10.8 Changing Population Characteristics Flashcards
1
Q
What are the steps of natural selection?
A
- Genetic variation within a population
- Those with favourable alleles survive the selective pressure
- Breed and pass on the alleles to offspring
- This happens over many generations
- Increasing the frequency of the favourable alleles in the population
2
Q
What is directional selection?
A
Favours individuals at one extreme
3
Q
What is stabilising selection?
A
Favours individuals towards the middle of the range
4
Q
What is an example of stabilising selection?
A
Birth weights
5
Q
What is an example of directional selection?
A
Peppered moths
6
Q
What is disruptive selection?
A
Favours both extremes in a population - generates 2 averages
