Evolutionary physiology is the study of how animals (including people) have changed and adapted over time to survive in different environments. Scientists use evolutionary physiology to learn how bodies, organs, and chemical processes in animals have evolved to help them survive. For example, if animals live in an arid climate, they may have evolved to need less water to survive or they may have adapted to find other sources of water in the environment. Other studies may look at how animals have adapted to survive in colder temperatures or how they have adapted to live with certain diseases. With evolutionary physiology, scientists can watch, measure, and predict how animals will evolve and adapt over time.