Hardy Weinberg!

The Hardy Weinberg equation is the mathematical equation used to calculate the genetic variation of a population at equilibrium. The equation starts off with p^2 + 2pq + q^2. p + q also equals 1. P squared represents the frequency of the homozygous dominant allele, Two p q represents the frequency of the heterozygous allele, and q squared represents the frequency of the homozygous recessive allele. The two men who came up with this were Godfrey Hardy and Wilhelm Weinberg. They also stated that evolution in a population would not occur if the following happen: mutation does not occur, natural selection does not occur, the population is infinitely large, all members of the population breed, all mating is totally random, everyone produces the same number of offspring, and there is no migration in or out of the population. Going back to the equation, here is an example of a problem:

1. You have sampled a population in which you know that the percentage of the homozygous recessive genotype (aa) is 36%. Using that 36%, calculate the following:
1. The frequency of the "aa" genotype.
2. The frequency of the "a" allele.
3. The frequency of the "A" allele.
4. The frequencies of the genotypes "AA" and "Aa."

The frequency of the aa is already mentioned in the problem, 36%. To find B, firs square root .36. The answer is .6. So the frequency is 60%. For C, since q+p=1, and q=.6 then p=.4. So 40%. For D, .4 squared is .16 so the frequency of the AA is 16% and 2pq is equal to 2 times .4 times .6 so .48 or 48%.

Here is a good video about this:

Hardy Weinberg Video