Yes. And considering there was no alternative to the big bang/evolution (on the basis that it, well, happened), if we assume determinism. Assuming determinism, if we ran repeated trials of the universe, it would end up exactly the same each time (including evolution and the big bang). Therefore, evolution and the big bang have a probability of 1. Perhaps your instinct here is to appeal to quantum indeterminacy. Keep in mind, however, that these quantum effects average out on the macro scale and so the quantum indeterminacy has negligible macroscopic effect. So I guess in this case I can only claim that these probabilities are really, really close to 1. Oh well.