Natural Selection is the process by which the most adapted, or fittest, species survive and the least adapted, or unfit, species do not survive. An example of Natural Selection is if there are two species of birds that eat the same thing, but one of the species has a beak that makes it harder to eat the food, naturally the species that has the beak fit to eat that food will survive. The species that is not fit to eat that food will either adapt or will be unable to survive. Evolution is a species adapting to the enviornment over a period of time. There is microevolution and macroevolution.