Comparative Physiology is the study of how different organisms function and adapt to their environments. It examines the similarities and differences in biological processes, such as respiration, circulation, and digestion, across various species. This field helps scientists understand how evolutionary pressures shape physiological traits. By comparing the physiological systems of diverse organisms, such as mammals, birds, and reptiles, researchers can gain insights into their adaptations. For example, studying how fish extract oxygen from water can inform us about the evolution of lungs in terrestrial animals. This knowledge is crucial for fields like medicine and conservation.