Semester of Graduation
Fall 2025
Degree Type
Dissertation/Thesis
Degree Name
Masters in Integrative Biology
Department
Ecology, Evolution, and Organismal Biology
Committee Chair/First Advisor
Nicholas S. Green
Second Advisor
Todd Pierson
Third Advisor
Thomas McElroy
Abstract
Urbanization alters landscapes in ways that can reshape wildlife populations by changing habitat connectivity, resource availability, and selective pressures. To investigate how urbanization influences both genetic differentiation and morphology in small mammals, I examined Peromyscus leucopus (PELE) across an urban–rural gradient in northern Georgia. Using RADseq SNP data from PELE individuals across 13 sites, I quantified pairwise genetic differentiation (FST) and tested how various environmental variables, including impervious surface cover, human population density, and tree canopy cover, predict genetic differentiation after accounting for geographic distance. Genetic differentiation increased with geographic distance and, after controlling for isolation by distance, also increased with impervious cover and human population size while decreasing with tree canopy cover. These results indicate that urban landscape features limit gene flow and contribute to genetic differentiation among sites. In contrast, morphological measurements showed limited responses to urbanization. Most external body measurements did not differ significantly among urbanization categories, though body mass was significantly higher in suburban than in urban individuals. Linear and geometric morphometric analyses of skull morphology revealed no association with geographic distance. Morphological variation was better explained by differences among individual sites than by broad urbanization categories, suggesting that fine-scale environmental factors may outweigh the influence of urbanization level. Overall, these findings show that urbanization can influence genetic differentiation in PELE while morphological response remains subtle, emphasizing the importance of fine-scale habitat features in shaping urban wildlife populations.