Darwin Turns 200
The gentleman-naturalist who reinvented biology.
Dec 28, 2009, Vol. 15, No. 15 • By DAVID GELERNTER
Darwin is a huge presence in the modern world, in two ways. He was a remarkable thinker, a great scientist, and the most influential biologist in history. He revolutionized the study of nature. He is also a cultural presence. Increasingly he is the venerated image carried in torchlight processions by bands of angry, chanting atheists ("Darwin! Darwin! Darwin!") who dominate the impoverished streets of the intellectual world.
Berra recites the facts, but rarely comments. We know (for example) that Darwin's was an extraordinary mind. Yet he spent eight years in the prime of life studying barnacles. Berra explains why: His eminent colleague Joseph Dalton Hooker had told him that "no one has hardly a right to examine the question of species who has not minutely described many." Darwin had already conceived his big idea of evolution by natural selection, but instead of publishing it, he hunkered down and worked on barnacles. He himself grew colossally bored--but he soldiered on. How could this brilliant scientific virtuoso stifle his imagination for eight years while he focused on nothing but the finger exercises of biology?--playing scales and arpeggios and never one measure of music? Strange. Berra has no comment.
But the main theme comes through loud and clear. Darwin's (and Alfred Russel Wallace's) theory of evolution by natural selection is made to seem simple and inevitable, which it is. Ordinary farmyard breeding produces new variants as a result of deliberate crosses and spontaneous genetic errors, or mutations. When the breeder sees a new variant he likes, he does his best to propagate it; this is "artificial selection." But it's clear also that, regardless of the breeder's plans, certain new variants are more robust than others: are better suited to survive and thrive in the environments in which they live. And left to their own devices, the more robust variants supplant, over time, the less robust varieties.
Given these simple observations, natural selection must happen, and must bring about the gradual transformation, or evolution, of living things. Spontaneous mutations create variant forms of life. Some variants are more robust than others; some are more robust than the original. In a world of limited resources, the better-adapted versions stand a better chance of surviving, thriving, and reproducing. Darwin guessed, further, that natural selection is powerful enough to transform one species into another (or many others)--and also to eradicate a species, leaving the field to its tougher competitors. What scientists have learned from the study of ancient and modern life strongly supports Darwin's guess.
"The theory of evolution," writes Berra in the first sentence of his introduction, "is arguably the greatest idea the human mind ever had," and this sentence is arguably one of the silliest. If you put Darwin next to a Newton or an Einstein, a Beethoven or an Isaiah, he is out of his league and beyond his depth. Treating Darwin as one of the presiding geniuses of human thought is unfair to him; he never asked to be compared to Newton. In fact, thinking back to the barnacle years, the heretical idea tiptoes shyly across the mind that Darwin was not so much brilliant as shrewd. In any case, his ideas have been profoundly influential. Darwinian evolution is the core (the elevator stack) of modern biology, paleontology, and genetics, which have grown up gradually around it. Moreover, Darwin took good care of his family and was generous to his colleagues. He was a gentleman genius.
Nowadays some thinkers question Darwin's role at the center of modern thought. The most impressive accept evolution by natural selection (which is impossible not to accept) but aren't sure that this mechanism is enough to explain nature as we find it.
Some of their qualms are unconvincing. A dissident often cites some marvelously subtle and complex piece of human anatomy (the eye, the hand, etc.), points to the countless millions of exquisitely graduated steps required by natural selection (that blindfolded drunk) in order to reach this goal, notes the staggering improbability of such a sequence of developments happening just by accident, and rests his case.
Except there is no case. In evolution, all outcomes are equally improbable--but there is no reason to think that the one we know is somehow the ideal; is somehow the tiny bull's eye that natural selection (by a stupendously implausible run of luck) somehow managed to hit. Evolution deals in failures, not successes. All we know about the "successes" is that they have survived so far, because they've proved stronger than the other contestants with which they were matched along the way. The human eye is impressive, but it's easy to imagine a human-type creature with eyes that see only infrared, or with some sort of radar instead of eyes. And although our eyes are impressive (I am not filing a complaint), why can't they see infrared, giving us a sort of built-in night vision? Why can't they tune in radio waves? And would it have been asking so much for them to be slouch- and deformation-resistant, so that no one would ever need glasses?
Yet Darwinian evolution does sometimes seem to crash into a wall.
Consciousness is a hard problem for Darwinians. Imagine a "zombie" (which is a standard exercise not just at the movies but in philosophy) that looks and behaves just as we do, speaks in the same way, and is completely indistinguishable from a human being. But a zombie has no mental life. Inside its head, there is nobody home. It forms no mental images and, although it registers the world around it, it experiences nothing. Tell it to imagine a rose and it's capable of describing an imaginary rose, but it sees no picture in its mind's eye; it's no more capable than your laptop of calling to mind mental images. Kick it hard in the shins and it shouts--but it's all just an elaborate act, because the zombie experiences neither pain nor anything else.
Some thinkers hold that zombies are impossible. But others see no reason in principle why they couldn't exist. And if they did, such zombies could thrive just as well as we do. But if that's so, why should self-aware, conscious beings like us ever have emerged? What good does consciousness do us? What selective advantage does it confer? It might simply have come bundled with the "fancy brain" package, as an accidental byproduct. But such a hypothesis seems to violate the economy and efficiency we associate with the ruthless mechanism of natural selection. To imagine consciousness, the central fact of human existence, as traveling beneath the radar of natural selection is not satisfying.
It's also true that the more biologists insist on our near genetic kinship to apes and other mammals, the more striking our utter incomparability to all other creatures, plain and fancy. We have known all along that apes are much closer to us than to jellyfish, and the narrow genetic footing on which this towering difference stands makes it all the more amazing. We've heard all about the intelligence of dolphins, whales, and apes; but if they're so smart, why don't they make Ape-TV documentaries about us? Why is it only we who study them? Why don't they build hospitals, write books, paint pictures, make jokes, or argue about God?
David Berlinski, one of the most impressive Darwin dissenters, quotes (in a Commentary essay) a smugly childish pronouncement by the journal Nature: "With all deference to the sensibilities of religious people, the idea that man was created in the image of God can surely be put aside." But what makes these ignoramuses so sure they know what the Bible means by "create"? How do they know that "evolution by natural selection" is not exactly what the Bible does mean? And how do they know that man is not "in the image of God"? Yes, we all know about the Bible's famous seven days, but has Nature never heard of a parable? It's not such a difficult concept. Does Nature fault the Bible for not starting with an account of Darwinian evolution?--right after the verses dealing with the Big Bang and astrophysics, which in turn follow the verses that brush everyone up on the necessary algebra, geometry, and calculus?
"The Torah speaks in the language of man," say the rabbis, and when the Bible emerged, men did not speak Darwin's language. But they did care about right and wrong, good and evil, justice and mercy, sanctity and man and God, and these (not biology or astrophysics) are the Bible's topics.
David Gelernter, a contributing editor to THE WEEKLY STANDARD, is a professor of computer science at Yale and the author, most recently, of Judaism: A Way of Being.