What is the definition of microevolution?

The definition of microevolution is accurately captured by the notion of change in allele frequencies within a population over generations. This concept emphasizes the small-scale changes that occur within a specific population, stemming from mechanisms such as natural selection, genetic drift, mutation, and gene flow. Microevolution focuses on the gradual changes that can lead to variations in traits among individuals within a population, ultimately influencing how those traits are distributed over time.

In contrast to larger-scale evolutionary changes, which are defined as macroevolution, microevolution addresses these subtle shifts within populations rather than the emergence of new species or significant evolutionary transitions. Understanding microevolution is critical for grasping how evolutionary processes work at a more immediate level, impacting species adaptation and survival.