Question

Two students describe natural selection to their classmates. Student 1 describes that individuals are able to evolve to fit their changing environment and thus result in populations that are well adapted over time. Student 2 proposes that natural selection occurs when selective pressures act on individuals but evolution affects whole populations. Which student should refine their explanation of natural selection and why?
Responses
A Student 1 should revise the explanation because individuals in a population cannot change the genetic component of their DNA, so they cannot evolve.Student 1 should revise the explanation because individuals in a population cannot change the genetic component of their DNA, so they cannot evolve.
B Student 1 should revise the explanation because environments cannot change enough in an individual's lifetime to see evidence of natural selection.Student 1 should revise the explanation because environments cannot change enough in an individual's lifetime to see evidence of natural selection.
C Student 2 should revise the explanation because selective pressures only act on entire populations while survival occurs with individuals.Student 2 should revise the explanation because selective pressures only act on entire populations while survival occurs with individuals.
D Student 2 should revise the explanation because it does not account for the extinction of populations after heavy selective pressures.Student 2 should revise the explanation because it does not account for the extinction of populations after heavy selective pressures.

Answer 1

A — Student 1 should revise their explanation. Individuals do not evolve; evolution is a change in allele frequencies in a population over generations, so natural selection acts on individuals but evolution affects populations.