1. What is allele frequency?
17.1 Genes and Variation
LT: Analyze shifts (changes) in numerical distribution of traits and use these shirts as evidence to support evolution by natural selection
Focus Questions:
What is allele frequency?
What causes allele frequency to change in a population?

2. FQ: How does evolution by natural selection change a population over time?
ET: Get into a group of 3 and pick up one copy of the lab from the front of the room
Read the lab with your group of 3

3. Gene Pool: The combined genetic information of all the members of a particular population
All the members of a population may interbreed so they share a group of common genes

4. What are the 2 main sources of genetic variation?
Mutations: Any change in a sequence of DNA
Q: how do mutations occur?
radiation, environment, replication of DNA
Gene Shuffling: Your 23 pairs of chromosomes can produce 8.4 million different combinations of genes!
Q: how do chromosomes get arranged so differently?
Independent assortment and crossover

5. Directional Selection
When nature selects individuals at one end of the bell curve as the fittest

6. Stabilizing Selection
When nature selects individuals in the middle of the curve as more fit and the bell narrows

7. Disruptive Selection
When nature selects individuals at opposites ends of the curve as more fit.