Memory is a passion no less powerful or pervasive than love.
—ELIE WIESEL,
All Rivers Run to the Sea
BENZER’S FRIEND Gunther Stent loved to philosophize, and Benzer was always quick to help him get to the bottom line. Once Stent inhaled for what was clearly going to be a long verbal essay. He began, “All reasonable men—”
Benzer cut in: “No men are reasonable.”
Benzer and his circle had an interest in the truth and a cavalier impatience with mouth artistry and eloquence, and their attitude, their style of science was extremely appealing to a certain kind of student. It is an old saw in organic chemistry that “like dissolves like.” That is the principle of the countercurrent method by which the chemist separates oil-lovers from water-lovers. In the first days of their genes-and-behavior projects, Benzer with his flies and Brenner with his worms attracted some students and repelled others. Those who gravitated to them were a special breed, looking for a certain kind of adventure. Like Benzer and Brenner, they hated the safe, careerist path. “There were a lot of young people who were already feeling that molecular biology and genetics had reached a kind of confined road,” Brenner says. “In other words, they didn’t feel there was opportunity for originality or initiative anymore. So we attracted a large number of people who were willing to take the chance and enter the field. And, of course, those are the people you want.” Most of their students were coming to them from classical phage genetics. “And for a lot of those people that was quite a big step into the void.”
Those who visited Benzer’s Fly Room found an atmosphere not unlike Morgan’s Fly Room, which had been a madhouse. Morgan had wedged eight desks into his little room at No. 613 Schermerhorn Hall for his Raiders. Escaped flies drifted around the desks and the garbage can, which was never completely empty. More flies swarmed around a bunch of bananas that hung in the corner. When the boys came into the room in the mornings, bearing stolen milk bottles, they would pick and eat bananas and drop the peels into their desk drawers. “During the two years I worked in the inspiring spiritual atmosphere of the Fly Room,” wrote one of Morgan’s finest, Curt Stern, “I never opened my desk drawer without looking away for a while to give the cockroaches a chance to run into the darkness. Once I said breathlessly, ‘Dr. Morgan, if you put your foot down you’ll kill a mouse.’ He did!”
“Morgan was a bit crazy,” says Jeff Hall. “He used to say, ‘To know your organism, you must eat it.’ Not just the flies: the pupae. And not just to horrify people, but to know. Grape Nuts had just been invented, by C. W. Post. One of the first breakfast cereals.” (Post put Grape Nuts on the market in 1897.) “So Morgan justified eating the pupae—when people stared at him, he said, ‘They taste like Grape Nuts.’ ”
Benzer brought to his own Fly Room a growing fascination with the bizarre, the extremities and ultimities of human behavior. “The whole lab was infected by his spirit of the unusual,” says Bill Harris, who was a graduate student in those early days and is now the chairman of the department of anatomy at Cambridge University. Benzer took his students and his wife, Dotty, to the Charles Manson courtroom. He visited the grave of Marilyn Monroe and crashed Hollywood funerals. And of course Benzer often brought surprises to his lab’s lunchroom, known locally as Seymour’s Sandwich Shop. Harris remembers in particular a Chinese century egg, an egg that had been buried in the ground for years. The white of the egg was a translucent red, and the yolk a very dark green. “He ate it up and made everyone taste some. My old boss—always liked to challenge his palate.”
For Benzer it was all part of the same curiosity: “All part of the same aberration,” he says. And his students saw it that way too, according to Harris. “That was one of the most attractive things about his science. I didn’t know him in his early years, when he was working on the gene. But this was definitely science at the fringe.” There was so much wide-open space between a mutation and a piece of behavior. Benzer was always quoting Samuel Butler: “A hen is only an egg’s way of making another egg.” Behavior, Benzer said, is “the way that the genome interacts with the outside world,” the way the egg produces that next egg. Benzer’s approach, getting a mutant and looking at a behavior, underscored how little was known about the whole circle from the egg to the winged life and back to the egg. “There was so much uncharted territory in between,” Harris says, “that most scientists believed it was an unfillable gap. And most of us were attracted to it because of that.” They did not know that the tools of molecular biology would soon allow them to follow up these first explorations with fantastic power, allowing them to study the links between genes and behavior at a new level. “But we knew that it was a process, that little by little we would inch away at this problem,” says Harris. Precisely because the gap was so wide and because many scientists thought the project was absurd, it attracted a certain kind of student. “It was not a step,” Harris says. “It was kind of like a leap.”
“The lab in those days was very laissez-faire,” says Chip Quinn, who joined it as a postdoc in 1971 and now runs a Fly Room at the Massachusetts Institute of Technology. “There were these fairly interminable lunches, which were sometimes movies and bullshit and sometimes real science. I think at that time in the lab nobody knew exactly what should be done. There was this whole cafeteria of things that one might do.” Quinn remembers one student who made the rounds of Benzer’s three-ring fly circus looking more and more disgusted. “He said, ‘Well, here I am training for Harvard Neurobiology and it’s sort of like all these guys with coonskin caps. And you want me to come here and put on a coonskin cap and be a pioneer.’ ” That student went off and did something safer.
No one knew how important these experiments would turn out to be. “Nobody knew,” says Quinn. “Seymour always thought, you know, enlightenment is just around the corner. He really had confidence in himself as he came off the big successes in phage, and he thought, ‘Well, we can do it, we can figure out the nervous system.’ ” To Quinn it was a noble gamble, like Pascal’s wager. “If you think you can’t do anything, then you are guaranteed that you can’t do anything,” he says.
OF ALL THE PROJECTS in the lab, Quinn’s was the farthest out. Quinn wanted to dissect the invisible events that take place in the brain during and after each experience, the changes we call learning and memory. Quinn even hoped to find the engram, which is the holy grail for scientists who study nerves and brains. The engram is the seat of memory, the physical change in a brain that encodes memory itself. “Tell me what is a thought, & of what substance is it made?” asks William Blake, as if he were asking an unanswerable question. The engram is the substance of memory. In 1971 it was still a cloud-wrapped, faraway summit, but Quinn thought it might turn out to be easier to reach than some of the other summits on the horizons of science. “What’s the trick or the set of tricks that the brain uses to encode a change based upon experience?” he asked years later, after his own experiments and those of many others had brought them closer to the summit. “It may be relatively simple. I mean, there’s really that hope: the brain is too complicated, and intelligence is too complicated, and consciousness is too complicated, but there is a possibility of understanding this trick.”
This is the trick Quinn wanted to study using the tools of genetic dissection, the trick that allows us to catch something from our experience in a kind of mesh of the nerves and hold it there for the rest of our lives. Somehow the memories are written in atoms, and somehow we keep the memories even though we lose the atoms.
And of course there is a wide range from individual to individual in our ability to remember. The psychologist A. R. Luria wrote a famous memoir of his encounters with a newspaper reporter who was sent to him by the reporter’s editor because the man seemed to forget nothing. Luria sat him down and read out a short table of numbers, and afterward the reporter repeated them back to him digit by digit.
1 6 8 4
7 9 3 5
4 2 3 7
3 8 9 1
The psychologist read him longer and longer tables, row after row, stream after stream of digits, and the reporter kept repeating them back. He could recite them backward, forward, or even diagonally. At last, the psychologist writes in his memoir, The Mind of a Mnemonist, “I simply had to admit that the capacity of his memory had no distinct limits; that I had been unable to perform what one would think was the simplest task a psychologist can do: measure the capacity of an individual’s memory.”
This subject had a special interest to the Lords of the Flies in the Benzer lab because many of them had bottomless memories themselves. They needed them for their work. Ron Konopka was born with a photographic memory. Jeff Hall carried in his head thousands of references to papers in genetics, and often he could remember not only the authors of a paper and the genealogies of the flies but also the year, volume, and page numbers. Sturtevant used to read the Encyclopaedia Britannica for pleasure in the evenings, and in his later years he had a hard time finding an article that he had not already read and committed to memory.
This is the phenomenon that Quinn wanted to explore through genetic dissection. He also hoped to explore the way the dance of the atoms changes over time. As we get older, most of us feel the holes of the sieve widening and widening, the mesh fraying, so that more and more of what happens from morning till night falls through. This change in our daily experience probably corresponds to a change in the sieve and mesh of the molecules and neurons of memory. Something changes in the way we store memories or in the way we retrieve and read them. Quinn hoped he could find clues to those changes too with the dissecting needle of the genes.
“For us to learn anything at all, we must already know a lot,” says another early postdoc of Benzer’s, Yadin Dudai, who now runs a Fly Room at the Weizmann Institute of Science in Rehovot, Israel. We have to know how to live to know how to learn. As Dudai writes in his book The Neurobiology of Memory, “What the frog’s eye tells the frog’s brain is based on a memory established during millions of generations; so is the escape of the fly from the frog’s tongue.” In this very broad sense, genes themselves are ancestral memories of life on earth. Near the beginning of Remembrance of Things Past, Proust says that memory is “a rope let down from heaven to draw me up out of the abyss of not-being.” All of DNA is a twisted rope ladder let down from heaven to draw us up from the abyss of not-being. We do not lift a finger without three kinds of information: the information we are getting from our senses at that moment; the information we have gotten from our senses in the past; and the information our ancestors have acquired since life began on Earth—that is, the information that is represented by genes themselves. Evolution is learning. Species store learning in chromosomes the way individuals store learning in their brains and societies store learning in books.
In this sense our ability to learn and remember is itself a memory. It is the memory of a discovery that has been passed down from generation to generation since near the beginning of life, a discovery approximately as old as the sense of time, perhaps almost as old as the instinct to reproduce. And of all the discoveries that living things have acquired in their 3.5-billion-year tenure on Earth, the mnemonic device of memory itself is one of the most crucial. For an individual to be able to profit from its experience and carry each experience forward to the next choice point is one of the most useful adaptations ever evolved.
A sentimental sense of history. Once, back in the 1940s, Benzer had traded haircuts with his mentor Max Delbrück. Now, in the 1960s and 1970s, while he explored the molecular biology of behavior, Benzer traded haircuts with his postdocs. Here Chip Quinn endures the tradition, in June 1974. (Illustrations credit 10.1)
Quinn had picked up an interest in the memory problem from Benzer, but he felt almost mystically primed for it. As Quinn puts it, “I think that it was my karma as well as his.” To Quinn, the engram, the secret of memory, was by far the most exciting problem he could hope to study in Benzer’s lab. “Everything else seemed trivial compared to that.”
AT THAT TIME, flies were assumed to be hard-wired. That is, every one of the hundred thousand neurons in their brains was thought to be glued, taped, or soldered to its neighboring neurons in a pattern that was laid down once and for all in the embryo. The layout of the nerves was supposed to be as fixed and standardized as the layout of the six legs and two wings. A fly’s brain never changed no matter what happened to that fly between the moment it eclosed from the egg and the moment it met its maker (or mutater). Without memory, John Locke once wrote, each of us would be no better than “a looking-glass, which constantly receives a variety of images, or ideas, but retains none; they disappear and vanish, and there remain no footsteps of them; the looking-glass is never the better for such ideas.” A fly was thought to be as unimpressionable as a looking glass. All it had to fly on was the ancestral memories in its genes: a pure robot, a set of instruments flying on instruments. Students in Benzer’s lab sometimes wondered if worlds exist where there is no other sort of memory but this, the slow, instinctive memory built up out of thousands and millions of generations. It was an amazing thought. What would such a world be like? Billiard balls, pure billiard balls! A planet almost as barren as a planet without life. Our own planet in the days of the very first living forms must have been like that, before an organism somewhere in the sea learned to profit even dimly from experience—learned to learn.
For years a fly man at the University of Pennsylvania, Vincent Dethier, had suspected that even flies could learn. Where most people see flies as “little machines in a deep sleep,” Dethier once wrote, he looked through the microscope at their fantastically intricate armored bodies, “their staring eyes, and their mute performances,” and could not help wondering if there might be “someone inside.” Dethier tried to prove that flies can remember but he never could, and after eighteen years he gave up. Today when Benzer lectures about genes and memory, he often flashes on the projection screen an old headline from the Washington Post about Dethier’s conclusions. The Post ran a rather unflattering close-up photograph of the face of a fly with a caption that passed the finger-shaking judgment “Can’t learn anything.”
In those years Benzer taught an undergraduate course in behavior at Caltech. He always put the same question at the end of the final exam. The question was worth a case of beer and five hundred points (which meant an A-plus for a satisfactory answer): “Design an experimental situation in which you can show that Drosophila learn.” Many young techies rose to the challenge. One graduate student in Benzer’s laboratory arranged a tiny spotlight so as to cast a shadow of the fly on a sensor. By administering a series of little punishments in the form of heat, the student, Jeff Ramm, tried to train the fly to alter its posture. After a while he got discouraged and left the laboratory. Benzer used to complain that Ramm had quit just before the flies learned. “But I think that Jeff and Seymour had incompatible personalities,” says Chip Quinn. “Jeff Ramm was someone who didn’t have this tolerance for starting experiments when you don’t know what you are doing. And so he diffused off to Felix Strumwasser’s lab.” Strumwasser was a neurophysiologist, an expert in the workings of nerves. He had been one of the biggest naysayers when Benzer presented his genes-and-behavior project to the Sperry group.
Another student of Benzer’s wrote a paper proposing to adapt a cockroach experiment called Horridge Leg Lifting. A student of invertebrate behavior, Adrian Horridge, had stuck a cockroach on a tiny diving board. If the cockroach’s legs dangled into the water, it would get a shock. Eventually the cockroach learned to lift its legs out of the water. Benzer’s student thought Horridge Leg Lifting might work with flies. But he quit the lab and went off into computer science. “Again,” says Quinn, “I think he quit just before they learned.”
Benzer himself tried to teach flies in his countercurrent machine. He put an electric grid inside one of the test tubes and shocked the flies to teach them to stop going toward the light. If he shocked the flies over and over again, they would go toward the light less and less. When he turned off the current, the flies still did not run toward the light. For one brief happy period, Benzer thought he had taught his flies to avoid the light. But when he put them into a fresh test tube, they ran for the light as urgently as ever. Apparently the flies were not learning after all. They were laying down some sort of odor—perhaps the odor of panic, or the odor of singed fly hairs and feet—and avoiding a bad smell in a test tube is not the same thing as learning; it does not imply a remembrance of things past.
When Quinn joined Benzer’s laboratory, he looked over the countercurrent machines and shock grids that Benzer had made. “And at some level, I had no idea what to do,” Quinn says. So he started simplemindedly repeating Benzer’s experiments and replicating his results, “just to see what was going on, because I didn’t know what to do.” He found that the flies did seem to be stinking up the test tubes. But he also found that if he took fresh flies—naive subjects, unshocked troops—and ran them through the countercurrent machine, these new flies would ignore the odor and head for the light as if the odor were not there. Quinn concluded that the odor of panic (or whatever it was) repelled the flies only if they had smelled it in conjunction with an electric shock. In other words, Benzer’s flies might have learned something after all: they might have learned to avoid the odor. “So that looked relatively encouraging,” Quinn says.
Since the flies apparently paid some attention to odors, Quinn (guided by Benzer) decided to try perfuming one of Benzer’s countercurrent machines. “Caltech had a whole room full of old bottles of chemicals. So I went around and opened them and sniffed them.” Quinn had no way to know which odors to pick, because he did not know if the odors would smell the same to flies as they smelled to him. On the other hand, he had no better way to pick and choose than to please himself. He wanted a compound to be volatile enough that he could smell it, but not so volatile that it would go away immediately. So he went around the room opening vials at random. He chose a vial labeled “Octanol,” which smelled like licorice. He also chose a vial labeled “Methylcyclohexanol,” which smelled—as someone in his lab later put it—“a lot like tennis shoes in July.”
Quinn lined the test tubes in the countercurrent machine with copper grids—very fine mesh, like tiny rolled-up window screens. He perfumed one test tube with octanol, another with methylcyclohexanol. The odors would linger powerfully on the grids for two hours or so. When he was ready to start the experiment, he laid this set of test tubes on his benchtop, just as Benzer had done, and lit Benzer’s fifteen-watt fluorescent bulb. He put about forty flies in the first tube and let them explore it for sixty seconds. Then he tapped the whole apparatus on a rubber mat to knock the flies down to the bottom of the tube (just like Benzer), as if he were making an official pronouncement in the dark room: “This meeting will now come to order.” Finally he slid the tubes so that the flies could walk, if they chose, into the tube ahead of them, which smelled of octanol.
As in Benzer’s first experiments, almost all of the flies walked or ran toward the light—where they encountered a shock of seventy volts for fifteen seconds, which might kill a human being but only ruffled the fly’s bristles a bit. Then Quinn tapped the tubes on the benchtop again to return the flies to the first tube and he gave them sixty seconds to recover from the shock.
Next he slid away the tube that smelled of octanol and replaced it with a tube that smelled of methylcyclohexanol. Again the flies ran for the light. This time Quinn did not give them a shock. After fifteen seconds he returned them to the first test tube.
Quinn repeated this cycle: octanol and a shock, meth and no shock. In a way, he was talking to the flies: octanol, bad; methylcyclohexanol, good. (Of course, there was nothing intrinsically good or bad about either; he had tossed a coin before starting the experiment.)
Finally, the test. Quinn slid into place a fresh test tube, one the flies had not encountered before. The tube was perfumed with octanol. He bent over the tubes by the fifteen watts of the fluorescent light and watched. More than half of the flies milled around and did not go into the tube.
After returning all of the flies to the first test tube and giving them a minute to rest, he slid away the tube of octanol and slid into place a fresh tube of methylcyclohexanol. Most of the flies went into that tube.
It was an eerie thing to watch. The flies were acting on their experience. Ever since Morgan’s Fly Room, geneticists had known that fruit flies have genes and chromosomes as we do and that they inherit their bodies and behavior as we do. But here the flies were doing something that even Quinn had not really expected to see a fly do: they were learning from their own experience. They have something inside that allows them to remember what has happened to them, as we do; and they can act on what they remember, as we do. It was a sight to give a human being pause, like William Blake’s visionary line: “Am not I a fly like thee / Or art not thou a man like me?”
Quinn repeated the experiment with a second crowd of flies, and they learned the lesson, too. He tried teaching a third crowd of flies the reverse lesson: methylcyclohexanol bad, octanol good. The flies learned that lesson, too. Each time the change in the flies’ behavior was eerie to watch. It was as if something palpable had changed for them, as if the odors had turned into invisible doors. They acted as if one door was still wide open but the other door was almost closed and looked forbidding to most of the flies.
To make sure he was not just kidding himself, Quinn asked a friend in the lab to set up the teaching machine for him, to arrange the perfumed test tubes. This way, when Quinn ran the experiment, he could not know which test tube held which odor and he could not know which odor led to a shock. He ran the experiment blind and recorded the flies’ behavior impartially: how many chose this tube and how many chose that one. Then he checked his friend’s notebook (in effect, taking off the blindfold) to see if the flies were really learning their lessons. They were.
Not only were the flies learning, they were learning fast, as Benzer enjoyed pointing out chauvinistically. In one standard laboratory test of learning, an experimenter rings a bell and then blows a puff of air at a rabbit’s eye to make it blink. The rabbit learns to blink before the puff of air, but that takes about eighty lessons. Quinn’s flies learned in three.
Once Quinn happened to notice that his flies avoided walking on a spill of dry powder—quinine sulfate. So instead of electrifying his grids, he tried dusting them with the powder, spreading some quinine sulfate on the copper with a fine artist’s brush. The flies learned to avoid the powder the same way they learned to avoid a shock. Benzer’s graduate student Bill Harris built a Y maze of black Plexiglas with small brass knobs. At the choice point of the Y maze the flies could go toward either a red light or a blue light. The flies learned those lessons too: red good, blue bad; or red bad, blue good.
They seemed to be learning much the way human beings learn: by repetition. It is adaptive for living things’ memories to require repetition. A three-month-old baby will not remember something that happens once, but if the lesson is reinforced on a regular schedule, she will. “A single experience that is never to repeat itself is biologically irrelevant,” the physicist Schrödinger wrote. “Biological value lies only in learning the suitable reaction to a situation that offers itself again and again, in many cases periodically, and always requires the same response if the organism is to hold its ground.”
Next, Quinn played with his flies to see how long they would remember their lesson. He taught a fresh group of conscripts to avoid octanol and let them rest for an hour. Then he put them through their paces again. One hour in the lives of fruit flies is like a few months in ours. After the break, most of the flies still remembered to avoid octanol, but some of them forgot. He gave another group of flies twenty-four hours (six years in human lives) to sit around in fly bottles and forget. Many of them still remembered; more of them forgot.
“CHIP QUINN once described the ideal organism as one that has three large neurons, divides rapidly, and can learn to play the piano,” Benzer says. “Everybody wants a simple system.” Delbrück, Benzer, and Brenner had thought of the fungus, the fly, and the nematode worm as simple systems when they started: as something like gadgets in physics, atoms of behavior. “Sydney’s idea was, the nematode has a small number of neurons; therefore, it’s a simple system,” Benzer says. “I think he has changed his mind a little bit. He describes the lineage and the development of the nervous system of the nematode as ‘baroque.’ ” (This discovery was foreseeable even in the first days of the Enlightenment. “A worm is only a worm,” said Diderot. “But that only means that the marvelous complexity of his organization is hidden from us by his extreme smallness.”) Now Benzer and his students were beginning to realize that the fly is baroque too; they were delighted to discover that it can learn and act on what it learns.
Because the fly has memory in its repertoire, Benzer and his students could begin to dissect this behavior too. They could use their tools of genetic dissection to take apart the act of remembering the same way they were taking apart the sense of time and the dance of love. A new student at the Benzer lab, Duncan Byers, dosed flies with the laboratory’s favorite mutagen, EMS, producing five hundred separate lines of mutants, and he began to test their memories, strain by strain, mutant by mutant, using the whole Quinnian rainbow of odors, including octanol, methylcyclohexanol, and quinine sulfate. Out of the five hundred lines of mutant flies, about twenty lines failed to learn. But almost all of those flies flunked other tests too. Some turned out to have problems seeing; others had problems smelling; some were sluggish or shaky walkers. Only one of the lines that flunked had normal instincts, normal senses, a healthy level of energy, but no talent for learning. That line of mutants turned up in Bottle 38. For them to appear so early in the search was auspicious. They fit Konopka’s Law: “If you don’t find it in the first two hundred, quit.” Byers examined them through the microscope. As eggs, larvae, and pupae, they looked normal, and they lived as long as normal flies. They ran to the light, they climbed walls, they flew, walked, courted, and copulated like normal flies. But for them every odor was an open door. They never seemed to learn.
Benzer and his crew decided to name this new mutant after John Duns Scotus, the thirteenth-century philosopher. Duns Scotus’s disciples were known as Scotists, dunses, or dunces. In the sixteenth century, the dunces lampooned the new learning, and they were lampooned back by the natural philosophers who were the world’s first true scientists. The dunces lost the war, and the scientists made them eternal symbols of stupidity.
Benzer’s raiders tried very hard to get dunce to learn something. They exposed the new mutants to a wide range of odors in all kinds of dilutions and combinations, and to a wide range of shocks, from 20 volts to 140 volts. But the flies kept their dunce caps. Benzer was delighted. With mutants like these, he and his students could now dissect the act of memory into a series of steps. They would search for mutants that could remember a little better than dunce—some for a few minutes, some for a few hours, some for a few days. If they could find them and figure out what made each one different from the next, they might be able to use dunce and the rest to trace the invisible steps through which an experience becomes a short-term memory and then a long-term memory. Benzer’s crew mapped dunce. The gene lies on the far left tip of the X chromosome, just a few map units away from white and from the mutants of Konopka, the mutants that lost the sense of time.
BENZER’S PROJECT, the genetic dissection of behavior, was off to a strong start. He and his students had used genes to open three locked doors that had fascinated poets and philosophers from the beginning of Western thought.
“The body is but a watch,” said Julien Offray de La Mettrie at the start of the Enlightenment, coining a slogan for a worldview that has lasted from his time to ours. The clockwork has been called the central metaphor of modern Western civilization. Certainly from the very beginning of modern science, we have seen the space around us as a clockwork of stars and the space inside us as a clockwork of organs, a clockwork of atoms. Benzer and his students, with one of their first stabs in the dark, had found a clockwork gene. They did not know yet if they had the key to the clock; but they hoped they had a piece of it, a point of entry into a type of behavior that is as potent for us as a symbol of science as it is basic to life itself.
“The selfish gene” is another slogan for a worldview: a catchphrase for biologists—particularly biologists who study genes and behavior—since the 1970s. A body is a gene’s way of making more genes or an egg’s way of making more eggs, as in the quip that Benzer loves to quote from Butler. Mutants like fruitless were points of entry into the universal instinct that allows genes to move from one generation to the next and go wheeling across the longest geological reaches of time, from the beginning of life to the present, a span of four billion years.
“A man is but what he knoweth,” wrote Sir Francis Bacon in a third slogan, a slogan that defines for us one of the traits we most value in being human. If we could not remember where we have been, we would not profit by our experience and we would not know who we are. The mutant dunce was a point of entry into the mechanisms that allow each of us to accumulate histories and apply the lessons we have learned at our choice points; mechanisms whose elaboration in our species has helped to set us apart from all the rest.
Darwin’s process has worked powerfully and unceasingly to shape all three of these classes of genes. If animals and plants did not have clock genes, they could not keep time with the world. They would drift in and out of day and night, living less efficiently than their competitors and sometimes falling into fatal encounters. If we did not have instincts for recognizing and winning the attentions of the opposite sex, we could not pass on our genes; we would die without issue. And if we did not have memories, we could not pass these other genes safely onward and most of us could not last a day without a great deal of help from our friends.
Time, love, and memory are three bases of experience, three cornerstones of the pyramid of behavior. Benzer and his group had found a way inside all three in the first years of their Fly Room. Like Konopka’s discovery of a time-wounded fly in his two hundredth bottle, it was all surprisingly fast work. Konopka’s Law is broader than it sounds. Like so much that came out of the fly bottle, the message is universal. The Iliad and the Odyssey are the greatest epics ever written. Gutenberg’s Bible is the most beautiful book ever printed. Some of the world’s most memorable photographs were made during the first tests of the first photographic chemicals by Joseph Niepce and Louis Daguerre. Benzer’s sister’s husband, Harry Lapow (who gave Benzer his bar mitzvah microscope), spent years at Coney Island snapping pictures with a second-hand Ciroflex. The first day he brought the camera to the beach, he took a photograph that was included by Edward Steichen in the “Family of Man” exhibition at the Museum of Modern Art.
So Benzer’s first years in Church Hall, from the first run of his first countercurrent machine, were one long confirmation of Konopka’s Law. Benzer had hardly started his study of genes and behavior before he and his raiders found the time, love, and memory mutants, mutants that seem even more remarkable now than they did then, knowing what came afterward. If Benzer had tried to hoard the mutants, as many laboratory heads do, they might have died on the shelf. But Benzer chose instead to let his students and postdocs leave with them and build careers on them. As a result, each gene opened extraordinary views. By the end of the century they were helping to change our view of all behavior, including the behavior of the human family.