- Prayer and Worship
- Beliefs and Teachings
- Issues and Action
- Catholic Giving
- About USCCB
Cloning is a way of producing a genetically identical organism without sexual reproduction. The method commonly employed is called "somatic cell nuclear transfer." The nucleus of a body cell ("somatic cell," in contrast to a sperm or egg cell) is transferred into an unfertilized egg whose nucleus has been removed or made inactive. An electric pulse is used to stimulate development of the resulting embryo.
There are several sources of embryos for human embryonic stem cell research: "left over" embryos from IVF clinics, embryos newly created for research by IVF (combining a human egg and sperm in a petri dish), and embryos newly created by cloning--combining the nucleus of a human somatic cell with the enucleated egg of a cow or pig or human.
Proponents of these experiments have come up with ingenious marketing terms to distinguish their work from that of the Raelians et al. When the resulting embryo is transferred into the womb of a mother, as with IVF technology, and carried to birth, they call this "reproductive" cloning. When the embryo is created in order to be killed for his or her stem cells after developing for 5-7 days, they call this "therapeutic" cloning. The stem cells may be transplanted directly into the cell donor's body, or they may first be tweaked with growth factor or other substances to cause them to differentiate in vitro and grow into the type of tissue desired. These terms guide and distort the moral debate. Restricting the term "reproductive" cloning to cases of live birth obscures the fact that one "reproduces" whenever one creates a new human life, even by a bizarre laboratory procedure. "Therapeutic" cloning is really just the opposite, because it involves nontherapeutic experiments on a defenseless human being–that is, experiments that harm and kill that human solely for the benefit of others.
Why Biotech Firms are Involved in Human Cloning
Some companies want to clone embryos so they can perfect the procedure and eventually produce live-born children by cloning. The procedure could then be offered to infertile couples, people who want to copy themselves, etc. Other researchers are more interested in the cloned embryos themselves. The ability to produce large numbers of identical embryos by cloning may make it easier, for example, to test the effect of different stimuli or toxic drugs on human development.
Cloning could produce an unlimited supply of human "guinea pigs" for controlled experiments, dissection to produce cell lines, and so on. Others, of course, clone human embryos solely to harvest their stem cells for research into treatments for diseases such as Alzheimer's, Parkinson's, diabetes or spinal cord injury. They call this "therapeutic cloning" because they hope treatments will eventually come from this–and they want to avoid the fact that here and now it involves a lot of killing. They also downplay the fact that the most promising advances in stem cell research today use stem cells from adult tissue, umbilical cord blood and placentas–not from killing embryos. (See the latest news on these advances at www.stemcellresearch.org.)
State of the Art in Cloning
Christians should readily understand why creating human embryos for research, subjecting them to risk, and then destroying them is morally wrong. Many Christians, how-ever, fail to see the wrong in creating a child for an infertile couple through IVF. Catholic teaching sees IVF as violating the integrity of marriage because new life issues from a laboratory procedure instead of from the loving union of husband and wife. But even believers who do not appreciate this truth object to IVF when they learn that for every embryo brought to birth, nine others end up discarded or destroyed. Many IVF clinics freeze embryos, experiment on them, or practice selective abortion ("reduction") when more embryos implant in the womb than expected.
The track record with cloning in animals is far worse. "Dolly's creators started with 277 reconstructed eggs. The 29 that appeared to develop normally were implanted in 13 sheep" (Ross, "The issue of human cloning is born," The Washington Times, Aug. 14, 2000). Only Dolly survived.
Rudolf Jaenishch, Ph.D., a professor of biology at M.I.T., summarized the extent of cloning failures in his March 28 House testimony:
"To date, five mammalian species (sheep, mice, goats, cows and pigs) have been cloned, however, survival of the nuclear clones has been uniformly low. The great majority of clones ... die either at various stages of embryonic development, at birth, or soon after birth. Most newborn clones are overweight and have an increased and dysfunc-tional placenta. Those that survive the immediate perinatal period may die within days or weeks after birth with defects such as kidney or brain abnormalities, or with a defective immune system. Even apparently healthy adult clones may have subtle defects that cannot be recognized in the animal.
"The most likely cause of abnormal clone development is faulty reprogramming of the genome. This may lead to abnormal gene expression of any of the 30,000 genes residing in the animal.
"Faulty reprogramming does not lead to chromosomal or genetic alterations of the genome, so methods that are used in routine prenatal screening ... cannot detect these reprogramming errors. There are no methods available now or in the foreseeable future to assess whether the genome of a cloned embryo has been correctly reprogrammed.
"The experience with animal cloning allows us to predict with a high degree of confidence that few cloned humans will survive to birth and of those, the majority will be abnormal." (For a more detailed discussion, see article by Jaenishch and Wilmut in Science, March 30, 2001.)
How does Panos Zavos respond to the mountain of evidence that virtually all clones end up miscarried or malformed? He explained to the "60 Minutes" audience that his collaboration with Antinori will be different: "We're going to do it the right way to get there. We don't intend to step on dead bodies. We'll do regular autopsies on the human embryos and screen out the ones that are not developing normally." Well, that's a relief! They'll kill them, but won't go so far as to step on their dead bodies.
Of course, Dr. Zavos' cavalier attitude toward developing life is not the biggest threat here. To Dr. West, Dr. Okarma and others, the problem of a 99%+ death rate can be solved by making sure it rises to 100%–cloning human embryos only for research that will destroy them. In some circles today, that qualifies as ethically responsible science.
The Law on Cloning
Several years ago, when cloning was last in the headlines, President Clinton assured the American public that he was opposed to cloning humans and ordered a five-year moratorium, as recommended by the National Bioethics Advisory Commission (NBAC). But this moratorium was all talk and no substance. For one thing, it was voluntary. More importantly, it covered only the use of cloning to produce a "child," by which Clinton and NBAC meant live-born child. Thus it still allows unlimited cloning to produce human embryos, so long as the embryos are then destroyed. Such experiments can be used to refine the procedure and test its likelihood of causing birth defects. After years ofdestructive experiments, the ban on allowing live birth can be reconsidered. Instead of being a ban on cloning, the moratorium amounts to a permission slip for experimenting on embryos and a mandate for destroying them.
Some foreign countries have banned human cloning, but typically "reproductive" cloning only. Some states, like California and Rhode Island, have taken that approach, while newer laws in Michigan and Virginia offer a real ban on creating new human beings by cloning. A bill introduced in 1998 by Senators Kennedy and Feinstein to prohibit transferring a cloned human embryo to "a woman's uterus" would allow researchers to clone embryos and experiment on them without limit. The law would be violated only if they failed to throw away the embryos afterwards.
Pro-life Senators (Bond, Frist and Lott) introduced a well-crafted bill that would actually ban the use of cloning to produce human embryos, instead of banning live birth for embryos already produced by cloning. The bill died under intense lobbying pressure from the biotech industry and its supporters in academia. These groups confused the debate greatly with false claims that a true human cloning ban would cut off promising areas of research involving the production of animals other than humans, molecules, and cells and tissues other than human.
Now that Congress's interest in cloning has revived we can expect to see a renewed debate on what it means to "ban" human cloning. Will we try to prevent scientists from creating humans by cloning, or only try to kill the resulting clones?
By accepting this message, you will be leaving the website of the
United States Conference of Catholic Bishops. This link is provided
solely for the user's convenience. By providing this link, the United
States Conference of Catholic Bishops assumes no responsibility for,
nor does it necessarily endorse, the website, its content, or