Cloning | Introduction
In February 1997, Ian Wilmut and his colleagues at the Roslin Institute in Scotland announced the stunning news that they had cloned a lamb from the cells of a mature sheep. Although many animal cloning experiments had been performed in the past, they had succeeded only in cloning the cells of embryos. This latest experiment was remarkable because it was the first successful attempt to clone a mature mammal, producing an exact physical replica of the adult animal.
Wilmut and his lamb, whom the researchers named Dolly, became instant celebrities and found themselves at the center of intense debate. However, the uproar that resulted from the scientists’ announcement was focused not on the creation of Dolly, but on the possible application of cloning technology to other mammals—specifically humans. Indeed, the arrival of Dolly brought the realization, as the British scientific journal Nature stated, that “cloning humans from adults’ tissues is likely to be achievable any time from one to ten years from now.” The news of Dolly’s birth therefore led to a great deal of discussion about the scientific, moral, and ethical issues surrounding the prospect of human cloning.
The science of cloning
In normal mammalian reproduction, sperm and egg fuse naturally, each contributing half of the material that makes up a genetically unique individual. In the process that was used to create Dolly, known as gene transfer, scientists mechanically fused a cell from one animal onto an enucleated egg cell—that is, an egg cell whose nucleus (which contains the cell’s DNA) has been removed. Because the egg cell lacks DNA, the embryo that is created contains DNA from only one source. Thus, the embryo will develop into an exact physical replica of the animal from which the cell containing the DNA was taken.
Prior to the creation of Dolly, scientists had thought that gene transfer could only be performed using embryonic cells, in which all the genes are active. They believed that the process could not be conducted using adult cells because in these cells some genes are active and others are inactive. However, Wilmut and his colleagues discovered a way to make adult cells behave like embryonic cells. They then fused 277 nuclei from adult Finn Dorset ewes onto enucleated egg cells taken from Scottish Blackface Ewes. Thirty of the eggs developed into embryos, and twenty-nine of these embryos were implanted into Blackface ewes. One of these pregnancies was carried to term and resulted in the birth of a Finn Dorset lamb, Dolly, who was the exact replica of the adult from which the cell had been taken.
Dolly would seem to be proof that it is possible to perform gene transfer using adult cells, thereby cloning an adult mammal. But as the scien- tists readily admit, the fact that only one live sheep was born out of twenty-nine tries is a shaky basis for such a conclusion. Confirmation of the success of this breakthrough in cloning technology therefore relies on the reproduction of this experiment by independent researchers. As Time magazine correspondent Sharon Begley reports, though, that confirmation may come quickly, as scientists in America and Europe attempt similar cloning experiments with cattle, sheep, and rabbits.
The ethical implications
Wilmut and his colleagues had only envisioned that their technique would be used on animals in the areas of animal husbandry and biomedical science. However, the British government immediately cut its financial support of research at the Roslin Institute until the cloning technology’s possible applications to humans could be considered. In the United States, President Bill Clinton announced an immediate moratorium on federal funding of cloning research, arguing that “science often moves faster than our ability to understand its implications.” He then requested the National Bioethics Advisory Commission (NBAC) to study the ethical and legal aspects of the issue and to present him with a report containing recommendations for future action by the government. The NBAC held public hearings on the issue in March and April of 1997 and invited comments from scientists, ethicists, religious leaders, and others concerned with the controversy.
Opponents of human cloning believe that it could have numerous negative consequences for society. For example, individuals might have themselves cloned in order to have “spare parts” for organ transplants. Parents might use cloning as a means of replacing a dead or dying child. Some people might be motivated to create clones of famous or extremely talented people. Moreover, many argue, cloning could start society on a “slippery slope” toward attempts to perfect the human race by reproducing genetically “superior” individuals—such as people who are highly intelligent and attractive—and stigmatizing people with genetically “inferior” traits. These and additional social concerns have been expressed by numerous commentators and ethicists in the wake of Dolly’s birth.
Other arguments against cloning focus on the implications for the children who would be produced in cloning experiments. For example, some ethicists emphasize the physical danger that the technology poses to these children. Leon R. Kass, a professor at the University of Chicago, contends that cloning experiments on humans are likely to produce “mishaps and deformities” similar to those that result from research on animals. Kass is among those who insist that due to the possibility of creating deformed children, human cloning experiments are unacceptable.
In addition to the risk of physical dangers, some ethicists assert that cloning is unacceptable because it would violate the human dignity of cloned children. Because cloned children would essentially be manufactured rather than conceived, they could potentially be viewed by society as commodities and treated as less than fully human, these critics maintain. According to Gilbert Meilaender of Valparaiso University, “To beget a child is to give birth to one who is like us, equal in dignity, for whom we care, but whose being we do not simply control. To ‘make’ a child is to create a product whose destiny we may well think we can shape.” Moreover, critics argue, because a cloned child would inherit the exact DNA of an existing person rather than a blending of DNA from two sources, the child would be robbed of the genetic uniqueness that is essential for the formation of a distinct identity.
However, ethicists and scientists who support further research maintain that the dangers posed by human cloning have been exaggerated. They argue that many of the predictions made by opponents are unrealistic “science-fiction” scenarios. For example, in response to the fear that people might create clones for spare parts, supporters of human cloning research counter that cloned humans would be no different from humans produced through other means of reproduction and therefore would not be treated any differently. According to Robert Wachbroit, “Regardless of the reason that someone has a clone produced, the result would nevertheless be a human being with all the rights and protections that accompany that status.”
Many contend that cloning could become a viable alternative means of reproduction. For example, Ruth Macklin, a professor of bioethics at Albert Einstein College of Medicine, argues that cloning could provide an option for infertile couples or for couples in which one partner has a genetic defect that could be passed on to the child. Alun M. Anderson, editor of New Scientist magazine, concedes that the prospect of a child’s having the identical genetic makeup of one of his or her parents might seem strange, but he suggests that it “might not be that difficult an idea to get used to. After all, no one finds twins or even triplets too strange to deal with.” According to many scientists, such potential benefits of human cloning far outweigh the possible negative consequences and warrant further exploration through research.
After hearing arguments on both sides of the cloning issue, the NBAC delivered its report and recommendations to the president in June 1997. The commission called for a three- to five-year continuation of the moratorium on research designed to create a cloned child. The cloning process is unsafe to be used on humans at present, the commissioners maintained, and the continued moratorium would give scientists a chance to perfect the technique. This time could also be used to educate the public about the technology involved in cloning and to encourage widespread debate about cloning’s moral and ethical implications, the commission wrote. Commission members argued that cloning research with human cell tissue should be allowed to proceed, as should animal research that met with guidelines on the ethical treatment of animals. The president accepted the proposal to leave the moratorium on human research in place.
Debate over the implications of this scientific innovation—especially the seemingly impending possibility of human cloning—continues in many quarters. As noted by a legal ethicist who presented testimony at the NBAC hearings, this is one of the rare occasions when the ethics of a scientific advancement can be discussed and debated before it becomes a reality. At Issue: Cloning presents a variety of opinions on the moral, ethical, and legal issues surrounding cloning.
