Topic 6 -Evolution

Question 1

Evolution is a

Answer 1

Change in the genetic composition of a population over time

Question 2

Adaptation

Answer 2

Is the change in a genetically determined trait in response to environmental conditions that enhance the ability to cope with the environment

Question 3

Fitness

Answer 3

Fitness is the proportionate contribution of an individual to future generations

Question 4

What does fitness involve?

Answer 4

Number of offspring produced

Number of offspring surviving to reproductive age

Question 5

Natural selection operates on the

Answer 5

Individual

Question 6

Assumptions for natural selection and evolution to occur

Answer 6

Individuals of a species are not identical -genetic variation

Some of the variation is heritable

Individuals leave different numbers of descendants -varying fitness

Fitness depends on the interaction between an individuals traits and it’s abiotic and biotic environment

Question 7

Biological species concept

Answer 7

Distinguishes species based on their potential to interbreed and produce fertile offspring

Question 8

Allopatric speciation

Answer 8

Individuals are geographically isolated by a physical barrier
ex. river or mountain

Question 9

Sympatric speciation

Answer 9

Sub populations are isolated without geographical isolation

Ex. Timing of breeding or behavioural differences

Question 10

Pre-mating speciation

Answer 10

Separation of mating events in space and time

Behaviour- male song birds

Mechanical or structural incompatibility

Question 11

Post-mating speciation

Answer 11

Reduced survival or reproductive success of offspring