Key Area 7: Genetic Drift

Question 1

What is genetic drift?

Answer 1

The random change in the frequency of alleles/genes/sequences.

Question 2

What are the three main causes of genetic drift?

Answer 2

• small population
• neutral mutations
• founder effect

Question 3

Describe the effect population size has on genetic drift

Answer 3

Smaller populations have less chance of seeing all the different variations of alleles and therefore only their small range is of genes is passed on

Question 4

Describe the effect neutral mutations have on genetic drift

Answer 4

Neutral mutations have no effect on effect on the protein and little effect means they’re not subject to natural selection

Question 5

Describe the founder effect

Answer 5

When a small number of individuals leave to colonise a new area and the available genes in this new, smaller population will differ from the original