What is "microevolution"

n. small-scale changes in the history of life, such as changes in allele frequencies in a population (over a few generations); also known as change at or below the species level.

n. evolution resulting from small specific genetic changes that can lead to a new subspecies

Microevolution is the change in allele frequencies that occurs over time within a population. This change is due to four different processes: mutation, selection ( natural and artificial), gene flow, and genetic drift. This change happens over a relatively short (in evolutionary terms) amount of time compared to the changes termed 'macroevolution' which is where greater differences in the population occur.

Population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution. Ecological genetics concerns itself with observing microevolution in the wild. Typically, observable instances of evolution are examples of microevolution; for example, bacterial strains that have antibiotic resistance.

Microevolution over time leads to speciation or the appearance of novel structure, sometimes classified as macroevolution. Macro and microevolution describe fundamentally identical processes on different scales.