There's no shame in not knowing something, I'm proud that you can admit it. Not everyone can. Unfortunately I do not have all of the answers. I can use what we know about life, and come up with conclusions but I can't be certain. However its important to realize that just because we don't know something, doesn't mean God did it. A couple billion years is a very long time, much longer than most people realize. A lot can happen in that time.