Selection is the functional relationship between phenotypes and fitness. Natural selection is the production of organisms based on their physical attributes, whereby the offspring of younger generations take on the strong, desired, and hereditary aspects of their parents. They adapt better to the environment, although some fare better than others depending on their individual traits attributed to their phenotypes (Sinervo, 1997). According to Charles Darwin, fitness can be described in three different forms of selection that interfere with the average phenotypic traits of a population. They include: directional selection; stabilizing selection; and destructive selection. Long-term directional selection can lead to the formation of new organisms from existing ones because traits are linearly related to fitness. Stabilizing selection, on the other hand, leads to the refinement of the existing type by eliminating the extremes of a distribution of phenotypes. The third selection trait, destructive selection, can lead to the formation of two new types of species from...