Please help! Unsure what to write and need help!!

One possible theme of The Call of the Wild could be that only the strongest survive. Explain how this relates to Darwin’s theory of natural selection and the survival of the fittest. Do you agree or disagree with this idea? Is there one aspect with which you agree but another with which you do not? Your answer should contain the following: a full explanation of this theme and its connection to natural selection; citation of supporting examples from the novel that illustrate the theme; and your opinion and reasons.