How can the hardy-weinberg equation be calculated?
To calculate Hardy-Weinberg equation you need to have the proportion of the studied genotype in order to calculate their frequence in the population from which you will find theorical frequency and then check if it matches reality.
To start let's recall the Wardy Weinberg equation :
with p the frequency of an allele A1 and q the frequence of an allele A2.
Let's try an example. In a population there are two alleles M and N with three possible genotypes:
homozygote MM : 1787 individuals
homozygot NN : 1303 individuals
heterozygot NM : 3039 individuals
Total population : 6129
We can calculate the frequency of each genotype :
F11 = frequency of MM
F22= frequency of NN
F12= frequency of NM
We then calculate the frequency p of M and q of N in the population:
Now that we have the Hardy Weinberg frequency, we can calculate the theorical frequency of the genotype by multiplying the frequency by the total population:
theoretical frequency of MM
theoretical frequency of NN
theoretical frequency of NM
Now that we have those theoretical frequencies, we can compare them to the real frequencies and check if the population is or isn't at the Hardy Weinberg equilibrium with, for instance, a
When calculating for a ratio in a species that is in HW equilibrium, the two important equations are
If you know the value for either p or q and need to know the other, you can use the equation
Let's look at a quick example:
In a rat population that is in Hardy-Weinberg equilibrium, 60% of the population is homozygous dominant for the trait of brown fur. Calculate the percentage of the population that is heterozygous for the trait of brown fur.