Human knowledge will be erased from the world’s archives before we possess the last word that a gnat has to say to us.
—HENRI FABRE
OUT ON THE BATTLEFIELD at Gettysburg, more than one hundred molecular biologists gather again and again in great semicircles around their guide, who is shouting out the history of the fight through a white bullhorn in hectic italics, like the hero of a comic book: “This is the Wheat Field, and it’s a shame they don’t keep it planted in wheat! They keep the Corn Field at Antietam planted in corn. As well they should!”
It is a fine fall afternoon, and the molecular biologists and their families tromp along in broken ranks, chattering among themselves in English, Japanese, Chinese, French, and German. They cannot help marveling at the supernatural quantities of military information that their guide has stored in his head, although when one of the graduate students in the front ranks hurries ahead to compliment the guide himself, he lowers his bullhorn for a moment and replies, “If an idiot savant can be said to know.”
The symbol on their ID tags is the Princeton University heraldic shield, orange and black, with little legs added to the bottom of the shield to make it look like a virus: a bacteriophage. This is Princeton’s Department of Molecular Biology the university’s wealthiest and fastest-growing department. Their laboratory on the edge of the Princeton campus was designed by Robert Venturi with architectural allusions to the Doge’s Palace in Venice. When the heads of the department chose Gettysburg for this year’s annual retreat, they asked a colleague at Princeton, the historian James McPherson, author of Battle Cry of Freedom, if he would be willing to show them around. McPherson told them to call Jeff Hall. “Hall knows more about the Gettysburg battlefield than I do,” McPherson said, “and Hall is a biologist besides.”
Last night in the Robert E. Lee Room of the Gettysburg Ramada Inn, the drosophilist Eric Wieschaus, who prepared for this retreat by reading The Blue and the Gray, sat with Hall, talking about Gettysburg and about genes and behavior. Late in the evening, Wieschaus was grappling with the paradoxes of Hall’s field—and grappling with his own hair, shoulders, and torso as he struggled for precise thought. Hall announced to the table, “We’ve just watched Eric Wieschaus wrestle himself to the ground. As he does often.”
Wieschaus laughed. “Even in the middle of talks,” he said. “Even in the middle of major talks.” Twelve months later he would be getting his dawn call from Stockholm.
Even out here on the battlefield, most of the molecular biologists in the ranks are talking molecular biology. Their science is racing ahead so last that they rarely take time out for an afternoon like this or for a look backward at the history of their own battlefields. Not long ago in Pasadena, Seymour Benzer’s Korean postdoc brought him a petri dish. He had injected the fly gene drop-dead into the bacteria in the dish, and now the bacteria were dropping dead. Benzer studied the plate with amusement. He knew that his postdoc was disappointed. The postdoc was trying to make the bacteria express the drop-dead gene so he could study the drop-dead protein; instead, the bacteria were simply dying. “I like the idea of making bacteria drop dead,” Benzer said. “I used to make them drop dead with phage.”
“How do you do that?” asked the postdoc.
“They eat bacteria. The phage I worked with—” Then it struck Benzer. “You don’t know that? Oh, my God!” he cried with good-natured despair. “So the whole phage literature passed you by?”
With the science accelerating so rapidly, all of the founders feel like ghosts standing in their own fields. There are postdocs in an institute named for Delbrück in Germany who have no idea what Delbrück did. Postdocs at meetings in Cold Spring Harbor see Watson striding by and exclaim out loud, “He’s still alive?”
“Molecular biology has no history for the young scientist,” one of the old guard declared not long ago.
Sydney Brenner qualified that: “I hold the somewhat weaker view that history does exist for the young, but is divided into two epochs: the past two years, and everything that went before.”
E. O. Wilson believes that this short-term memory may be a good thing. He contrasts it with the veneration that psychologists pay to Freud and Jung or that social theorists still pay to the heroes in their pantheons. “Much of what passes for social theory is still in thrall to the original grand masters,” Wilson wrote recently, “—a bad sign, given the principle that progress in a scientific discipline can be measured by how quickly its founders are forgotten.”
As Jeff Hall approaches the climax of his story, leading the ranks up the path of Pickett’s Charge, a few molecular biologists, absorbing the spirit of the place, are thinking and talking about the beginnings of their own charge. The Civil War was the moment in time during which Mendel’s peas and T. H. Morgan himself were, as Morgan used to say, “laid down.” The chairman of Princeton’s molecular biology department this year, Arnie Levine (they call him General Levine today), reminisces with Lee Silver about Schrödinger’s What Is Life? Schrödinger speculated in his book that quantum jumps might cause mutations. “It was wrong,” Levine says with a laugh. “But that didn’t matter. It got the physicists in.”
“Brought in Francis Crick,” Silver agrees. “Seymour Benzer … Gunther Stent.…”
But like most molecular biologists, Silver prefers looking into the future. He feels his science is racing toward a climax. “We thought there were all these barriers, and they don’t exist,” he often says. “We’re finding things we thought we’d never be able to find. Barriers to knowledge keep disappearing one by one. I think in the end we’re going to know it all. I really do. It’s just a question of how long, just a question of when.”
Soon it will be straightforward to take a small sample of someone’s DNA and use an electronic device called a DNA chip to probe for variant forms of every single gene. At a glance a molecular geneticist will know what genes that individual carries and what genes are on right now and what genes are off. Genetics start-up companies are already manufacturing the first generations of these DNA chips in a union of computer science and molecular biology that seems likely to race ahead at the customary speed of both.
By screening the DNA of one hundred thousand people, combining that information with personality tests, and letting a computer crunch it all together, molecular geneticists will put together pictures of gene complexes working together to produce the most complex traits of personality. “It’s going to happen fast!” Silver says. “If there are ten genes that make somebody aggressive, you’re going to see them!” The twentieth century began with a man looking at one white-eyed fly in a bottle, he says. Before we are that far into the twenty-first, he says, “we’ll be able to take ten thousand people and match different combinations of alleles across the whole genome and come up with a behavioral profile.” Of course, each profile will have been modified by the environment. “That’s certainly the case,” Silver says. “But it’s an incredible story. I think people don’t realize the power of genetics. You can figure out which genes are responsible for a trait—without knowing anything.” Knowing nothing about the gene, the environment, the psychology, or the physiological machinery, you can find your way in. “Knowing nothing! Because once you figure out what the connection is, then you go back and figure out why. You can do all that afterwards.” Take shyness, which Silver believes is very much genetically determined. With the kind of mass screen that Silver is envisioning, he could find two dozen genes, each with multiple alleles, that contribute to shyness. He could do that without knowing what each gene does. “Then you can ask, What does it do? What protein does it make? When is it turned on? When is it turned off? Incredibly powerful, to do all this.
“People who don’t believe in relativity don’t understand relativity. People who don’t believe in evolution don’t understand evolution. And it’s the same with genetics. And I think some people are just reluctant to let their imaginations run.
“My feeling is that molecular biologists are going to move into psychology and take over the field. I think that’s the way psychology is going to be rejuvenated.
“In the 1970s, they said genetic engineering would be impossible. Then they said cloning would be impossible. Amazing that people can be so shortsighted. It’s an explosion of science. Right now we’re really at the beginning of biology. That’s really the way to look at it. The end of biology in this century is like the end of physics in the last century.”
JEFF HALL holds his megaphone tipped at a rakish angle to fire out the sound over the heads of the front rows of the crowd. He is bulling into the microphone, angrily miming the action. He is almost at the top of the path of Pickett’s Charge. The statue of General Lee is far behind him, and the statue of George Meade is just ahead, beyond the Clump of Trees. In Hall’s view, the Civil War was the greatest drama in the history of the United States; the battle at Gettysburg was the climax of the war; and “the climax of the climax, the central moment of our history,” as one of Gettysburg’s historians puts it, was Pickett’s Charge. On July 3, 1863, fourteen thousand Confederate soldiers marched up this slope, toward what is now known as Cemetery Ridge. They marched through cannon fire and rifle fire toward a bend in a low stone wall at the top, now known as the Angle. They advanced, flags waving, into the very center of the Union lines at the top of Cemetery Ridge. Only two hundred of Pickett’s troops made it to the Angle, about the size of the band Hall is leading up the path today, counting the children. In that hour the battle was lost and won.
IT IS ALREADY POSSIBLE—in fertility clinics it is done every day—to screen the DNA of a set of eight embryos at the eight-cell stage and let the parents pick the one they want to implant in the mother’s womb. The more genes there are to screen and the better these gene complexes are understood, the more wealthy parents will select not only the healthiest but also the best and the brightest embryo they can, designing the genes of their children. With the same tools that Hall used to inject the first instinct into an animal, it may someday be possible for people in fertility clinics to inject a wide selection of human instincts and traits as well. As these choices are made more and more often, the old dream of Galton and the eugenicists who followed him will be fulfilled willy-nilly over the next few centuries whether governments legislate for it or against it. The rich will pick and choose the genes of their children; the poor will not. The gap between rich and poor may widen so far in the third millennium that before the end of it there will be not only two classes of human beings but two species, or a whole Galapagos of different human species. These human species could be prevented from interbreeding by the genetic engineering of chemical incompatibility, so that the egg of one would reject the sperm of the other. Silver is thrilled by the power of his science and by the vision of barriers falling away, and yet looking into the far future he sometimes thinks he sees disaster, a Darwinian nightmare; out of utopian eugenics, a dystopian origin of species.
“We have reached this point down a long road of travail and self-deception,” E. O. Wilson wrote recently. “Soon we must look deep within ourselves and decide what we wish to become. Our childhood having ended, we will hear the true voice of Mephistopheles.” He is sure we will not want to turn ourselves into protein-based computers; we will not want to lose what makes us human. Wilson’s ants, for instance, never play. We will not want to give up what we have evolved over billions of years, going back to the very origin of life. But what changes will we make in our natures—deliberately or casually and without plan—beginning in the next few years? “What lifts this question above mere futurism,” Wilson writes, “is that it reveals so clearly our ignorance of the meaning of human existence in the first place.”
ON MOST NIGHTS, by nine o’clock, Benzer is almost alone on his floor of Church Hall. By ten or eleven, his desk lamp is one of the last lights burning in the windows. For Benzer the smell of the fly food has never lost its savor: home, sweet home.
Sometimes when he is alone in his lab, he thinks of putting up plaques on the doors with the names of the people who worked there. They made his revolutions their beacon, and some of them found harbors and some lost their ships. Not all of Max Gottlieb’s Arrowsmiths stay in the game—and some of Benzer’s first were the first to drop out. Konopka now lives a few blocks away from the Caltech campus, alone in a small house half hidden by palm trees and magnolias, as anonymous as Kafka’s K. Once in a while he gets a new clock paper in the mail. He looks at the tables and he thinks, “Well, heck, these are all my mutants!” He spends his days collecting butterflies now, tipping his forehead sharply forward to peer at them over his glasses. He also collects Grateful Dead tapes and photographs of local waterfalls. He has a big Lionel model train set on the shag carpet by his front door and a pinball machine shoved against the dining room wall: “Gottlieb’s FAR OUT.” Back in the summer of 1968, the scientists in Church Hall said Konopka would never find what he was looking for. Then, when he found it, they said it was meaningless. Now it is meaningful, and he is out of science. “Story of my life,” he says. “They just didn’t believe it. You think scientists are open-minded, but ha, ha, ha.”
In the middle of the night in Church Hall, Benzer often wanders up to T. H. Morgan’s filing cabinets in the third-floor hall to raid and riffle through the founding papers of genetics, ancient references he wants to see. Then he stops in to see Sturtevant’s old student Ed Lewis. Staring at the baby octopi in Lewis’s aquarium tank at two in the morning, Benzer is filled with the feelings that sometimes come to him down at Sturtevant’s bed of experimental irises. The same thought possesses him even standing over a puddle, thinking of all the microscopic vorticelli and rotifers and pond creatures doing their tricks in there. “It’s a wonderful, fabulous world, and it’s been kicking around a long time,” he says. “And there’s so much going on all the time. It’s just amazing how much we’re neglecting.”
Through his microscope Benzer zooms in on the eye of the fly. He admires one facet. On this facet there is a hair, and the hair has a nerve that goes into the brain. If he looks at it closely enough, the single facet starts to look like the whole eye. Even through an electron microscope at 20,500 times magnification, he still sees more fine structure. “The more you look, the more you find,” he says. And this is just looking at the surface. Looking inside, you find worlds within worlds of detail: coils and coils of wires, cables, and corrugated gooseneck tubing, buttons and corks, tufts, four-leaf clovers, and odd projections like golf balls on tees. “The eye is the microcosm that contains all of biology in it. Maybe even including consciousness,” says Benzer. “But that’s the way it is; every kernel contains all of biology, practically.” Feynman once said it beautifully: “Nature uses only the longest threads to weave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry.”
Behavior was fun, hut I don’t care,
I’m on to something else next year,
I must stick with the new frontier
Until I’m old and gray.
Now here he is old and gray, and once again behavior is looking to him like the new frontier. So is aging, the whole phenomenon of lifespan: How much of that is in the genes? Once again he is wondering if science can find answers to the recurrent questions that Max despaired of answering—find something worth telling Aurora, the goddess of the dawn.
By 3 a.m., the Church Laboratory is very quiet. At the far end of the hall and down one flight of stairs, a small night shift of lab technicians is washing flasks, racking test tubes, and filling fly bottles for the next day’s rounds of experiments, including hundreds of vials, test tubes, and antique milk bottles marked BENZER. At four o’clock in Church Hall, the night shift will go home. At six o’clock, the day shift will arrive, in the form of a woman whose name happens to be Aurora. And Benzer, going out the door, will meet Aurora, coming in.
Not long after Benzer married Carol Miller, Francis Crick asked her to show him the human brain. Crick had been thinking and theorizing about the brain for a few years, but he had never actually seen one. He wanted Carol to show him the cerebral cortex so that he could see the edges.
Just after Benzer’s seventy-seventh birthday, he and two of his postdocs, Yi-Jyun Lin and Laurent Seroude, announced the discovery of a mutant fly that lives more than one hundred days. They named it methusaleh. Other drosophilists had shown that flies’ lifespans are influenced by genes, but none of them had ever cloned one. Now Benzer plans to hunt for more lifespan mutants. He is embarking on the new career he hopes to pursue in his eighties: the genetic dissection of aging. When he introduces methusaleh in lectures, Benzer shows a slide of a mutant with a fly’s eyes and Darwin’s beard. (Illustrations credit 19.1)
So Carol set a brain on an ordinary white plastic cutting board from the hardware store, while Crick watched in a borrowed white lab coat. Around them the cabinets and shelves held dozens of brains, some intact, some already dissected to bits. On the shelf above the cutting board was a row of straight-sided jars full of grayish eyeballs.
The convolutions of the cerebral cortex are like the coiling and super-coiling of the double helix: origami tricks by which evolution has managed to pack a great deal of information into a very small space. Carol explained that if she could spread it out, its edges would fall off the cutting board on all sides—almost a square yard of cortex. There were millions of nerve cells packed into every square inch, each nerve making thousands of contacts with its near and distant neighbors according to patterns that were laid down first by the genes and the growing nerves in the embryo, then by a lifetime of choices inside that gray-brown sheet.
Quite a contrast with the brain of the fly, which fits into a head case so small that it is hard for us to see without a magnifying glass.
The reasons that we evolved such massive brains remain obscure, but one reason may have been to help us at the choice points. Our brains allow each of us to bring a maximum amount of learning and experience to each and every choice point, all that our species has learned and all that we have learned in our lifetimes. A fly does this to some small degree, and we do it to a large degree—more than any other creature on this planet.
For some years now, Crick and a few colleagues have been trying to figure out the difference between unconscious vision and visual awareness. Crick assumes that there must be some difference in the way incoming information is processed that determines whether we are aware of it or whether we are not. By tracing this difference in the brain, Crick hopes to find a clue to the way in which any experience can become conscious, allowing us to get maximum benefit from our big brains at the choice points. Crick thinks this will be the problem of the twenty-first century, although Benzer raises his eyebrows and smiles his molecular smile whenever they talk about it.
“He teases me because I’m interested in consciousness and so on,” Crick says with a laugh. “And of course in the case of Drosophila it wouldn’t be very sensible, because we’ve no idea—we hardly know what it means to be conscious in a mammal; when we get down to Drosophila, we really don’t know whether they’re automata or not. So I can see why he doesn’t feel really interested himself in that topic. And I wouldn’t be if I worked on Drosophila.” “You know,” Crick once joked from a podium at a meeting in Pasadena, “Jacques Monod used to say that everything that was true of E. coli was true of the elephant. But I don’t think that even he said that everything that was true of the elephant was true of E. coli. I don’t necessarily think the fly is as smart as Seymour, even though Seymour doesn’t know how to land on the ceiling.”
Cerebral cortex, drawn by the anatomist Andreas Vesalius. Vesalius published his De Humani Corporis Fabrica in 1543, the same year that Copernicus published his De Revolutionibus Orbium Coelestium. Copernicus opened a journey outward, Vesalius a journey inward. The journey outward has now led to the discovery of light from the Big Bang and the birth of the universe. The journey inward has led to the discovery of the first links between genes and behavior. Someday these discoveries too will be remembered as beginnings, first openings, points of departure. (Illustrations credit 19.2)
“If you will be good enough as to give me a definition of consciousness,” Benzer retorted (from the floor), “then I will try to devise a test to see whether it is present in Drosophila. But so far you have been unable to come up with a definition.”
Crick hopes that studies of the human brain’s visual processing system will lead him there. He assumes that there is also a part of the brain devoted to planning and looking ahead, and here he suspects the frontal lobes. The frontal lobes are the most forward part of the human brain, the part just behind the forehead. The very frontmost portion of the frontal lobes, the prefrontal fibers, are thought to be sites of our social reins and bridles; they keep us from saying and doing things that veer off the path of what is socially expected and accepted. The archetypal case of frontal lobe dementia was one Phineas Gage, foreman of a work crew on the Rutland and Burlington Railroad in Cavendish, Vermont. Gage lost much of his frontal lobes in a dynamiting accident on September 13, 1848, when an iron bar rammed into his head just below the left eye, shot through his skull, and flew out through the crown of his forehead, smeared with blood and brains. He astonished his crew by walking, talking, and joking soon after the accident, although it soon became clear, as his doctor’s notes show, that he was “no longer Gage”:
October 15 (32nd day) … Intellectual manifestations feeble, being exceedingly capricious and childish, but with a will as indomitable as ever; is particularly obstinate; will not yield to restraint when it conflicts with his desires.
October 20th (37th day) … Sensorial powers improving and mind somewhat clearer, but very childish.
November 15th (64th day) … Is impatient of restraint and could not be controlled by his friends.
Studies of patients with damage caused by strokes have suggested that frontal lobes have very specific and localized functions. A lesion in one place produces disinhibition like Gage’s, but a lesion in another place produces apathy. (The prefrontal lobotomy works because it induces apathy.) A lesion in a third place produces blindsight. Subjects with blindsight can see, but they claim not to. They can point to objects around the room when an experimenter asks them to, but they will deny that they can see them. Their eyes work and their brains can process the information, but they are no longer conscious of the results. Carol demonstrates these areas of the brain on a cutting board with the same mix of expressions, half matter-of-fact, half reverent, that Benzer has when he gives guided tours of the brain of a fly. “This is the frontal cortex,” she says. “This is the dura mater. Here is part of the basal ganglia. The apathy area is here. And disinhibition is down here. Frontal temporal dementia.”
She has begun to apply Seymour’s method of genetic dissection to the frontal lobes. There are forms of frontal lobe dementia that run in families; one form of the disease with late onset (in the fifties or sixties) seems to be linked to chromosome 17. By dissecting the brains of victims of the disease in autopsies and staining them with fly stains to examine fine-scale changes under the microscope, she is trying to trace the links from gene to behavior just as Seymour does in flies. Through the microscope her brain sections stained with fly stains are abstract landscapes, some of them like stylized artist’s impressions of a tree stained pink and some rather beautiful aerial landscape views, with alluvial curves and scallop-edged patterns. The stain swivels and follows the contours and the curves, oblivious to the pathos of mortality. Somewhere in there, Crick believes, may be the answer to the problem of free will.
THE ROMAN PHILOSOPHER Lucretius imagined that atoms must swerve somehow; “if the atoms never swerve so as to originate some new movement that will snap the bonds of fate, the everlasting sequence of cause and effect—what is the source of the free will possessed by living things throughout the earth?”
At the end of the day in Cold Spring Harbor, Watson also thinks in terms of some kind of Lucretian swerves. “My hypothesis is that free will comes from the imperfect working of the brain,” he says. “The machine is inherently uncertain.” He smiles at the pun.
“But on certain occasions I know,” he says, alluding here to a particularly trying meeting he has just endured, a board meeting in which he has listened to the president of a new biotechnology company that Watson thinks is mismanaged. “You know, when I’m in a room, and I hear shit, after a while the word ‘shit’ is going to come out. You just can’t take it anymore. Now that’s, hmmm, a predictable response. It’s hound to come out. I think to myself, maybe I’ll sit through nonsense and not say it. But …” Watson sighs. “So in that sense you don’t have a free will. Your reactions are programmed. You know, you start asking the difference,” he says with a nod toward the Fly Room next door. “What free will is there in Drosophila? You put the question of the free will of a fly. And what’s really different about the fly’s brain from ours—which gives us free will?
“I’m sure once we know how the brain works, we’ll no longer talk about free will in the Jesuit sense. It will cease to be, you know—” Freedom will cease to be a mystery requiring Jesuitical debate; it will cease to be a theological or philosophical question. “It will just be how the brain works. You will describe how the brain works. You won’t use the words ‘free will’; you know, you’ll understand.… Because you’re asking, how does the brain work?” he says in a softer voice. “That’s what you’re really asking.” The bell in the double-helical bell tower outside his office window begins to toll. “And that’s really the ultimate question to ask,” he says, speaking through the tolling of the bell with a pleased chuckle in his voice, suddenly sounding very much like his old friend Crick.
WHEN BENZER himself thinks about the free-will question, he always remembers his first moments watching the flies in his test tubes run toward the light. In the very first experiment he did, most of the flies went to the light, but some didn’t. He tested them again; most went to the light, but some didn’t. That was why he made the countercurrent apparatus. “If you mean a certain randomness in behavior—then flies have free will,” Seymour says sometimes at the Red Door Cafe when the talk turns to drosophilosophy. Why did each of those individual flies make each of those individual decisions and revisions? “That’s free will if you want to call it that.”
But when he talks this way at the Red Door, his postdocs are likely to give him the same raised eyebrows and molecular smiles they have learned from Benzer. “If flies had free will,” they tell Benzer, “your lab would be empty.”
Benzer gets no further when he talks about this question with Carol, describing the zigzags of his flies in the countercurrent machine. “So what is that?” he asks. “Is that free will? If the fly makes up its own mind?”
“Well, the problem is, you don’t know what its mind is to make up,” Carol says.
“I’d say free will means, if you are subjected to identical stimuli, you don’t necessarily do the same thing …”
And so they go around and around, even people who live with their hands in rubber gloves deep in genes and brains. Perhaps it is still too soon to talk about the question. A sense of paradox still hovers over the whole picture of life, from the smallest scale to the largest.
How is it possible that these two things should be true at once? Schrödinger asks in What Is Life?: first, that his body is a mechanism, a clockwork, and runs according to the laws of nature; second, that he knows “by incontrovertible direct experience” that he is running the show, that he is directing the motions of his body, that he can foresee what he is doing, and that he can take responsibility for his actions. As he struggles to answer these questions in the last pages of What Is Life?, Schrödinger begins to sound a little like Berger on the wall of Seymour’s Sandwich Shop. He quotes Schopenhauer and Kant; the cultural milieu (Kulturkreis); the Upanishads’ recognition that ATHMAN = BRAHMAN (the eternal self); and the Christian mystics’ phrase DEUS FACTUS SUM (I have become God). Schrödinger concludes that there is only one consciousness “and that what seems to be a plurality is merely a series of different aspects of this one thing, produced by a deception (the Indian MAJA); the same illusion is produced in a gallery of mirrors, and in the same way Gaurisankar and Mt. Everest turned out to be the same peak seen from different valleys.”
Each of us feels like an “I.” “What is this ‘I’?” Schrödinger asks. How is it that each of us feels like one single person even though we began life so long ago that we have lived through a succession of more identities than the instars of insects, and the world of our first memories feels to us like a distant country? In spite of all the living and all the forgetting that we have done, and in spite of all the mechanisms that science has discovered over our heads and inside our heads, we are all still here living life. “In no case,” Schrödinger wrote, “is there loss of personal existence to deplore.”
And, he concluded, “Nor will there ever be.”
NERVES, as they grow in an embryo, seem to wander like flies in a countercurrent machine. Each of them is guided by genes, yet on each scale there seems to be some play in the system.
Likewise, there seems to be play in the system for each of us as we make the choices we do. “A human behavior pattern is not a monument to a life that is gone, but a drama full of life,” writes the philosopher Abraham Heschel. “It is a system as well as a groping, a wavering, a striking forth; solidity as well as outburst, deviation, inconsistency; not a final order but a process, conditioned, manipulated, questioned, challenged, and guided.”
“Diversity is as wide as all the tones of voice, ways of walking, coughing, blowing one’s nose, sneezing,” writes Pascal. “We first distinguish grapes from among fruits, then muscat grapes, then those from Condrieu, then from Desargues, then the particular graft. Is that all? Has a vine ever produced two bunches alike, and has any bunch produced two grapes alike?
“I have never judged anything in exactly the same way,” he continues. “I cannot judge a work while doing it. I must do as painters do and stand back, but not too far. How far then? Guess.…”
Even in the behavior of our thoughts, there is play in the system. We all feel them zigzag, heading for the light, but on again, off again, like the fly in the countercurrent machine. “Thoughts come at random, and go at random,” Pascal wrote. “No device for holding on to them or for having them.
“A thought has escaped: I was trying to write it down: instead I write that it has escaped me.”
Emerson wrote, “Thoughts come into our minds by avenues which we never left open, and thoughts go out of our minds through avenues which we never voluntarily opened.”
“I am lying in bed, for example, and think it is time to get up,” wrote William James,
but alongside of this thought there is present to my mind a realization of the extreme coldness of the morning and the pleasantness of the warm bed. In such a situation the motor consequences of the first idea are blocked; and I may remain for half an hour or more with the two ideas oscillating before me in a kind of deadlock, which is what we call the state of hesitation or deliberation.
Somehow or other, after lolling around in the bed like this for half an hour, the philosopher confessed, “I shall suddenly find that I have got up.” It is as if his mind had a mind of its own. Is his springing out of bed free will? (“Free will,” Seymour says to Carol, “is if you get back in.”)
Even with the wanderings of science, there is play in the system. Science blunders along, like every sort of behavior. Max Delbrück knew that science is always improvisatory: “The grand edifice of Science, built through the centuries by the efforts of many people in many nations, gives you the illusion of an immense cathedral, erected in an orderly fashion according to some master plan. However, there never was a master plan. The edifice is a result of channeling our intellectual obsessive forces into the joint program. In spite of this channeling, the progress of science at all times has been and still is immensely disorderly for the very reason that there can be no master plan.” In science, as in the rest of life, the paths are paths only in retrospect.
And in the tree of life itself there seems to be play in the system: what look like swerves and random branches. The shape of a growing nerve tree in the brain, the shape of the decision trees of an individual lifetime, and the shape of the whole tree of life share the same branching form on successively larger and larger scales. What is the Tree of Life but a decision tree, a drawing of a series of choice points in which one line of life went one way and another another way? And were those choices forced or free? Some of them were based on new behavior at choice points, as when a fish first began hanging around longer and longer at the margins of the sea and taking gulps of air.
“The things we thought would happen do not happen;/The unexpected God makes possible,” Euripides wrote in the last lines of one of his last plays. Since we see paradox at all scales, is it possible that the answer to this paradox on one scale will someday unlock them all? In his laboratory, Jeff Hall is trying to move from the particular to the general, exploring more and more interconnections among the time, love, and memory genes, continually e-mailing Tim Tully and Ralph Greenspan, who was Hall’s first graduate student, now at the Neurosciences Institute in San Diego. One of their clock genes seems to mesh with one of their memory genes like the teeth of two gears. Clock genes also seem to mesh with the genes that build the body of the fly from the egg. And the human period gene is expressed not only in the human brain but in the pancreas, kidney, skeletal muscle, liver, lung, and placenta—almost everywhere its discoverers have looked for it. Although no one is sure what that means, they are sure that the fly clock is interwoven with the rest of the fly’s genes and that the human clock is interwoven with much of what is human.
In Tokyo, Yoshiki Hotta, who helped Konopka find the clock mutants, is also thinking about the way the genes fit together. So is another old student, Alberto Ferrús, in Madrid. Ferrús thinks we stand in relation to the atomic theory of behavior now the way biologists stood in relation to the atomic theory of inheritance at the turn of the twentieth century. Then, biologists had accumulated an enormous amount of information about what happens when you cross different species of plants or different species of animals. But they did not understand the basis of heredity. Then, in 1900, they rediscovered Mendel’s laws. When these laws were rediscovered, vast amounts of information were wiped out because there was no need for them anymore. Biologists now had an organizing principle by which they could understand heredity in any organism. “And maybe we need for neurobiology a similar type of breakthrough,” says Ferrús. “We would like to find some sort of neural code to understand how perception is encoded in our brains, for instance.” Or how we memorize a piece of information we have perceived. “Code. How does a brain of a fly or a man operate? The basic principle. The details are going to be different in every organism, of course. But maybe, maybe there is such a basic principle, such a code that it is of universal value. And if such a thing is once discovered, then we would have made a gigantic step ahead, as gigantic as Mendel’s laws were for genetics.”
The next generations of genetic dissectors are beginning to think about systems of genes. They are beginning to think about genes the way Konrad Lorenz thought about instincts: “Unless one understands the elements of a complete system as a whole, one cannot understand them at all.” Like the rest of molecular biology, genetic dissection has always pushed toward the particular. The genetic scalpel uncovered one gene in one behavior at a time. But each gene is involved in many kinds of behavior. Hall, Tully, and Greenspan are writing a book on the subject of genes as networks, genes as systems, genes as constellations. They mail their manuscripts back and forth, struggling toward a difficult vision that they cannot put into words. One day Greenspan scribbled in his draft in huge letters: “I’M GROPING, NOT TRACKING HERE. There’s an idea struggling to get out. HELP!!!” Sometimes Greenspan seems to get a dim glimpse of a web of interweavings, a web that feels something like a new view of life and something like inner experience. Being alive does not feel like an assortment of conflicting separate instincts, pieces, and inclinations; we feel, when we introspect, that there are many parts but that they are at least loosely woven together, loosely connected in what Lorenz called “the great parliament of instincts.” In life, emotional wisdom resides in seeing around particles of mood, moments of mood, to the whole in time, putting it all together. In life we are not particles but evolution. The word “religion” comes from the Latin religare, “to bind loose things together.” Hall, Greenspan, and Tully struggle with thoughts of networks; the book will not come together. And Hall escapes more and more to Gettysburg and drives home with the bumper sticker SAVE THE BATTLEFIELDS.
Could it be that the answer to the paradox has something to do with the way we break the world into categories, and will we see the answers to all these paradoxes when we have learned to think in new categories? Maybe the free-will problem has to do with categories of thought we cannot see because they are innate in us, because they are part of the instincts with which we are born.
“What is your aim in philosophy?” Ludwig Wittgenstein asked in his Philosophical Investigations in 1953, the year that Watson and Crick put together their model of the double helix, and Benzer figured out how to map the interior of a gene. The philosopher answered himself, “To show the fly the way out of the fly bottle.” Well, the fly is out of the bottle now. Whether we like it or not, the fly zigzags through all our meditations “like crack through cup,” as the poet Rilke writes in one of his Duino Elegies. In ways we may love or hate, the science that came out of the fly bottle is changing our sense of what it means to live. And maybe the science will help us understand this overarching paradox. This is the question that the fly bottle has posed from the beginning, and maybe the answer, too, will come out of a fly bottle. “Who’s turned us around like this?” Rilke asks in his elegy. “Who’s turned us around like this, so that we always, do what we may, retain the attitude/of someone who’s departing?” Maybe the fly will lead, in someone’s night thoughts, to a new union of Pascal’s two infinites. Maybe the fly will lead us out of the bottle into territory that is as blurred and vague now as the gene was before the first flies flew in the window.
Butler’s line about eggs making eggs is a variation on the theme of the old riddle: Which came first, the chicken or the egg? Maybe the answer to that riddle will prove to be the answer to them all: some kind of engagement, collaboration, development involving both gene and world. And maybe it is the same with consciousness. Maybe all these branches have the same shape because they are all products of some interaction, some drama or dance of life and world that we have yet to find a way to wrap our minds around. Maybe this is the way out of the fly bottle of the twentieth century. Our genes and brains work only by engagement with the world around them, so we are not imprisoned by our genes and brains. “Denmark’s a prison,” says Prince Hamlet. “Then is the whole world one,” his college friend replies. If our genome is a prison, then is the whole world one.
This is the kind of problem that more and more neurobiologists and neurophilosophers are trying to solve, but Benzer only raises his eyebrows and smiles his molecular smile: “Oh, they can have it. I’ll leave it to them.”