span sea level to high elevations, and a subset undertake extreme migratory journeys from low to high elevations biannually.

“My dissertation combined diverse approaches across levels of biological organization to understand how elevation impacts the ecology, evolution, physiology and migration of montane birds,” she said. “I examined ‘extreme’ elevational migration in birds worldwide, blood physiology of Andean hummingbirds, and migration, genomics, and phylogeography of the giant hummingbirds.”

She said that a major finding from the dissertation was that “extreme” elevational migration can facilitate speciation.

“We now know that the world's largest hummingbird is two deeply divergent species,” she said.

The results were reported in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Jessie Williamson (r.) and co-author
Jessie Williamson (r.) and Natalia Ricote affix a satellite transmitter to a Southern Giant Hummingbird in Chile. Photo credit: Chris Witt

Williamson said it was an honor to receive the Popejoy Prize.

“This dissertation involved intensive data collection from the coasts of Chile to the high Andes of Peru. It took more than 9 months in the field, and it would not have been possible without the tremendous genetic resources and natural history specimens at the Museum of Southwestern Biology,” she said. “This work demonstrates how molecular, phenotypic, and behavioral changes underly pervasive biogeographic patterns, highlighting the profound role of elevation in shaping biodiversity.”

Next August, she will start as an assistant professor in the Department of Zoology and Physiology at the University of Wyoming.

The Popejoy Dissertation Prize was established as a permanent memorial to the late Tom L. Popejoy, president of UNM from 1948 to 1968. The award recognizes and encourages the highest level of academic excellence, with competition structured among academic units on a three-year rotation. A $2,500 stipend is awarded at fall commencement.

Additional information about eligibility for the prize and the nomination process can be found online or by emailing grad@unm.edu.