How to Determine Allele Frequencies

Calculate Allele Frequency in a Population

• 1

  Find out how many copies of the specific allele of interest are in the population.

• 2

  Find out the total number of alleles, including the allele of interest, that are in the population.

• 3

  To determine the allele frequency, divide the total number of alleles in a population (Step 2) by the number of alleles of interest (Step 1).

Calculate Allele Frequency With the Hardy-Weinberg Equation

• 4

  Assume there are two alleles of a gene in the population. Let the first allele of a gene in a population be denoted as 'W' and the second allele 'w'.

• 5

  Find the allele frequency of each allele.

• 6

  Since there are two alleles in the population, adding the frequencies of the alleles together should equal to one.

  W + w = 1.

  Therefore, if you were to find out the frequency of one of the alleles, for instance, w, simply subtract W from 1.

  w = 1 - W

• 7

  Calculate the genotypic frequency of the allele distribution in the population using the Hardy-Weinberg equation. Since there are two alleles in a gene, the possibilities of an offspring receiving the combination of alleles from their parents are: WW, Ww, wW and ww. This represents the genotype of an individual. Since Ww is the same as wW, there are two chances that the individual will receive this genotype, hence you can group it as '2Ww'.