Master of Science

thesisCoevolution occurs when different species affect each other's evolution, which can drive major evolutionary trends. Host-parasite systems are a model for coevolution studies, and the rock pigeon (Columba livia) - feather louse (Columbicola) system is a particularly useful model system because it is relatively easy to observe, mark, and quantify these permanent, obligate ectoparasites. Many life history traits have been examined in this system, such as the effect of body size, temperature, humidity, and fecundity. However, there are still life history traits critical to understanding adaptation in these lice that have not yet been examined. In this thesis, I examine generation time, mechanisms of endosymbiont transfer, and the effects of divergence on lice in the genus Columbicola. In Chapter 1, I provide a brief overview to this system, and an outline of my experiments. In Chapter 2, I investigate the generation time of Columbicola columbae lice on their host and compare it to a previous in vitro study of generation time. I found the generation time on the host to be 22 days. Generation time is an important life history trait that affects the population dynamics and evolution of a species. In Chapter 3, I investigate a potential mechanism for the transfer of endosymbionts between two different species of lice, Columbicola columbae and Columbicola tschulyschman. I found that these two species do mate when they are in contact, but they do not produce hybrid offspring. In Chapter 4, I investigate if divergent selection for body color in Columbicola columbae lice inadvertently leads to reproductive iv isolation, as is found with divergent selection on louse body size. I did not find any evidence of reproductive isolation between lineages of lice that had undergone divergent selection for colo