My research focuses on understanding adaptation to the environment from both a mechanistic and evolutionary perspective; i.e., how organisms function in natural environments, the mechanisms underlying this function, the evolutionary origin, maintenance, and constraint of this function, the evolutionary consequences of variation in function, and how all of these aspects are encoded or reflected in the genome. Thus, my research focuses at the intersection of the four disciplinary domains shown to the left; i.e., evolutionary and ecological functional genomics. My research program addresses this suite of issues through a multidisciplinary, problem-oriented approach.

My present emphasis is on ecological and evolutionary physiology of the stress response [the induction of a specific suite of proteins (stress or heat-shock proteins) by extreme temperatures and other stresses]. Several projects are underway, with a common theme: HEAT-SHOCK PROTEINS AND GENES

Specifically, my laboratory investigates the heat-shock protein Hsp70, its encoding genes, and its regulation in Drosophila as a model system for understanding evolutionary adaptation. Hsp70 is a molecular chaperone that deters stress-induced protein aggregation, but has numerous other functions. Hsp70 is necessary for full-strength tolerance (in terms of survival, normal development, normal function) of high temperature. Such tolerance is critical in nature, where non-adult Drosophila undergo harmful to lethal high temperatures. In nature, Drosophila populations vary in stress tolerance and Hsp70 levels. Our current major focus is on understanding the genomic basis for this variation. The number of hsp70 gene copies and evolution of the hsp70 coding sequence are partial or inadequate explanations. Evidently cis-regulatory regions such as proximal promoters underlie intraspecific variation in Hsp70 levels. Repeated insertion of mobile genetic elements into these promoters is a recurrent mechanism of evolution.