DOI
https://doi.org/10.25772/4PYQ-0821
Defense Date
2017
Document Type
Thesis
Degree Name
Master of Science
Department
Biology
First Advisor
Andrew J. Eckert, Ph.D.
Abstract
Environmentally related selective pressures and community interactions are well-documented drivers for niche differentiation, as natural selection acts on adaptive traits best fit for survival. Here, we investigated niche evolution between and within Pinus taeda, Pinus rigida, and Pinus pungens and sought to identify which climate variables contributed to species divergence. We also sought to describe niche differentiation across genetic groupings previously identified for P. taeda and P. rigida. Ecological niche models were produced using Maximum Entropy followed by statistical testing based on a measure of niche overlap, Schoener’s D. Both niche conservatism and niche divergence were detected, thus leading us to conclude that directional or disruptive selection drove divergence of the P. taeda lineage from its ancestor with P. rigida and P. pungens, while stabilizing selection was associated with the divergence of P. rigida and P. pungens. The latter implies that factors beyond climate are important drivers of speciation within Pinus.
Rights
© Constance E. Bolte
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-15-2017