My theory is that theories are not the kind of thing that can be proven or disproven. Theories are explanations. Theoretically, the number of explanations for any event is unlimited. However, some explanations are more plausible than others. For example, if the Mona Lisa were discovered in someone's cellar which of the following explanations would you think is most plausible?

(a) human beings physically removed and made an unauthorized transfer of the painting
(b) aliens from another planet removed and transferred the painting
(c) the painting appeared miraculously in the cellar
(d) the painting was transferred there by Uri Gellar using only the power of his mind to manipulate physical reality (psychokinesis)

I maintain that of these four explanations, theft is more plausible than extraterrestrial, miraculous or psychic event. I think any reasonable person would agree. I hope you would agree. We may never be able to prove theory (a), but it is still the most plausible and reasonable.

Likewise with evolution vs. creationism: evolution is a more plausible and reasonable explanation of species than is special creation. We can't prove either theory.

My theory is that religious writings such as the Bible originated for spiritual and social purposes, not to teach science. But if one wants to treat Genesis as if it were a scientific theory and match it with natural selection, I think any reasonable person, skeptic or not, would select natural selection as more plausible