Why do they? When you get back to a singularity, you are outside of time. Time does not exist. Evolution does not deal with events before the big bang and the start of wordly time. Thats an area that is unknowable. Its a matter of faith. You dont have to be an athiest to belive in Evolution. In fact, Darwin was a Christian.
Yeah, it really does. Biological evolution is a consequence of the evolution of matter, is it not?
I used the word "singulartiy" not in the sense you're referring to, from the standpoint of Physics. I was using it in the sense of causes and first cause being unique and unrepeatable.
A species, being unique, can only evolve or be created once. It is a singular event.
Confirmation or "proof" of scientific hypotheses depends on the repetition of experimental results. It is the nature of some hypotheses to be outside the realm of experimentation, and I think Evolution is one. Small scale experimental standards of scientific proof aren't really applicable to issues of vast time scales such as evolution or cosmology.
That's why I suggested the phrase "Postulate of Evolution" above. "Big Bang Postulate" would be another.