The phylogenetic position of Rana sylvatica compared with North American and Eurasian brown frogs

This thesis is a phylogenetic investigation of the North American Wood Frog (Rana sylvatica) and the Eurasian brown frogs, all of the genus Rana. It is unclear if the brown frog range extends into North America with the inclusion of Rana sylvatica, or if Rana sylvatica is genetically more related to its North American ranid relatives. In addition, within the Eurasian brown frogs, there are members with a reduced 24-chromosome karyotype. These 24-chromosome brown frog species could be the result of a single reduction event or the reduction may have occurred several times in the history of this group. I used the sequence of two mitochondrial genes; cytochrome b and 16S ribosomal RNA of North American and Eurasian ranids to answer these questions. Rana sylvatica was found to be most closely related to its North American relatives, and the 24 chromosome members of the brown frog group are the result of two separate reduction events.