1. The Genetics of Evolution
What is the relationship between the genes of a population and evolution?

2. Standards:
BI7. a. Students know why natural selection acts on the phenotype rather than the genotype
of an organism.
BI7. c. Students know new mutations are constantly being generated in a gene pool.
BI8. c. Students know the effects of genetic drift on the diversity of organisms in a population.

3. Objectives:
SWBAT…
Explain that new mutations are constantly being generated in a gene pool, and this can cause evolution.
Understand the decrease in genetic diversity in a population caused by genetic drift.

4. Where does the genetic variation come from for evolution?
Gene pool-combined alleles for all the individuals in a population
Genetic variation is stored in the gene pool
Alleles-different forms of trait (eye color)
Allele frequency-measure of how common an allele is in a population

5. What are the five factors that can cause evolution?
Genetic drift-allele frequencies can change due to chance alone
Gene flow-the movement of alleles from one population to another, changes allele frequencies in each pop.
Mutation-can form new alleles, creates genetic variation needed for evolution
Sexual selection-certain traits may improve mating success
Natural selection-certain traits can help survival, these traits increase in frequency

6. What is gene flow?
Gene flow-movement of alleles from one population to another
Occurs when individuals of species move between populations
Increases genetic variation

7. What processes allow genetic drift to take place?
Genetic drift-changes in allele frequency due to chance, decreases genetic diversity
Bottleneck effect-GD that occurs after an event greatly reduces the size of the population. (overhunting)
Founder effect-GD that occurs after a small number of individuals colonize a new area. (islands)

8. Genetic Drift
Bottleneck Effect Polydactyl (Amish)

9. Summary Questions What is the gene pool of a population?
Name two genetic factors that can cause evolution.
Does genetic drift decrease or increase genetic diversity?
What is the relationship between the genes of a population and evolution?