Sunday, January 17, 2010

Shaw and Darwin

Bernard Shaw's preface to Back to Methuselah, "The Infidel Half Century," is something you don't see much of these days: a non-creationist attack on Neo-Darwinism.

Back to Methuselah was published in 1921, a good 15 years before the modern synthesis got underway, so "Neo-Darwinism" as Shaw uses the term means something different: not Darwin-plus-Mendel, but Darwin-minus-Lamarck. Unlike Darwin himself, who was willing to grant that Lamarckian processes (the inheritance of acquired characteristics) might play some role, the Neo-Darwinians broke with Lamarck completely and insisted that evolution was driven almost exclusively by what Shaw -- not wishing to profane the name of Nature -- insists on calling Circumstantial Selection.

It's not that Shaw doesn't believe in natural selection -- he grants that it occurs and that it influences evolution -- but he considers it to be an incidental process. He thinks of natural selection the way a more orthodox evolutionist thinks of genetic drift: It undeniably happens, but it's not all that important and evolution could go on just fine without it. The real driving force behind evolution is voluntary change.
If you can turn a pedestrian into a cyclist, and a cyclist into a pianist or violinist, without the intervention of Circumstantial [that is, natural] Selection, you can turn an amoeba into a man, or a man into a superman, without it. All of which is rank heresy to the Neo-Darwinian, who imagines that if you stop Circumstantial Selection, you not only stop development but inaugurate a rapid and disastrous degeneration.

Let us fix the Lamarckian evolutionary process well in our minds. You are alive; and you want to be more alive. You want an extension of consciousness and of power. You want, consequently, additional organs, or additional uses of your existing organs: that is, additional habits. You get them because you want them badly enough to keep trying for them until they come. Nobody knows how: nobody knows why: all we know is that the thing actually takes place.
The details of this process are admittedly a little sketchy, even if we take the heritability of acquired characteristics for granted. It's easy enough to imagine how a giraffe -- the canonical example, which Shaw dutifully trots out ("I do not remember how this animal imposed himself illustratively on the Evolution controversy; but there was no getting away from him then; and I am old-fashioned enough to be unable to get away from him now.") -- might want a longer neck, try to get one by stretching, and succeed in lengthening its neck a bit. But when one tries to picture a cartilaginous fish "trying" to have bones, or a monkey "trying" not to have a tail (not to mention a plant or an amoeba "wanting" or "trying" to do anything at all), the theory seems to break down.

For Shaw, the important thing about Lamarckism is not the inheritance of acquired characteristics, but the importance of will in the evolutionary process. In fact, Shaw seems to think that the former depends on the latter -- that acquirements are inherited if and only if they were acquired deliberately rather than by accident. (He expresses this in a rather confusing way, saying that only "habits" can be inherited, but makes it clear that he is using "habit" in a special sense which includes not only customary behavior patterns but anatomical features as well. A Shavian "habit" is any feature that is voluntarily acquired and thereafter becomes involuntary and automatic.)

Because of Shaw's focus on the inheritance of voluntarily acquired characteristics, he dismisses the experiments of August Weismann -- in which he cut off the tails of 20 successive generations of rats and observed that their offspring were nevertheless born with tails -- as missing the point. Shaw considers it self-evidently ridiculous to suppose "that injuries or accidents coming from external sources against the will of the victim could possibly establish a [heritable] habit: that, for instance, a family could acquire a habit of being killed in railway accidents." He proposes the following as an alternative experiment which, if it were practicable, would be more relevant to the Lamarckian hypothesis as he understands it.
The scientific form of his experiment would have been something like this. First, he should have procured a colony of mice highly susceptible to hypnotic suggestion. He should then have hypnotizes them into an urgent conviction that the fate of the musque [sic] world depended on the disappearance of its tail, just as some ancient and forgotten experimenter seems to have convinced the cats of the Isle of Man. Having thus made the mice desire to lose their tails with a life-or-death intensity, he would very soon have seen a few mice born with little or no tail. These would be recognized by the other mice as superior beings, and privileged in the division of food and in sexual selection. Ultimately the tailed mice would be put to death as monsters by their fellows, and the miracle of the tailless mouse completely achieved.

The objection to this experiment is not that it seems too funny to be taken seriously, and is not cruel enough to overawe the mob, but simply that it is impossible because the human experimenter cannot get at the mouse's mind.
The odd thing about this -- okay, there are a lot of odd things about it, but one of the odd things about it -- is how thoroughly Darwinian it is. A true Lamarckian would perhaps expect that, once the mice had been suitably hypnotized, they would somehow try very hard to reduce the length of their own tails and would succeed in doing so, if perhaps only to a very slight degree. (Exactly how this would be done is, as I have said, not so clear.) Their children would then be born with very slightly shorter tails, which they in their turn would shorten a bit by the same method, and after many repetitions of this process a generation of tailless mice would finally be produced.

Shaw predicts something completely different. Instead of the mice changing their own bodies by willpower and then passing on those changes to their children, he imagines that the mice's desire for taillessness would somehow cause a few tailless mutants to appear a generation or two later, and that the tailless mutation would become the norm by means of a process which can only be described as eugenics -- that is, self-imposed artificial selection, which is nothing more than a special case of Darwinian natural selection. The bit about the mutation arising "very soon" as a result of the mice's desire (rather than arising eventually by chance) is the only hint of anything non-Darwinian in Shaw's story.

Unlike the mouse story in the preface, which is not Lamarckian at all, the Back to Methuselah plays themselves do feature the inheritance of acquired characteristics. In the story, a few people read a book arguing that the human lifespan must be extended to at least 300 years, and as a result they themselves -- not the next generation, as in the case of the mice -- go on to live for 300 years! Somehow their desire directly causes sweeping physiological changes, which are then inherited by their children. The implication is that, had they instead read a book arguing that humans all ought to be nine feet tall, they could simply have taken thought and added the requisite cubits to their stature. (The physiological changes implied in increased longevity are internal and invisible, which helps make the story seem a little less obviously ridiculous. That's probably why the mouse story, featuring a more obvious physical feature, used a different mechanism. It would be too clearly bogus if the mice's own tails had simply disappeared after the hypnosis.) After that, eugenics -- in the form of sexual selection and genocide -- once again takes over. The long-lived people seek each other out as mates "for the good of the race," and eventually they decide to kill off all the short-lived ones. No matter how hard he tries to be a good Lamarckian, Shaw's imagination keeps being drawn back to Darwinian mechanisms.

5 comments:

  1. William John TychonievichJanuary 25, 2010 at 7:48 AM

    Thanks for bringing my attention to this preface. I know I read it, along with most of GBS’s plays and prefaces, while in high school, but just the title and first two paragraphs of your blog sent me scurrying to the library to check out Back to Methuselah. After reading and contemplating your blog for a while, I read the preface in question and contemplated a little more.

    While you present the preface as a non-creationist attack on Neo-Darwinism, you fail to note that in it Shaw offers something he calls Creative Evolution as not only an alternative to Scientific Evolution, but also as an alternative religion in itself. The basic difference between creationists and Shaw is quite obvious. The former postulate a humanoid God creating all the intricacies of mortal existence unilaterally. The latter postulates a creative impulse innately infusing and driving the chemistry, the matter and energy, of that mortal existence toward superhuman status. Rather than being created in God’s image, we strive to create ourselves in that image. In the play and preface of Man and Superman, the sexual selection dynamic of the Shavian evolutionary system is openly unveiled. The female of the human species is sexually driven to seek out, shall we say, the most evolved male possible with which to mate and reproduce; sort of a psychoanalytical egalitarian take on the “sacred marriage” of Goddess to king.

    I find Creative Evolution quite analogous to the Collective Unconscious, since it is in the unconscious that “habits” are “acquired” and housed, and quite compatible with Super Theology. Shaw replaces the creationists’ external Creator with an internal evolutionary Create-ability. Super Theology replaces Intelligent Design with Intelligence itself. To rephrase that: the physical “laws” of the universe, like gravity and inertia, are not products of Intelligence, they are Intelligence. It holds that intelligence exists outside the biochemical confines of the brain, though the two are still inextricably bound together, individually and collectively, in the Blakean sense that the “body is the soul as perceived by the five senses.” Evolution, therefore, is yet another example of that Intelligence.

    Shaw wrote the Methuselah preface in 1921, when he was 65 years old. Since Methuselah’s main claim to fame is living several hundred years, and since the play includes characters who increase their own life spans to hundreds of years by simply desiring to do so, I think it should be noted that Shaw lived another 39 years after this and died at the age of 94 when he fell out of a tree while attempting to saw off a limb. In the first act of the play, Adam agonizes over the prospect of living forever, of being immortal, and is told he should pick a date far into the future on which to die and stop worrying about it. I think these facts present at least circumstantial evidence that Shaw not only knew what he was talking about but was unrepentantly offering himself as proof of it.

    Scientists of today fiddle with and change genetic codes in the laboratory. Is it such a stretch to think it possible to do so with unconscious internal processes?

    ReplyDelete
  2. Thanks for your comments, William John. I never knew Shaw had lived so long or how he had died. His death -- kidney failure following an accident while doing chores -- is weirdly reminiscent of that of Tolstoy's Ivan Ilyich.

    I'm not sure what you mean by saying that physical laws such as gravity and inertia "are" intelligence. It's hard for me to see how these purely mechanical processes involve thinking or learning or problem-solving or goal-directed behavior, so perhaps you mean something else. Can you explain what you're getting at?

    While it's conceivable that there are internal processes, conscious or unconscious, by which we can modify our genes, I think it's very unlikely. For one thing, it runs counter to the logic of natural selection. A gene which allowed an animal to tinker with its genes would be sabotaging itself, reducing its own chance of being passed on to the next generation. Also, if people could modify their genes, and if the mechanism were as simple as the Shavian one of wanting to change, you'd think we would see it happening all the time, but we don't.

    Which is not to say that evolution cannot be intelligently directed -- but the part we can direct is selection, not mutation. As I tried to point out in this post, sexual selection and other forms of eugenics account for most of the story Shaw is telling. And of course modern science now allows us to create artificial mutations as well. So even if Shaw's science is wrong, the prospect of humans consciously directing their own evolution is still very real.

    ReplyDelete
  3. Methuselah, by the way, is an interesting character. He died in the year of the flood, which can be interpreted in two ways: that he was a sinner who died in the flood; or that he was the last righteous person outside of Noah's immediate family, and that God therefore delayed the flood until after his death. (Rashi favors the latter interpretation.) In any case, the flood coincided with the "death of Methuselah" in a broader sense as well, since lifespans became significantly shorter after the flood.

    ReplyDelete
  4. William John TychonievichJanuary 30, 2010 at 7:27 AM

    What I’m getting at is this: Matter/Energy was smart enough to arrange itself in such a way that existence became possible and Space/Time was smart enough to provide the arena. Without something to hold it together, matter dissipates into infinity. So it conceived gravity, the attraction of matter to matter, as the antidote to this problem and acquired the ability to hold itself together. Without inertia, however, matter would then become one gigantic (or perhaps infinitesimal?) lump and energy would be useless. So energy conceived inertia, the propulsion and alignment of matter against gravity, and blew matter apart into the celestial pattern of the Universe, early edition. Inertia, like gravity, was also an acquired ability, something energy had the intelligence to learn how to do. As the Universe grew older, these Matter/Energy abilities, so basic to its intelligent arrangement, became habitual until they finally devolved into “laws of physics.”

    Of course, the intelligence I’m talking about in this regard is very basic, much like the intelligence Shaw assigns the amoeba. Its presentation, implying a certain consciousness for inanimate objects and forces, is also highly metaphorical. However, by acting intelligently, Matter/Energy and Space/Time became part of Intelligence while at the same time generating Intelligence forward. The Intelligence I’m postulating here is the Universe’s equivalent, as I said, of the human psyche’s Unconscious. It’s not the brain-based intelligence of “thinking or learning or problem-solving or goal-directed behavior” so much as the organic intelligence of a plant reaching for water with its roots and turning toward the sun with its leaves. Understanding gravity and inertia as “purely mechanical processes” confuses the Newtonian metaphorical conception of the Universe as an immense machine with reality. Einsteinian and post-Einsteinian conceptions are much more organic and therefore more reductive of reality, though these too are metaphorical delineations of reality and not reality itself, no matter how scientifically utilitarian they prove to be. Anyway, the suspension in midair of a ping pong ball between two waves of sound is mechanical; the Earth settling down in its Space/Time groove as it spins around the Sun is organic. Still speaking metaphorically then, I think it might be better to conceptualize gravity and inertia, and even evolution and photosynthesis, etc., the way early animists viewed the forces of nature, as gods rather than mechanical processes.

    I didn’t know Methuselah died in the Flood and I find that information to be very interesting. So thanks. As for the idea that there were no nice, kind, friendly, respectable people except Noah and family in the world at that time, I think it’s a form of denial needed by the faithful, by the religious, to distinguish themselves from evil, from the war and oppression of the world and society they live in and interact with but are too cowardly to confront or even question. Combined with biblical principles like the Chosen Few, I think the basic message of the Flood these people should be getting from their God today goes something like this: “I don’t grade on a fucking curve!”

    Also regarding the Flood, it occurred to me a while back that it constituted a fairly good metaphor for evolution itself. Noah’s family and the selected pairs of animals in the Ark represent the species which prevail within the protection of their adaptability, while the people and animals drowned represent the 99.9% of all species that ever existed which are now extinct. And if you accept the fact that life crawled out of the seas, there’s a certain poetic justice in almost totally reversing that process by flooding the world.

    ReplyDelete
  5. William John TychonievichFebruary 1, 2010 at 2:34 PM

    Forgive the poor math in my original comment. GBS lived 29 years after 1921, not 39!

    ReplyDelete