Noises from the Darkroom: The Science and Mystery of the Mind. Guy Claxton

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СКАЧАТЬ to persist. Computers can be left switched off for years and (all being well) will leap into action again, as if no time had passed at all, when they are next turned on.

      Human beings and other animals grow and evolve. Computers get redesigned, sometimes from scratch. People need to eat to live. No computer has yet been discovered taking a bite out of its desk. There has been a film called The Cars that Ate Paris, but not yet one called The Laptops that Ate IBM. You can understand everything important about a computer by looking at it ‘now’. You can understand very little about the human mind without investigating how it came to be. Computers can be built out of a variety of different materials, and they may end up doing very similar kinds of things. The operation of brains and minds is entirely dependent on the stuff of which they are made, and the worlds they and their ancestors grew up in.

      Yet the conscious mind’s view of itself downplays its evolutionary history, and its unconscious substratum, shamelessly. Part of the problem with the human brain-mind is that it has come to see itself as a kind of computer – without embodiment, without any history other than its own experience, without ecology. It has even come to identify only with what comes up on the screen of consciousness, and to ignore its own circuit boards and microchips. To straighten the mind out, it is necessary to remind it of its relationship to its brain, its body, its world and its ‘unconscious’. That is where we have to start.

      A Brief History of Slime

      Let us briefly go back right to the beginning of life: to the primaeval ooze. A very long time ago – 4 billion years or so – there was no life; only an atmosphere containing simple molecules such as methane, ammonia, carbon dioxide, nitrogen and water vapour. There was no free oxygen, no ozone layer between the Earth and the sun, so powerful ultraviolet rays could enter the atmosphere unfiltered. Since Stanley Lloyd Miller’s classic experiment in the early 1950s, it has been known that some at least of the basic molecular building blocks of life – the amino acids – can be produced by subjecting mixtures of these gases to the levels of ultraviolet radiation and the types of electrical discharge that would have been around in those early days. Simple chemical processes would have enriched the prehistoric broth to the point where it contained several of the necessary chemical ingredients of life.⁴

      It is a long way, though, from simple proteins and sugars to the molecules and structures that are characteristic of all living systems, from amoebas to Buddhas. There are 200 or so of these essential ‘molecules of life’, and they collaborate with each other in such intricate and self-supporting ways that the whole structure of relationships on which life depends seems to hang together like a multidimensional archway – remove one piece and the whole thing collapses. And while some of them can be found in different brands of primordial soup, many of them, in order to be synthesized, seem to need exactly the kind of environment provided by the living cellwhose origins we are eventually trying to account for. We are faced with a classic ‘Chicken and Egg’ situation: in order to explain how cells were made, we seem to need to postulate the existence of cells!

      There are a number of ingenious theories about how the bridge between simple molecules, and life, was built. Graham Cairns-Smith of the University of Glasgow has suggested that, just as an archway needs a temporary support while it is under construction, which can then be taken away when the arch is finished, so the first molecules of life were able to be synthesized and concentrated within the tiny cell-like cavities that are present in certain types of clay. Once these carbon-based molecules had formed their mutually supportive society, they were then able to kiss the clay goodbye.⁵ However it happened, there emerged, amongst these molecules of life, the ones that were to serve as the powerhouse for the whole of evolution: the self-replicating molecule known as DNA. Each DNA molecule is like a long message, an instruction manual for making all the different constituents of living matter, written in an alphabet comprising only four letters. A simple bacterium needs a manual equivalent to about 1000 book pages to make it and keep it going. The ‘library’ needed to construct and run a human being, contained within the 46 chromosomes of every cell in the body, is equivalent to about a million pages. And, of course, each of these chromosomes is able to photocopy itself with incredible accuracy and elegance, whenever its parent cell divides.

      Under the conditions that might have been expected 3,500 million years ago, amino acids have been shown to form into primitive celllike structures. By 3,000 million years ago, cells had developed which were able to generate energy from light: they were capable of photosynthesis. As this process consumes carbon dioxide, and liberates oxygen gas, the composition of the atmosphere was slowly but radically changed. The development of the ozone layer meant further reductions in the amount of ultraviolet radiation penetrating through to the Earth’s surface, and increasingly hard times for the original bacterial or prokaryotic cells. In order to take advantage of the changing conditions, much more complex kinds of cells developedthe eukaryotic cells, from which all multicellular species are derived. These basic building blocks of animal tissue are themselves comprised of collections of different kinds of simpler prokaryotes.⁶ Each of our human cells, for example, contains mitochondria, which were originally completely independent little creatures. They still have their own DNA which is quite different from that contained within the nucleus of their adopted parent cells, yet have chosen to settle down and work as the energy factories of the cell in return for board, lodging and protection.

      The first multi-cellular organisms began to appear on the Earth about 700 million years ago. The basic design of the animal body has over millions of years ramified into the galaxy of different species of which television nature programmes constantly remind us. But the fundamental specification has remained surprisingly constant. Just as city society has evolved in strikingly similar ways all over the world, so the body has come to delegate its necessary functions to a familiar repertoire of subsystems. Like a colony of ants, but more compact and sticky, cells cling together, throwing their lot in with each other, and contributing their specialized talents to the overall good of society, in the hope that ‘All for One and One for All’ will turn out to be a successful strategy.

      For example, all bodies develop subsystems whose job it is to turn food into a usable form, transport it round the far-flung part of the empire, and deal with waste disposal. Some citizens roll themselves into a tube, the walls of which learn to weep lubricants that soften the food and start the process of converting raw antelope or sunflower seeds into a usable nutritious juice. To make use of a greater variety of raw materials, some of them quite tough, other brave citizens build themselves into hard white rocks at the entrance to the tunnel, and crush the ore that passes between them. Constant supplies of fresh water are needed by the food processors, and the development of a flappy pink proboscis helps to flip moisture into the front end of the tunnel. While at the other end, sewage operatives divide the waste products into liquids and solids, and develop short-term holding capacities, so that the garbage can be dumped when it is safe, and smart, to do so. If you are evolving into a fish, it does not matter too much if you leak as you go; but if you are on your way to becoming a bird, you are at an evolutionary advantage if you can learn the trick of not fouling the nest.

      To work properly cells, like cars, need not only suitable liquid fuel but air, so another subsystem evolves to extract the vital ingredients of air and deliver them. The body grows an internal complex of beaches, a vast coastline along which the air can continually lap, and where chemicals can trap the precious oxygen. In order to maximize the vigour and intimacy of this contact, the enfolded coastline develops into an internally-regulated bellows that constantly exchanges used air with fresh. While inside the body there develops an intricate network of canals that make Venice look like the Sahara desert, again with a central pumping station that keeps the currents flowing, and ensures that supplies reach every nook and cranny.

      Ingestion is a crude process, and sometimes things get sucked in at the front end of the tube СКАЧАТЬ