Sunday, September 16, 2007

The Human Genome in Human Context

On June 26, two teams of scientists announced jointly that they had virtually completed the task of mapping the human genome. The announcement was made at a White House ceremony featuring the President of the United States, the Prime Minister of England, and the heads of the two teams. The following day, the banner headline in the New York Times read, "Genetic Code of Human Life is Cracked by Scientists." The Times devoted ten full pages to the subject. Time magazine made it the cover story. The Wall Street Journal opined, "This is truly big stuff."

Though big stuff, it was really not a big discovery or even big news. That there is such a thing as a human genome and what it does have been known for several decades; and the project to map it, which is now all but complete, was initiated ten years ago. The mapping of the human genome is a milestone, not a breakthrough.

In spite of the hoopla and hype attending the announcement, much of the media commentary and analysis was reasonably sober and matter of fact. It focused chiefly on the anticipated benefits to biology and medicine, which are indeed potentially immense. These include a much greater understanding of the processes of life, and the prediction, treatment, and cure of many diseases. Amidst all the justified celebration, however, some darker notes were sounded. President Clinton warned that in using future discoveries "we must ... not retreat from our oldest and most cherished human values." Francis Fukuyama, writing in the Wall Street Journal, expected that "we probably won't like the answers" that genome research will give to age-old questions. The editors of that paper agreed and suggested that future findings may "stand many of our beliefs on their heads." Articles in the New York Times, while mostly optimistic, also warned of the "risks" and "temptations" that would come with progress.

What are those risks, temptations, and frightening answers? The perceived dangers of genetic research fall into several categories, ranging from the practical to the apocalyptic. At the practical end are issues relating to medical privacy, the insurability of people with genetically identifiable risks for disease, and the use of genetic information "to stigmatize or discriminate against individuals or groups," as President Clinton put it.

Still at the practical level, but reaching much deeper, are a host of fears surrounding the "genetic engineering" of human beings. Here there are at least three dangers. First, there is the possibility that social unbalances may arise as the result of parents "improving," "enhancing," or even designing their own offspring. Lee Silver, professor of biology at Princeton University and author of Remaking Eden, has warned that the technology of inserting genes into fertilized eggs--which he calls "reprogenetics"--will lead to a two-tier society: the "GenRich," who can afford to genetically enrich their children, and the "Naturals," who can't and will be left behind. Aside from such egalitarian concerns, there is the possibility that human genetic engineering will simply skew the human gene pool. As some traits are selected for, other traits that are less obviously desirable, or less understood, or more subtle, but nevertheless needed by society, may inadvertently be selected against.

A second danger of the engineering of humans is that it will profoundly change the relationship between parent and child. The child who is designed by his parents is in some measure made, not begotten, and becomes no longer a given to be accepted, but an invention, a technical artifact.

The third and most fearsome danger is that this kind of genetic control will eventually lead to the radical transformation of the human species itself. In the words of Fukuyama, "The way is then open to superseding the human race with something different" Indeed, the prophecy of Prof. Silver is that the GenRich and the Naturals will form not two social classes, but two distinct human species. As the scientist and futurist Freeman Dyson observes in The Sun, the Genome, and the Internet, "When we have mastered the technology of reprogenetics, we shall be creating our own genetic barriers, not in opposition to nature, but enabling the natural processes of human evolution to continue." In Imagined Worlds, Dyson develops this scenario further: "The process of speciation, the division of our species into many varieties ... will then be under way... The most serious conflicts of the next thousand years will probably be biological battles, fought between different conceptions of what a human being ought to be."

Aside from what it will allow mankind to do to itself, genetic research may also alter the way humanity thinks about itself. Philosophers will certainly be tempted to demystify man, seeing people as mere sequences of digits that can be stored in a database rather than as beings made in the image of God with immortal souls. (The old fear of "becoming a statistic," a number in a file, would then be realized in a way more awful and profound than anyone expected.) This view will feed belief in genetic determinism, already a common response to the news of June 26. One of the cherished beliefs that the Wall Street Journal foresees being stood on its head is "the idea that man can choose between right and wrong." The "answer" that Fukuyama says "we probably won't like" is that "we are much less free to choose our destinies" than we thought. Even more radically, the knowledge of the human genome may further the already pronounced trend toward a materialistic view of man, the view that we are at bottom naught but "a fortuitous concourse of atoms."

In the face of all these threats to humanity should we panic? I do not think so. Or at least, if we do panic, it should not be because of knowing the genome.

First, we should keep in mind that in a certain sense the remaking of man has been going on since the Stone Age. Genetic engineering might be used, say, to increase our powers of sight. But we have done that already with the invention of eyeglasses, telescopes, binoculars, magnifying glasses, microscopes, infrared scopes, and countless other devices. Genetic engineering may or may not lead to supermen, but we already have X-ray vision; we just don't carry it around with us.

It might be objected that I have given examples of mere sensory enhancements, not improvements in mental abilities. But memory is a key mental ability, and many inventions have enhanced that power: writing, books, printing, photography, tape recorders, and moving pictures, to name but a few. This shows why remodeling human beings--even if possible--is unlikely in itself to radically change our lives. Enhancements in human abilities that may come through genetic engineering will in most cases be negligible compared to those already achieved, or achievable in the future, through tools.

Suppose we can make the average man able to run a three-minute mile. What is that when he can go much faster with a bicycle or car? Or suppose we can give each man the strength of Samson? What is that compared to what he can do with a forklift truck? It is true that genetic engineering can make the changes directly into the human body. But that too has been done, albeit by cruder methods. Will men want bigger biceps, abs, and lats? There are exercise machines and creatine. Will women want bigger breasts? There are silicone implants.

As far as fears that human beings will end up evolving themselves into shapes unrecognizable, this ignores the human hunger for normality. Breast implants, for example, have not led to breasts of ever increasing size. Contrary to Mae West's famous dictum, too much of a good thing is not necessarily wonderful, or perceived as such. To pursue the example of body shape further, there are biological factors that condition what we want. Cross-cultural studies have shown, for instance, that the ideal female waist-to-hip ratio in the eyes of men is 0.7, and the ideal male waist-to-hip ratio in the eyes of women is 0.9. Biologists believe that there are evolutionary reasons for these inborn preferences. What this suggests, rather than a danger of going to extremes, is a danger of too much normality. It is not just inborn preference mat favors the mean, but practicality. Being seven feet tall is an asset in the NBA, but a disadvantage almost everywhere else. Most parents will not want that for their children.

Of course, there are some things of which more is always better, such as talent or intelligence. And it is precisely the mental remaking of man that provokes the greatest worry. Will man, in attempting to improve himself mentally, turn himself into a creature altogether different psychologically, emotionally, aesthetically, morally, and spiritually--a creature no longer human?

There is reason to doubt the possibility of such a hideous outcome. What militates against it is the sheer difficulty of achieving a radical transformation of human nature. It should be appreciated to begin with that we have not come anywhere near to "cracking" the human genetic code, the headline in the Times notwithstanding. To "crack" the genetic code would involve three levels of understanding: of the human organism and its mechanisms down to the cellular level; of the developmental processes by which the structures of the body and brain are built up; and of the way in which these developmental processes are guided by the information encoded in the genome.

Suppose, for instance, one wanted to engineer into a person some radically new mental power, such as the ability to visualize five-dimensional shapes and diagrams. This would be very useful in many kinds of mathematical, scientific, and technical work. First, one would have to understand the neural paths involved in our present powers of visualization. Then one would have to invent new circuitry for the brain and find the developmental steps by which it could actually produce such circuitry. And finally, one would have to figure out genetic instructions to get those steps to take place. To state the task is to see its impossibility.

What we might really be able to do is either imitate what nature already knows how to do, or use trial and error, as nature did, to learn to do new things. By comparing the genomes of people with different athletic abilities, for instance, we can perhaps learn how to enhance athletic ability. Or we can learn tricks from the genomes of other species. But imitation of existing models will not bring great improvements in, say, human intellectual powers, since there are no models of higher intellect in nature to imitate. We might try to use geniuses as models, but it is foolish to suppose that by rooting around in the genome we will ever find out why Mozart wrote greater music than Salieri, or why Aquinas had more profound ideas than A.J. Ayer.

Nor will we make supermen by trial and error. The trouble is that almost all the trials will be errors, given the immense complexity of human beings. The problem is compounded by the fact that the relation of genes to traits is not one-to-one. Some traits are influenced by many genes, and some genes influence many traits. The law of unintended consequences is therefore bound to operate with a vengeance. The full results of some genetic "improvements" may only become evident a generation or two later, when it will be much too late. People will not long tolerate the succession of mental freaks and failures that will result from trying to engineer the human mind.

The bad news here is also, in a way, good news: man lacks not only the wisdom to play God, but also the intelligence. It is blasphemous and wicked to try to outdo God's work in creating man, but it will also prove to be futile, since we are no more up to the job technically than we are morally. In Rerum Novarum, Pope Leo XIII observed, in regard to socialism's Utopian schemes that, "all striving against Nature is vain." That is still true. Socialism failed to create the promised New Man, and the new eugenics will fail just as surely. We can only pray that the toll of suffering brought on by human arrogance and folly will be less horrible this time around.

In the meantime we should recognize that many of the evils that are discussed hypothetically in connection with genetic engineering are already upon us. Children are already being manufactured using in vitro fertilization, surrogate mothers, and sperm banks. Fertilized human eggs are put into cold storage or disposed of as waste products of the child-manufacturing process. People right now are designing their offspring by means of donated eggs or sperm. True, the present methods are technically crude, but the technically most sophisticated methods aren't always the most widely employed. In the half century in which we have had nuclear weapons, they have killed fewer people than were slaughtered in Rwanda over a few months with machetes and clubs.

Genetic engineering will indeed skew the human gene pool, but we have been doing that for thirty years by means of contraception with hardly anyone raising a cry of protest. In every developed country today, the most talented and the most intelligent are having far fewer children than average. This is an unprecedented genetic experiment on a massive scale, whose dysgenic effects will surely swamp any "positive" results that eugenicists could hope to achieve.

Finally, it seems safe to say that just as in the long run the Utopian fantasy of genetic engineering will wither in the light of scientific reality, so will the philosophical fantasy of genetic determinism. In fact, there is already quite conclusive evidence that human behavior, though strongly conditioned by genetics, is not completely determined by it. The identical twins of homosexuals, for instance, have only a 50 percent chance of being homosexual themselves. And even statistical correlations as high as 50 percent do not imply causation. Certain genes may be correlated with a kind of sensitivity that makes one more susceptible to environmental influences in favor of being an artist, say, or a hairdresser, or a homosexual. That would not be the same as a "gay gene," or a "hairdresser gene," or an "art gene." And even if genes do control certain of our inclinations, it does not follow that they therefore control our behavior.

Valid or not, the philosophical conclusions that are drawn from science often depend on what people want to believe. Some, for instance, will point, as President Clinton did, to the fact that all human beings genetically overlap by 99.9 percent as proof that we all have equal human dignity. Others, with as much or as little logic, will argue from the 98 percent genetic overlap of humans and chimpanzees that we have no special dignity at all. In short, the genome can tell us much about ourselves, but not the most important things. Genetics will not answer philosophical questions, nor will genetic engineering make us better philosophers. There is no wisdom gene. One safe prediction, therefore, is this: after all eugenic efforts have been made, the amount of human folly, and the suffering it brings, will be as great as ever.

Stephen M. Barr is a theoretical particle physicist at the Bartol Research Institute of the University of Delaware.

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