Evolution is the process of biological change over time. Such changes, especially at the genetic level, are accomplished by a complex set of evolutionary mechanisms that act to increase or decrease genetic variation. Changes at the genetic level are often directly caused by physical phenomena (e.g., cosmic rays). Genetic changes are also indirectly acted upon by the physical environment in such a manner that the number of genetic changes (e.g., mutations) within a population can either increase or decrease in subsequent generations.

Evolutionary theory is the cornerstone of modern biology, and unites all the fields of biology under one theoretical umbrella to explain the changes in any given gene pool of a population over time. Fundamental to the concept of evolutionary mechanism is the concept of the syngameon, the set of all genes. By definition, a gene is a hereditary unit in the syngameon...