A re-analysis of Great Basin Mountains as islands: Implications of island configuration

The insularity of Great Basin Mountain ranges with regard to small mammal species has been a rich topic for biogeographic research. Several earlier studies concluded that the mountains of the Great Basin were so isolated from one another that small mammals were unable to migrate between the ranges and that they would eventually become extinct in the ranges as a result.; This study re-analyzes the problem using a Geographical Information System. Instead of elevational contours as a proxy for environmental conditions, a map of pinyon-juniper is used to define montane islands. Island configuration is important, and the central Great Basin appears not to be extinction-driven on the whole and nor does it appear to be a mainland. Rather, extinctions and immigrations among the species in question appear to be in approximate equilibrium. (Abstract shortened by UMI.)...