Well given that the brain has evolved from single-celled organisms into humans today, through all the stages in between, there have been varying levels of consc

Well given that the brain has evolved from single-celled organisms into humans today, through all the stages in between, there have been varying levels of consciousness. You have things with just nerve nets, like jellyfish. Then you have ganglia, in things like worms and insects. Then you'd have what we'd consider the first actual "brains", in bilaterians ... things like flatworms. Then the vertebrates, with brains, such as hagfish and lampreys. Somewhere along the line, between these types of things and human beings, consciousness developed, and it would have been on a sliding scale. These things eventually evolved into complex being such as primates and humans. There is no "evidence" of this because I can't even prove that another human is conscious (solipsism). But I'm assuming that monkeys, lions, dogs, etc. are conscious even though that is lower on the spectrum of human consciousness. The question remains as to where on this long lineage of things, self-awareness rose, and what exactly causes that? If the first life arose from RNA in the ocean (or whatever), I don't think RNA is conscious. But a hagfish? Well, it has a spinal cord, ganglia, and a brain. So maybe, yes? What is it about that arrangement that causes it to occur? Again, I'm mostly interested because the answer to that question can help us answer if machine consciousness is possible. Right now, there are a few theories out there that could be applicable to AI if any of them are true: - Integrated Information Theory - Global Workspace Theory - Predictive Processing Theory - Orchestrated Objective Reduction (not as much with this one) - Panpsychism (not really scientific) It's just very, very hard (or impossible) to obviously objectively test any of these.