Organizer: Craig McClain, Duke University. The lifespan of metazoans ranges from timescales of days to centuries. Understanding the drivers of this variation may elucidate key processes that regulate aging. Considerable variation in both spatial and temporal in energy availability also occur globally are hypothesized to control longevity. Increased temperature, i.e. thermal energy, is predicted to decrease lifespan as it increases metabolism and molecule damaging free radicals. Caloric restriction, i.e. decreases in chemical energy, may increase lifespan by either slowing metabolism or trigging a neural mediated stress response that prevents free radical damage. How much of the natural variation in lifespan among metazoans reflects variation in these factors is incompletely understood. I propose to assemble a scientific team spanning disciplinary and careers stage boundaries. This group will quantify the relationship between longevity and energy availability among a broad suite of metazoans in the wild specifically examining how spatial and temporal variation in thermal energy, i.e. temperature, and chemical energy, i.e. food availability, impact the lifespans of wild populations in an evolutionary context.