3. 2. 2 - Natural selection in action

Question 1

what is the selection pressure?

Answer 1

the pressure exerted by a changed environment or niche on individuals in a population, causing changes in the population as a result of natural selection

Question 2

what is industrial melanism?

Answer 2

the evolution of dark-coloured individuals in a habitat that has been made darker by industrial pollution (e.g soot)

Question 3

what is selecting for reproductive success?

Answer 3

when natural selection operates on adaptations that are specifically used when attracting a mate
- e.g: tail of a peacock and adaptations of pollinated flowers that help attract pollinators to the plant

Question 4

what is a directional selection?

Answer 4

natural selection showing a change from one dominant phenotype to another in response to a change in the environment

• one phenotype is selected for over all the others
• it occurs anywhere that environmental pressure is applied to a population

Question 5

define gene pool

Answer 5

all of the alleles of all the genes in a population