Which term describes the gradual process by which species evolve over time due to small genetic changes?

The term that describes the gradual process by which species evolve over time due to small genetic changes is microevolution. This concept refers to evolutionary changes that occur on a small scale, typically within a single population or species, as a result of processes such as mutation, gene flow, genetic drift, and natural selection. These small changes can accumulate over generations and may eventually lead to noticeable differences within a population or even the emergence of new species.

In contrast, macroevolution refers to large-scale evolutionary changes that occur over long time periods, such as the evolution of major new groups of organisms or the extinction of species. Convergent evolution describes instances where different species independently evolve similar traits in response to similar environmental pressures, rather than through common ancestry. Adaptive radiation refers to the diversification of a group of organisms into forms filling different ecological niches, often following the appearance of a new environment or a significant change in conditions. Each of these concepts reflects different aspects of evolutionary theory, but microevolution specifically captures the gradual, incremental changes within a species that lead to evolution over time.