Our research group focuses on the evolution of plant adaptation. We concentrate specifically on how grasses and shrubs native to the Sonoran Desert respond to water, which is the most variable and important environmental factor affecting plant growth and survival in deserts. The amount of water available to a plant is the product of many extrinsic factors including the timing and amount of precipitation, and temperature, topography, soil, and intra- and interspecific competition. Understanding the interplay among these factors in evolutionary history may be complicated in the southwestern United States by recent and extensive environmental change associated with livestock grazing, invasive species, fire management, urbanization, and climate change. By studying how species have responded to environmental changes we hope to make informed predictions about their future evolutionary trajectory and permit knowledge-based management decisions.