I think the way evolution operates is quite a bit more complicated than "one bitflip at a time". The way evolution operates is a meta-process that itself was shaped by an evolutionary process which took place (mostly) long ago.

IMO, the genome is like an abstract system which was "designed" for evolution. It can move in one direction or another on the phenotypic plane actually extremely quickly under strong environmental pressures (on the order of only a few hundred or thousand years). And the winds of environmental pressures are frequently shifting, producing what was likely a very thorough and aggressive search of the state space.

I agree there is probably a lot to be learned from further study of the human body and brain, but we will have to re-invent a lot ourselves too since the machine capabilities we are looking for are really a lot different than the constraints that humans were shaped under.