Adaptation to Deserts: Understanding the evolution of adaptive traits is one of the primary goals in evolutionary biology, with the study of the relationships between fitness and phenotype often providing deep insight into the processes that underlie adaptive phenotypes. Systems in which the mechanisms (e.g., the genotype) linking fitness to phenotype are tractable are uncommon, and deserve continued study. The proposed research of one such system leverages a deep understanding of desert ecology against modern whole genome sequencing and population genomics. Specifically, we will study the evolution of adaptation to deserts using wild animals in a natural setting, then perform a classic common garden experiment using wild animals from highly divergent populations taken into captivity to perform carefully controlled experiments of gene expression and to determine fitness. This work integrates multiple disciplines including evolutionary genomics, computational biology, and ecological physiology. Gaining a deeper understanding of the genome architecture of desert adaptation (e.g., osmoregulation and water metabolism) has important and broad impacts, with implications for studies of conservation, climate change, and human health (for instance, kidney disease).