Transcript Hardy Weinberg

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
p
pp(p2)
pq
q
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/biol1
114/tutorials/Flash/life4e_15-6-OSU.swf
Sources
LabBench

http://www.phschool.com/science/biology_place/l
abbench/index.html
Biologycorner

http://www.biologycorner.com/bio4/notes/hardy_
weinberg.php
TIEM

http://www.tiem.utk.edu/bioed/bealsmodules/har
dy-weinberg.html