Organisms face multiple biotic and abiotic challenges. The physiological responses that have evolved in response to these challenges can maintain fitness across variable and complex environments, and are important determinants of species’ ranges. My lab investigates the evolutionary, physiological and genetic basis for how species acclimate and adapt to their environment. My seminar will focus on adaptive cellular and energetic responses in Drosophila melanogaster, an ectotherm that has diversified across a wide thermal range and simultaneously become specialized on resources rich in the byproducts of fermentation. I will present data demonstrating that thermally variable environments selectively favor cellular plasticity, that cellular responses can incur significant metabolic costs, and that the thermal environment can mask or reveal genetic incompatibilities, particularly those underlying the pathways and processes of energetics.