Biological evolution is the genetic changes that occur in a population over successive generations. It is a process whereby changes occur on the genetic level of a population and it is being transferred from one generation to another. Biological evolution takes place as a result of natural selection and its result may be minimal (unnoticeable) or significant (noticeable). Biological evolution includes microevolution (minor genetic changes within a specie or population) and macroevolution (large evolutionary changes above the species level).