Comparative physiology is a fascinating field of study that aims to understand how different organisms have adapted to their environments. There are many synonyms for comparative physiology, including evolutionary physiology, physiological ecology, comparative anatomy, and functional morphology. Each term emphasizes a slightly different aspect of the field. Evolutionary physiology emphasizes the role of natural selection in shaping the physiology of organisms, physiological ecology focuses on how organisms respond to their environments, comparative anatomy emphasizes the similarities and differences between organisms, and functional morphology focuses on the relationships between form and function in living organisms. Whichever term is used, comparative physiology provides a powerful tool for understanding the diversity of life on Earth.