Sliding down the double helix toward peril

It took 14 years, but Bill McKibben has produced a book that is both a sequel and an equal to his brilliant “The End of Nature.” Not that McKibben has been coasting all this time. He has produced several fine books and a score of insightful articles. But nothing he’s written in the intervening years has quite matched his dazzling debut in which he argued, persuasively, that global warming isn’t just a matter of species extinction or the ocean level rising, as dire as those changes are. By altering our planet’s climate, McKibben argued in 1989, humans have been doing nothing less than permanently changing nature, creating in essence an artificial world. “The End of Nature” was an intellectual tour de force and an instant environmental classic.

“Enough: Staying Human in an Engineered Age” is an equally ambitious and important book. In it, McKibben examines the dark potential at the center of three glittering and converging technologies: genetic engineering and, to a lesser extent, robotics and nanotechnology. Where “The End of Nature” described a widening gulf between humans and our environment, “Enough” suggests that an even more terrifying break looms: a technologically driven division between the human past and a post-human future. In the name of progress, he asserts, we are about to engineer ourselves out of existence.

McKibben is a gifted writer and thinker, and there is no better proof of his prodigious talents than the fact that he is able to make such a scenario seem not just plausible but likely. After reading “Enough,” the question must be asked whether or not this dystopia can be avoided.

McKibben begins by probing the promises and perils of genetic engineering. No Luddite, he doesn’t oppose gene therapies per se. He makes a distinction between the two technologies now conflated under the single heading of genetic engineering. The first is somatic gene therapy, by which doctors try to cure a disease, or at least alleviate its symptoms, by inserting new genetic material into an existing patient, usually by piggybacking the new gene onto a virus. As radical and cutting-edge as this technique is, McKibben argues that it is an extension of existing technology. “The gravitational force that we call civilization,” he warns, “is just strong enough to hold somatic gene therapy in its orbit.”

Germline engineering, the second technology, is another story. It introduces fundamental genetic changes by removing a single cell from the earliest stages of a developing embryo, adding or removing genes, and then inserting the new cell into an egg whose nucleus has been removed. This new embryo would be implanted into a woman’s womb and allowed to grow. Every cell now contains a copy of the new genetic information, and these changes will be passed along to future generations. McKibben holds that germline engineering “will break us free from the bounds of our past and present and send us winging off into parts unknown.”

Proponents of germline engineering hail the benefits of this radical technology. We could, for example, simply “edit out” the malfunctioning gene that causes cystic fibrosis. Who could oppose relieving suffering of this magnitude? Probably nobody -- if only it were possible to confine the technology to solving such problems. But once we start down this path, not even advocates believe germline engineering will remain in the realm of disease prevention. Princeton biologist Lee Silver, as McKibben points out, suggests that once we open this door, we will likely take the next step, removing genetic predispositions to conditions such as obesity.

This course is more problematic than it first appears. Not only are we now looking for a disease and a predisposition to a disease, but we’re also talking about eliminating a condition, which is a short ethical leap to enhancing positive traits such as raising intelligence quotients. Although enhancing human intelligence through genetic engineering is beyond current capabilities, researchers at facilities around the globe are trying to isolate the specific genes linked to intelligence.

James Watson, the Nobel Prize-winning co-discoverer of the double helix structure of DNA, recently took this scenario one step further when commenting on future applications of germline engineering: “Who wants an ugly baby?” It’s a succinct question that brings us from what began as a lofty plea to end suffering caused by genetic diseases into a plan for producing better-looking progeny. Surely McKibben is correct when he writes that “the line between fixing problems and ‘enhancing’ offspring is meaningless.” Germline engineering isn’t a slippery slope; it’s a launchpad on which sits a rocket with a billion pounds of thrust, waiting for the countdown.

“Designer babies” may be inevitable, as some researchers believe, but is that really so bad? McKibben argues that what appears to be a liberating gift of technology is, in fact, a thief in disguise that will rob our lives of their most precious attribute: meaning. When advocates extol a happy future populated by genetically engineered super-athletes, music prodigies and hyper-intelligent people, McKibben asks us to consider the experience from the perspective of the recipients of these “gifts.”

What will it mean to run a 6.0-second 100-yard dash without breaking a sweat? To rattle off an impeccable Chopin Polonaise as if it were “Chopsticks”? Or solve equations like Fermat’s Last Theorem while simultaneously jotting down your grocery list? What will it mean if these accomplishments are not personal but merely the fulfillment of your design specs? It will mean nothing, or worse.

Take the child who is a piano prodigy, whose parents selected that particular combination of genes innocently, even benevolently. They loved music and wanted to pass this joy along. Researchers have already isolated genes that influence and perhaps govern psychological processes. How then do rebelling adolescents protest when the path selected for them is now governed by cells pumping out proteins that create particular attributes? What will it feel like to know that your parents manipulated this most intimate confluence of desire and ability? Under these circumstances, will you consider yourself a mere player piano, as McKibben suggests? You may resent your parents, but your deepest loathing will likely be reserved for your gifted self and for a life robbed of mystery and meaning.

McKibben’s ability as a polemicist is in full display in “Enough.” Not content to merely present the problem, he convincingly plays out all the implications. Parents, for instance, who tweak their babies’ intelligence would almost certainly set off a “kind of biological arms race,” available only to those who can afford such procedures. Those who can’t will become part of a biological underclass. Germline engineering will, predicts McKibben, “take the gap in power, wealth, and education that currently divides both our society and the world at large, and write that division into our very biology.” There will be the GenRich, and then there will be everybody else. Given that these are heritable characteristics, the GenRich will over time likely become a new species. In this scenario, evolution will be based not on natural selection but on fads, marketing and money.

Furthermore, McKibben discusses how advances in robotics and nanotechnologies amplify the threats posed by germline engineering. Crediting Bill Joy, one of the gurus of the high-tech revolution, who, in April 2000, shocked his peers with a piece in the influential Silicon Valley magazine Wired, he discusses the dangers posed by robots engineered to be smarter than humans and by an army of machines so tiny that they could manipulate molecules.

Toward the end of “Enough,” McKibben focuses upon the Holy Grail of genetic engineering -- the quest for immortality -- and makes clear the distinction between scientific altruism and hubris. “Our intention,” commented a senior executive of Advanced Cell Technology, the company that two years ago claimed to have produced the world’s first human embryo clone (albeit one that only grew to six cells), “is not to create cloned human beings but rather to make lifesaving therapies for a wide range of human disease conditions, including diabetes, strokes, cancer, AIDS, and neurodegenerative disorders.” But as McKibben points out, Michael West, chief executive of the firm, may also sound reasonable, but once he warms to the subject, his tone becomes more obsessive than scientific: “All I think about, all day long, every day, is human mortality.”

But can we shut the door on these technologies? McKibben believes we can. Unfortunately, the three examples of possible solutions -- represented by Amish, Japanese and Chinese societies -- he cites are, at best, shaky. The Amish may have successfully chosen to do without inventions most of us think of as necessities, but do they really offer a model that is applicable to the lives most Americans live? Japan may have rejected the use of firearms for 300 years, but in the end, they adopted guns. Finally, when China was poised in the early 1400s to dominate the world with its naval fleet, it chose to scuttle the ships, but that, too, was a temporary decision.

McKibben may well be right to argue that with a concerted effort we can, as a society, reject these technological paths, but in reality will it be possible? The end of nature, first heralded 14 years ago, has only advanced. While McKibben has crafted an impassioned and elegantly reasoned argument for rejecting these technologies -- for declaring that while we are far from perfection, being human is, in a word, enough -- the gravity of “Enough” leaves little room to believe his words are not a warning but a prediction.