There are plenty of things that mn has been working on for millions of years and we still manage to build things that do the same job - is it just a matter of time before we build something to go between the ears?
Problem is there are two AIs - strong and weak. Weak AI is just about replicating stuff humans can do - chess playing, diagnosis, vison, talking etc. Strong AI is all about building something that thinks and is consious - like a human. Weak AI never dies - strong AI goes through cycles as it hits a high and then a low. See:
http://www.i-programmer.info/babbages-bag/297-artificial-int...