the Theory of Evolution is a fact in the same way that the Theory of Gravitation is a fact and the Germ Theory is a fact.
The meccanisms are by which Evolution opperates are also theories. Its a semantic big T vs. little t, argument.
Evolution is the founding theory, to say you can't test it because its too big is silly.
By testing the meccanisms by which Evolution opperates you are directly testing Evolution.
Evolution is not a generality, it is a specific natrual law, Theory with a big T.
wa:do