SOMERO, G.N.; Stanford University: Thermal Limits to Life: Underlying Mechanisms and Adaptive Plasticity

Temperature affects all biological structures and processes and serves as a major factor in establishing the biogeographic patterning of species. Among the important questions that link together thermal physiology and distribution patterns are the following. First, what physiological systems seem most critical in establishing thermal limits? Are there weak links in the physiological chain? Can we predict the highest temperatures at which life is possible? Second, what types of adaptive modifications underlie alterations in thermal limits? Third, what types of physiological and genetic differences distinguish eurythermal and stenothermal species? Why are some species more adaptationally plastic than others? Fourth, how do species differ in terms of the threats posed by global warming? Which species live “closest to the edge?” Data from studies of orthologous enzymes, the heat-shock response, membrane structure and function, and gene expression systems in diverse taxa will be used to address these questions.