Author ORCID Identifier
https://orcid.org/0000-0001-9273-8034
Defense Date
2024
Document Type
Thesis
Degree Name
Master of Science
Department
Environmental Studies
First Advisor
Dr. Rodney Dyer
Abstract
Understanding the spatial distribution of genetic diversity and structure in endangered species is vital for effective conservation management. This research discusses the results of an initial analysis of the genetic structure and variation of the spotted turtle (Clemmys guttata), a species of conservation interest. The study sampled 913 individuals from 78 unique locales across 16 states in the eastern portion of the species' range. Utilizing ddRADSeq, a de novo genome assembly was developed to identify nearly 20,000 potential loci. A total of 926 were selected for this analysis. Results revealed no spatial clustering of genetic diversity or structure, which is unexpected for turtles. However, a gradual south-to-north reduction in heterozygosity, indicative of a relictual pattern left by post-Pleistocene range expansion, was found. Estimates of genetic differentiation were low, suggesting minimal population structuring. Although no structural clustering was observed, weak isolation by distance was noted, likely due to limitations in dispersal distance relative to the spatial extent of the sampling area. Future work would benefit from augmenting the dataset with samples from the rest of the species distribution and developing a whole-genome reconstruction to aid in population assignment, phylogeographic analysis, and investigation of adaptive genetic variance. These findings provide valuable insights for creating a comprehensive conservation strategy for spotted turtles.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-10-2024