Although gene flow does not change allele frequencies for a species as a whole, it can alter allele frequencies in local populations.
How does gene pools relate to allele frequencies?
Allele frequency refers to how common an allele is in a population. It is determined by counting how many times the allele appears in the population then dividing by the total number of copies of the gene. The gene pool of a population consists of all the copies of all the genes in that population.
What can change the allele frequency in a gene pool?
Natural selection, genetic drift, and gene flow are the mechanisms that cause changes in allele frequencies over time. When one or more of these forces are acting in a population, the population violates the Hardy-Weinberg assumptions, and evolution occurs.
What causes change in allele frequency?
Allele frequencies in a population may change due to gene flow, genetic drift, natural selection and mutation. These are referred to as the four fundamental forces of evolution. Note that only mutation can create new genetic variation. The other three forces simply rearrange this variation within and among populations.
How does population size affect the allele frequency in a gene pool?
The smaller a population, the more susceptible it is to mechanisms such as genetic drift as alleles are more likely to become fixed at 0 (absent) or 1 (universally present). Random events that alter allele frequencies will have a much larger effect when the gene pool is small.
What is the difference between gene frequency and allele frequency?
Definition. Genotype frequency refers to the number of individuals with a given genotype divided by the total number of individuals in the population while allele frequency refers to the frequency of occurrence or proportions of different alleles of a particular gene in a given population.