evolution is the process that catalyzes genetic changes within a population of organisms. so evolutionary change can't occur without changes in allele frequency while a change in allele frequency is an indication that evolution is occurring
An example of macroevolution is the evolution of a new species. One mechanism that drives evolution is natural selection, which is a process that increases the frequency of advantageous alleles in a population. Natural selection results in organisms that are more likely to survive and reproduce.
