1. Population Genetics A.The Hardy-Weinberg principle B.Factors that can change allele frequencies

2. A. The Hardy-Weinberg Principle The frequency of an allele in a population will remain constant over time, provided that the following conditions are met: –The population is large and randomly breeding –There are no conditions acting on the population to change the allele frequency

3. A. The Hardy-Weinberg Principle Consider a gene that has two alleles, A and a Let p = the frequency of A (in a population) q = the frequency of a The frequency of AA = p 2 The frequency of aa = q 2 The frequency of Aa = 2 pq p 2 + 2 pq + q 2 = 1

4. B. Factors That Change Allele Frequencies Mutation Migration Natural selection Random genetic drift