1. 1. Sexual Selection
In order for random mating to occur, all members of the population must have equal opportunity to produce offspring. M
any species select mates based on
certain traits such as size, strength or coloration
FEMALES do the choosing!

2. 2. Large Population
A population must be very large, so genetic drift doesn’t cause changes in allele frequency by random chance.

3. 3. No Immigration or emigration
When organisms move into (immigration) or out of (emigration) a population, they bring or take genes with them
If enough organisms move, the gene pool will be adjusted
If the gene pool is adjusted then it can not reach genetic equilibrium

4. 4. No mutations
For genetic equilibrium to occur, there must be no mutations, which introduce new alleles, and no Natural Selection can take place
which gives any one phenotype a survival advantage over another.

5. 4. No mutations
For genetic equilibrium to occur, there must be no mutations, which introduce new alleles
Mutations that change phenotype can affect an organism’s fitness(ability to survive and reproduce)

6. LEARNING OBJECTIVE
6. The Hardy Weinberg Principle

7. The Hardy-Weinberg Principle
In order to tell whether or not Genetic Equilibrium is happening scientists use the Hardy-Weinberg Principle
This equation compares how often an allele is found in a population to how often a phenotype is in a population

8. p2 + 2pq + q2 = 1 p2=the frequency of homozygous dominant genotype
2pq=the frequency of heterozygous genotype
q2=the frequency of homozygous recessive genotype

9. In some populations, these conditions
may be met or nearly met over long
periods of time, and little or no
Evolution occurs.
BUT in most populations it is difficult
for ALL conditions of Hardy-Weinberg
to be met.
Hank Video