Stepping into an uncharted intersection of science and morality, President Clinton on Tuesday banned the use of federal funds for human cloning research and called upon private sector scientists to voluntarily refrain from such experiments.
Responding to last week's report that a Scottish scientist had cloned a sheep using genetic material from an adult sheep--and more recent news of the cloning of two monkeys in Oregon--Clinton cautioned that the emerging science is creating new ethical burdens for humanity even as it holds great promise for agriculture, medicine and other areas of commerce.
"Science often moves faster than our ability to understand its implications," said Clinton, who chose to ban funding for human cloning work while a special presidential bioethics panel studies the issues.
"That is why we have a responsibility to move with caution and care" to harness the emerging technology, he said.
"There is much about cloning that we still do not know," he added. "But this much we do know: Any discovery that touches upon human creation is not simply a matter of scientific inquiry, it is a matter of morality and spirituality as well."
Members of the National Bioethics Advisory Commission are expected to report back to the president this spring.
Clinton's action appeared to have more psychological impact than immediate scientific significance.
The National Institutes of Health, which provides the bulk of research money to U.S. scientists, does not now support any research projects involving human cloning.
Furthermore, as part of the 1996-97 legislation reauthorizing NIH, Congress explicitly prohibited any federally funded human embryo research.
Also, in 1994, Clinton banned the use of federal money to support the creation of human embryos solely for research purposes.
Clinton said the purpose of his action Tuesday was to close any possible loopholes in existing policy that still might allow research on human cloning to go forward.
The order does not affect animal cloning research.
"My own view is that human cloning would have to raise deep concerns, given our most cherished concepts of faith and humanity," Clinton said.
"Each human life is unique, born of a miracle that reaches beyond laboratory science," Clinton said as he issued the executive directive.
"I believe we must respect this profound gift and resist the temptation to replicate ourselves," he said.
"At the very least, however, we should all agree that we need a better understanding of the scope and implications of this most recent breakthrough."
Long grist to science fiction's mill and a distinctly distant future, the idea of cloning human beings abruptly seemed more plausible last week when Scottish scientist Ian Wilmut announced that he had succeeded in cloning a lamb named Dolly, which since has grown into a healthy adult--a genetic carbon copy of the single adult sheep that provided the genetic material.
Several days later, it was revealed that scientists in Oregon had cloned from embryonic cells two rhesus monkeys, a species much closer to that of humans.
Cloning is the production of an exact genetic duplicate of a living organism.
In normal sexual reproduction, an egg and a sperm--each containing half the genetic complement of an adult--fuse, combining their DNA to produce the complete genetic blueprint of a third adult.
In cloning, however, all of the genetic material comes from one parent, and the offspring is genetically identical to that parent.
NIH Director Harold E. Varmus said Tuesday that the president "was trying to provide some reassurance to the public that federal monies are not being used to do specific cloning of human beings," thus allowing the commission "time to think things through."
"This should calm people's fears about those nightmarish possibilities that are extremely unlikely, and get them to focus on the real dilemmas," Varmus added.
Art Caplan, director of the center for bioethics at the University of Pennsylvania, agreed, calling Clinton's move a sensible approach to a volatile scientific issue.
Human cloning research--at this time--"is too risky, too dangerous to undertake," Caplan said. "We're only at the Wright Brothers stage of development with respect to cloning technology," he said.
"A sheep is in a barn, and a monkey is in a cage," he said. But to reach that point, "a number of dead embryos and deformed animals were made as well. This is not a technique that is ready right now for human application. It makes sense to impose a moratorium and let society catch its collective moral breath."
Clinton's move did not seem to provoke the usual tension that results when a politician intervenes in scientific matters--further indication, perhaps, of the widespread recognition that cloning research is a moral minefield.
Political involvement in scientific research is neither new nor has it been partisan in nature.
Clinton's two predecessors, George Bush and Ronald Reagan, both Republicans, maintained a ban sought by many in the antiabortion movement on federally funded research using fetal tissue.
Rep. John D. Dingell (D-Mich.) rattled the biomedical community by initiating a series of scientific fraud and abuse cases when he chaired the House Energy and Commerce subcommittee on oversight and investigations.
Over the past two years, the friction between science and politics accelerated further under the Republican Congress, with GOP lawmakers taking legislative aim at certain research areas, such as work involving human embryos, that they didn't like.
Varmus said he believed Clinton's action would have the opposite effect.
"It takes the pressure off any need to legislate," he said.
Bioethicist Caplan agreed. "Some may cry, 'Censorship,' but it's simply silly to think that research this controversial, and that has such potential for misuse, is not going to elicit a political response."
In addition to a ban on federal funding, Clinton called upon the private sector to voluntarily refrain from research in this area until the national debate is concluded.
It was unclear how privately funded scientists would respond.
Varmus acknowledged that scientists in the private sector "probably will not be happy about it," but predicted most would respect it. "I can't think that there is much commercial interest in this subject."
Varmus added: "It's impossible to exclude the science-fiction rogue scientist idea. But it's very hard to do this stuff, and it's remote that anything could happen in 90 days. I don't think this is imminent."
Nevertheless, embryology experts speculated that one or more researchers at in-vitro fertilization clinics might already be engaged in some form of exploratory research, although none would comment publicly.
IVF clinics, which receive little, if any, federal funding, are supported by client fees and a limited amount of private funding.
Other experts predicted that a long-term ban could prompt some U.S. researchers to move that element of their research abroad.
When Australia and other countries banned IVF research, for example, scientists left for more amenable countries like Singapore.
But for all his caveats, Clinton agreed Tuesday with numerous experts who have said that the Scottish sheep cloning held the potential for stunning benefits in medical applications, food production, and even the saving of endangered species.
"The recent breakthrough in animal cloning is one that could yield enormous benefits, enabling us to reproduce the most productive strains of crop and livestock, holding out the promise of revolutionary new medical treatments and cures, helping to unlock the greatest secrets of the genetic code," Clinton said.
"But like the splitting of the atom, this is a discovery that carries burdens as well as benefits."
Times staff writers Thomas H. Maugh II in Los Angeles and Elizabeth Shogren in Washington contributed to this story.