Date of Award
Ph.D. in Biological Science
University of Mississippi
Termites in the genus Reticulitermes (Blattodea: Rhinotermitidae) are distributed across the eastern United States, including the southern Appalachian Mountains, a region incredibly rich in biodiversity. The eastern subterranean termite, Reticulitermes flavipes, has been uninentionally introduced to South America and Europe, and is predicted to further expand its geographic range. My goal was to determine how eco-evolutionary processes, operating at both long and short timescales, may have contributed to R. flavipes becoming an invasive species. I examined geographic and environmental influences at historical and contemporary timescales. To do this, I first determined the extent of niche divergence among three geographically overlapping Reticulitermes species, R. flavipes, R. malletei, and R. virginicus, and also identified the geographic areas and environmental conditions in which R. flavipes occurs to the exclusion of the other two species. Then, I assessed evidence for the influence of glacial-interglacial cycles on changes in the geographic distribution of R. flavipes, as well as potential genetic divergence within the species resulting from these past distributional shifts. In addition to historical eco-evolutionary processes, at the contemporary timescale I investigated how epigenetic mechanisms–specifically, DNA methylation–facilitate rapid responses to human-mediated disturbance of forest ecosystems. Finally, I developed a new landscape connectivity metric, MSconn, to help understand the effect spatial heterogeneity of environments plays on biological diversity at multiple levels of organization, from alleles to communities. In principle, MSconn can be integrated into an eco-evolutionary framework, making it possible to quantify the effect of biotic and abiotic environments on gene flow between populations, and vice versa, the effect of gene flow on species interactions within and between communities.
Hyseni, Chaz, "Evolutionary History Of Subterranean Termites In The Geographic And Ecological Context Of The Appalachian Mountains In The United States" (2020). Electronic Theses and Dissertations. 1976.