What do we call evolutionary changes in response to environmental pressures?

The term that refers to evolutionary changes in response to environmental pressures is natural selection. This process occurs when certain traits become more or less common in a population based on the advantages or disadvantages those traits confer in a given environment. Organisms with beneficial traits are more likely to survive and reproduce, passing those advantageous traits to their offspring. Over time, this leads to the adaptation of species to their environments.

Natural selection is a central mechanism of evolution and explains how species evolve in response to their ecological circumstances. The other options, while related to evolutionary processes, describe more specific phenomena. For instance, directional selection refers specifically to a mode of natural selection where one extreme phenotype is favored, while adaptive radiation describes the diversification of a common ancestor into various forms that adapt to different environments. Convergent evolution describes how unrelated species develop similar traits due to similar environmental pressures. These processes are components of natural selection but do not encapsulate the broader concept as effectively as natural selection itself.