Molecular Evolution in the Mountains: Genetic Affinity and the Environment led to Adaptive Variation in the American Pika (Ochotona princeps)

Author

Zachery M. Farrand, Northern Michigan UniversityFollow

Date of Award

12-2022

Degree Type

Thesis

Degree Name

Master of Science

Department

Biology

Program

Biology (MS)

First Advisor/Chairperson

Dr. Katherine Teeter

Abstract

The American pika (Ochotona princeps) is discontinuously distributed in high elevation and montane regions across western North America, where isolated lineages have potentially evolved along divergent trajectories since the mid-Pleistocene. Ochotona princeps encounters cold temperatures, hypoxia, and dietary toxins, and therefore has thermoregulatory, metabolic, and behavioral adaptations related to these environmental challenges. Studies have confirmed interspecific adaptive variation between O. princeps and other Ochotona species, but there is limited research regarding intraspecific adaptive variation within O. princeps. I investigated adaptive responses in a panel of candidate genes with functions related to these conditions in Ochotona and other mammal species. I aimed to identify variation in genotype-environment associations across five O. princeps lineages and determine ancestries of these selective signals. I sequenced candidate genes in 179 Ochotona samples using custom hybridization baits. Resultant SNP datasets were tested for genotype-environment associations using redundancy analysis and latent factor mixed models. Significant outlier alleles were identified from relationships with elevation, temperature, and precipitation and varying ancestral relationships in key adaptive genes were determined. I argue that genetic affinity in O. princeps significantly interacts with landscape features, resulting in unique genotypes among genes related to environmental adaptation.

Recommended Citation

Farrand, Zachery M., "Molecular Evolution in the Mountains: Genetic Affinity and the Environment led to Adaptive Variation in the American Pika (Ochotona princeps)" (2022). All NMU Master's Theses. 730.
https://commons.nmu.edu/theses/730

Access Type

Open Access

Justification for Restricting Access

Restricting access will provide my committee and I time to publish my results in a peer-reviewed journal before making conclusions and methodologies available to the public.