Biological adaptation refers to the process by which living organisms evolve over time in response to their environment in order to survive and reproduce. This can involve changes in an organism's physical traits, behaviors, or physiological processes that help them better adapt to their surroundings. Adaptations can be both structural, such as the development of specialized organs or appendages, or functional, such as changes in metabolic processes. Biological adaptation is a key concept in evolutionary biology and plays a crucial role in shaping the diversity and complexity of life on Earth.