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Evolutionary Theory Consciousness and Evolution
The "C" Word: Consciousness Calvin began with some opening remarks about the "C" word. Like the "E" word (evolution), the word consciousness is a catch-all phrase that has many connotations and associations. Calvin is fond of mentioning the biologist Francis Crick, who said the boundary between the living and non-living has faded into the varied gradations of molecular biology. Consciousness is likely to go the same way. Our understanding of it will morph into many differentiations and gradations. Calvin remarked that he is not particularly interested in arguing over exactly when consciousness begins. Many have noted that organisms as ancient and simple as bacteria are capable of following a glucose gradient. Does this mean that they are conscious? Who knows? What Calvin is interested in is "higher intellectual functioning" in humans. As children grow and learn, Calvin pointed out that they seem to be able to pyramid intellectual tasks, meaning they can build more complex tasks upon simple ones they accomplished previously. Soon, children are able to recognize long sequences, complex syntactical patterns, and narratives. Wanting to know the full gestalt of a sequence of thoughts, they start to demand proper endings to their parent’s bedtime stories! Calvin believes that searching for patterns in the midst of chaos seems to be central to higher intellectual functioning. We get pleasure from detecting patterns. Much of our humor is based upon our ability to see coherence. Why do we enjoy crossword puzzles so much? Calvin compared the development of consciousness to the building of a house of cards. We stabilize levels one at a time. Higher intellectual functioning is built upon a number of lower levels of consciousness. Calvin pointed out that most neurologists are studying the lower levels of consciousness, and he mentioned that Walter Freeman has joked that looking for consciousness in the brain stem is like confusing the light switch for the light. Many neurobiologists will say that consciousness is simply selective attention, but Calvin likes how author and fellow neurologist Antonio Damasio has distinguished between two kinds of consciousness: 1 Core consciousness: which is the part of our awareness centered in the here and now and is related to excitement, energy, sickness, attention, and relaxation. 2 Extended consciousness: which is the part of our awareness that cognizes the past, present, and future and enables one to illuminate the present moment with past knowledge (memory). Quoting from Damasio’s book, The Feeling of What Happens, which Calvin recently reviewed for the NY Times Review of Books, Calvin noted the remarkable fact of the human sense of identity, which is central to our experience of human consciousness. Damasio writes, It is astonishing that we have a sense of self at all—astonishing that we have continuity of structure and function that constitutes identity [and the] stable traits of behavior we call a personality. And on extended consciousness, Damasio writes, When we think of the greatness of consciousness we have extended consciousness in mind. [It] goes beyond the here and now of core consciousness, both backward and forward. The here and now is still there, but it is flanked by the past, as much past as you may need to illuminate the now effectively, and, just as importantly, it is flanked by the anticipated future…. The time scale is no longer the fraction of a second that characterizes core consciousness. Evolution and Secondary Uses How do you get new function in evolution? Calvin believes that although variation and selection are important, his study of the evolutionary record has shown how secondary uses emerge from already existing structures. In other words, most structures that are "selected for" in evolution are multi-functional, and thus a trait may appear that was not the direct selection in evolution but more akin to a by-product. Calvin provided an interesting analogy to explain. The intentional purpose of sidewalk curb cuts is for wheelchairs, yet 99% of the use one gets is for other activities, such as skateboarding, biking, wheeling suitcases, etc. Likewise, in evolution: something new most often gets used for other things. Parts of the human brain in particular have multi-functional purposes that were selected in evolution for other reasons. The language cortex, for example, has many uses, so Calvin speculates that it may have evolved for other or at least partly other reasons than just language. Structured Thought and Language When trying to explain how humans evolved the ability to speak and process language, Calvin emphasized that the comprehension of words and short sentences is not the problem. Even bonobos and parrots can learn vocabularies of 100 plus words. The real problem with language starts when we need to explain comprehension of a half-dozen or more things. One needs rules of structure that enables one to handle longer strings of sentences. In short, syntax is needed. What separates us from chimps and parrots is our higher intellectual functioning, including (but not limited to): - The ability to understand arbitrary rules, such as for a game of hopscotch. - The ability to speculate and imagine. - The ability to make ethical decisions, which depend heavily on the ability to anticipate a course of action and decide whether or not to do it. - The ability to make novel ballistic movements, such as throwing at an angle. This is very demanding on the brain. Calvin has drawn attention to how throwing accuracy helped develop the brain in evolution. Mark Turner: Narrative as Central to Consciousness Calvin next discussed briefly the work of the English professor at the University of Maryland, Mark Turner. In his book, The Literary Mind, Turner asserts that the mind operates on the basis of parable and story. Narrative imagining is fundamental to higher mental functioning. Paraphrasing from Turner’s book, Calvin elaborated on a few passages to explain this idea further: We duck when we see someone ready to throw a stone. We imagine and then respond. We predict this way. Narrative imagining is our fundamental form of predicting. When we evaluate the future of an act, we are predicting. Narrative imagining is our way of evaluating. We have executed a plan based on a story. We have executed the story as the plan. Narrative is our way of planning. We imagine a story to explain things. When a drop of water falls on us, we imagine how it could have originated. We imagine stories all the time as part of our consciousness. Narrative imagining is our fundamental cognitive instrument for explanation Competing for Consciousness: A Darwinian Process on a Much Faster Time Scale Calvin’s recent work has looked at how a Darwinian evolutionary process could have given rise to consciousness. He believes that superficial layers of our neocortex have the neuro-circuitry capable of operating a Darwinian process of pattern, replication, variation, and selection—although he grants that it does happen on a much faster time scale than the evolution of animal populations, for example. Unfortunately, we do not currently have detailed enough brain scanning equipment to verify Calvin’s thesis, but all of the basic physiological elements are in the brain for a full-fledged Darwinian process to occur. In accord with recent evidence that indicates that consciousness is spread throughout the brain, Calvin emphasized that consciousness is more like a "movable feast" inside the brain. Conclusion Overall, Calvin noted that although there are many mysteries yet to be explained about why humans are conscious, scientists are making progress everyday towards having a more refined understanding of how a Darwinian process could have produced the intricate network of neural activity in our brains that is central to our experience of consciousness.
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