Physiological adaptation refers to the changes in an organism's internal processes that enhance its ability to survive in a specific environment. These adaptations can include alterations in metabolism, temperature regulation, or respiratory efficiency. For example, animals living in high altitudes, like the Tibetan antelope, develop increased lung capacity to take in more oxygen. These adaptations occur over generations through the process of natural selection, where individuals with beneficial traits are more likely to survive and reproduce. Physiological adaptations can be temporary, such as increased heart rate during exercise, or permanent, like the thicker fur of Arctic foxes in cold climates.