Evolution is a genetic change in the population.

Natural selection is the consequence of certain individual organisms in a population being born with characteristics that enable them to survive better and reproduce more than the offspring of other individuals in the population.

The four evolutionary mechanisms are mutation, genetic drift, migration and natural selection.

Genetic drift is a non-random change in allele frequencies in a population.

Migration (gene flow), leads to a change in allele frequencies in a population as individuals move into or out of the population.