Unlike humans, who can exquisitely regulate their internal temperature over a broad range of conditions, body temperature in insects and other ectotherms reflects the temperature of the external environment.  As temperatures increase, so do the rates of cellular processes, accelerating growth, development, metabolism, reproduction, and aging, with extreme cold and extreme heat leading to immobilization, damage, and even death. 

Although they cannot control their internal temperature, however, insects are not defenseless; they can proactively protect themselves against future stressors, a process called thermal acclimation.  We are investigating how flies use gene expression changes to mount a beneficial acclimation response, and testing the role of epigenetic mechanisms in producing these responses. 

To understand how thermal tolerance and acclimation evolve in nature, we are exploiting latitudinal and elevational variation in temperature conditions to test for thermal adaptation in five Drosophila species: D. melanogaster, a cosmopolitan species found worldwide; D. affinis, a North American species distributed across the northeast, D. pseudoobscura, a similarly widespread western North American species; and D. sproati and D. basisetae, picture-winged Drosophilids native to Hawaii.