9317945 ZINK The arid lands or deserts of southwestern North America provide an exciting context for phylogenetic and historical biogeographic studies. Many sedentary taxa are endemic or restricted to desert regions, providing opportunities to explore patterns of isolation by past geologic events or climatic changes among various vertebrate lineages. This research project will utilize molecular methods to explore relationships and biogeography of four groups of birds (thrashers, towhees, gnat catchers and quail) in these desert regions. Molecular variation among populations within the same species will also be discovered. For each group of bird species, patterns of relationship will be derived from restriction site and direct sequence data from mitochondrial DNA. Those patterns will then be compared with each other to find any shared patterns suggesting a common geologic/climatic history for isolation of groups. %%% Studies such as this shed light on the subject of long term climate change and its effects in fragmenting populations that may lead to the origin of new species. Information may also be obtained that bears on conservation efforts for these birds. ***
