Jin Young Huh Joo Hee Kim Sec III Hardy Weinberg Jin Young Huh Joo Hee Kim Sec III

Introduction to Hardy Weinberg In 1908, G.H. Hardy and W. Weinberg suggested a scheme whereby evolution could be viewed as changes in frequency of alleles in a population of organisms. The Hardy-Weinberg model consists of two equations: one that calculates allele frequencies and one that calculates genotype frequencies. “Allelic frequency will remain same unless acted upon outside force.”

Hardy Equilibrium Equation p+q=1 p2+2pq+q2=1 p q pp(p2) pq qq(q2)

Conditions of Hardy Weinberg Equilibrium A large breeding population Mating is random No mutation No migration No selection

Example problem In lions the allele for the albino trait is recessive over the normal tawny-striped coloration. A sample of 100 wild lions was examined, and it was determined that 9 of these lions were white (aa). How many lions in this population would you expect to be heterozygous for the albino trait? How many homozygous and tawny colored?

Solution 9/100 = 0.09 of the population is aa (q2) The square root of 0.09= 0.3 (q) 1- 0.3 = 0.7 (p) p2= 0.49 (proportion of the lions that are homozygous dominate) To get the actual number of lions that are homozygous dominant multiple 0.49 by your total population of 100. 49 lions are tawny and homozygous dominant. Use 2pq to find the proportion of heterozygous individuals. (2)(0.3)(0.7) = 0.42. 0. 42 out of the 100 lions are heterozygous. Check your work. 0.09 + 0.49 + 0.42 = 1.

Animation about Hardy Weinberg http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/life4e_15-6-OSU.swf

Sources LabBench Biologycorner TIEM http://www.phschool.com/science/biology_place/labbench/index.html Biologycorner http://www.biologycorner.com/bio4/notes/hardy_weinberg.php TIEM http://www.tiem.utk.edu/bioed/bealsmodules/hardy-weinberg.html