Introductory chapter: population genetics - the evolution process as a genetic function.

Abstract

Population genetics is defined as the sub-area of biology that studies the distribution and change in frequency of alleles. The population genetics is also the basis of evolution, and it has been established as a science; its main founders were JBS Haldane, Sir Ronald Fisher, and Sewall Wright. Since 1966, from the pioneering work of Fisher, Haldane, and Wright, the population genetics had accumulated a large mathematical theory, statistical tools, laboratory techniques, molecular markers, and huge information of polymorphisms in databanks [1]. The main concept in population genetics is focused on the Hardy-Weinberg theorem (also known as Hardy-Weinberg theorem or Hardy-Weinberg law). This central theorem preconizes that if the population size is large, with random mating, and mutation, selection, and migration are not significant, the allelic frequencies do not change over the generations. If not, the allelic and genotype frequencies will change from one generation to the next. These changes can affect directly in population’s adaptive fitness, so information for applied studies and decisions can be provided by accessing the genetic variation in populations.