Nic
The questions you propose are the very same ones that Darwin contemplated as I know you are well aware of. It's these many questions which are all part of the inquisitive tapestry driving us to enjoy the questions and answers we patch together with which I have reached conclusion like so many other athiests, that there is no divine plan but instead extraordinary ongoing random events which allows us to clearly see life for what it is - tragic and stunningly beautiful.