1. Evolution
Evolution is driven by natural selection favoring phenotypes (expressed traits) that are better suited for the environment.
Better suited individuals survive longer and reproduce more.
The more they reproduce, the more they pass down the genes that code for the favored phenotypes.
Evolution, therefore, is defined as a change in the genetic make up of the population.

2. Hardy-Weinberg Principle
G.H. Hardy and G. Weinberg came up with the idea that evolution would not occur as long as certain assumptions were true.
If a population is not evolving, the allele frequencies are not changing, and the population is said to be in Hardy-Weinberg Equilibrium.
Frequency is the fraction of the allele’s abundance in a population [part/whole or a percentage expressed as a decimal value]

3. Assumptions of Hardy-Weinberg
Very large population. In small populations of finite size, genetic drift, which is chance fluctuation in the gene pool can case genotype frequencies to change over time.
No migration. Gene flow can increase the frequency of any genotype that is in high frequency among the immigrants.
No net mutations. By changing one allele into another, mutations alter the gene pool.
Random mating. If an individual picks a mate then random fertilization does not occur.
No natural selection. Differential survival and reproductive success of genotypes will alter their frequencies.

4. Hardy-Weinberg Equation
p = the frequency of the dominant allele
q = the frequency of the recessive allele
p + q = 1
If we square this formula, we get:
p2 + 2pq + q2 = 1
p2 = the frequency of homozygous dominant individuals
q2 = the frequency of homozygous recessive individuals
2pq = the frequency of heterozygotes

5. How Do We Know Evolution Occurred?
If you see a change in the allele frequency, then there was a change in the genetic make up of the population.
This means that when p and q change values, then evolution has occurred.

6. Practice Problems H-W Lab Bench Practice Problems (Resources Page)

7. Video Solving H-W Problems- Bozeman (Resources Page)