Date of Award
5-1-2026
Document Type
Dissertation
Degree Name
Ph.D. in Biological Science
First Advisor
Brice P. Noonan
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
The Tugaloo River is a 50-mile-long stretch of river that serves as an important political and biogeographical boundary in far northeastern Georgia and northwestern South Carolina. The extreme topography, complex geological and hydrological history, and unique assemblage of soils, flora, and fauna of the Tugaloo region make it a prime candidate for study. I used the diverse salamander community there to conduct two studies. Study 1 investigated how the population genomics of select species in the genera Desmognathus and Plethodon were impacted by ancient drainage modifications from the Pleistocene which included not only the Tugaloo River but also the Tallulah, Chattooga, and Chattahoochee rivers. Study 2 investigated a newly discovered host-parasite system between hairworms (phylum Nematomorpha) and the Tugaloo-endemic Patch-nosed Salamander (Urspelerpes brucei), aiming to ascertain the prevalence, intensity, and abundance of infection across the range of U. brucei in addition to testing if hairworm infection was species-specific. For Study 1, the genomic dataset revealed three broad patterns across all study taxa: 1) Populations in the Chattahoochee and Tallulah drainages were most closely related despite not being connected by water, a pattern reflecting ancient river connections instead of contemporary ones. 2) Populations in the Chattooga drainage are genetically distinct and often, though not always, cluster with Brasstown Creek populations on the eastern side of the Tugaloo River. 3) Populations on the western side of the Tugaloo River often, though not always, form a unique genetic cluster. For Study 2, surveys revealed that hairworm infection was not specific to U. brucei, with infections also being found in larval dusky salamanders (Desmognathus spp.). However, infection was very rare in dusky salamanders (prevalence = 0.13; intensity = 3.25; abundance = 0.41) while being quite common in U. brucei (prevalence = 0.74; intensity = 119.94; abundance = 88.65). Both of my studies highlight unique phylogeographical patterns and ecological interactions to be found in association with the Tugaloo River, suggesting its importance in shaping diversity in northeastern Georgia and northwestern South Carolina.
Recommended Citation
Brock, Tyler Lewis, "The Tugaloo Effect: Preliminary Analyses of Population Genomics and Parasitism in Salamanders of Northeast Georgia" (2026). Electronic Theses and Dissertations. 8801.
https://egrove.olemiss.edu/etd/8801