Hardy Weinberg Principle
This video is very mathematical – we may not get into the math of Hardy Weinberg depending on the time we have left at this stage. http://www.bozemanscience.com/science-videos/2012/5/6/solving-hardy-weinberg-problems.html
All the following information was taken from Wikipedia at the following link: http://en.wikipedia.org/wiki/Hardy%E2%80%93Weinberg_principle
The Hardy–Weinberg principle (also known by a variety of names: HWP, Hardy–Weinberg equilibrium,
Hardy–Weinberg Theorem, HWE, or Hardy–Weinberg law) states that both allele and genotype frequencies in a population remain constant—that is, they are in equilibrium—from generation to generation unless specific disturbing influences are introduced.
So, essentially it means … (please write it out in your words)…
The factors that can affect the HWP:
Violations of the Hardy–Weinberg assumptions can cause deviations from expectation . How this affects the population depends on the assumptions that are violated. Generally, deviation from the Hardy–
Weinberg equilibrium denotes the evolution of a species.
 Random mating . The HWP states the population will have the given genotypic frequencies
(called Hardy–Weinberg proportions) after a single generation of random mating within the population. When violations of this provision occur, the population will not have Hardy–
Weinberg proportions. Three such violations are: o o o
Inbreeding , which causes an increase in homozygosity for all genes.
Assortative mating , which causes an increase in homozygosity only for those genes involved in the trait that is assortatively mated (and genes in linkage disequilibrium with them).
Small population size , which causes a random change in genotypic frequencies, particularly if the population is very small. This is due to a sampling effect, and is called genetic drift .
The remaining assumptions affect the allele frequencies, but do not, in themselves, affect random mating. If a population violates one of these, the population will continue to have Hardy–Weinberg proportions each generation, but the allele frequencies will change with that force.

 Selection , in general, causes allele frequencies to change, often quite rapidly. While directional selection eventually leads to the loss of all alleles except the favored one, some forms of
 selection, such as balancing selection , lead to equilibrium without loss of alleles.
Mutation will have a very subtle effect on allele frequencies. Mutation rates are of the order 10 −4 to 10 −8 , and the change in allele frequency will be, at most, the same order. Recurrent mutation will maintain alleles in the population, even if there is strong selection against them.
 Migration genetically links two or more populations together. In general, allele frequencies will become more homogeneous among the populations. Some models for migration inherently include nonrandom mating ( Wahlund effect , for example). For those models, the Hardy–
Weinberg proportions will normally not be valid.
How these violations affect formal statistical tests for HWE is discussed later.
Unfortunately, violations of assumptions in the Hardy–Weinberg principle does not mean the population will violate HWE. For example, balancing selection leads to an equilibrium population with Hardy–
Weinberg proportions. This property with selection vs. mutation is the basis for many estimates of mutation rate (call mutation-selection balance ).
So, the biggest thing to consider is how genetics can effect evolution. Can you see any relation between the two??

Hardy Weinberg Problem Set p 2 + 2pq + q 2 = 1 and p + q = 1 p = frequency of the dominant allele in the population q = frequency of the recessive allele in the population p 2 = percentage of homozygous dominant individuals q 2 = percentage of homozygous recessive individuals
2pq = percentage of heterozygous individuals
1. View the Dragons below. The winged trait is dominant.