As an evolutionary ecologist, I’m interested in how genetic variation and the environment interact to produce the amazing trait diversity we see in nature. Sexual traits often are disproportionately variable. Furthermore, because these traits are involved in mating interactions, they are expected to play an important role in the evolution of reproductive isolation and speciation. I study variation in mating traits and the evolutionary consequences of this variation using freshwater amphipods in the genus Hyalella as a model system. My approach is to: 1) Identify the mechanism(s) of sexual selection that lead to mating biases observed in nature, 2) understand the fitness consequences (for males and females) of mating with individuals with certain phenotypes across relevant ecological gradients (e.g., predation, resource regimes), and 3) address patterns of reproductive isolation using behavioral experiments.