Date of Award

11-2024

Degree Type

Thesis

Degree Name

Master of Science

Department

Biology

Program

Biology (MS)

First Advisor/Chairperson

Dr. Diana Lafferty

Abstract

The gut microbiome (GMB) of mammals hosts an important community of microbes that perform countless micro-ecosystem services for the host and are influenced by numerous factors including host physiology, environment, and phylogeny. Phylogeny may have a unique effect on GMB diversity and community structure (i.e., a GMB profile) via phylosymbiosis, a theory in which the evolution of hosts matches the evolution of their associated microbiota. Elucidating phylosymbiosis in mammals is difficult because multiple intrinsic and extrinsic factors collectively drive individual GMB variation. Thus, there is a need to simultaneously analyze the role of physiology, environment, and phylogeny on shaping host GMB profiles. I investigated this concept in 11 herbivore species across Etosha National Park (ENP), Namibia by extracting microbial DNA from fecal samples for 16S rRNA amplicon sequencing. I identified “core” bacterial taxa within herbivore species based on abundance and occurrence within samples. I discovered that certain bacterial taxa serve as environmental and physiological indicators in hosts. I found that GMB alpha diversity is influenced by sex and herbivore family, while GMB beta diversity is influenced by herbivore family and correlated with host divergence times in bovid species. However, ENP’s herbivore community did not exhibit phylosymbiosis, likely due to the influence of individual variation, dietary niche, and environment. This study fills knowledge gaps by quantifying the strength of multiple eco-evolutionary factors on GMB variation, and forms a foundation for future studies to incorporate GMB monitoring into conservation planning, which can serve as early warning signals for changes in host health.

Access Type

Open Access

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