Allele Flow Information

Biological Theory

This program shows the change of the allele frequency of populations over time due to several different driving forces. The driving forces which come into play are: selection, mutation, and genetic drift. First, selection occurs. Selection allows the genotypes of an organism which are best adapted to the environment to increase in frequency relative to the less well-adapted genotypes. Random mating then occurs in this mature population which guarantees that the potential offsprings are in Hardy-Weinberg population. Next, Mutation occurs. Mutation is usually due to DNA copying errors during meiosis. Usually mutation rates are very small. The resulted genotypic frequencies are used as ranges from which individuals are chosen at random (the larger the range the more likely an individual is to be chose of that genotype). This choosing of individuals simulates genetic drift. Genetic drift is the random changes in genotypic frequency in a population. Genetic drift is only a large driving force when the population size is small.