As the world waits for scientific confirmation or debunking of claims by the Raelians that they have cloned a human being, much attention has been paid to just how odd the group is. And rightly so. I interviewed Rael at UFOland, his Quebec headquarters, last summer, and it was among the strangest days of my life: a cordial chat with a former sportswriter wearing a white jumpsuit that looked like something from a "Star Trek" prop closet, just down the hall from a mock-up of the spacecraft where "the Elohim" first revealed themselves to him.

But the weirdness of the Raelians should not be allowed to obscure the wider mission they share with other self-proclaimed pioneers on the human genetic frontier -- people who, though cloaked in science instead of sectarianism, foresee remaking human beings in ways that make the genesis of baby Eve seem almost innocent.

Robert Lanza, for instance, a vice president at Advanced Cell Technology, called the Raelian announcement "appalling," "irresponsible" and "a sad day for science." Yet Lanza, two years ago, predicted that soon we would not just be cloning children but genetically souping them up: "We're close to being able to add 20 or 30 IQ points, and an equivalent boost of their muscle mass" to embryos, he said, adding "Who among us wouldn't say 'yes.' "

His boss at Advanced Cell Technology, Michael West, recently met with incoming Senate majority leader Bill Frist to promote his firm's cloning work. In the past West has complained bitterly about Rael, asking, "Why is Congress debating this by talking to someone who says he flies around in flying saucers?" And yet this same Michael West has acknowledged to many interviewers that his real goal is physical immortality. We can imagine, he says, "body components one by one each made young by cloning. Then our body would be made young again segmentally, like an antique car is restored by exchanging failing components." Should this lead to planetary overcrowding, well, "The answer is clearly to limit new entrants to the human race, not to promote the death of those enjoying the gift of life today."

And they are not isolated examples. Even James Watson, who will celebrate the 50th anniversary of his co-discovery of the double helix this spring, has advocated genetic manipulation to ensure that people aren't born "stupid" or "ugly" or "cold fish."

Understanding this kind of genetic grandiosity is key to making sensible political decisions in the months ahead. As a practical matter, cloning would be a necessary step toward the genetic manipulation of embryos -- toward adding IQ or muscle mass or, as other researchers have speculated, a host of behavioral and emotional traits. Similar work already has been carried out on a range of other animals. The threat posed by such work to the human species and to our societies is far greater even than the possibility that Rael or his competitors may have damaged the particular children they set out to clone.

Some researchers, like Lanza and West, now say they seek not to clone children but merely to harvest stem cells from cloned embryos for use in treating Parkinson's and other diseases. If so, they should fall in behind a moratorium proposal from a presidential commission that is designed to allow enough time to write legislation guaranteeing that such stem-cell work does not inadvertently ease the work of baby cloners or of those who would "enhance" human embryos by altering their minds, bodies or personalities. Such legislation is being backed not only by right-to-lifers and religious conservatives but by feminists, environmentalists, human and civil rights advocates and others who understand the threat these new technologies pose to a coherent human future.

As important as such legislation is, however, it's even more crucial that the scientific community take the opportunity offered by these events to repudiate the pernicious notion that we should "improve" the species through genetic tinkering. Rael may be a kook -- but his rhetoric, and his vision, resemble all too closely a spreading idea of a post-human world.

The writer is a scholar in residence at Middlebury College in Vermont and author of the upcoming book "Enough: Staying Human in an Engineered Age."