Cloning Name Games

Proponents of therapeutic cloning seek to clone human embryos, but don’t want them implanted into women. Instead, they want to use them to produce stem cells that might some day be developed into therapies. These stem cells and resulting tissues would be immunologically compatible with the person from whom they were cloned, thereby overcoming the

by Donal P. O’Mathuna, PhD

Editor's Note: This article represents the opinion of the author, and does not necessarily represent the official position of CMDA on this issue. For CMDA's official stance on Human Cloning, click here.


At the end of November 2001, researchers at advanced Cell Technology (ACT) in Massachusetts announced they had cloned human embryos. This was allegedly the first published report of the application to human cells of the technique that had cloned "Dolly," the sheep. Immediately condemned by President Bush, the Vatican and many others, the researchers went to great lengths to claim they weren't really cloning humans. The president and CEO of ACT, Michael West, said they were "making human cellular life, not a human life."1 The report itself put it in more scientific terms, stating the experiments focused on "reprogramming of a somatic cell" to generate stem cells.2  I'm just trying to help people who are sick," explained Dr. West.

The ACT researchers were attempting "therapeutic cloning," a term developed to distinguish it from reproductive cloning," which would produce a cloned baby. Proponents of therapeutic cloning seek to clone human embryos, but don't want them implanted into women. Instead, they want to use them to produce stem cells that might some day be developed into therapies. These stem cells and resulting tissues would be immunologically compatible with the person from whom they were cloned, thereby overcoming the risk of rejection that plagues tissue transplantation from other people.

The debate over human cloning will most likely now focus on the distinction between therapeutic and reproductive cloning, and whether this distinction is ethically significant. The National Academy of Sciences (NAS) issued a report recommending that the type of research conducted at ACT be funded by the federal government.3 In contrast, the European Parliament voted a few days after the ACT announcement to fund some human embryo research, but to continue its ban on funding any form of human cloning.4  An attempt to take up the issue in the U.S. Senate failed at the end of 2001.

Earlier, a sizeable majority of the U.S. House of Representatives passed the Human Cloning Prohibition Act of 2001. The bill, introduced by Republican Dave Weldon of Florida and Democrat Bart Stupak of Michigan, would ban all human cloning in the U.S., whether funded privately or publicly. If this bill became law, violators (such as ACT researchers) would face up to ten years in prison and fines of $1 million. Supporters of the bill included unfamiliar allies, such as prominent pro-life organizations and ardent feminist and pro-choice groups. Those who spoke against the bill were primarily patient advocacy groups and a lobbying organization called the Biotechnology Industry Organization (BIO), said to represent more than a thousand clients.

The Weldon-Stupak Bill had to compete against another bill introduced by Republican James Greenwood of Pennsylvania. The Greenwood Bill would have permitted therapeutic cloning and put a ten-year moratorium on reproductive cloning. This debate will be reenacted in the Senate when some version of the Greenwood Bill will come up against a complete cloning ban to be introduced by Senator Sam Brownback (Republican of Kansas).5  The result of this debate will have huge implications for the direction of U.S. biotechnology in the coming decades.

The NAS report attempts to demonstrate that therapeutic cloning is procedurally distinct from reproductive cloning. But both forms of cloning use the same procedure, called somatic cell nuclear transfer (SCNT) or cell nucleus replace-ment.  The nucleus of any adult somatic cell is diploid, meaning it has a complete set of genetic material. Germ cells (egg or sperm) have only half an individual's chromosomes and are called haploid. In SCNT, a diploid nucleus is transferred from a somatic cell into an enucleated egg (one with its own haploid genetic material removed). The resulting cell is diploid and is therefore just like a fertilized egg, or zygote. Under appropriate conditions, it will grow and differentiate like any embryo.

The cloning procedure for reproductive purposes isexactly the same as that carried out for "therapeutic" purposes. Once the embryo is made, the cloning part of the process is complete. After this, the embryo is handled using the techniques developed for in vitro fertilization. The only difference with therapeutic cloning is that the researchers promise not to implant the cloned embryos into women. Those embryos are destined for destruction, primarily as sources of stem cells. The term "therapeutic cloning" is thus disingenuous, as the Chair of President Bush's new bioethics advisory council, Leon Kass, has written--a way to "obscure the fact that the clone will be 'treated' only to exploitation and destruction, and that any potential future beneficiaries and any future 'therapies' are at this point purely hypothetical."6

Proponents of therapeutic cloning usually remain firm opponents of reproductive cloning. The lead scientist on the project that cloned Dolly the sheep at the Roslin Institute in Scotland, Ian Wilmut, wrote that current "attempts to clone human beings . . . are dangerous and irresponsible."7  At the same time he believes therapeutic cloning should proceed because its potential benefits "will be enormous." Another embryologist in the Dolly experiments, Keith Campbell, has stated, "I see no reasons for cloning humans to term. I am against using nuclear transfer to produce humans. Full stop!"8  Rudolf Jaenisch, a prominent cloning researcher at MIT and the Whitehead Institute for Biomedical Research, has stated that given the current status of cloning research "any attempt to clone humans is reckless and irresponsible."9  Yet he reacted to passage of the Weldon-Stupak Bill by stating that, "It is premature to ban a technique that is still in the process of evolving."10  However, the concern is precisely that human cloning will evolve into an acceptable technique.

The push to legitimize therapeutic cloning is inextricably tied to the debate over stem cell research. The American Society for Reproductive Medicine reacted with disappointment to passage of the Weldon-Stupak Bill, stating that, "Therapeutic cloning using Somatic Cell Nuclear Transfer will likely be the application that fulfills the promise stem cell research holds for patients."11  Therapeutic cloning is attractive because it may lead to an embryo with the genetic identity of a patient. The cloned embryo would be a source of stem cells that might give tissues that would not be immuno-logically rejected if transplanted into the patient. This would only be possible if the embryo were a clone of the patient. That, by definition, is human cloning.

Arlene Klotzko, a bioethicist and editor of The Cloning Sourcebook, claims that "therapeutic cloning is conceptually distinct from reproductive cloning."12 Such a distinction is not apparent. According to Klotzko, therapeutic cloning is ethical because the intent behind it differs from the intent behind SCNT for reproductive cloning. Intent is certainly important, as clearly articulated by those who defend the use of morphine for pain relief, but not to hasten death. But intent is ethically significant when the means used are ethically neutral or permissible. Good intentions do not whitewash the use of ethically questionable or illegitimate means. Given that these scientists denounce human cloning, consistency would demand that no form of human cloning should be permitted, regardless of intent.

But those opposed to human reproductive cloning do not view human cloning as inherently unethical. They are currently restrained only by pragmatic concerns. A spokesperson for the American Society for Reproductive Medicine holds that once the safety issues are resolved "human reproductive cloning will be permissible."13

These views reflect a purely utilitarian approach to ethics. According to this perspective, reproductive cloning would currently benefit a small number of people, and carry significant safety concerns. The risks outweigh the benefits, so reproductive cloning should be prohibited--at least for now. But with therapeutic cloning, the benefits are huge (so we are told) because stem cell research will (apparently) lead to cures for many diseases. No cloned babies will be born because the cloned embryos will be destroyed during research. The benefits now outweigh the risks, and what is unethical in one situation becomes ethical in another. This approach to ethics neglects the fact that some things are inherent unethical regardless of how good the results might be.

Weighing risks and benefits is important. Reproductive cloning has many risks, which should also raise concerns about therapeutic cloning. To appreciate some of these risks, some further details on the cloning process are needed. The birth of Dolly overthrew the prevailing consensus that cell differentiation could not be reversed. Differentiation is the specialization of cells as an organism develops. The belief was that differentiated cells were genetically locked into functioning in specialized ways. Dolly demonstrated  that this is not always the case.

Every somatic cell contains all the individual's genes. In an embryo, certain genes must be turned on to allow normal embryonic development, and these are later turned off.14  As a cell becomes specialized, particular genes are turned on and others off. As eggs and sperm mature, all their genes are reprogrammed into the "settings" needed in the embryo. This process normally occurs over months or years. However, when an adult somatic nucleus is transferred into an enucleated egg, the reprogramming must occur within minutes or hours. Reprogramming is naturally prone to errors, which become even more likely during cloning.

While sheep, cattle, goats, pigs and mice have now been cloned, the success rate is very low. Generally, between one and five percent of the cloned embryos come to term.15 The Roslin researchers claim they may have been lucky to get Dolly after 277 attempts; they speculated that the birth rate might be as low as one in ten thousand.16 Another cloned sheep born at Roslin shortly after Dolly was subsequently put down due to significant respiratory problems.17 We heard very little about her. Cloned monkey embryos that looked healthy were described as a "gallery of horrors" with their chromosomes scattered all over their cells.18 Additionally, cloned fetuses are often much larger than normal with enlarged placentas necessitating late deliveries by Cesarean section.19 In cloning cows, both late-term fetuses and their surrogate mothers have died.20

Many clones who survive delivery die of respiratory and circulatory problems. Results with cloned mice have indicated that "even apparently healthy cloned animals can have gene expression abnormalities that are not severe enough to impede development to birth but that may cause subtle physiological abnormalities which could be difficult to detect."21 In other words, the effects of being cloned may not become visible until later in the clone's life, or possibly not until offspring are born.22 Concerns have been expressed about Dolly's health, and Wilmut announced in January 2002 that she has arthritis at a very young age and in joints rarely affected in sheep. Some have wondered if Dolly's genes are older than her birth age. One theory about aging is that the end regions of chromosomes (called telomeres) break down with aging. Dolly's telomeres (and those of other, but not all, clones) are shorter than normal.23

The unanswered question is whether stem cells derived from cloned embryos might contain these sorts of "epigenetic" problems. Would they pass these problems to patients through stem cell therapies? Since 95-99 percent of animal embryos formed by SCNT die before birth, the chances of their stem cells carrying genetic risks are high. Mouse research has found reprogramming problems in their stem cells.24Reprogramming must happen even earlier in human embryos (before the eight-cell stage) than sheep embryos, which the Dolly researchers note "may make the cloning of humans more difficult or less successful."25 In the ACT human embryo research, only one embryo reached the six-cell stage, which has led many scientists to question whether these cells were truly embryos (and also why the journal published such weak science).26

Given the recently announced tragedies from implanting human fetal cells into the brains of people with Parkinsonism, caution is needed.27 The dangers may be higher than expected, and the potential benefits exaggerated. The arguments of those opposed to fetal implantation research were drowned out by what has now been called little more than "hype" about the potential benefits of an ethically questionable, experimental treatment.28 With adult stem cell research producing encouraging results, therapeutic cloning should not be carried out with humans.

Human cloning should also be seen as unethical because of the way it depersonalizes human life, what Kass calls, "the transformation of begetting into making, of procreation into manufacture."29 Human lives should never be viewed as means towards some ends, but as ends in themselves. All human lives are made in the image and likeness of God, and should be respected by being nurtured and protected so they can develop into all that God has planned for them.30 The commodification of human life is transparent in those who seek to clone human babies. Panos Zavos, who plans to clone a human baby by the end of 2002, has stated: "We can grade embryos. We can do genetic screening. We can do quality control."31 Ultrasound will be used to monitor further development, presumably followed by abortion for those who fail further tests. How far removed is the approach that deliberately creates human embryos only to destroy them while harvesting their stem cells?

Proponents of therapeutic cloning defend one questionable procedure (human cloning) by promising to carry out another questionable deed: killing human embryos. Kass envisions a realistic problem with this approach.32 What if someone clones an embryo, promising to destroy it in research, but then somehow implants the cloned embryo into a woman? Would she be forced to abort if reproductive cloning were banned? It could be a federal offense to bring the unborn to term! Such an unconscionable situation helps demonstrate that legitimizing therapeutic cloning is both unworkable and unethical.

Daniel Perry, executive director of the Alliance of Aging Research, testified against Weldon-Stupak, stating, "Proposals to criminalize laboratory techniques that otherwise might help us find cures for diseases such as cancer and Alzheimer's would cast a pall over the conduct of academic science."33Research that respects the highest ethical standards puts science on high moral ground. Academic science suffers when the rights of human subjects are neglected, or unnecessary suffering is inflicted on animals. Scientific freedom should not extend to the deliberate creation and destruction of human life, even if their lives are only a few days long. The purposeful cloning of human embryos, solely to subsequently destroy them, would be another dark and gory page in the history of medical research. As Edmund Pellegrino has stated, "The new threat to the human embryo is another example of why biotechnology is a human good only if it is good for humans."34

Underlying this debate is the assumption, rarely made explicit and even more rarely defended, that human embryos are not human persons. Proponents of therapeutic cloning quoted here object to the cloning of "human beings" or "humans," but not human embryos. Klotzko, the bioethicist, even went so far as to define therapeutic cloning as "human cloning that produces embryos, not persons."35 Yet the human embryo is a complete human being who needs only to grow and develop, in spite of what ACT's Michael West claims: "A human life, we know scientifically, begins upwards, even into two weeks, of human development, where this little ball of cells decides, 'I'm going to become one person or I am going to be two persons.' It hasn't decided yet."36 These scientists neglect to make clear that they carry into their scientific discussions value statements about the human embryo. Dr. West gave no experimental details regarding how he discovered scientifically that human embryos make choices about their personhood.

The cloning technique itself is not controversial when used with individual genes or cells. But when a human embryo is cloned, we have human cloning. Some may then ask, "Who is a person?" Jesus was asked, "Who is my neighbor?" His reply avoided abstract philosophical discussions of personhood.37 In the parable of the Good Samaritan (Luke 10:29-37), Jesus took the focus off moral status and addressed the practical issue of what our actions say about us. The Samaritan protected the injured man, brought healing and promoted his well-being. He was more concerned with being a good neighbor than with evaluating the injured man's neighbor-status. He showed mercy. Jesus tells us to do likewise.

Those who bring human embryos into being should act as caretakers, nurturing and protecting these tiny human lives. Killing them is not an act of mercy. Deliberately creating them for destruction is not justified, no matter how good the intentions. We must not submit to the temptation of accepting therapeutic cloning while rejecting reproductive cloning. Therapeutic cloning is unethical, not only because it is human cloning, but also because it sacrifices human embryos on the altar of technological imperialism and a healing-at-all-costs mentality.


1 CNN. Human embryo created through cloning. Accessed at
www.cnn.com/2001/TECH/science/11/25/human.embryo.clone/index. html on November 25, 2001.
2 Cibelli JB, et al. Somatic cell nuclear transfer in humans: pronuclear and early embryonic development. e-biomed: The Journal of Regenerative Medicine 2001;2:25-31.
3 Institute of Medicine. Stem Cells and the Future of Regenerative Medicine. Washington, DC: National Academy Press, 2001. Available at www.nap.edu to read or download.
4 CNN. EU embryo research ban rejected. Accessed on December 14, 2001 at: www.cnn.com/2001/TECH/science/11/29/cloning.eu.
5 Greenwood J, Brownback S. Q: Should Congress use tax dollars to fund therapeutic cloning? Insight 29 October 2001:40-43.
6 Kass LR. Preventing a Brave New World: why we should ban human cloning now. The New Republic 21 May 2001;224:30-39. Available at www.thenewrepublic.com/052101/kass052101_print.html.
7 Jaenisch R, Wilmut I. Don't Clone Humans! Science 2001;291:2552.
8 Klotzko AJ. Voices from Roslin: The creators of Dolly discuss cloning science, ethics, and social responsibility. In: Klotzko AJ (ed.). The Cloning Sourcebook. New York: Oxford University Press, 2001; 24.
9 Borman S. Genomics advances. Chemical & Engineering News. 2001;79:54.
10 Agres T. Cloning capsized? The Scientist 2001;15:1, 18-21.
11 American Society for Reproductive Medicine news release (31 July 2001).
12 Klotzko AJ. In cloning, will one person really make a difference? The Scientist 2001;15:51.
13 Soules MR. Human reproductive cloning: not ready for prime time. Fertility & Sterility 2001;76:232-4.
14 Borman S. Genomics advances. Chemical & Engineering News. 2001;79:43-57.
15 King J. Creating healthy, long-living cloned animals. The Scientist 2001;15:26.
16 Klotzko AJ. Voices from Roslin: The creators of Dolly discuss cloning science, ethics, and social responsibility. In: Klotzko AJ (ed.). The Cloning Sourcebook. New York: Oxford University Press, 2001; 16.
17 Travis J. Dolly was lucky: Scientists warn that cloning is too dangerous for people. Science News 2001;160:250. Accessed at www.sciencenews.org/20011020/bob15.asp on October 23, 2001.
18 Pagan S. Cloned monkey embryos are a "gallery of horrors." New Scientist. Accessed on December 14, 2001 at: www.newscientist.com/news/news.jsp?id=ns99991679.
19 Eggan K, et al. Hybrid vigor, fetal overgrowth, and viability of mice derived by nuclear cloning and tetraploid embryo complementation. Proceedings of the National Academy of Sciences 2001;98:6209-14.
20 Soules MR. Human reproductive cloning: not ready for prime time. Fertility & Sterility 2001;76:232-4.
21 Humphreys D, et al. Epigenetic instability in ES cells and cloned mice. Science 2001;293:95-7.
22 Renard J-P, et al. Lymphoid hypoplasia and somatic cloning. Lancet 1999;353:1489-91.
23 Shiels PG, et al. Analysis of telomere lengths in cloned sheep. Nature 1999;399:316-7.
24 Humphreys D, et al. Epigenetic instability in ES cells and cloned mice. Science 2001;293:95-7.
25 Klotzko AJ. Voices from Roslin: The creators of Dolly discuss cloning science, ethics, and social responsibility. In: Klotzko AJ (ed.). The Cloning Sourcebook. New York: Oxford University Press, 2001; 15.
26 Marshall E, Vogel G. Cloning announcement sparks debate and scientific skepticism. Science 2001;294:1802-1803; Varmus H. The weakness of science for profit. New York Times 4 December 2001.
27 Freed CR, et al. Transplantation of embryonic dopamine neurons for severe Parkinson's disease. NEJM 2001;344:710-9.
28 Caplan A, McGee G. Fetal cell implants: what we learned. Hastings Center Report 2001;31:6.
29 Kass LR. Preventing a Brave New World: why we should ban human cloning now. The New Republic 21 May 2001;224:30-39. Available at www.thenewrepublic.com/052101/kass052101_print.html.
30 O'Mathuna DP. The Bible and abortion: what of the "Image of God"?. In: Kilner JF, Cameron NM, Schiedermayer DL (eds.). Bioethics and the Future of Medicine: A Christian Appraisal. Carlisle, UK: Paternoster, 1995; 199-211.
31 Zavos P. Quoted in: Jaenisch R, Wilmut I. Don't Clone Humans! Science 2001;291:2552.
32 Kass LR. Preventing a Brave New World: why we should ban human cloning now. The New Republic 21 May 2001;224:30-39. Available at www.thenewrepublic.com/052101/kass052101_print.html.
33 Agres T. Cloning capsized? The Scientist 2001;15:1, 18-21.
34 Pellegrino E. Human embryos and the stem cell controversy. NaProEthics Forum 2001;6:2-3.
35 Klotzko AJ. Voices from Roslin: The creators of Dolly discuss cloning science, ethics, and social responsibility. In: Klotzko AJ (ed.). The Cloning Sourcebook. New York: Oxford University Press, 2001; 24.
36 CNN. Human embryo created through cloning. Accessed Nov. 25, 2001 at: www.cnn.com/2001/TECH/science/11/25/human.embryo.clone/index.html.
37 O'Mathuna DP. The Bible and abortion: what of the "Image of God"?. In: Kilner JF, Cameron NM, Schiedermayer DL (eds.). Bioethics and the Future of Medicine: A Christian Appraisal. Carlisle, UK: Paternoster, 1995; 199-211. 20 (c)
2002 Donal P. O'Mathuna & Today's Christian Doctor, CMDA, PO Box 7500, Bristol, TN 37621.