The main function of the sentence at the end of the paragraph is to finish the introduction about Darrow by completing the basic information about him.
We can arrive at this answer because:
In this case, the sentence shown in the question, ends the introduction about Darrow, concluding the basic information about him, but allowing more information to be presented throughout the text.
More information on text introduction at the link:
https://brainly.com/question/11994283