Question

The model shows the process of evolution at work in a population of aphids with varying amounts of pesticide resistance. Select ALL of the requirements for evolution to occur.
Responses
A Sexual reproduction must occur.Sexual reproduction must occur.
B The final population is purely random.The final population is purely random.
C Genetic variation must exist in the population.Genetic variation must exist in the population.
D Those with the highest pesticide resistance reproduced.Those with the highest pesticide resistance reproduced.
E Only those with the highest pesticide resistance level survived exposure to the pesticide.

Answer 1

Correct choices: C and D.

- C (Genetic variation must exist): Required — evolution needs heritable variation in traits/alleles.
- D (Those with the highest pesticide resistance reproduced): Required in the sense that differential reproductive success (higher resistance → higher fitness/reproduction) is what drives change by natural selection.

Not required:
- A: Sexual reproduction is not required (asexual populations can evolve).
- B: The final population being purely random is not a requirement.
- E: "Only those with the highest resistance survived" is too strict — some individuals with lower resistance can survive and reproduction need only be differential, not absolute.