The Theory of Natural Se******n is accepted because there is evidence to prove that beings ascended to the "top of the food chain" because they did things that kept them alive when others of their species died because they didn't adapt. That does not prove that a deity "oversees" that process. Natural se******n, per se, means that there is no "grand plan". Life evolves because beings did/do things that the rest of the crowd didn't. When mankind first crawled out of the forest and stood on two legs, the survivors were the ones who didn't stand upright immediately and get hammered by a big raptor, or they evaded the predatory cat others didn't.

It also goes back to simpler life when a genetic deviation allowed a creature to avoid being eaten because it sensed a shadow and got out of the way.

All of this happened millions (billions?) of times with the survivors adapting to their environment, ensuring that genetic mutation survived. There was no "guiding" hand that maintained control. It was/is all random.

Easy:

Q: What is a human soul?
A: No such thing

Q: Where do souls come from, and are they finite in number or unlimited?
A: No such thing

Q: Do you believe in reincarnation (ie, an old soul in a new body)?
A: No

Q: Do you believe in resurrection (of the flesh; will the resurrected have a human form as we have today)?
A: No

Q: Do animals have souls?
A: No

Q: Do you believe in Heaven and Hell?
A: No

Q: Do you believe you will be reunited (physically) with those who have died? Or those who will die in the future?
A: No (unless your cemetary plot is next to someone else).

Q: Will pet owners be reunited with their dearly loved pets?
A: No

Q: When is "The End of Existence" and "The Beginning of the Everlasting?"
A: When you die, and never.

Q: Am I sinning by asking these (and many more) questions?
A: Depends on your religion. I am not sinning by answering them.