4: Natural & artificial selection of quantitative traits

Question 1

Describe selection analysis on discrete traits

Answer 1

Measuring the relative fitness of each genotype
Using these fitness values to predict how allele frequencies change

Question 2

How do we know that natural selection is causing the evolution of a quantitative trait?

Answer 2

1. Heritable variation in the trait
2. Competition for resources
3. Differences in fitness that depend on trait

Question 3

Why doesn’t selection always decrease genetic variance?

Answer 3

• Mutation
• Migration
• Diff forms of selection

Question 4

Describe directional selections affect on genetic variance

Answer 4

Decreases it

Question 5

Describe stabilising selections affect on genetic variance

Answer 5

Decreases it by alot

Question 6

Describe disruptive selections affect on genetic variance

Answer 6

Increases