1. Evolution of Populations: Part I

2. Gene Pools
Gene Pool: combined genetic information of all members of a particular population.
Relative Frequency of an Allele = number of times that allele occurs in a gene pool

3. 2 Main Sources of Genetic Variation
1. mutations
2. Genetic Shuffling
during sexual reproduction

4. Single-Gene Vs. Polygenic Traits
Many Possible Phenotypes
Trait controlled by two or more genes
Two or more alleles
2 Distinct Phenotypes
Trait controlled by one gene
Two possible alleles

5. Natural Selection and Phenotypes
Natural Selection can affect the distribution of phenotypes in three ways:
1. Directional Selection
2. Stabilizing Selection
3. Disruptive Selection

6. Directional selection: Individuals at one end of the curve have higher fitness than individuals in the middle or at the end.

7. Stabilizing Selection: When individuals near the center of the curve have higher fitness than individuals at either end of the curve.

8. Disruptive Selection: When individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle.