Biology (and, indeed, physics) contains fractal levels of complexity. The existence of debate does not mean that we don't understand it well enough to mimic it.

Biology (and, indeed, physics) contains fractal levels of complexity. The existence of debate does not mean that we don't understand it well enough to mimic it. At one time, people had no idea how the brain worked at all. Now we know that the brain is a collection of neurons, special cells which have filaments called an axon and dendrites that extend from it to other neurons at junctions we call synapses. At these synapses, electrochemical signals are transmitted to and from other neurons. When a neuron receives certain signals, it may transmit that signal on to other neurons. That's basically the Anatomy 101 chapter on the nervous system, and has been pretty well established for about a century. It's true that we're constantly learning new things about diseases that affect the function of the nervous system. There remains some debate on how exactly neurons arrange themselves, repair themselves, and change. We're still investigating internal computations within the dendrites to see how those work to decide when to propagate a signal or not. The signals are analog in some ways, but mostly digital 'all or nothing' responses, there's time coding, different types of discharge patterns...fractal complexity. If you set the goalposts at a comprehensive understanding of every bit of trivial minutiae that exists in the human body, yeah, we are (and probably will always be) far off. If you just want to predict the function of a nematode worm with 302 neurons, observing that if you engage this particular set of sensory neurons, then these few hundred synapses are activated with this pattern of impulses, and soon those other motor neurons are stimulated and the worm curls in that direction...that seems entirely within the realm of possibility. In my opinion, the goalposts ought to be "A better understanding than what we have today". We'll reach them by tomorrow, and move them forward again!