Questions 19-22

Question 1

Toadstools Can Sometimes Feel Squishy

Explain how adaptive radation leads to speciation with examples

Q19

[6]

Answer 1

• Trait changes
• Subspecies formation
• Speciation

Question 2

1st adaptive radiation to speciation

Expand on ‘trait changes’

Q19

[6]

Answer 2

Species alter traits when resources are limited, leading to the adoption of new behaviours and traits. E.g. Darwin’s finches, mockingbirds

Question 3

2nd adaptive radiation to speciation

Expand on ‘subspecies formation’

Q19

[6]

Answer 3

Trait changes result in subspecies, which further evolve behaviours or traits, eventually leading to reproductive isolation from the founder species

Question 4

3rd adaptive radiation to speciation

Expand on ‘speciation’

Q19

[6]

Answer 4

Reproductive isolation from the founder species leads to speciation, as genetic and behavioural differences prevent interbreeding

Question 5

Definition & Example

With examples, explain an evolutionary trade-off

Q20

[4]

Answer 5

• Definition: Evolutionary trade-offs occur when a change in one trait increases fitness but leads to a change in a negative trait, preventing the organism from optimising their fitness.
• Example: Mammals moving into water, like whales. While they become very good at swimming, their adaption to aquatic life renders them unable to walk on land

Question 6

Definition & 2 examples

With examples, explain convergent evolution

Q21

[5]

Answer 6

• Definition: When unrelated species develop similar traits in response to similar pressures
• Example 1: Streamlined bodies of sharks and dolphins, both adapted for efficient swimming, despite different evolutionary origins
• Example 2: Bats and birds both evolved independently for flying

Question 7

Don’t Have Extra Caffiene Ever

Explain the founder effect using examples

Q22

[6]

Answer 7

Definition
Human example
Continued evolution

Question 8

Define the founder effect

Q22

[6]

Answer 8

The loss of genetic variation that occurs when a new population is established by a small number of individuals

Question 9

2nd founder effect

Expand on ‘human example’

Q22

[6]

Answer 9

The migration of humans from Africa to Europe illustrates the founder effect. The smaller group that left Africa will have a different allelic makeup than the original species, thus experiencing the ‘founder effect’

Question 10

3rd founder effect

Expand on ‘continued evolution’

Q22

[6]

Answer 10

Geographic separation between populations results in ongoing genetic differences, as each group continues to experience unique mutations and genetic drift, perpetuating the founder effect