This paper examines the ethical dimensions of human cloning by first outlining the two principal cloning techniques — embryo twinning and nuclear transplantation — and tracing the scientific milestones that led to the cloning of Dolly the sheep in 1997. It then surveys the major ethical objections raised by scientists, bioethicists, religious bodies, and governments, including safety risks, premature aging in clones, the Kantian principle that humans must be treated as ends in themselves, and concerns about commodifying human life. The paper also presents the case made by cloning enthusiasts, who draw comparisons to the gradual social acceptance of in vitro fertilization, and closes by acknowledging that the ethical debate is unlikely to be resolved in the near future.
In the 1980s, numerous scientists began researching methods of cloning higher-order animals, particularly mammals (Kass 2002, p. 7). The growing success of their research and experiments has resulted in widespread discussion about the possibility of human cloning. This discussion has elicited extensive disagreements within the scientific community and among the general public over whether research into human cloning is ethically justified. The two major techniques for cloning higher-order animals are each the subject of wide-ranging scientific study.
One method occurs naturally in some humans when a woman bears twins or triplets. This happens when the zygote, or fertilized egg, divides into separate units during the initial stages of development (McLaren, 2002, p. 25). These parts then grow into identical, genetically matching individuals. Scientists have stimulated this process artificially in cattle. Researchers in Washington, D.C. conducted trials on human twinning by artificial means, performing cloning on embryos that were genetically abnormal and had no chance of survival.
Nuclear transplantation is the other major cloning technique. In this method, a cloning specialist transfers the nucleus of a living cell into an enucleated egg — one from which the nucleus has been removed — or fuses the nucleus with it. When most people discuss human cloning, they envision some form of nuclear transplantation. For a long period, many scientists maintained that applying nuclear transplantation to create a clone from a mature mammal cell was impractical due to serious biological obstacles. Since all mammalian cells contain the same complete genetic information as the original fertilized egg, they develop toward specialization over time. As cells develop, some genetic information is regularly switched on and off to form skin cells, nerve cells, blood cells, and other cell types.
The major barrier to scientists' success in cloning human beings was an insufficient understanding of how to assimilate and reprogram cells. The goal would be to subdivide a cell, develop it into a whole animal, without simply reprogramming the cell to produce more cells of the same type. In the 1980s and 1990s, scientists managed to clone mammalian cells through nuclear transplantation, but the experiments used cell nuclei from developing embryos rather than from fully grown animals (McLaren, 2002, p. 35).
Early in 1997, researchers from Scotland shocked the world by announcing that their team had successfully cloned a sheep using nuclear transplantation (Kass, 2002, p. 73). The clone, known as Dolly, had three female parents. The scientists used the nucleus of a cell from the udder of one sheep, fused it with an enucleated egg from a second female, and then implanted the resulting embryo into the uterus of a third sheep. Dolly quickly became famous worldwide. She later reproduced through normal reproductive processes, demonstrating that she was a fully functional organism.
The scientists who created Dolly denied any intention of cloning human beings, stating that the purpose of their future research was to improve methods of producing genetically identical animals in large quantities. The announcement, however, fueled substantial public criticism centered on the prospect of human cloning. Polls indicated that a large majority of people strongly disapproved of cloning human beings. Many scientists and bioethicists voiced firm opposition. The Roman Catholic Church called for a global ban on human cloning, and President Clinton moved to restrict federal funding of cloning research.
In response to heightened public concern, the National Bioethics Advisory Commission (NBAC) — an expert body Clinton had created to examine ethical issues surrounding biotechnology — undertook an investigation into the matter. After receiving testimony from ethicists, religious organizations, scientists, and other parties, the NBAC recommended a five-year continuation of the announced federal funding ban on cloning research designed to produce a human child (Kass, 2002, p. 65). The NBAC further called for a halt to research involving the cloning of human tissues and cells.
The ethical questions many people have raised regarding human cloning operate on several levels. Some opposition centers on the safety of human cloning procedures. Cloning is not a reliable process — scientists required 277 attempts to produce Dolly (MacKinnon, 2001, p. 3). In many cases, fused egg gametes did not develop successfully; in others, they exhibited abnormalities that appeared dangerous during gestation. The stark success-to-failure ratio observed in animal experiments is, for many critics, sufficient grounds to ban cloning research. Questions also remain about the long-term physical health and potential premature aging of clones. The NBAC concluded in its report that such safety concerns necessitated a suspension of experiments involving human cloning.
Premature aging and other safety issues are technical barriers that may or may not be overcome as cloning science advances. Many people have raised moral objections to human cloning that go beyond questions of physical well-being (Dudley, 2001, p. 34). Cloning is seen by some as contravening fundamental religious beliefs about how human reproduction ought to occur. Others fear that cloning could produce confused or destabilized family relationships.
Additional ethical questions focus on the motivations behind human cloning and whether some justifications are more acceptable than others. For example, some might consider it morally permissible for a married couple at risk of passing on a genetic abnormality to clone a healthy parent. It is more questionable whether it is moral for a couple to clone a child simply because a father desires an exact genetic replica of himself, or whether parents could legitimately clone cells from a deceased child in order to produce a replacement. Some people also question whether society has any role in regulating the reproductive decisions of individuals by restricting cloning (Dudley, 2001, p. 50).
"Kant's principle applied to cloning debates"
"Pro-cloning arguments and uncertain future"
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