Alright Atheists, lay it on me.?

I can only start from what I understand from what I have learned from science... Primitive Ape like creatures developed or mutated in a small way allowing us to stand on our feet and use our hands for things other then walking... Then we again mutated reducing the size of muscle that goes from the skull through the jaw and connects to the lower jaw, which decreased our jaw muscle strength but allowed for our brain cavity to grow without being crushed by said muscle. Now having a small jaw muscle at first would seem like a disadvantage due to the inability to use our teeth to defend ourselves as well as other animals, but by increasing our brain cavity we started to developed other abilities like deductive reasoning (however primitive it may have been at the time) so we started using crude tools and our hands to fight, eat, and hunt. With this ability and the increased proteans, and diversity of food, we began to populate the earth with greater ease, and lost our fur, formed languages, pictures, and our greatest strength the ability to work together for a common unselfish goal.