Population Genetics Hardy-Weinberg Equations Let us start with a given trait that has two alleles T and t. To find the frequency of allele T(p) in the population, we would use the following formula: p = (# of copies of T in the population) / (total # of copies of all alleles in the population); or p = (2(# of individuals homozygous for T) + (# of individuals heterozygous for T)) / 2(# of individuals in the population). We can find the frequency of allele t (q) in the same way. Once we have the values of p and q, we can set up an equation based on the Hardy-Weinberg equilibrium. If the frequency of each allele is constant, then the following equation, called a Hardy-Weinberg Equation, is always true: ( p + q ) 2 = 1 ; or p 2 +2 pq + q 2 = 1 The second form of the above equation is the most useful, since each of its factors represents a portion of the population. P 2 and q 2 represent those individuals homozygous for T and t, respectively, while 2pq represents all heterozygous individuals. Using these equations, we can
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 01/27/2012 for the course BIOLOGY BSC1005 taught by Professor Rodriguez during the Winter '09 term at Broward College.