ABSTRACT
One of the requirements for a genetic equilibrium is that the population be infinitely large. Infinite populations exist only as theoretical concepts, not in nature. The American geneticist and evolutionary biologist, Sewall Wright, was the first to call attention to the effects of chance on genetic composition in small populations, in a series of papers published in the 1930-1940s. These effects were first considered negligible, but later recognized as potentially very important. These random effects, called genetic drift and random fixation are considered a most important driving force in evolution, at least at the molecular level. It is possible to simulate these effects by the use of a simple, familiar toy, a slanted board into which nails are driven. Random processes may have a profound effect on the evolutionary fate of a new, colonizing population, because it depends on the gene pool of the sample of founding individuals. This effect is termed ‘the founder principle’.
