I don't want to act flamey here, but you should read [The Blind Watchmaker][1], R. Dawkins. The whole book is pretty interesting and analyzes exactly that complexity from an evolutionary perspective. There's also a chapter in which he describes his own "genetic algorithm" which produces life-like creatures. Pretty related to the topic in question.

[1]: https://en.wikipedia.org/wiki/The_Blind_Watchmaker