Definition - What does Natural Selection mean?
Natural selection is the primary driving force in evolution where only the strong can survive. Natural selection occurs continually in nature, and aids the survival of a species by only allowing the fittest and best of the species to survive and reproduce, allowing the offspring to inherit the good traits that allowed its parents to survive.
Safeopedia explains Natural Selection
Natural selection helps creatures evolve and adapt by allowing those who possess traits and qualities that are advantageous to the survival of the species to live and reproduce. For example, if a zebra is born with a hereditary genetic defect that makes it run more slowly than other zebras, it is considered a liability, and natural selection will prevent this trait from being passed down. The zebra will be killed by predators from which it is unable to escape due to its genetic predisposition of slowness. Natural selection helps to maintain the breeding pool of a species, as only the strongest of the species live to reproduce.