1. Quantitative genetics

2. Continuous traits have a complex genetic basis
Polygenic trait: influenced by many genetic loci
Interaction between alleles (epistasis)
Interaction with environment (phenotypic plasticity)
Quantitative genetics: study of the genetic mechanisms of continuous phenotypic traits

3. Hardy-Weinberg extended to polygenic traits

4. Complex traits vary continuously

5. Components of phenotypic variation
VP = VG + VE
Total phenotypic variance in population
Variance due to genetic differences
Variance due to environmental differences

6. Genetic and environmental influences create continuous distribution

7. How we measure heritability
Slope = heritability

8. The effects of selection can be large

9. STRONG VS. WEAK SELECTION

10. RELATIONSHIP BETWEEN Selection and heritability
R = h2 x S
Selection can be strong, but response also depends on heritability!

12. To remember: Evolution and selection are not the same
Selection can occur without evolution
(Evolution also occurs without selection)
The magnitude of selective evolutionary change depends on:
Strength of selection (selection differential)
Heritability