Comment by dekhn

and that's also completely and totally irrelevant to the problem at hand.

Proofs don't apply in biology. Nothing in biology is a truly logical system that can be proved or disproved. That's true for chemistry and physics too- the only system where anything can be proved is math.

In science, instead we gather evidence and evaluate it, and often come to the conclusion that it is so unlikely something is dangerous (given the data) that we presume it's safe. People use the term "scientific proof", but I'm not aware of any in biology that would truly be classified as proof.