Beyond cloning: the larger agenda of human engineering. (Introduction).

Advances in human engineering are moving ahead largely without public debate. Industry proponents have hyped the benefits, but a growing number of experts are now warning that the risks may be substantial.

How do you feel about altering human nature... forever?

There's probably not a parent in the world who hasn't wished for a magic wand that would make a sad child happy, or transform an unruly child into a civil one. And history is littered with the myriad methods cultures have applied to bend their members toward a particular definition of human nature.

But for the first time in human history, we are confronted with an entirely new approach to altering human nature, one that could have great benefits but could also carry great risks. Geneticists are closing in on a mythic power that humans once only dreamed of, the power to alter the genetic materials we pass on to future generations by engaging in "inheritable genetic modification" (IGM) or "germline engineering." (In contrast, "somatic engineering" affects only the person being treated, without producing changes in patients' germ cells--their eggs or sperm--that can be passed on to future generations.)

The personal, social, and political dangers inherent in asserting control over the human germline were well apparent when Aldous Huxley published his prophetic novel Brave New World in 1932. At that time, well-intentioned, highly educated scientists and politicians were wielding the surgeon's scalpel to realize a vision of genetically "improving" human nature by eliminating "bad genes" from the human gene pool.

Starting in 1907, several dozen U.S. states adopted laws allowing involuntary surgical sterilization for people deemed to be "feebleminded," "mentally defective," or "epileptics." In an infamous 8-1 ruling in 1927 upholding a Virginia forced sterilization law (Buck v. Bell), U.S. Supreme Court Justice Oliver Wendell Homes wrote, "It is better for all the world, if instead of waiting to execute degenerate offspring for crime, or to let them starve for their imbecility, society can prevent those who are manifestly unfit from continuing their kind.... Three generations of imbeciles are enough."

When Brave New World appeared, Adolf Hitler was only one year away from seizing power and passing his own "Law for the Prevention of Offspring with Hereditary Diseases," a 1933 statute that closely followed sterilization statutes in the United States. The Nazis began by sterilizing the blind, the deaf, chronic alcoholics, and the physically and mentally handicapped, before moving on to the extermination of Jews, gays, and gypsies.

The sobering history of the role of eugenics in the darkest moments of modern history looms in the background of any discussion about heredity and human nature. As environmentalists, we have always been interested in how different cultures defined human nature, since these definitions bear heavily on how those cultures interact with their physical environments and the rest of life on the planet. And we would be the last to claim that we know what human nature "is."

But our study of the history of science and technology has led us to be deeply skeptical about faith in the unexamined, unregulated power of science and technology to solve all our problems. This faith has been sorely tested time and again, as the large-scale rollout of one new technology after another has confronted us with unpredicted consequences. In contemplating the internal combustion engine, no one foresaw traffic jams, urban sprawl, smog, and global warming. DDT was hailed as a miracle pesticide, until whole populations of birds began to crash. Dams and levees built to control floods have resulted in even more destructive floods.

These repeated encounters with the unanticipated have led environmentalists to fight for a new approach to regulating the introduction of new technologies, the "precautionary principle." Under this principle, before we unleash a new technology, its proponents must first demonstrate convincingly that the technology is not likely to subject us to major new risks. In the event that there are serious uncertainties about what problems may appear, governments are empowered to regulate and restrict development until these uncertainties can be resolved.

In a sense, the precautionary principle is a way of legislating the humility which humanity has so long lacked in dealing with technological change. We have put this special issue of World Watch together because we believe that if ever there were a time to apply the precautionary principle, the advent of human germline engineering is it.

Some proponents of germline engineering want to race ahead with experiments specifically designed to alter human nature, to correct "mistakes," add "improvements," or even to launch an entirely new species that will leave Homo sapiens behind.

But the more sophisticated supporters of germline engineering are fully aware of the dark history of eugenics, and they reassure us by disparaging scientists and companies who try to move too fast as "cowboys." They take pains to distance themselves from the likes of Severino Antinori, the Italian doctor who claimed this spring that one or more women in his care were pregnant with human clones.

Instead, these proponents argue that new regulation of germline engineering will curb patient autonomy, reproductive choice, and disease prevention. They are willing to gamble that the possible gains from this technology outweigh the still poorly understood risks. They use images that play on our desire to be healthy and to live long lives. They avoid a bold frontal assault, and sell us on the idea of germline engineering in small, incremental steps, one "modest" intervention at a time, while characterizing those who advocate greater caution as unconcerned with human welfare.

Environmentalists are hardly opposed to the betterment of the human condition through the development of science and technology. At the Worldwatch Institute, we have welcomed many technologies that promise to lighten the impact of humanity on the natural world, such as solar panels to replace fossil fuels in generating electricity or sophisticated crop rotations to foil agricultural pests without using pesticides. And we have championed improving the lot of all of humanity, and especially the poor, through greater spending on education, strengthening women's rights, providing universal access to contraception, and funding simple public health measures like access to clean water.

But the biotechnology industry's failure to proceed under the precautionary principle has left us less sanguine about genetic engineering in all its forms. Many of the concerns that our contributors raise about human germline engineering apply with almost equal force to the exploding use of such techniques to alter the germlines of other species. Our sense of caution is reinforced by the growing body of knowledge demonstrating that genes do not act in a vacuum--that the function of a particular gene changes, depending on the environment, on the stage in the organism's life, and on interaction with other genes. In such a complex context, trying to distinguish "good" genes from "bad" genes becomes a fool's errand.

But as the old torch song goes, fools rush in where angels fear to tread. Instead of proceeding thoughtfully, the genetic industry is rushing ahead pell-mell in the commercial marketplace, developing a plethora of techniques that could be used for human germline engineering. The United States Patent Office now accepts patent claims for sections of human DNA. The number of patents pending for these human DNA sequences has gone from 4,000 in 1991 to 500,000 in 1998 to several million today. Aided by the equally rapid revolution in computing, laboratories that once took two months to sequence 150 nucleotides can now process over 30 million in a day, and at a small fraction of the earlier cost. The U.S. biotech industry--which dominates the global industry--has become an increasingly powerful economic and political force, with revenues growing fivefold between 1989 ($5 billion) and 2000 ($25 billion).

Aldous Huxley is not the only great artist who has wrestled with the implications of genetic engineering. In the dramatic Sorcerer's Apprentice sequence in the 1940 cartoon Fantasia, Walt Disney and his cartoonists gave us an animated metaphor of the unintended consequences of a kind of magical genetic manipulation. The sorcerer's apprentice brings a broom to life to speed his chores, failing to anticipate the dangers of creating new forms of life. But when the living broom proves too mindlessly efficient and starts to flood the Sorcerer's quarters, efforts to bring his creation under control by chopping it up backfire: the pieces of the shattered broom multiply out of control, and wreak even greater havoc.

For Disney, all is well in the end, because a higher power intervenes to set everything right. The angry sorcerer appears and casts the necessary spell to vanquish the brooms, stem the flood, and restore order in the universe, while the apprentice hangs his head in shame.

There is no sorcerer who will come for us once we have waved the wand of human germline engineering and begun to "people" the earth with offspring that carry new and novel combinations of DNA.

We are under no illusions that the arguments our contributors make here are ahead of the curve. The hour is already late; there appears to be little disagreement that to actually wield this wand will be technologically possible within a decade or two, if not sooner. We publish this issue in the hope that we still have enough time remaining for a fully informed public debate about this technology that could change human nature forever.

RELATED ARTICLE: Somatic, or Non-inheritable, Genetic Modification: a procedure that changes the genes in cells other than egg or sperm cells, in order to treat a disease. This kind of change is not passed on to the person's children. Applications of this sort are currently in clinical trials, and are generally considered socially acceptable.

Germline Engineering, or Inheritable Genetic Modification: a procedure that changes genes in eggs or sperm cells or very early embryos, so that the child will have certain characteristics. The procedure changes not only the child being born, but the child's descendants as well. Such applications have not yet been tried on humans.

Cloning: the creation of a genetic duplicate of an existing person. In research cloning, embryos created through cloning are used for research purposes, with the eventual goal of treating disease. In reproductive cloning, the embryo is implanted in a woman's uterus to produce a child. This process has been banned in over 30 countries.

Stem cells: cells from the membrane around an embryo which have the potential to develop into almost any type of tissue. Therapy using stem cells offers great potential for repairing damaged or diseased tissue in an individual.

Brian Halweil is a research associate and Dick Bell is a senior policy advisor at the Worldwatch Institute.