by James Gleick
Are there genes for such things? Not if a gene is a particular strand of DNA that expresses a protein. Strictly speaking, one cannot say there are genes for almost anything—not even eye color. Instead, one should say that differences in genes tend to cause differences in phenotype (the actualized organism). But from the earliest days of the study of heredity, scientists have spoken of genes more broadly. If a population varies in some trait—say, tallness—and if the variation is subject to natural selection, then by definition it is at least partly genetic. There is a genetic component to the variation in tallness. There is no gene for long legs; there is no gene for a leg at all.♦ To build a leg requires many genes, each issuing instructions in the form of proteins, some making raw materials, some making timers and on-off switches. Some of these genes surely have the effect of making legs longer than they would otherwise be, and it is those genes that we may call, for short, genes for long legs—as long as we remember that long-leggedness is not directly represented or encoded directly in the gene.
So geneticists and zoologists and ethologists and paleontologists all got into the habit of saying “a gene for X” instead of “a genetic contribution to the variation in X.”♦ Dawkins was forcing them to face the logical consequences. If there is any genetic variation in a trait—eye color or obesity—then there must be a gene or genes for that trait. It doesn’t matter that the actual appearance of the trait may depend on an unfathomable array of other factors, which may be environmental or even accidental. By way of illustration, he offered a deliberately extreme example: a gene for reading.
The idea seems absurd, for several reasons. Reading is learned behavior. No one is born able to read. If ever a skill depends on environmental factors, such as education, it is reading. Until a few millennia ago, the behavior did not exist, so it could not have been subject to natural selection. You might as well say (as the geneticist John Maynard Smith did, mockingly) that there is a gene for tying shoelaces. But Dawkins was undaunted. He pointed out that genes are about differences, after all. So he began with a simple counterpoint: might there not be a gene for dyslexia?
All we would need in order to establish the existence of a gene for reading is to discover a gene for not reading, say a gene which induced a brain lesion causing specific dyslexia. Such a dyslexic person might be normal and intelligent in all respects except that he could not read. No geneticist would be particularly surprised if this type of dyslexia turned out to breed true in some Mendelian fashion. Obviously, in this event the gene would only exhibit its effect in an environment which included normal education. In a prehistoric environment it might have had no detectable effect, or it might have had some different effect and have been known to cave-dwelling geneticists as, say, a gene for inability to read animal footprints.…
It follows from the ordinary conventions of genetic terminology that the wild-type gene at the same locus, the gene that the rest of the population has in double dose, would properly be called a gene “for reading.” If you object to that, you must also object to our speaking of a gene for tallness in Mendel’s peas.… In both cases the character of interest is a difference, and in both cases the difference only shows itself in some specified environment. The reason why something so simple as a one gene difference can have such a complex effect … is basically as follows. However complex a given state of the world may be, the difference between that state of the world and some alternative state of the world may be caused by something extremely simple.♦
Can there be a gene for altruism? Yes, says Dawkins, if this means “any gene that influences the development of nervous systems in such a way as to make them likely to behave altruistically.”♦ Such genes—these replicators, these survivors—know nothing about altruism and nothing about reading, of course. Whatever and wherever they are, their phenotypic effects matter only insofar as they help the genes propagate.
Molecular biology, in its signal achievement, had pinpointed the gene in a protein-encoding piece of DNA. This was the hardware definition. The software definition was older and fuzzier: the unit of heredity; the bearer of a phenotypic difference. With the two definitions uneasily coexisting, Dawkins looked past them both.
If genes are meant to be masters of survival, they can hardly be fragments of nucleic acid. Such things are fleeting. To say that a replicator manages to survive for eons is to define the replicator as all the copies considered as one. Thus the gene does not “grow senile,” Dawkins declared.
It is no more likely to die when it is a million years old than when it is only a hundred. It leaps from body to body down the generations, manipulating body after body in its own way and for its own ends, abandoning a succession of mortal bodies before they sink in senility and death.♦
“What I am doing,” he says, “is emphasizing the potential near-immortality of a gene, in the form of copies, as its defining property.” This is where life breaks free from its material moorings. (Unless you already believed in the immortal soul.) The gene is not an information-carrying macromolecule. The gene is the information. The physicist Max Delbrück wrote in 1949, “Today the tendency is to say ‘genes are just molecules, or hereditary particles,’ and thus to do away with the abstractions.”♦ Now the abstractions returned.
Where, then, is any particular gene—say, the gene for long legs in humans? This is a little like asking where is Beethoven’s Piano Sonata in E minor. Is it in the original handwritten score? The printed sheet music? Any one performance—or perhaps the sum of all performances, historical and potential, real and imagined?
The quavers and crotchets inked on paper are not the music. Music is not a series of pressure waves sounding through the air; nor grooves etched in vinyl or pits burned in CDs; nor even the neuronal symphonies stirred up in the brain of the listener. The music is the information. Likewise, the base pairs of DNA are not genes. They encode genes. Genes themselves are made of bits.
* * *
♦ He added: “Old terms are mostly compromised by their application in antiquated or erroneous theories and systems, from which they carry splinters of inadequate ideas, not always harmless to the developing insight.”
♦ In listing twenty amino acids, Gamow was getting ahead of what was actually known. The number twenty turned out to be correct, though Gamow’s list was not.
11 | INTO THE MEME POOL
(You Parasitize My Brain)
When I muse about memes, I often find myself picturing an ephemeral flickering pattern of sparks leaping from brain to brain, screaming “Me, me!”
—Douglas Hofstadter (1983)♦
“NOW THROUGH THE VERY UNIVERSALITY of its structures, starting with the code, the biosphere looks like the product of a unique event,”♦ Jacques Monod wrote in 1970. “The universe was not pregnant with life, nor the biosphere with man. Our number came up in the Monte Carlo game. Is it any wonder if, like a person who has just made a million at the casino, we feel a little strange and a little unreal?”
Monod, the Parisian biologist who shared the Nobel Prize for working out the role of messenger RNA in the transfer of genetic information, was not alone in thinking of the biosphere as more than a notional place: an entity, composed of all the earth’s life-forms, simple and complex, teeming with information, replicating and evolving, coding from one level of abstraction to the next. This view of life was more abstract—more mathematical—than anything Darwin had imagined, but he would have recognized its basic principles. Natural selection directs the whole show. Now biologists, having absorbed the methods and vocabulary of communications science, went further to make their own contributions to the understanding of information itself. Monod proposed an analogy: Just as the biosphere stands above the world of nonliving matter, so an “abstract kingdom” rises above the biosphere. The denizens of this kingdom? Ideas.
Ideas have retained some of the properties of organisms. Like them, they tend to perpetuate their structure and to breed; they too can fuse, recombine, segregate their content; ind
eed they too can evolve, and in this evolution selection must surely play an important role.♦
Ideas have “spreading power,” he noted—“infectivity, as it were”—and some more than others. An example of an infectious idea might be a religious ideology that gains sway over a large group of people. The American neurophysiologist Roger Sperry had put forward a similar notion several years earlier, arguing that ideas are “just as real” as the neurons they inhabit. Ideas have power, he said.
Ideas cause ideas and help evolve new ideas. They interact with each other and with other mental forces in the same brain, in neighboring brains, and thanks to global communication, in far distant, foreign brains. And they also interact with the external surroundings to produce in toto a burstwise advance in evolution that is far beyond anything to hit the evolutionary scene yet.…
I shall not hazard a theory of the selection of ideas.♦
No need. Others were willing.
Richard Dawkins made his own connection between the evolution of genes and the evolution of ideas. His essential actor was the replicator, and it scarcely mattered whether replicators were made of nucleic acid. His rule is “All life evolves by the differential survival of replicating entities.” Wherever there is life, there must be replicators. Perhaps on other worlds replicators could arise in a silicon-based chemistry—or in no chemistry at all.
What would it mean for a replicator to exist without chemistry? “I think that a new kind of replicator has recently emerged on this planet,”♦ he proclaimed at the end of his first book, in 1976. “It is staring us in the face. It is still in its infancy, still drifting clumsily about in its primeval soup, but already it is achieving evolutionary change at a rate that leaves the old gene panting far behind.” That “soup” is human culture; the vector of transmission is language; and the spawning ground is the brain.
For this bodiless replicator itself, Dawkins proposed a name. He called it the meme, and it became his most memorable invention, far more influential than his selfish genes or his later proselytizing against religiosity. “Memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation,” he wrote. They compete with one another for limited resources: brain time or bandwidth. They compete most of all for attention. For example:
Ideas. Whether an idea arises uniquely or reappears many times, it may thrive in the meme pool or it may dwindle and vanish. The belief in God is an example Dawkins offers—an ancient idea, replicating itself not just in words but in music and art. The belief that the earth orbits the sun is no less a meme, competing with others for survival. (Truth may be a helpful quality for a meme, but it is only one among many.)
Tunes. This tune
has spread for centuries across several continents. This one
a notorious though shorter-lived invader of brains, overran an immense population many times faster.
Catchphrases. One text snippet, “What hath God wrought?” appeared early and spread rapidly in more than one medium. Another, “Read my lips,” charted a peculiar path through late twentieth-century America. “Survival of the fittest” is a meme that, like other memes, mutates wildly (“survival of the fattest”; “survival of the sickest”; “survival of the fakest”; “survival of the twittest”;…).
Images. In Isaac Newton’s lifetime, no more than a few thousand people had any idea what he looked like, though he was one of England’s most famous men, yet now millions of people have quite a clear idea—based on replicas of copies of rather poorly painted portraits. Even more pervasive and indelible are the smile of Mona Lisa, The Scream of Edvard Munch, and the silhouettes of various fictional extraterrestrials. These are memes, living a life of their own, independent of any physical reality. “This may not be what George Washington looked like then,” a tour guide was overheard saying of the Gilbert Stuart painting at the Metropolitan Museum of Art, “but this is what he looks like now.”♦ Exactly.
Memes emerge in brains and travel outward, establishing beachheads on paper and celluloid and silicon and anywhere else information can go. They are not to be thought of as elementary particles but as organisms. The number three is not a meme; nor is the color blue, nor any simple thought, any more than a single nucleotide can be a gene. Memes are complex units, distinct and memorable—units with staying power. Also, an object is not a meme. The hula hoop is not a meme; it is made of plastic, not of bits. When this species of toy spread worldwide in a mad epidemic in 1958, it was the product, the physical manifestation of a meme, or memes: the craving for hula hoops; the swaying, swinging, twirling skill set of hula-hooping. The hula hoop itself is a meme vehicle. So, for that matter, is each human hula hooper—a strikingly effective meme vehicle, in the sense neatly explained by the philosopher Daniel Dennett: “A wagon with spoked wheels carries not only grain or freight from place to place; it carries the brilliant idea of a wagon with spoked wheels from mind to mind.”♦ Hula hoopers did that for the hula hoop’s memes—and in 1958 they found a new transmission vector, broadcast television, sending its messages immeasurably faster and farther than any wagon. The moving image of the hula hooper seduced new minds by hundreds, and then by thousands, and then by millions. The meme is not the dancer but the dance.
We are their vehicles and their enablers. For most of our biological history they existed fleetingly; their main mode of transmission was the one called “word of mouth.” Lately, however, they have managed to adhere in solid substance: clay tablets, cave walls, paper sheets. They achieve longevity through our pens and printing presses, magnetic tapes and optical disks. They spread via broadcast towers and digital networks. Memes may be stories, recipes, skills, legends, and fashions. We copy them, one person at a time. Alternatively, in Dawkins’s meme-centered perspective, they copy themselves. At first some of Dawkins’s readers wondered how literally to take that. Did he mean to give memes anthropomorphic desires, intentions, and goals? It was the selfish gene all over again. (Typical salvo: “Genes cannot be selfish or unselfish, any more than atoms can be jealous, elephants abstract or biscuits teleological.”♦ Typical rebuttal: a reminder that selfishness is defined by the geneticist as the tendency to increase one’s chances of survival relative to its competitors.)
Dawkins’s way of speaking was not meant to suggest that memes are conscious actors, only that they are entities with interests that can be furthered by natural selection. Their interests are not our interests. “A meme,” Dennett says, “is an information packet with attitude.”♦ When we speak of fighting for a principle or dying for an idea, we may be more literal than we know. “To die for an idea; it is unquestionably noble,”♦ H. L. Mencken wrote. “But how much nobler it would be if men died for ideas that were true!”
Tinker, tailor, soldier, sailor … Rhyme and rhythm help people remember bits of text. Or: rhyme and rhythm help bits of text get remembered. Rhyme and rhythm are qualities that aid a meme’s survival, just as strength and speed aid an animal’s. Patterned language has an evolutionary advantage. Rhyme, rhythm, and reason—for reason, too, is a form of pattern. I was promised on a time to have reason for my rhyme; from that time unto this season, I received nor rhyme nor reason.♦
Like genes, memes have effects on the wide world beyond themselves: phenotypic effects. In some cases (the meme for making fire; for wearing clothes; for the resurrection of Jesus) the effects can be powerful indeed. As they broadcast their influence on the world, memes thus influence the conditions affecting their own chances of survival. The meme or memes composing Morse code had strong positive feedback effects. “I believe that, given the right conditions, replicators automatically band together to create systems, or machines, that carry them around and work to favour their continued replication,”♦ wrote Dawkins. Some memes have evident benefits for their human hosts (“look before you leap,” knowledge of CPR, belief in hand washing before cooking), but memetic success and genetic success are not the same. Memes can replicate with
impressive virulence while leaving swaths of collateral damage—patent medicines and psychic surgery, astrology and satanism, racist myths, superstitions, and (a special case) computer viruses. In a way, these are the most interesting—the memes that thrive to their hosts’ detriment, such as the idea that suicide bombers will find their reward in heaven.
When Dawkins first floated the meme meme, Nicholas Humphrey, an evolutionary psychologist, said immediately that these entities should be considered “living structures, not just metaphorically but technically”:
When you plant a fertile meme in my mind you literally parasitize my brain, turning it into a vehicle for the meme’s propagation in just the way that a virus may parasitize the genetic mechanism of a host cell. And this isn’t just a way of talking—the meme for, say, “belief in life after death” is actually realized physically, millions of times over, as a structure in the nervous systems of individual men the world over.♦