 Selective Shadowing is one of the evolutionary theories of aging based on the presumption that selection of an individual generally decreases once they essentially pass the sexual mature phase.As a result, this forms a shadow without the account of sexual fitness, which is no longer considered as an individual ages.This supports the idea that the force of natural selection declines as a function of age, which was first introduced by Peter B. Medewar and J.B.S Haldane.