Theses and Dissertations Collection

Comparative phylogeography is the study of the effects of biogeography and evolutionary history on the spatial distribution of genetic variation of codistributed species. This approach allows investigation of the links between population processes and regional patterns. Here, I present three comparative phylogeographic studies, each focused on different assemblages of gastropod species that are endemic to the temperate rainforests of the North American Pacific Coast and Northern Rocky Mountain interior regions. Slug and snail endemism in these areas is high and several factors are likely responsible for generating the high levels of diversity. The results suggest that codistributed species likely exhibit distinct patterns that reflect the unique aspects of species’ phylogeographic histories, which emphasizes that phylogeographic structure is complex and is shaped by more than just a few abiotic factors. In addition, the results presented here significantly increase the taxonomic and natural history knowledge of several rare gastropod lineages, which is important because there is an increasing need to obtain data on the genetic and spatial structure of endemic taxa in areas such as the Pacific Northwest.