Consciousness and Evolution

Consciousness and Evolution

Evolution by natural selection is a gradual process, not a jumpy jerky one.[1] Small modifications not sudden leaps forward. Complex organs don’t spring into existence from nowhere as a result of spectacular random mutations. This basic Darwinian principle applies as much to the mind as the body. And it applies to consciousness as much as to anything else. It is not to be supposed that human or mammalian consciousness arrived fully formed on planet earth one bright morning. It arose, step by miserly step, from a state of unconsciousness, long ago—probably in the ancient oceans. A genetic mutation in an organism produced a minute variation in brain structure that led to the first glimmers of what we would describe as consciousness—a hint or seed of what was to come. It wouldn’t even be recognizable as consciousness, as we know it today, and its future development by equally small steps would not be predictable (compare the first experiments in eyes). I think it highly probable that pain consciousness was the first kind to grace the planet, so that the initial seed was a type of intermediate stage in which organisms started the transition from absolute unconsciousness into a version of what would become conscious pain. We can’t even call it pain; it was a kind of proto pain, or incipient pain, or pain precursor (like fins to legs, or scales to feathers). We have no name for this intermediate state—it was neither conscious nor unconscious. I will refer to it as “semi-conscious”, intending nothing explanatory. Semi-consciousness is the kind of state that mediated the move from purely physical unconsciousness to the kind of biological state we think of as consciousness. It was a condition of semi-what-it’s-likeness. Think of it as occurring in some mollusk or mite in the primeval ocean—not an impressive creature by any means. Its future would be glorious, but for now it was nothing to write home about, merely a faint stirring. Such a thing must have existed, because nature doesn’t evolve by sudden spurts; it needs intermediate forms, biological bridges.

Does this type of micro-adaptation exist today? Is there any semi-consciousness still around? We don’t know, still less do we know how it might be detected. It might be extinct now, having performed its bridging act. I doubt that our own minds contain anything of it, though they contain much that goes back a long way: we are never semi-conscious (as I understand that term). Our brains either correlate with conscious stuff or with unconscious stuff, never anything in between. Successive mutations and natural selection have dispensed with the semi-conscious. It was never much use, though it evidently had its moment in the sun; it conferred a slight advantage in those early days on creatures that had it. Do any species have it today? Perhaps insects do, or worms, or little fish. How could we tell? Think of a surveillance tape covering all of evolution from bacteria to humans: could we pinpoint the moment at which semi-consciousness appeared? Suppose we could: then we could examine the brains of organisms that have it and those that don’t. We could speculate that this or that change in brains is responsible for the onset of semi-consciousness. We could then trace its evolution into something we would call consciousness proper, noting the cerebral correlates. This would be pretty interesting, no doubt. We would have a gradualist brain science to set beside our gradualist consciousness science, with no stage missing; there would be no gap in the psychophysical record. If we found that some living organisms resembled these long-extinct creatures, we could investigate them thoroughly—dissect them, electrically stimulate their brains, map their genome, tabulate their behavior. Then we would have a model for the creatures that originally gave birth to what would later become consciousness. We might even come up with an explanatory theory of the semi-conscious, a solution to the semi-mind-body problem; we could see how brains give rise to the semi-conscious mind (if that phrase isn’t contradictory). Admittedly, that would not solve the conscious-mind-body problem, but it would be somewhere in the vicinity. Of course, the whole thing would be a methodological nightmare, maybe totally quixotic, but the idea of such a theory does not seem impossible in principle. We do know that a theory of this kind must exist in Platonic heaven, because an intermediate evolutionary stage must have occurred (granted gradualism) and there must be a truth about it. There must be a non-miraculous story to be told. It might even be intelligible within the terms of current science.

Why am I prattling on about this missing link in the evolutionary chain? Because it promises to provide an intelligible path from the insentiently physical to the sentiently mental. The transition is sufficiently gradual to form a bridge from one thing to the other. Of course, I have no idea what this bridge would look like; I don’t have the theory whose existence I am surmising. But this is the place to look if you want to make headway with the problem: go the source, don’t belabor the end-point. Look at the early primitive stages, don’t get weighed down by the final flourishes. The story is going to be complex, intolerably so, but it is a story with narrative structure, not a series of unprecedented lurches forward, sudden plot twists. It makes sense, or would if we had it. This century we tame the semi-conscious mind of lowly creatures like insects; the next we proceed to the simple consciousness of higher organisms like reptiles; maybe one day we can take on mammalian consciousness. We don’t run before we can walk. One point will occupy center stage: the motivational properties of the relevant mental states. It is very plausible to suggest that natural selection favored conscious minds (and the semi-conscious minds before them) because they afford motivational oomph; for some reason these states make the organism more determined to achieve its goals, and more able to. Pain is a great motivator, as is hunger, as is lust. Animals that have these states will win out over those that don’t. The state of unconsciousness is a sluggish state, encouraging sloth; but consciousness (and its precursors) seems designed to galvanize the organism. The more conscious, the livelier—that seems like a biological law (don’t ask me why—the whole thing is pretty mysterious). So, how does the motivating power of consciousness depend on the brain? How does the brain produce conscious motivation? That seems like a tractable problem: there is what it is like and what it makes you do, and these are connected. Subjectivity and willpower go together—seeming and doing. This is not behaviorism but the recognition that consciousness enhances motivation. Semi-consciousness did the same, though to a lesser degree, and it gradually transformed into the consciousness we know today, with its impetus to action. The zombie is apt to be a sluggish operator; the sentient being with alert eyes and pricked-up ears is quick and coordinated (I am not talking about the philosophical conceit of molecular duplicates). Thus, we might trace the evolution of motivation from its earliest days in the semi-conscious up through its later manifestation in the consciousness of mammals.

Notice that a Cartesian consciousness cannot evolve by Darwinian principles. For there can be no gradual transition between material substance and immaterial substance. There is no such thing as a Cartesian semi-mind. On no planet has an immaterial mind evolved; for that you really do need God (which rules out such minds altogether). Any evolved mind must be a physical mind, in the innocuous sense that it arose from physical raw materials by gradual purposeless steps (this is compatible with genuine emergence). There was no sudden saltation to an immaterial soul at some pivotal moment in evolution. There were only slight modifications of unconscious bodily tissue—some of these being quite mysterious. Since minds did (and must) evolve by Darwinian principles, they cannot be Cartesian, necessarily so. What we need to understand is howconsciousness arose by incremental steps, smoothly, naturally, one small step at a time. Somewhere in this history the mystery is removed, perhaps quite unspectacularly, certainly not magically.

Suppose for the sake of argument that the hard nut (as I once dubbed it) of the mind-body problem was belief not consciousness. Consciousness we have solved, but belief leaves us baffled. How can mere brains produce states of belief? Neurons don’t believe, even bunches of them, so how do they enable people to believe? The essence of belief is assent plus propositional content—how does the brain contrive to do this? Well, let’s look at the evolutionary history. We know that belief must have evolved gradually over a long period of time by small modifications, so it must be capable of such an evolution. Therefore, there must have been a transition from non-belief to belief, with accompanying brain transitions. Since this transition can’t be saltatory, there must have been an intermediate state of semi-belief. Perhaps this state no longer exists in life on earth; or perhaps some living creatures still possess it, if not quite in its original form—reptiles, birds, octopuses. We might try investigating such creatures, their behavior and brain. We find slight differences between their brain and the brains of simpler creatures as well as more complex ones (true believers). This is the cerebral mark of the state of semi-belief. Then we would see how non-belief led to belief, physiologically; this would be pretty interesting, and might lead to insights into belief proper (“Ah, so that’s how the brain did it!”). We would have an origin story—about how belief came to be. I venture to suggest that such a story is possible: for we already have ideas about states of semi- or quasi-belief—informational states of various kinds. These are not quite belief but close to it; they could be precursors to belief. And the same can be said of other types of mental state—desires, perceptions, emotions. Each has its own gradualist history, its Darwinian dawn, its continuous ascent up the evolutionary ladder. Such ladders are illuminating, if difficult of access, and may shed light on the end result. An evolutionary perspective may thus help with understanding the mind and its relation to the body and brain. At the least it can supplement frontal attacks on the problem.[2]

[1] If you need a defense of gradualism, see Richard Dawkins, “Universal Darwinism”, reprinted in Science in the Soul (2017).

[2] I might cite the conversion of leaves into flowers, scales into feathers, arms into wings, bacteria into mitochondria, kin altruism into general altruism, and other wonders of evolutionary transformation. Consciousness and the mind in general must have resulted from transformations of other traits into what we see today, in ourselves and other animals. There is a story to be told, whether we can tell it or not. And surely, this history must illuminate what it is the history of. Does the secret of consciousness lie in its early days in semi-conscious pain? What ingredients were added? How did it come to be so dominant in controlling the life of the organism? How did it come to be the center of human existence? It wasn’t even a distant dream in our unconscious forebears. An history of consciousness would be well worth reading: “Once upon a time, long long ago, in a swamp in Africa, there lived a mollusk that felt a tingle in its extremities, and that was when consciousness first entered the natural world…”.