Date of Award

8-2018

Degree Type

Thesis

Degree Name

Master of Science

Department

Biology

Program

Biology

First Advisor/Chairperson

Dr. Kurt Galbreath

Abstract

Current anthropogenically-driven climate change is accelerating at an unprecedented rate. In response, species’ ranges may shift, tracking optimal climatic conditions. Species-specific differences may produce predictable differences in the extent of range shifts. I evaluated if patterns of predicted responses to climate change were strongly related to species’ taxonomic identities and/or ecological characteristics of species’ niches, elevation and precipitation. I evaluated differences in predicted range shifts in well-sampled small mammals that are restricted to North America: kangaroo rats, voles, chipmunks, and ground squirrels. I used species distribution modeling to develop predictions for the distributions of species under current and future climate scenarios, and quantified the differences. AIC analysis was used to compare alternative models. Elevation held the most explanatory power to predict how species may respond to climate change, while clade identity was not a good predictor. However, a refined perspective based on phylogenetic relatedness provided some evidence of a relationship between evolutionary history and the biological factors that underlie species responses to climate change. I hypothesized that species responses to climate change reflect underlying ecological characteristics that are evolutionarily conserved. The small mammal groups showed varying levels of phylogenetic signal within different parameters. The strongest support was in the parameter representing the southern boundary, where the most warming is likely to be occurring. This may create a strong physiological constraint for species to stay within optimal climatic conditions.

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