Date of Award

1-1-2015

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

College/School/Department

Department of Biological Sciences

Content Description

1 online resource (x, 164 pages) : color illustrations, color maps

Dissertation/Thesis Chair

Ing-Nang Wang

Committee Members

Jeremy Kirchman, Mary Katherine Gonder, April Davis

Keywords

Biogeography, Genetic Bottleneck, Infectious Disease, Myotis lucifugus, Pleistocene Refugia, White-Nose Syndrome, Little brown bat, White-nose syndrome, Animal population genetics

Subject Categories

Biology | Genetics

Abstract

A myriad of biotic and abiotic factors contribute to the fluctuations in geographic range and size of animal populations. In the Nearctic, bat species have experienced drastic historic changes in available habitat due to Pleistocene glaciations, and are recently imperiled by the introduction of a novel fungal pathogen, Pseudogymnoascus destructans within the last decade. Myotis lucifugus in particular has lost 90-95% of the population in the eastern US due to the fungal disease White-Nose Syndrome (WNS). A population decline of this magnitude will likely result in a loss of allelic diversity as a result of a genetic bottleneck. My study aims to quantify the genetic structure and variation of this eastern population prior to the arrival of WNS, to determine changes to the structure and variation have occurred as a result of WNS, and to show if historic demographic changes have contributed to any changes in its genetics. By utilizing three separate genotyping techniques, I am able to demonstrate that 1) mitochondrial DNA indicate this species underwent a massive population expansion following the retreat of Pleistocene glaciations, 2) microsatellite loci show weak evidence of a recent bottleneck that corresponds with the arrival of WNS, and 3) SNPs have similar structure to that of both mitochondrial DNA and microsatellites, and some regions show limited support for divergent selection at a number of loci. My results from the microsatellite data are likely confounded by the potential migration of uninfected individuals from the south or west of the Central region of NY following WNS mortality, and my mitochondrial and SNP data also support my hypothesis of migration of unique individuals from outside of the Northeastern US. I conclude that temporal changes in population structure is evidence of migration of naïve bats to the center of the outbreak, and that an ecological response of the population is more likely than any evolutionary response due to the limited timeframe of the outbreak of disease.

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