Population geneticists study the genetic composition and variability of natural populations as well as the theories that explain this variability in terms of natural selection, mutation, recombination, genetic drift and gene flow. Population genetics was first developed among eukaryotes in an attempt to reconcile Darwin’s theory of evolution by natural selection and Mendelian genetics. When Darwin postulated that natural selection is the main force of evolutionary change, a great controversy was created. As Darwin did not fully understand the inheritance mechanism, he was unable to answer one of the main criticisms of his thesis. If selection is gradually to modify a population, the individuals that constitute this population.
