I tend to avoid terms like 'prove': poetry is an expression of a chunk of biology, as are thoughts and feelings, and I've yet to encounter an example of poetry that doesn't have a biological/material source. If you have examples of poetry that has a source other then human biology then feel free to cite some.
Poetry, thoughts and feelings a subset of Biology....an interesting thesis which I think you should expand on given the explanatory gaps
Here's a clue - poets tend to be material people.
Who generate poetry which does not seem to fit what we know of matter scientifically speaking. People, some of whom seem to
find poetry and awe in the fact we are atoms and yet when we examine those same atoms scientifically, we do not find poetry. And some don't find poetry or awe in atoms. That is no basis for a scientific theory of poetry I would have thought. Use science to find poetry or awe in, well anything.
If there were no people, would atoms still be found to be poetic? If a copy of Burns is still floating about in a universe where humans are extinct, is it still poetry?
I must lay my cards on the table. Stuff like poetry, that is unencompassable by scientific explanation, can be described as spiritual and, if you like, Woo, and there is thus plenty of it floating around in humanism and scientism.