Undergraduate Honors Theses

Thesis Defended

Fall 2018

Document Type


Type of Thesis

Departmental Honors


Ecology and Evolutionary Biology

First Advisor

Andrew Martin

Second Advisor

Cheryl Pinzone

Third Advisor

Barbara Demmig-Adams

Fourth Advisor

Erin Huebert

Fifth Advisor

Chris Pague


In the late 1800s, the American plains bison (Bison bison) suffered from a severe reduction in population size, known as a bottleneck event. Their numbers, once in the millions, were reduced to less than a thousand individuals, but populations were able to recover owing to the diligence of several private ranchers and other private and governmental groups. While bison populations have improved today, their genetic diversity has been impacted by the bottleneck event, habitat fragmentation, and hybridization with domestic cattle (Bos taurus). With advances in genetic technology, it is now possible to gather genetic information of a species to aid in their conservation. Here, using genetics software, I analyzed nuclear genetic data previously used to detect cattle genes in the Medano-Zapata bison herd located in Colorado, USA. I was able to determine (1) the number of genetic clusters and (2) calculate different indices of genetic variation to estimate population viability. I hypothesized that more than one cluster would occur within the population due to its large size. My results rejected this hypothesis, with the strongest likelihood supporting a single cluster. This information is important for understanding the genetic diversity of the herd. It is also important for understanding the impacts of cattle genes on bison populations and what they mean for the species’ future conservation.