Biology ETDs


Kayce Bell

Publication Date



Diversification of parasite species, in light of their host association, is an area ripe for testing hypotheses of evolution when one species requires another for survival. The 23 species of western North American chipmunks (genus Tamias) host two species of ectoparasitic sucking lice (Anoplura) and two species of endoparasitic pinworms (Nematoda). I used a phylogenetic approach to investigate the evolutionary histories of the parasites in light of the hosts and the landscape. In comparing the parasites, I found that the two pinworm species have similar diversification patterns, linked to hosts, but those processes occurred on different time scales. As another paired investigation, the chipmunk sucking lice revealed some lineages that correspond to host relationships, but the lice have different histories from the hosts, as well as each other. Overall, this system demonstrates that parasite diversification cannot be explained as a simple process of codivergence and that parasite evolution, even when comparing parasites from the same hosts and ecological roles, is complex and the history is unique to each species. While I found a role for hosts, host demographic history, and landscape in shaping genetic structure in all four parasites, these processes impacted each parasite species differently.

Project Sponsors

National Science Foundation, American Society of Mammalogists, Society of Systematic Biologists, American Society of Parasitologists, Lloyd David and Carlye Cannon Wattis Foundation




phylogenetics, codiversification, parasites, chipmunks, lice, pinworms, phylogeography

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Advisor

Cook, Joseph

First Committee Member (Chair)

Demboski, John

Second Committee Member

Salinas, Irene

Third Committee Member

Whitney, Kenneth

Fourth Committee Member

Light, Jessica