Clone: The Road to dolly and the Path Ahead.

by Gina Kolata, New York: William Morrow & Co., 276 pages, $23.00

Cloning human cells could one day save your life and the lives of the people you love. Yet Congress seems hellbent on stopping the medical advances that cloning can make possible. Congress is responding to polls that show most Americans are opposed to the cloning of human beings. But carelessly crafted legislation would restrict not only research leading to the birth of cloned people but research that could find cures for cancer, genetic diseases such as cystic fibrosis, and damaged hearts, livers, and brains.

Now readers interested in this topic have two good, complementary introductions to the science, morality, politics, and future of animal and human cloning. Gina Kolata, who works for The New York Times, is one of the best science reporters in America. Lee Silver is a professor in the departments of molecular biology, ecology, and evolutionary biology and the program in neuroscience at Princeton University. Kolata does a particularly good job of describing the science that led up to Dolly, while Silver explores the futuristic medical and reproductive techniques that cloning makes possible.

In February 1997, the Roslin Institute in Scotland, an Obscure farm animal research facility, announced that it had succeeded in toning a sheep from an adult, differentiated cell. The cloned sheep, Dolly, made headlines around the world and launched a fierce debate over the potential uses for this new technology. The breakthrough showed for the first time that genetic information encoded in the DNA of an adult cell could be "reset" and made young again. Once reset, the cells with rejuvenated DNA could produce all of the cells needed to grow a complete organism. "[S]uperficially, it's a step toward immortality," explained Ronald James, whose company, PPL Therapeutics, paid for the cloning research. "And if you take a step toward immortality, everybody stops and takes notice."

Since Dolly, much has happened. President Clinton imposed a ban on federally funded cloning research, and Pope John Paul II declared that each human being has a "right to a unique human genome." UNESCO has issued a Universal Declaration on the Human Genome and Human Rights declaring, "Practices which are contrary to human dignity, such as reproductive cloning of human beings, shall not be permitted." The European Union has also adopted a ban.

In the United States, the National Bioethics Advisory Commission issued a report last June calling for federal legislation to ban human cloning for three to five years. "Freelance" physicist Richard Seed created a mini media firestorm in December when he said he was looking for investors to open a toning clinic. Congressional hearings have been held, and in February the U.S. Senate debated a bill that would ban cloning research on human embryos. Throughout it all, bioethicists have been offering grim warnings about the moral dangers of human cloning.

As Kolata shows, the science of cloning is fascinating. The achievement of Ian Wilmut and his colleagues at the Roslin Institute was the culmination of decades of research on eggs, embryos, and in vitro fertilization. The researchers inserted the nucleus of an adult udder cell into a sheep egg cell whose nucleus had been removed, a technique called "somatic cell nuclear transfer." Once the egg with its new nucleus began to divide, Wilmut implanted the developing embryo into the uterus of another sheep, the surrogate mother who gave birth to Dolly.

If it can be done with sheep, there appears to be no biological reason it cannot be done with human beings. Putting that possibility aside, however, cloning techniques could be the basis for a variety of life-saving medical treatments. Cloning probably will first be used to create animals that excrete important therapeutic human proteins, such as insulin or interferons, in their milk. This is what Wilmut was trying to do.

Another exciting possibility is that doctors, using somatic cell nuclear transfer, could create embryonic stem (ES) cells, the self-renewing precursors to blood, skin, heart, and nerve cells.

The treatment for leukemia, a cancer in which the bone marrow overproduces white blood cells, could be revolutionized. Today, one of the more successful treatments involves the destruction of a patient's bone marrow through chemotherapy and the transplantation of healthy marrow cells taken from a closely matched donor. The problem is that many leukemia patients die because they can't find appropriate donors. With cloning, healthy marrow cells that are perfect genetic matches for a leukemia patient could be created from the patient's own cells. Doctors could take a skin cell nucleus and implant it in an enucleated human egg, resetting the cell's DNA. Once reset, the cell could become an embryonic stem cell. After the ES cells began to divide, they could be treated with hormones that would cause them to develop into marrow cells, which could then be returned to the patient.

Similarly, islet cells could be created from the skin cells of a diabetic and returned to the patient's pancreas, where they would produce insulin. Eventually, ES cells could be turned into healthy heart or liver cells that could be used to repair tissue damaged by heart attacks or hepatitis.

Congress is considering several bills, sponsored mainly by Republicans, that would ban the research that could lead to these new treatments. Stampeded by the anti-abortion lobby, congressional Republicans want to treat ES cells like human embryos, even though their ultimate form depends entirely on the intentions of the patients and doctors who create them.

Silver highlights the important distinction between growth and development. ES cells can grow and divide into millions of identical cells, but they do not develop into any particular kind of cell until told to do so through biochemical signals. In a sense, the creation of ES cells in vitro would be like enhancing the natural production of ES cells in vivo. ES cells created from a patient's skin to treat disease are no more ethically problematic than veins taken from his legs to be used in a heart bypass operation. Both are the patient's cells, and both are being used for purposes different from their original function.

Down the road, it may be possible to reset cells without using enucleated human ova. Scientists in Wisconsin are doing some promising work using cow eggs to rejuvenate DNA taken from other species. But right now, researchers need to use human eggs in order to learn about the process of resetting cells. Such knowledge could lead to cures for cancer by teaching doctors how to turn off the uncontrolled growth of cancer cells, avoiding the relatively crude radiation and chemotherapy treatments used today. If research using human ova is blocked, the development of new treatments will be delayed, and many people who might have lived will die.

But what about cloning a complete human being? This prospect seems to cause the greatest unease among bioethicists and the general public, but it's not clear exactly why. A clone would be a delayed identical twin of the person from whom the cell's nucleus was taken. A clone is therefore a human being with all of the rights and responsibilities of any other human being. "How could we expect God to treat anyone born through cloning any different from the rest of us?" asks Ted Peters, a fellow at the Center for Theology and the Natural Sciences and a professor at Pacific Lutheran Seminary. "Surely, they would be just as much a child of God and loved by God. They would have their individuality, they would have their dignity, and certainly they would have their own souls."

The National Bioethics Advisory Commission suggested that human cloning be banned for three to five years on the grounds that it is not yet "safe" for the children who might be born using the procedure. The commission based its decision on the fact that Dolly was born after 277 attempts, which it argued is too high a failure rate when applied to human cloning. But is it really?

Lee Silver notes that hundreds of human eggs and embryos were used before the birth of the first test-tube baby, Louise Joy Brown, in 1978. Dolly was actually the beneficiary of well-established human in vitro fertilization technology: In the 277 tries, only 29 of the fused udder cells actually became embryos, which were implanted in 13 ewes, of which one became pregnant and gave birth. In a sense, this was a perfect success rate, since the only pregnancy resulted in a healthy birth. It is certainly far superior to the success rates achieved in early human IVF efforts. Silver claims that reproductive human cloning is no more dangerous than current human IVF procedures, which result in fewer birth defects than do natural births. An estimated 150,000 test-tube babies have been born worldwide.

Many of the same bioethicists who decried test-tube babies, including Leon Kass of the University of Chicago and Daniel Callahan of the Hastings Institute, are in the forefront of the attempts to ban human cloning. Twenty years ago, these bioluddites portentously warned that testtube babies would break the natural bonds of family, with unimaginable consequences for society. Although their warnings have proven unjustified, the naysayers are dusting off the old arguments and applying them to this new advance.

The National Bioethics Advisory Commission correctly refused to take a stand on the morality of human cloning, noting our society's diversity of values. The pope is free to advise Roman Catholics about what he believes the proper way to reproduce is, but his values are not universal.

The commission could not find a secular basis for banning the cloning of human beings. After all, who would be hurt by cloning? The person being cloned? Not if he gives permission. The baby? There is little reason to believe that "unnatural" methods of reproduction are any more harmful to offspring than the usual way of having children. There is no evidence, for example, that test-tube babies suffer especially high rates of physical or psychological problems.

Try this thought experiment. If tomorrow someone could prove that you were a clone, would you think your life was worth less, that your loves and experiences were devalued? You would be the same person you always were. Nothing would be different simply because you were born from a "previously experienced genome," in the tortured language of the cloning prohibitionists. A clone would likely have no more issues about self-worth and life chances than test-tube babies or adopted children do today.

One often hears that cloning will bring on Aldous Huxley's Brave New World. But that is nonsense. Huxley's dystopia was a centrally planned world in which clones were created by the state. In our society, choices will and should be made by individuals who are helping their children have a better life. One day, cloning technology probably will make possible changes in the genomes of embryos. Parents who risk having children with genetic diseases will be able to have the DNA of their prospective children repaired at the embryo stage, protecting them against maladies such as cystic fibrosis, PKU, and Tay-Sachs. A further benefit is that their grandchildren will never contract these diseases.

Parents will not only be able to prevent disease, they may also be able to enhance their children. Parents invest a lot of time, money, and emotional energy in providing good health care and a solid education for their children. If, by tweaking a base pair or two in a child's DNA, parents could boost the kid's intelligence and ensure against genetic diseases, what's so wrong with that? More to the point, who has the right to stop them?

"We control all other aspects of our children's lives and identities through powerful social and environmental influences and, in some cases, with the use of powerful drugs like Ritalin and Prozac," notes Silver. "On what basis can we reject positive genetic influences on a person's essence when we accept the rights of parents to benefit their children in every other way?"

Opponents of cloning talk a lot about hubris. But it takes more than a little hubris to believe you are wise enough to tell other people what is best for them - which is, after all, what a ban on cloning amounts to. What about the human consequences of banning a technology - the death, disease, disability, indignity, unhappiness, and blighted lives that would result from imposing limits on cloning discoveries and advances? Trying to exercise prior restraint on scientific and medical research is fraught with moral peril. Cloning prohibitionists must be held responsible for preventing the discovery of a cure for AIDS, cancer, Tays-Sachs, or heart disease. Their efforts to ban cloning could stop the creation of new medicines that would help millions of people.

Some opponents of cloning say it is too risky. But what opponents of a new technology regard as too risky may be acceptable for others. After all, some people parachute out of airplanes, while others won't even ride jetliners. "Risk" is not an objective quality of an object or technology; it is inextricably tied up with one's values. Why should cloning opponents get to impose their values on sick or dying people?

With regard to the perennial argument that cloning might violate "human dignity," bioethicist Ruth Macklin of Albert Einstein Medical College rightly observes that people who are worried about this issue "owe us a more precise account of just what constitutes a violation of human dignity if no one's rights are violated. Dignity is a fuzzy concept and appeals to dignity are often used to substitute for empirical evidence that is lacking or sound arguments that cannot be mustered." After all, what is so dignified about dying of cystic fibrosis, diabetes, or cancer?

Unfortunately, Silver mars his otherwise excellent book with a futuristic horror story of his own. He suggests that a few centuries from now, there will be a gap between the gene-enhanced and the nongene-enhanced. The rich will have taken advantage of the new cloning technologies, so their children will be smarter and free of disease, while the children of poor people will still suffer from the random draws of the natural genetic lottery, since their parents could not afford the new genetic treatments.

This is probably nonsense. Silver is assuming that the new treatments will always be expensive and that poor people will remain about as poor as they are today. More likely, the cost of genetic treatments will drop substantially, and poor people in the future will be much richer than poor people today are, so they will easily take advantage of the new medical technologies. For that matter, why not posit a future in which health insurance companies pay prospective parents to take advantage of genetic treatments and thereby avoid costly and painful medical procedures for their children later in life? That's more plausible than Silver's genetic class-warfare scenario.

Twenty-five years ago, bioluddites tried to stop recombinant DNA research, the technique which allows scientists to swap genes from one organism to another. Today Nobel laureate James Watson, the codiscoverer of the structure of DNA, is worried about the new assault on biotechnological progress. "Ever since we achieved a breakthrough in the area of recombinant DNA in 1973, left-wing nuts and environmental kooks have been screaming that we will create some kind of Frankenstein bug or Andromeda strain that will destroy us all," Watson tells Kolata. "Now we are threatened with a truly imbecilic law that could set back research for years." Kolata notes that "the transformation of recombinant DNA from the greatest threat since the atom bomb to a tool for the pharmaceutical industry occurred with little comment."

"Human essence came into existence simply because those with it could outcompete and kill those without it," writes Silver. "But if human minds have the ability to contemplate and direct changes in the copies of their own genomes that they give to future generations, the human mind is much more than the genes that brought it into existence." Let's hope that humanity will not shrink from using this promising new brainchild, continuing what Francis Bacon called "the conquest of nature for the relief of man's estate."

Ronald Bailey ([e-mail]) is a REASON contributing editor.