The Gene Read online

  Galton considered the obvious possibility that eminent men might produce eminent sons because the son “will be placed in a more favorable position for advancement.” Galton coined the memorable phrase nature versus nurture to discriminate hereditary and environmental influences. But his anxieties about class and status were so deep that he could not bear the thought that his own “intelligence” might merely be the by-product of privilege and opportunity. Genius had to be encrypted in genes. He had barricaded the most fragile of his convictions—that purely hereditary influences could explain such patterns of accomplishment—from any scientific challenge.

  Galton published much of this data in an ambitious, rambling, often incoherent book—Hereditary Genius. It was poorly received. Darwin read the study, but he was not particularly convinced, damning his cousin with faint praise: “You have made a convert of an opponent in one sense, for I have always maintained that, excepting fools, men did not differ much in intellect, only in zeal and hard work.” Galton swallowed his pride and did not attempt another genealogical study.

  Galton must have realized the inherent limits of his pedigree project, for he soon abandoned it for a more powerful empirical approach. In the mid-1880s, he began to mail out “surveys” to men and women, asking them to examine their family records, tabulate the data, and mail him detailed measurements on the height, weight, eye color, intelligence, and artistic abilities of parents, grandparents, and children (Galton’s family fortune—his most tangible inheritance—came in handy here; he offered a substantial fee to anyone who returned a satisfactory survey). Armed with real numbers, Galton could now find the elusive “law of heredity” that he had hunted so ardently for decades.

  Much of what he found was relatively intuitive—albeit with a twist. Tall parents tended to have tall children, he discovered—but on average. The children of tall men and women were certainly taller than the mean height of the population, but they too varied in a bell-shaped curve, with some taller and some shorter than their parents.I If a general rule of inheritance lurked behind the data, it was that human features were distributed in continuous curves, and continuous variations reproduced continuous variations.

  But did a law—an underlying pattern—govern the genesis of variants? In the late 1880s, Galton boldly synthesized all his observations into his most mature hypothesis on heredity. He proposed that every feature in a human—height, weight, intelligence, beauty—was a composite function generated by a conserved pattern of ancestral inheritance. The parents of a child provided, on average, half the content of that feature; the grandparents, a quarter; the great-grandparents, an eighth—and so forth, all the way back to the most distant ancestor. The sum of all contributions could be described by the series—1/2 + 1/4 + 1/8 . . .—all of which conveniently added to 1. Galton called this the Ancestral Law of Heredity. It was a sort of mathematical homunculus—an idea borrowed from Pythagoras and Plato—but dressed up with fractions and denominators into a modern-sounding law.

  Galton knew that the crowning achievement of the law would be its ability to accurately predict a real pattern of inheritance. In 1897, he found his ideal test case. Capitalizing on yet another English pedigree obsession—of dogs—Galton discovered an invaluable manuscript: the Basset Hound Club Rules, a compendium published by Sir Everett Millais in 1896, which documented the coat colors of basset hounds across multiple generations. To his great relief, Galton found that his law could accurately predict the coat colors of every generation. He had finally solved the code of heredity.

  The solution, however satisfying, was short-lived. Between 1901 and 1905, Galton locked horns with his most formidable adversary—William Bateson, the Cambridge geneticist who was the most ardent champion of Mendel’s theory. Dogged and imperious, with a handlebar mustache that seemed to bend his smile into a perpetual scowl, Bateson was unmoved by equations. The basset-hound data, Bateson argued, was either aberrant or inaccurate. Beautiful laws were often killed by ugly facts—and despite how lovely Galton’s infinite series looked, Bateson’s own experiments pointed decidedly toward one fact: that hereditary instructions were carried by individual units of information, not by halved and quartered messages from ghostly ancestors. Mendel, despite his odd scientific lineage, and de Vries, despite his dubious personal hygiene, were right. A child was an ancestral composite, but a supremely simple one: one-half from the mother, one-half from the father. Each parent contributed a set of instructions, which were decoded to create a child.

  Galton defended his theory against Bateson’s attack. Two prominent biologists—Walter Weldon and Arthur Darbishire—and the eminent mathematician Karl Pearson joined the effort to defend the “ancestral law,” and the debate soured quickly into an all-out war. Weldon, once Bateson’s teacher at Cambridge, turned into his most vigorous opponent. He labeled Bateson’s experiments “utterly inadequate” and refused to believe de Vries’s studies. Pearson, meanwhile, founded a scientific journal, Biometrika (its name drawn from Galton’s notion of biological measurement), which he turned into a mouthpiece for Galton’s theory.

  In 1902, Darbishire launched a fresh volley of experiments on mice, hoping to disprove Mendel’s hypothesis once and for all. He bred mice by the thousands, hoping to prove Galton right. But as Darbishire analyzed his own first-generation hybrids, and the hybrid-hybrid crosses, the pattern was clear: the data could only be explained by Mendelian inheritance, with indivisible traits moving vertically across the generations. Darbishire resisted at first, but he could no longer deny the data; he ultimately conceded the point.

  In the spring of 1905, Weldon lugged copies of Bateson’s and Darbishire’s data to his vacation in Rome, where he sat, stewing with anger, trying, like a “mere clerk,” to rework the data to fit Galtonian theory. He returned to England that summer, hoping to overturn the studies with his analysis, but was struck by pneumonia and died suddenly at home. He was only forty-six years old. Bateson wrote a moving obituary to his old friend and teacher. “To Weldon I owe the chief awakening of my life,” he recalled, “but this is the personal, private obligation of my own soul.”

  Bateson’s “awakening” was not private in the least. Between 1900 and 1910, as evidence for Mendel’s “units of heredity” mounted, biologists were confronted by the impact of the new theory. The implications were deep. Aristotle had recast heredity as the flow of information—a river of code moving from egg to the embryo. Centuries later, Mendel had stumbled on the essential structure of that information, the alphabet of the code. If Aristotle had described a current of information moving across generations, then Mendel had found its currency.

  But perhaps an even greater principle was at stake, Bateson realized. The flow of biological information was not restricted to heredity. It was coursing through all of biology. The transmission of hereditary traits was just one instance of information flow—but if you looked deeply, squinting your conceptual lenses, it was easy to imagine information moving pervasively through the entire living world. The unfurling of an embryo; the reach of a plant toward sunlight; the ritual dance of bees—every biological activity required the decoding of coded instructions. Might Mendel, then, have also stumbled on the essential structure of these instructions? Were units of information guiding each of these processes? “Each of us who now looks at his own patch of work sees Mendel’s clues running through it,” Bateson proposed. “We have only touched the edge of that new country which is stretching out before us. . . . The experimental study of heredity . . . is second to no branch of science in the magnitude of the results it offers.”

  The “new country” demanded a new language: Mendel’s “units of heredity” had to be christened. The word atom, used in the modern sense, first entered scientific vocabulary in John Dalton’s paper in 1808. In the summer of 1909, almost exactly a century later, the botanist Wilhelm Johannsen coined a distinct word to denote a unit of heredity. At first, he considered using de Vries’s word, pangene, with its homage to Darwin. But Darwin, in all tru
th, had misconceived the notion, and pangene would always carry the memory of that misconception. Johannsen shortened the word to gene. (Bateson wanted to call it gen, hoping to avoid errors in pronunciation—but it was too late. Johannsen’s coinage, and the continental habit of mangling English, were here to stay.)

  As with Dalton and the atom, neither Bateson nor Johannsen had any understanding of what a gene was. They could not fathom its material form, its physical or chemical structure, its location within the body or inside the cell, or even its mechanism of action. The word was created to mark a function; it was an abstraction. A gene was defined by what a gene does: it was a carrier of hereditary information. “Language is not only our servant,” Johannsen wrote, “[but] it may also be our master. It is desirable to create new terminology in all cases where new and revised conceptions are being developed. Therefore, I have proposed the word ‘gene.’ The ‘gene’ is nothing but a very applicable little word. It may be useful as an expression for the ‘unit factors’ . . . demonstrated by modern Mendelian researchers.” “The word ‘gene’ is completely free of any hypothesis,” Johannsen remarked. “It expresses only the evident fact that . . . many characteristics of the organism are specified . . . in unique, separate and thereby independent ways.”

  But in science, a word is a hypothesis. In natural language, a word is used to convey an idea. But in scientific language, a word conveys more than an idea—a mechanism, a consequence, a prediction. A scientific noun can launch a thousand questions—and the idea of the “gene” did exactly that. What was the chemical and physical nature of the gene? How was the set of genetic instructions, the genotype, translated into the actual physical manifestations, the phenotype, of an organism? How were genes transmitted? Where did they reside? How were they regulated? If genes were discrete particles specifying one trait, then how could this property be reconciled with the occurrence of human characteristics, say, height or skin color, in continuous curves? How does the gene permit genesis?

  “The science of genetics is so new that it is impossible to say . . . what its boundaries may be,” a botanist wrote in 1914. “In research, as in all business of exploration, the stirring time comes when a fresh region is unlocked by the discovery of a new key.”

  Cloistered in his sprawling town house on Rutland Gate, Francis Galton was oddly unstirred by the “stirring times.” As biologists rushed to embrace Mendel’s laws and grapple with their consequences, Galton adopted a rather benign indifference to them. Whether hereditary units were divisible or indivisible did not particularly bother him; what concerned him was whether heredity was actionable or inactionable: whether human inheritance could be manipulated for human benefit.

  “All around [Galton],” the historian Daniel Kevles wrote, “the technology of the industrial revolution confirmed man’s mastery of nature.” Galton had been unable to discover genes, but he would not miss out on the creation of genetic technologies. Galton had already coined a name for this effort—eugenics, the betterment of the human race via artificial selection of genetic traits and directed breeding of human carriers. Eugenics was merely an applied form of genetics for Galton, just as agriculture was an applied form of botany. “What nature does blindly, slowly and ruthlessly, man may do providently, quickly, and kindly. As it lies within his power, so it becomes his duty to work in that direction,” Galton wrote. He had originally proposed the concept in Hereditary Genius as early as 1869—thirty years before the rediscovery of Mendel—but left the idea unexplored, concentrating, instead, on the mechanism of heredity. But as Galton’s hypothesis about “ancestral inheritance” had been dismantled, piece by piece, by Bateson and de Vries, Galton had taken a sharp turn from a descriptive impulse to a prescriptive one. He may have misunderstood the biological basis of human heredity—but at least he understood what to do about it. “This is not a question for the microscope,” one of his protégés wrote—a sly barb directed at Bateson, Morgan, and de Vries. “It involves a study of . . . forces which bring greatness to the social group.”

  In the spring of 1904, Galton presented his argument for eugenics at a public lecture at the London School of Economics. It was a typical Bloomsbury evening. Coiffed and resplendent, the city’s perfumed elite blew into the auditorium to hear Galton: George Bernard Shaw and H. G. Wells; Alice Drysdale-Vickery, the social reformer; Lady Welby, the philosopher of language; the sociologist Benjamin Kidd; the psychiatrist Henry Maudsley. Pearson, Weldon, and Bateson arrived late and sat apart, still seething with mutual distrust.

  Galton’s remarks lasted ten minutes. Eugenics, he proposed, had to be “introduced into the national consciousness, like a new religion.” Its founding tenets were borrowed from Darwin—but they grafted the logic of natural selection onto human societies. “All creatures would agree that it was better to be healthy than sick, vigorous than weak, well-fitted than ill-fitted for their part in life; in short, that it was better to be good rather than bad specimens of their kind, whatever that kind might be. So with men.”

  The purpose of eugenics was to accelerate the selection of the well-fitted over the ill-fitted, and the healthy over the sick. To achieve this, Galton proposed to selectively breed the strong. Marriage, he argued, could easily be subverted for this purpose—but only if enough social pressure could be applied: “if unsuitable marriages from the eugenic point of view were banned socially . . . very few would be made.” As Galton imagined it, a record of the best traits in the best families could be maintained by society—generating a human studbook, of sorts. Men and women would be selected from this “golden book”—as he called it—and bred to produce the best offspring, in a manner akin to basset hounds and horses.

  Galton’s remarks were brief—but the crowd had already grown restless. Henry Maudsley, the psychiatrist, launched the first attack, questioning Galton’s assumptions about heredity. Maudsley had studied mental illness among families and concluded that the patterns of inheritance were vastly more complex than the ones Galton had proposed. Normal fathers produced schizophrenic sons. Ordinary families generated extraordinary children. The child of a barely known glove maker from the Midlands—“born of parents not distinguished from their neighbors”—could grow up to be the most prominent writer of the English language. “He had five brothers,” Maudsley noted, yet, while one boy, William, “rose to the extraordinary eminence that he did, none of his brothers distinguished themselves in any way.” The list of “defective” geniuses went on and on: Newton was a sickly, fragile child; John Calvin was severely asthmatic; Darwin suffered crippling bouts of diarrhea and near-catatonic depression. Herbert Spencer—the philosopher who had coined the phrase survival of the fittest—had spent much of his life bedridden with various illnesses, struggling with his own fitness for survival.

  But where Maudsley proposed caution, others urged speed. H. G. Wells, the novelist, was no stranger to eugenics. In his book The Time Machine, published in 1895, Wells had imagined a future race of humans that, having selected innocence and virtue as desirable traits, had inbred to the point of effeteness—degenerating into an etiolated, childlike race devoid of any curiosity or passion. Wells agreed with Galton’s impulses to manipulate heredity as a means to create a “fitter society.” But selective inbreeding via marriage, Wells argued, might paradoxically produce weaker and duller generations. The only solution was to consider the macabre alternative—the selective elimination of the weak. “It is in the sterilization of failure, and not in the selection of successes for breeding, that the possibility of an improvement of the human stock lies.”

  Bateson spoke in the end, sounding the darkest, and most scientifically sound, note of the meeting. Galton had proposed using physical and mental traits—human phenotype—to select the best specimens for breeding. But the real information, Bateson argued, was not contained in the features, but in the combination of genes that determined them—i.e., in the genotype. The physical and mental characteristics that had so entranced Galton—height, weight, beauty, inte
lligence—were merely the outer shadows of genetic characteristics lurking underneath. The real power of eugenics lay in the manipulation of genes—not in the selection of features. Galton may have derided the “microscope” of experimental geneticists, but the tool was far more powerful than Galton had presumed, for it could penetrate the outer shell of heredity into the mechanism itself. Heredity, Bateson warned, would soon be shown to “follow a precise law of remarkable simplicity.” If the eugenicist learned these laws and then figured out how to hack them—à la Plato—he would acquire unprecedented power; by manipulating genes, he could manipulate the future.

  Galton’s talk might not have generated the effusive endorsement that he had expected—he later groused that his audience was “living forty years ago”—but he had obviously touched a raw nerve. Like many members of the Victorian elite, Galton and his friends were chilled by the fear of race degeneration (Galton’s own encounter with the “savage races,” symptomatic of Britain’s encounter with colonial natives throughout the seventeenth and eighteenth centuries, had also convinced him that the racial purity of whites had to be maintained and protected against the forces of miscegenation). The Second Reform Act of 1867 had given working-class men in Britain the right to vote. By 1906, even the best-guarded political bastions had been stormed—twenty-nine seats in Parliament had fallen to the Labour Party—sending spasms of anxiety through English high society. The political empowerment of the working class, Galton believed, would just provoke their genetic empowerment: they would produce bushels of children, dominate the gene pool, and drag the nation toward profound mediocrity. The homme moyen would degenerate. The “mean man” would become even meaner.

  “A pleasant sort o’ soft woman may go on breeding you stupid lads [till] the world was turned topsy-turvy,” George Eliot had written in The Mill on the Floss in 1860. For Galton, the continuous reproduction of softheaded women and men posed a grave genetic threat to the nation. Thomas Hobbes had worried about a state of nature that was “poor, nasty, brutish and short”; Galton was concerned about a future state overrun by genetic inferiors: poor, nasty, British—and short. The brooding masses, he worried, were also the breeding masses and, left to themselves, would inevitably produce a vast, unwashed inferior breed (he called this process kakogenics—“from bad genes”).