- This paper is fair enough in pointing out that cloning doesn’t steal someone’s identity. We knew this already because of “identical” twins being different people.
- The author points to the complexity of the brain, and how – for mathematical reasons – its configuration cannot be encoded in the genes.
- But the article has nothing really to do with “souls”. The closing sentence is really a metaphor. The author points out that – on account of the complexity of the brain – each of us is distinct from all others. So – I suppose – on this account, our “soul” is our brain. But “soul” is being used as a principle of individuation, so doesn’t need to be so intellectualist.
- Explorers returning from distant lands tell of aborigines so afraid of cameras that they recoil from the sight of a lens as if they were looking down the barrel of a gun. Taking their picture, they fear, is the same as stealing their soul.
- You might as well just shoot them dead on the spot. Knowing that a photograph is only skin deep, people in the developed lands find such terror absurd. But the fear that one’s very identity might be stolen, that one could cease to be an individual, runs deep even in places where cameras seem benign.
- The queasiness many people feel over the news that a scientist in Scotland has made a carbon copy of a sheep comes down to this: If a cell can be taken from a human being and used to create a genetically identical double, then any of us could lose our uniqueness. One would no longer be a self.
- There are plenty of other reasons to worry about this new divide the biologists have trampled across. Nightmare of the week goes to those who imagine docile flocks of enslaved clones raised for body parts. But the most fundamental fear is that the soul will be taken by this penetrating new photography called cloning. And here, at least, the notion is just as superstitious as the aborigines’. There is one part of life biotechnology will never touch. While it is possible to clone a body, it is impossible to clone a brain1.
- That each creature from microbe to man is unique in all the world is amazing when you consider that every life-form is assembled from the same identical building blocks. Every electron in the universe is indistinguishable, by definition. You can’t tell one from the other by examining it for nicks and scratches. All protons and all neutrons are also precisely the same.
- And when you put these three kinds of particles together to make atoms, there is still no individuality. Every carbon atom and every hydrogen atom is identical. When atoms are strung together into complex molecules — the enzymes and other proteins — this uniformity begins to break down. Minor variations occur. But it is only at the next step up the ladder that something strange and wonderful happens. There are so many ways molecules can be combined into the complex little machines called cells that no two of them can be exactly alike.
- Even cloned cells, with identical sets of genes, vary somewhat in shape or coloration. The variations are so subtle they can usually be ignored. But when cells are combined to form organisms, the differences become overwhelming. A threshold is crossed and individuality is born.
- Two genetically identical twins inside a womb will unfold in slightly different ways. The shape of the kidneys or the curve of the skull won’t be quite the same. The differences are small enough that an organ from one twin can probably be transplanted into the other. But with the organs called brains the differences become profound.
- All a body’s tissues – bone, skin, muscle and so forth – are made by taking the same kind of cell and repeating it over and over again. But with brain tissue there is no such monotony2. The precise layout of the cells, which neuron is connected to which, makes all the difference. Linked one with the other, through the junctions called synapses, neurons form the whorls of circuitry whose twists and turns make us who we are.
- In the reigning metaphor, the genome, the coils of DNA that carry the genetic information, can be thought of as a computer directing the assembly of the embryo. Back-of-the-envelope calculations show how much information a human genome contains and how much information is required to specify the trillions of connections in a single brain. The conclusion is inescapable: The problem of wiring up a brain is so complex that it is beyond the power of the genomic computer.
- The best the genes can do is indicate the rough layout of the wiring, the general shape of the brain. Neurons, in this early stage, are thrown together more or less at random and then left to their own devices. After birth, experience makes and breaks connections, pruning the thicket into precise circuitry. From the very beginning, what’s in the genes is different from what’s in the brain. .And the gulf continues to widen as the brain matures.
- The genes still exert their influence — some of the brain’s circuitry is hardwired from the start and immutable. People don’t have to learn to want food or sex. But as the new connections form, the mind floating higher and higher above the genetic machinery like a helium balloon, people learn to circumvent the baser instincts in individual ways.
- Even genetically identical twins, natural clones, are born with different neural tangles. Subtle variations in the way the connections were originally slapped together might make one twin particularly fascinated by twinkling lights, the other drawn to certain patterns of sounds. Even if the twins were kept in the same room tor days, these natural predilections would drive them each in different directions. Experience, pouring in through the senses, would cause unique circuitry to form. Once the twins left the room, the differences between them would increase.
- Send one twin around the block clockwise and the other counter-clockwise and they would return with more divergent brains. For artificial clones the variations would accumulate even faster, for they would be born years apart, into different worlds.
- Photography is only skin deep. Cloning is only gene deep. But what about the ultimate cloning — copying synapse by synapse a human brain?
- If such a technological feat were ever possible, for one brief instant we might have two identical minds. But then suppose neuron No. 20478288 were to fire randomly in brain 1 and not in brain 2. The tiny spasm would set off a cascade that reshaped some circuitry, and there would be two individuals again.
- We each carry in our heads complexity beyond imagining and beyond duplication. Even a hard-core materialist3 might agree that, in that sense, everyone has a soul4.
- Part I - Science
- This essay first appeared in The Week in Review of The New York Times. March 2, 1997
- Well, as the author later admits, this is not a logical impossibility.
- But, the important point is that the cloned brains would then diverge so as no longer to be exactly similar.
- I don’t quite agree. The various brain cells are rolled off the production line like any others.
- But I do agree that it’s the wiring that matters, and only some of it is “in our genes”. Most of the wiring is a response to experience, albeit controlled by genetic dispositions.
- Genes no doubt govern certain gross matters about the brain, and maybe the efficiency of the hardware.
- “Experience” – in the sense of the environment – is also involved ante- and post-natal in the gross structure of the brain: diet, toxicity and all that.
- What’s this supposed to mean?
Text Colour Conventions (see disclaimer)
- Blue: Text by me; © Theo Todman, 2021
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