Form my limited understanding, it's simpler than it appears. It's a wire routing problem. Each neuron "knows" where it is going based on the proximity of its

Form my limited understanding, it's simpler than it appears. It's a wire routing problem. Each neuron "knows" where it is going based on the proximity of its fellows, just as other cells know to become a liver based on who their neighbors are. Given a nascent brain, it is trained into an intelligence by external input. Neurons are pruned and connections strengthened. As I see it, a significant problem is designing a substrate in silicon, or whatever, that has the requisite complexity. I would not be too surprised to find out that the layout program for an AI is not too different in complexity from today's largest software projects.