Date Approved

2020

Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)

Department

Biology

Committee Member

Katherine Greenwald, Ph.D.

Committee Member

Kristin Judd, Ph.D.

Committee Member

Brian Connolly, Ph.D.

Abstract

Climate change drives changes in organisms’ geographic ranges that can lead to shifts in population structure. Unisexual (all female) Ambystoma salamanders reproduce via kleptogenesis, resulting in ploidy-variable offspring. I analyzed genetic data of historic and modern-day unisexual and A. laterale samples from the University of Michigan’s E. S. George Reserve using epidermal cell nuclei measurements and microsatellite loci. I found that population composition has shifted away from the more northern-distributed A. laterale and toward populations dominated by unisexuals in five out of six ponds. There was a significant relationship between the proportion of A. laterale to unisexuals and pond size but not between the proportion of A. laterale and mean and maximum temperature, or canopy cover. Changes in population composition could help reveal the susceptibility of amphibians to climate change and whether adaptation can keep pace with rapid environmental change

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