Cited by Science magazine as the “breakthrough of 1997,” the world’s media flocked to cover the story of a cloned sheep named Dolly by scientists at Scotland’s Roslin Institute. While scientists had been cloning animals since 1952, when a tadpole was cloned, the creation of Dolly was significant because it was the first time a mammal had been successfully cloned. Since Dolly, researchers have cloned goats, cows, mice, pigs, cats, rabbits, and a gaur (an endangered species of wild ox). The application of cloning technologies to human beings raises a number of ethical concerns however.

It is important to understand that there are three types of cloning: (1) recombinant DNA technology, (2) reproductive cloning, and (3) therapeutic cloning. Note that the same technique is used in both reproductive and therapeutic cloning. The only difference is what is done with the resulting embryo. Some thus prefer to use the somewhat unwieldy terms “cloning for reproductive purposes” and “cloning for therapeutic or research purposes.”

In recombinant DNA technology, a DNA fragment of interest is transferred from one organism to a self-replicating genetic element such as a bacterial plasmid. This technology has been around since the 1970s and is a common practice in molecular biology labs today.

Reproductive cloning is used to generate an organism that has the same nuclear DNA as another currently or previously existing organism. Scientists implant DNA from non-reproductive cells of an organism into an egg from which the DNA nucleus has been removed. This is somatic cell nuclear transfer (SCNT). The egg is then shocked with electric current or chemically treated so that it behaves as if fertilization had occurred. Embryonic development of an organism that contains the entire genetic code of the first organism then proceeds, and, theoretically, could be born after sufficient gestation.

Therapeutic cloning uses the same technique discussed above in reproductive cloning—somatic cell nuclear transfer (SCNT)—in order to produce human embryos for use in research. Only the goal and thus the use of the resulting embryo differ. In this case, the goal is to harvest stem cells that can be used to study human development and to treat disease. Stem cells are important to biological researchers because they can be used to generate virtually any type of specialized cell in the human body (an attribute called ‘pluripotency’). Stem cells are extracted from the embryo after it has divided for five days. The extraction process destroys the embryo, which makes it ethically unacceptable. Many researchers hope that one day, stem cells can be used to serve as replacement cells to treat heart disease, Alzheimer’s, cancer, and other diseases. It is worth noting that embryos are not the only source for stem cells. In fact, important advances are being made with stem cells from sources such as umbilical cord blood, human fat tissue, and cells that have been reprogrammed to an embryonic-like state.

A number of objections have been raised against reproductive human cloning, among them the vanity and hubris of an unnatural act of self-engineering. Failure is common—the process often results in the production of severely deformed offspring. The boundaries of parenthood and social responsibility are completely violated. Cloning raises the prospect of designer babies, and questions about the ability of cloned children to have open, independent, and free futures when expectations connected to their DNA are placed upon them. For example, we might expect Michael Jordan’s children to be good basketball players, but what would our expectations be for a clone of Michael Jordan?

Significantly more cloned embryos fail during pregnancy than would in sexual reproduction. Errors or incompleteness in the reprogramming process cause high rates of death, deformity, and disability among animal clones. Dolly was only one success out of 276 attempts. In addition, a substantial majority of surviving cloned animals has had severe birth defects. Many attempts result in failure and lead to miscarriage, innumerable abortions, and births of massively deformed offspring. It is of the utmost importance to understand that many defects created in the reprogramming of the egg do not manifest until much later in life so that adult clones have frequently undergone unforeseen deaths. In fact, Dolly was euthanized at a significantly young age because of ill health.

The questions arising from reproductive cloning are seemingly endless. Who is socially responsible for cloned humans? What rights and legal protections do clones have? How are laws to be formulated to prevent cloning in the context of statutory and case law that favors reproductive autonomy? Does cloning legally violate a child’s right to a free and independent future? What disparities are furthered if (since) reproductive technologies are only available to those with significant financial means? Can those who clone themselves be considered appropriate parents?

The issues raised concerning the freedom of children created through cloning and the nature of the family and human communities are more than sufficient to realize that human cloning is incompatible with the notion of a humane civilization. Cloning takes human beings into a realm of self-engineering that vastly exceeds anything in the history of reproductive biotechnology.

In conclusion, human cloning is a hubristic act. While the proponents of eugenics sought to create a “master race” on a collective level, cloning represents eugenics on the individual level. It is the antithesis of the impulse to foster and appreciate human diversity in all its complexity, and to accept others as they are. It is the quintessential manifestation of human beings acting as if they are God.