Where do we start?

I know we are born, that it takes a man and a woman (sperm & egg) to make a baby, that's not my question. My question has been and is now is there God? If there were Adam and Eve why is there such irrefutable evidence of the caveman? We know that he (& she) existed but to say there were 2 people just plopped down on this earth in the midst of a beautiful garden? I know I know, that's what faith is for, right? Ok. I guess that's my other question where did we start?