• The genotype frequency is a measure of the relative proportions of different genotypes within a
◦ This is obtained by dividing the number of individuals with each genotype by the total
number of individuals.
• Hardy-Weinberg Equilibrium:Amathematical statement whereby, in the absence of nonrandom
mating and evolutionary forces, genotype and allele frequencies will remain the same from one
generation to the next.
• Evolutionary forces: four mechanisms that can cause changes in allele frequencies from one
generation to the next; mutation, natural selection, genetic drift, and gene flow.
• Nonrandom mating: patterns of mate choice that influence the distributions of genotype and
• Inbreeding: mating between biologically related individuals.
• The Evolutionary Forces:
◦ Natural Selection
◦ Genetic Drift
◦ Gene Flow
◦ Introduces new alleles into a population
◦ Polymorphism:Adiscrete genetic trait in which there are at least two alleles at a locus
having frequencies greater then 0.01
• Natural Selection:
◦ Does not create new genetic variation, but it can change the relative frequencies of different