1. Microevolution  Look at processes by which inherited traits change over time  Changes in numbers & types of alleles  Measured in terms of frequency in gene pool of a population  Called Population genetics

2. Tracking Frequencies Genotype frequencies See page 402 textbook Allele Frequencies

3. Processes of Microevolution Natural Selection – Can cause an increase or decrease in certain alleles in a population

4. Patterns of Natural Selection Directional Selection – Peak of normal distribution moves in one direction

5. Stabilizing Selection – Bell curve shape becomes narrower

6. Disruptive Selection – Bell curve is disrupted and pushed apart Into two peaks

7. Migration – Movement into, out or between populations – Can change the numbers and type of alleles

8. Mate Choice – Random selection results in random traits passed on – Limited or selected choice limits set of traits passed on

9. Mutation – Changes the numbers and types of alleles – These are rare

10. Genetic Drift – Random effects in everyday life can affect survival & reproduction of individuals – Some alleles may become more or less common – Significant in small populations