Date of Award

Spring 1-1-2015

Document Type


Degree Name

Doctor of Philosophy (PhD)


Ecology & Evolutionary Biology

First Advisor

Valerie J. McKenzie

Second Advisor

Andrew Martin

Third Advisor

Sharon Collinge

Fourth Advisor

Steve Schmidt

Fifth Advisor

Reid Harris


Ecologists have long been challenged to understand the role of host-­‐associated microbial communities in host health and pathogen defense. Recent technological advances in high throughput sequencing have allowed scientists to observe the immense microbial diversity of host-­‐associated habitats. However, we are only beginning to appreciate evolutionary interactions of the host and its microbiome. The ability to mitigate diseases of host organisms through biological manipulations of the host’s biotic community is a new research area for wildlife disease managers. One understudied area is how amphibian skin-­‐ associated microbial communities interact with a known fungal pathogen and how they may function to protect the host from developing disease. In order to address this understudied area, the first objective is to characterize the patterns of natural variation within species, across populations, and through developmental life stages of amphibians. This will elucidate the ecological drivers of host-­‐associated microbiota and how pathogen-­‐ inhibiting microbes are distributed across species, space, and life stages. The second goal is to test whether an amphibian skin microbiome can be manipulated to provide a protective effect against the fungal pathogen. How amphibian skin-­‐associated microbial communities respond to pathogen invasion and probiotic applications may provide unique insight into iv invasion ecology and disturbance ecology of the host-­‐associated microbiota. Amphibians and diverse bacteria and fungi that inhabit their skin provide an excellent model system for studying interactions between hosts, their microbial communities, and pathogens. Amphibian skin can be repeatedly and nondestructively sampled, and can be manipulated through antibiotics or bioaugmentation. This system also offers an opportunity to develop therapeutic tools for one of the world’s most threatened taxa.