I've noticed that we're getting a lot of questions like this one. I'm picking this question not in specific, but because it's a good example of a general question I had.
Sometimes, questions like these are very easy to prove, but extremely difficult to disprove. This primarily comes up when dealing with questions of prior example - i.e. are there any previous examples of X happening? All you need to do is find one example for the answer to be "yes," but for the answer to be "no," you might have to review someone's entire body of work, or maybe as broad as an entire century of literary thought.
I'm not saying that the answer to the above example is no, but imagine, for a second, that it is. That would mean Bob Dylan didn't draw from Timrod in any other earlier works, and demonstrating that would require combing his other works in an authoritative and comprehensive way.
How would an answer go about helpfully and meaningfully showing a negative result? What counts as authoritative and succinct, particularly if it hasn't necessarily been studied or reviewed by another source before?