Maintaining biodiversity in a changing world is a central challenge for conservation biology. Urbanization, climate change, and habitat modification alter the biotic and abiotic conditions that shape species distributions, often reducing habitat suitability and fragmenting populations. Connectivity among populations can mitigate the negative effects by maintaining gene flow, enhancing evolutionary potential, and reducing extinction risk. This project will use genomic data from the Common Side-blotched Lizard (Uta stansburiana) on California’s Channel Islands to investigate how colonization history, local habitat characteristics, and human-activity impact patterns of differentiation and connectivity. Uta stansburiana occurs on five of the eight Channel Islands through at least three colonization events and each island varies in geology, vegetational composition, climate, and anthropogenic influences, offering a natural experimental system to study evolutionary processes. I will generate a genomic RADseq library for individuals sampled to assess population structure and then use a landscape genomics approach to determine which landscape features are most important for U. stansburiana connectivity and how these patterns differ both across and between islands. This study system provides a unique opportunity to explore the relationship between connectivity, diversity, and isolation in heterogeneous environments that can be used to better inform management decisions and conservation efforts.