Landscape genetics of the western fence lizard (Sceloporus occidentalis becki) on Santa Cruz Island: the role of habitat complexity and climate on genetic connectivity of populations across the island.

The California Channel Islands is home to several endemic species and sub-species of amphibians and reptiles, yet comprehensive studies of the genetic relationships of Channel Island reptile species has yet to be done. We propose to examine the landscape genetic structure of Sceloporus occidental becki on Santa Cruz Island (California Channel Islands National Park). Landscape genetics seeks to understand the role of environmental variables (habitat and climate) on the genetic connectivity of populations. Santa Cruz Island is the ideal setting for a landscape study, due to the rich biome diversity and dramatic topographic relief. In addition to the biome diversity on the island, there are substantial climatic differences across the island, resulting in hot and dry habitats on the western part of the island, and cool and wet habitat on the eastern side of the mountain. These differences in habitat and climate could influence the fine-scale connectivity of populations. This research will examine the role of habitat and climate as important mediating factors that limit gene flow across the island. We predict that both habitat and climate variation are important features that structure populations, but our landscape models are required to identify the specific variables that play the most significant role. Current genetic analyses might reveal that the western fence lizard is an island endemic. If so, then our landscape genetics study, which seeks to understand the factors most important for the maintaining the evolutionary relationships among populations on the island, becomes a conservation imperative.