Final answer:
Microevolution pertains to changes within a species over time, while macroevolution refers to evolutionary changes that lead to the emergence of new species or significant new traits.
Step-by-step explanation:
Microevolution involves processes that occur within species, whereas macroevolution involves evolution above the species level (i.e., higher taxa). Microevolution refers to changes in the gene pool of a population over time which do not necessarily lead to the creation of new species. These changes can include the introduction of new genetic variations or the redistribution of existing genetic variations due to processes like natural selection, gene flow, mutation, and genetic drift. On the other hand, macroevolution encompasses the broad patterns of evolutionary changes that occur over long time periods, and it typically leads to the emergence of new species (speciation) or novel traits in a lineage.