Genetic Diversity

Question 1

What is directional selection?

Answer 1

Favours individuals in one direction from mean of population.
Changes characteristics of a population.

Question 2

What is stabilising selection?

Answer 2

Favour average individuals.

Preserves characteristics of a population.

Question 3

How does directional selection affect the normal distribution curve?

Answer 3

Individuals which fall left/right of mean will receive a phenotype = more suited to their conditions - survive longer + breed successfully to produce more offspring.
.: Mean moves in direction of these individuals (left/right on normal distribution curve).

Question 4

What does directional selection result in?

Answer 4

Phénotypes at one end being selected + those at other extreme being selected against.

Question 5

What does stabilising selection do?

Answer 5

In stable environmental conditions. Individuals with phenotypes closest to mean are favoured .: most likely to pass on these alleles. Individuals with alleles at extreme = less likely to survive. Stabilising tends to eliminate phenotypes at the extreme.

Question 6

What does stabilising selection result in?

Answer 6

Phenotypes around the mean being favoured, and phenotypes at the extremes being eliminated.