Dna: The Secret of Life

by Watson, James

  But even if our individual rights can be secured against what our DNA may disclose, our peace of mind may not be so easily restored; as Nancy Wexler well knows, genetic knowledge can be a scary prospect. And I agree with her: there is no point in knowing about something that we are powerless to remedy or ameliorate, Alzheimer is a major concern of people my age, but in the absence of proven treatment possibilities, I have no desire to be tested for the presence of the APOEε4 allele. Craig Venter, incidentally, does indubitably have one copy of it. We know this because he insisted on disclosing that the genome sequenced by Celera was his own. And this allele, through its role in cholesterol processing, is associated not only with a higher risk of Alzheimer but of heart disease as well. (APOEε4 is not an asset in any respect.) Stuck with this genetic self-awareness, Venter is wisely trying to respond prophylactically as best he can: he is taking drugs called statins, which lower cholesterol levels and may retard or prevent the onset of Alzheimer. Even without knowledge of my APOE alleles, I'm also taking statins, figuring that a little preemptive medication can't do any harm. If statins are as effective as some claim them to be, we can look forward to many more years of Venter-generated (and, hopefully, Watson-generated) controversy.

  Genetic knowledge will remain frightening so long as we remain in the present intermediate stage, possessing in general the power to diagnose but not to cure. But ours is not an unprecedented medical predicament. Think back to the early years of the twentieth century: a diagnosis of infant diabetes was a death sentence. Today, with insulin therapy, such a child can expect to live to a ripe old age. The hope of our research efforts is that one day soon a diagnosis of diseases like Huntington will be transformed in the same way – from death sentence to prescription.

  Already, we are in a far stronger position to deal with bad rolls of the genetic dice than we were even twenty years ago; the ever-increasing life expectancies of people with, for example, Down syndrome and cystic fibrosis attest to this progress. But for now our most powerful weapons are diagnostics. The choice of whether to be tested is one best left to each individual or parent, those who will most directly bear the burden of genetic knowledge. In the case of prenatal diagnosis, it is the prospective mother who should make the decisions. That is not to say that others shouldn't participate, but ultimately the choices should lie with the woman: not only is she the one having the baby, but, like it or not, our world is still one in which women are expected to bear the brunt of the day-to-day care of children. Regardless of the specifics of decision making, however, one thing is completely clear to me: over the ages genetic disorders have rained unthinkable misery upon countless families such as Carol Carr's, which has been ravaged by Huntington disease. Testing holds the power to reduce misery by preventing it. Having developed the tests, it would be unconscionable not to make their existence known to those who might want to use them, inexcusable not to make them universally available.

  CHAPTER THIRTEEN

  WHO WE ARE:

  NATURE VS. NURTURE

  Growing up, I worried quietly about my Irish heritage, my mother's side of the family. My ambition was to be the smartest kid in the class, and yet the Irish were the butt of all those jokes. Moreover I was told that in the old days signs announcing the availability of jobs often ended with "No Irish Need Apply." I wasn't yet equipped to understand that such discrimination might have to do with more than an honest assessment of Irish aptitudes. I knew only that though I myself possessed lots of Irish genes there was no evidence that I was slow-witted. So I figured that the Irish intellect, and the shortcomings for which it was known, must have been shaped by the Irish environment, not by those genes: nurture, not nature, was to blame. Now, knowing some Irish history, I can see that my juvenile conclusion was not far from the truth. The Irish aren't in the least stupid, but the British tried mightily to make them so.

  Oliver Cromwell's conquest of Ireland surely ranks high among history's most brutal episodes. It culminated in banishing the native Irish population to the country's undeveloped and inhospitable western regions like Connaught while the spoils of the more salubrious east were divided up among the lord protector's supporters, who would start to Anglicize the vanquished province. With the incoming Protestants believing the heresies of Catholicism to be a one-way ticket to perdition, Cromwell duly proclaimed in 1654 that the Irish had a choice: they could "Go to Hell or Connaught." At the time, it probably wasn't clear which was worse. Seeing Catholicism as the root of the "Irish Problem," the British took draconian measures to suppress the religion, and with it, they hoped, Irish culture and Irish national identity. The ensuing period of Irish history was thus characterized by a form of apartheid every bit as severe as that so infamously practiced in South Africa, with the principal difference being the basis of discrimination: religion rather than skin color.

  Among the "Penal Laws" passed to "Prevent the Further Growth of Popery," education was a particular target. One statute of 1709 included the following provisions:

  Whatever person of the popish religion who shall publickly teach school or instruct youth in learning in any private house, or as an usher or assistant to any protestant schoolmaster, shall be prosecuted.

  For discovering, so to lead to the apprehension and conviction of any popish archbishop, bishop, vicar general, Jesuit, monk, or other person exercising foreign ecclesiastical jurisdiction, a reward of 50 pounds, and 20 pounds for each regular clergyman or non-registered secular clergyman so discovered, and 10 pounds for each popish schoolmaster, usher or assistant; said reward to be levied on the popish inhabitants of the county where found.

  The British hoped that the Irish young attending British-sponsored Protestant schools would wean themselves off Catholicism. But they hoped in vain: it would take more than oppression or even bounty to prise apart the Irish and their religion. The result was a spontaneous underground educational movement, the "hedge schools," with itinerant Catholic teachers leading secret classes in ever-changing outdoor locations. Often conditions were appalling, as a visitor noticed in 1776: "They might as well be termed ditch schools, for I have seen many a ditch full of scholars." But by 1826, of the entire student body of 550,000 an estimated 403,000 were enrolled in hedge schools. Increasingly a romantic symbol of Irish resistance, the schools inspired the poet John O'Hagan to write:

  Still crouching 'neath the sheltering hedge,

  Or stretched on mountain fern,

  The teacher and his pupils met feloniously to learn.

  But if the British had failed in their goal to enforce religious conversion, they had, despite the heroic efforts of the hedge schoolteachers, successfully impaired the quality of education for generations of Irish. The resulting archetype of the "stupid" Irishman would have been more aptly identified as the "ignorant" Irishman, a direct legacy of the anti-Catholic policies of Cromwell and his successors.

  And in this way my boyish conclusion was not far off the mark: the so-called curse of the Irish was indeed the result of nurture – development in an environment of substandard educational opportunities – rather than nature – Irish genes. Today, of course, nobody, not even the most bigoted Englishman, can legitimately claim that the Irish aren't as smart as other people. Ireland's modern education system has more than undone the damage of the hedge school era: the Irish population is today one of the best educated on the planet. My youthful reasoning on the subject, however absurdly misinformed, nevertheless taught me a very valuable lesson: the danger of assuming that genes are responsible for differences we see among individuals or groups. We can err mightily unless we can be confident that environmental factors have not played the more decisive role.

  This tendency to prefer explanations grounded in "nurture" over ones rooted in "nature" has served a useful social purpose in redressing generations of bigotry. Unfortunately, we have now cultivated too much of a good thing. The current epidemic of political correctness has delivered us to a moment when even the possibility of a genetic basis for difference
is a hot potato: there is a fundamentally dishonest resistance to admitting the role our genes almost surely play in setting one individual apart from another.

  Science and politics are to a degree inseparable. The connection is obvious in countries like the United States, where a considerable proportion of the scientific research budget depends on the appropriations of the democratically elected government. But politics intrudes upon the pursuit of knowledge in more subtle ways as well. The scientific agenda reflects society's preoccupations, and all too often social and political considerations end up outweighing purely scientific ones. The rise of eugenics, a response on the part of some geneticists to prevailing social concerns of the era, is a case in point. With a scientific basis weak to the point of vanishing, the movement progressed mainly as a pseudoscientific vehicle for the notably unscientific prejudices of men like Madison Grant and Harry Laughlin.

  Modern genetics has taken to heart the lessons of the eugenics experience. Scientists are typically careful to avoid questions with overtly political implications and even those whose potential as political fodder is less clear. We have seen, for instance, how such an obvious human trait as skin color has been neglected by geneticists. It's hard to blame them: after all, with any number of interesting questions available for investigation, why choose one that might land you in hot water with the popular press or, worse, earn you an honorable mention in white supremacist propaganda? But the aversion to controversy has an even more practical – and more insidious – political dimension. It happens that scientists, like most academics, tend to be liberal and vote Democratic. While no one can tell how much of this affiliation is principled and how much is pragmatic, it's certainly the case that Democratic administrations are assumed to be invariably more generous toward research than Republican ones.* And so having signed on to the liberal end of the political spectrum, and finding themselves in a climate intolerant of truths that don't conform to ideology, most scientists carefully steer clear of research that might uncover such truths. The fact that they duly hew to the prevailing line of liberal orthodoxy – which seeks to honor and entitle difference while shunning any consideration of its biochemical basis – is, I think, bad for science, for a democratic society, and ultimately for human welfare.

  * Wrongly, it turns out. The stingiest science budget in recent history was Jimmy Carter's.

  Knowledge, even that which may unsettle us, is surely to be preferred to ignorance, however blissful in the short term the latter may be. All too often, however, political anxiousness favors ignorance and its apparent safety: we had better not learn about the genetics of skin color, goes the unspoken fear, lest such information be marshaled somehow by hatemongers opposed to mixing among the races. But that same genetic knowledge may actually be vitally useful to people like me, whose Irish-Scots complexion is vulnerable to skin cancer in climes sunnier than Tipperary and the Isle of Skye, where my mother's ancestors hailed from. Similarly, research into the genetics of difference in mental ability among people may raise awkward questions, but that knowledge would also be a boon to educators, allowing them to develop an individual's educational experience with his or her strengths in mind. The tendency is to focus on the worst-case scenario and to shy away from potentially controversial science; it is time, I think, we looked instead at the benefits.

  There is no legitimate rationale for modern genetics to avoid certain questions simply because they were of interest to the discredited eugenics movement. The critical difference is this: Davenport and his like simply had no scientific tools with which to uncover a genetic basis for any of the behavioral traits they studied. Their science was not equipped to reveal any material realities that would have confirmed or refuted their speculations. As a consequence, all they "saw" was what they wished to see – a practice that really doesn't merit the name science – and often they came to conclusions manifestly at odds with the truth: for instance that "feeblemindedness" is transmitted as an autosomal recessive. Whatever the implications of modern genetics may be, they simply bear no relation to this manner of reasoning. Now, if we find a certain mutation in the gene associated with Huntington disease, we can be sure that its possessor will develop the disease. Human genetics has moved from speculation to fact. Differences in DNA sequence are unambiguous; they're not open to interpretation.

  It is ironic that those who worry most about what unchecked genetics might reveal should lead the way in politicizing the field's most basic insights. Take, for example, the discovery that the history of our species implies that there are no major genetic differences among the groups traditionally distinguished as "races": it has been suggested that as a matter of general practice our society should accordingly cease to recognize the category "race" in any context, eliminating it, for instance, from medical records. The theory here goes that the quality of treatment you receive in a hospital may vary depending on how you identify your ethnicity on the admission form. Racism can surely be found in the ranks of any profession, medicine included. But it's not altogether apparent how much protection your ethnic anonymity on the form will confer once you are face-to-face with a doctor who is a bigot. What is more apparent, however, is the danger of withholding information that might be diagnostically important. It is a fact that some diseases have higher rates of incidence within certain ethnic groups as compared with the human population as a whole: Native Americans of the Pima tribe have a particular propensity to Type II diabetes; African Americans are much more likely to suffer from sickle-cell anemia than Irish Americans; cystic fibrosis affects mainly people of northern European origin; Tay-Sachs is much more common among Ashkenazi Jews than others. This is not fascism, racism, or the unwelcome intrusion of Big Brother. This is simply a matter of making the best possible use of whatever information is available.

  For such a young science, genetics has played a central role in a remarkable number of notably ugly political episodes. Eugenics, as we have seen, was partly of the geneticists' own making. The pseudoscience known as Lysenkoism, which flourished in the Soviet Union in the middle of the twentieth century, however, was visited upon genetics from on high – literally: Stalin had plenty to say on the matter. Lysenkoism represents the most egregious incursion of politics into science since the Inquisition.

  In the late 1920s, the Soviet Union was still finding its feet. Stalin had won the battle of succession after Lenin's death and was consolidating power. The collectivization of agriculture was under way. And in an obscure agricultural research station in distant Azerbaijan, an uneducated but ambitious peasant was making a name for himself. Trofim Lysenko, born in the Ukraine in 1898, appeared an unlikely choice to oversee Stalin's agricultural revolution. Barely literate, he was working as a minor technician at Gandzha at the Ordzhonikidze Central Plant-Breeding Experiment Station when, in 1927, he was catapulted from obscurity by a visiting Pravda correspondent who, perhaps at a loss for good copy, was inspired by the sight of Lysenko: here was the "barefoot professor" solving agricultural problems so that the local "Turkic peasant can live through the winter without trembling at the thought of the morrow." Critically, the article painted Lysenko as a problem solver, not a highfalutin academic: "He didn't study the hairy legs of [fruit] flies, but went to the root of things."

  The image of the barefoot professor was irresistible to Soviet apparatchiks. Here was a son of the soil, the true flowering of the Soviet man, of the rural peasant class; his agricultural intuition was surely worth more than all the book learning of the shiftless intellectuals. Not to disappoint, Lysenko was quick to capitalize on his newfound prominence by proposing that winter wheat be "vernalized." Winter wheat is normally planted in the fall; it overwinters as a shoot, with some of the crop perishing, the rest maturing during the spring. Through "vernalization," Lysenko suggested, the losses of winter could be avoided. He claimed that you could fool the wheat seeds into germinating in the spring simply by chilling and wetting them, and that increased yields would be achieved in the bargain (see Plate 5
8). The definitive experimental demonstration of the method was carried out by none other than Lysenko's father in his own fields. Indeed, the yield was some three times greater than that of conventional unvernalized wheat planted in the same district.

  Vernalization did not in fact originate with Lysenko; wherever he may have picked it up, the procedure dates back to the preceding century at least, appearing, for example, in the Ohio agricultural literature of the 1850s. But here Lysenko's lack of education (and therefore ignorance of what had been accomplished elsewhere) stood him in good stead when it came to claiming originality. The same, however, could not be said for every further attempt to apply the method, whose results can vary a good deal depending on local conditions – something the Ohio farmers knew but the barefoot professor apparently did not.

  Within a couple of years, beset by failures, Lysenko stopped advocating the vernalization of winter wheat and was pushing instead the vernalization of spring wheat – a ploy worthy of the sharpest Soviet satire, considering that the crop is indeed named after the season in which it is normally planted. Later, his wheat yield policy did another U-turn when Lysenko called for warming (instead of cooling) the seed prior to planting. Wheat vernalization was but one of many agricultural nostrums that Lysenko peddled, but it illustrates well his overall strategy. A complete disregard for expert knowledge was de rigueur, as was a refusal to conduct consistent and rigorous tests. Essentially, any idea intuitively appealing to Lysenko was good enough to be implemented. What scientific method he did espouse almost seems inspired by theological reasoning, odd coming from the tool of a godless Communist state: "In order to obtain a certain result, you must want to obtain precisely that result; if you want to obtain a certain result, you will obtain it."