Population Genetics
Contents Sample Problem 1

Let's return to our population of pigs. Remember that the allele for black coat is recessive. We can use the Hardy-Weinberg equation to determine the percent of the pig population that is heterozygous for white coat.


  1. Calculate q2

    Count the individuals that are homozygous recessive in the illustration above. Calculate the percent of the total population they represent. This is q2.
  1. Find q.

    Take the square root of q2 to obtain q, the frequency of the recessive allele.

  1. Find p.

    The sum of the frequencies of both alleles = 100%, p + q = l. You know q, so what is p, the frequency of the dominant allele?

  1. Find 2pq.

    The frequency of the heterozygotes is represented by 2pq. This gives you the percent of the population that is heterozygous for white coat:

Continue to Sample Problem 2.