Note: Please read The Little Lamb That Made a Monkey of Us All for the author's comments on the news of a successful lamb cloning (March 7, 1997). Also, please read the author's subsequent article Can Humans Be Cloned like Sheep? for an updated, expanded discussion.
In one respect, I sympathize with the scientists involved who naively felt their work was nothing unusual and who suddenly found themselves the subjects of New York Times and Time magazine cover stories as well as the special guests on "Good Morning America," "Nightline," and "Larry King Live." The spotlight did not suit them very well. Some aspects of the media hoopla were drastically overplayed, but other concerns are very real. What did the research actually accomplish?
Stillman and Hall, rather than cloning humans, actually just performed the first artificial twinning using human embryos. A similar procedure has been performed in mice successfully for twenty years and in cattle for ten years. Identical twins are produced when a fertilized egg divides for the first time and instead of remaining as one organism, actually splits into two independent cells. Stillman and Hall were able to achieve this same effect by removing the protective layer around the developing embryo (zona pellucida), splitting the cells apart, and replacing the outer coating with an artificial shell.
Essentially, this raises the possibility of creating as many as eight identical embryos where there was once only a single embryo consisting of eight cells. The procedure was pursued in order to assist couples seeking in vitro fertilization. Many women are unable to produce multiple eggs. Once fertilized, the resulting embryos only implant 10-20% of the time. Therefore, if you have 2 to 8 identical embryos, all formed from one original embryo, you can implant one and freeze the rest. If the first implant is unsuccessful, you can thaw one of the frozen twins and try again.
To call this cloning, as the media have done, is a bit misleading. The more usual meaning of cloning an individual would be to take a cell from an adult individual, remove the nucleus, implant it in a fertilized egg that has had its nucleus removed. Strictly speaking, this is not possible today. The feat was accomplished in frogs back in 1952 by taking the nuclei of cells from the intestinal lining of tadpoles and implanting them into fertilized eggs that had the nuclei destroyed by irradiation. However, only about one in a thousand implants are successful. Many of the frogs die early but others grow into rather grotesque monsters. No, true cloning is a long way away indeed.
So if true cloning has not actually been achieved, then is there any real cause for concern? Indeed, there is!
The initial outcry concerning the work of researchers Stillman and Hall at George Washington University has come from the public and the media. But many of their own colleagues are upset.
Many within the field have recognized for quite some time that artificial twinning would be possible with human embryos. But they knew that such experiments would raise a host of ethical concerns that they were unwilling to deal with. It is unfortunate that Stillman and Hall were so unprepared for the controversy because it just reinforces the idea many of us have that all scientists are blind to the ethical ramifications of their work. It is clear from interviews that Stillman and Hall care deeply, but just didn't think ahead.
Jerry Hall was asked in the Time magazine article (8 November 1993, p. 67) if he feared that his work would create a public backlash towards this kind of research. He said: "I respect people's concerns and feelings. But we have not created human life or destroyed human life in this experiment." What this statement implies is that Hall and Stillman do not consider the embryos they were working with as human life. The embryos used in this research project were doomed from the start because they were fertilized with more than one sperm. The extra genetic material precludes the possibility of normal embryonic development. But does this mean that these embryos are not human?
Many individuals carry a death sentence because of congenital conditions or genetic disease, but they are certainly human. We will all die eventually. The timetable is not important. I believe that these embryos were human beings and further experimentation was performed on them which added an additional risk to their already imperiled condition. If I had been a member of the ethical review board of George Washington University, I would have denied permission to pursue these experiments. Human experimentation was performed without informed consent.
Hall and Stillman have defended their work by saying they consider it only a logical extension of in vitro fertilization. These efforts are driven by a desire to relieve human suffering--in this case the suffering of infertile couples. I know of many couples who have battled infertility, and I know that their pain is real and deeply rooted. But I also believe that this is a case where our desire to live in a painless world is clouding our ability to make moral decisions. One woman who had undergone eight unsuccessful in vitro attempts was asked if she would be willing to try artificial twinning. She said: "It's pretty scary, but I would probably consider it as a desperate last attempt." She is clearly frightened by the moral and ethical implications, yet if nothing else worked, she'd do it! Our decisions are based more on the tug of our hearts and pocketbooks than with our minds. We are losing our moral will! The whole subject is rife with potential abuses by people on all sides of the issue.
While artificial twinning itself raises some serious ethical questions, other possible scenarios that this research can lead to are just as troubling.
The two researchers involved have remarked that they felt their research was just the next logical step after in vitro fertilization. One of the warnings of Kerby Anderson, a familiar voice on the Probe radio program, in his book Genetic Engineering over ten years ago, was the argument of the slippery slope. Once a new technology is perfected, it opens up other technologies which are more troublesome than the original. Once started down the slope, it is hard to reverse directions. Hall and Stillman, by their own admission, have taken the next step down the slippery slope after in vitro fertilization. It is now important to assess the next step.
There are several scenarios which have received attention. One concerns couples who are known to be at risk for a hereditary disease such as cystic fibrosis. If from a single fertilized egg, two to four identical embryos could be created by the artificial twinning process, then one could be tested for the genetic marker, and the others held in frozen storage. The genetic testing may require the destruction of the initial embryo. If the test is negative, then one of the reserve embryos could be thawed, implant- ed, and brought to term. This process is hardly respectful of human life. If the test confirms the presence of the genetic disease, all embryos could be destroyed.
Another suggestion is that the artificial twins could be kept frozen as an insurance policy even after the original child is born. If the original child dies at an early age, a frozen twin could be thawed, and the parent would have the identical child to raise again. Another suggestion has been to keep the frozen twins available in case the original twin needs a bone marrow transplant or some other organ. The tissues would match perfectly. A couple in California has already set a precedent by electing to have another child to provide bone marrow for their older daughter that had contracted leukemia. Fortunately for them, the tissues matched and both children are doing fine.
A final scenario suggests that frozen twins can be kept in reserve as the saleable stock for children catalogs. A catalog could be set up offering pictures and descriptions of the original twin and offering prospective parents the opportunity to have the very same child. This may sound foolish to you, but there are many in our society who would be willing to pay for just such a service. If you truly respect human life, then none of these possibilities should make sense. In light of what we have discussed, the subject of placing limits on scientific research also needs to be addressed.
One of the questions that inevitably comes up is whether such research should be allowed to be done at all. Some of the scenarios I mentioned earlier are chilling. We wonder if such things can be stopped by restricting the kinds of research that is done.
I have to admit that as a scientist myself, I am wary of giving the public a free voice to approve or disapprove what kinds of research are pursued by qualified scientists. Scientists themselves are usually the best judges of whether a particular project is worth doing on its scientific merits. Only other scientists can judge the worthiness of a research proposal based solely on its ability to contribute significantly to our body of scientific knowledge. In a society deeply rooted in the Judeo-Christian heritage, scientists could generally be trusted to make the correct moral decisions about their research as well. But this is not the case in our society today. We are a culture which is without a moral rudder. There is indeed a culture war going on. One of the consequences of this lack of direction is that many scientists and ethicists believe that scientists should be free to pursue their research goals regardless of what the long-term consequences might be.
John Robertson is a professor of law at the University of Texas. In a recent editorial, he said:
As long as the research is for a valid scientific purpose, embryos that would otherwise be discarded can, with the informed consent of the couple whose eggs and sperm produced the embryos, be ethically used in research. Neither the lack of guidelines, the moral objections of some people to any embryo research, nor the fears about where cloning research might lead justify denying researchers the ability to take the next step. (Chronicle of Higher Education, 24 November 1993, p. A40)
Essentially Professor Robertson has insulated himself from any criticism from outside the scientific community. As long as informed consent can be obtained from the parents, the sole criteria is a valid scientific purpose. Questions concerning the sanctity of human life are not allowed. Questions concerning the potential abuses are not allowed. In other words, scientists exist in some kind of a moral vacuum.
I am afraid that this kind of research is going to continue simply because there is not a large enough moral consensus present in society to prevent it. We have become too powerfully driven by the personal end in mind to repudiate the means to get there. Do we raise our voices in protest? Certainly. Do we continue to point out the moral and logical fallacies in the prevailing arguments? Certainly. But until the culture at large turns its attention from the immediate gain and considers what is right, the ethical slide will continue.
Moreover, there is the even more questionable and fear-provoking question of whether true human cloning is feasible.
True cloning, as opposed to artificial twinning, is much more involved. Cloning is a technique that is partly successful in frogs. Frogs can be cloned by collecting eggs from a female frog. The nucleus in the eggs is destroyed by irradiation. Next, cells are isolated from the intestinal lining of a tadpole. The nucleus is removed from the intestinal cell and placed within a previously enucleated egg. The egg now has the opportunity to begin cell division and development.
Most of these embryos do not survive. Of those that do survive, the majority grow into rather grotesque monsters. Only about one in a thousand develop into a normal looking adult frog. One small catch is that all of these normal looking frogs turn out to be sterile. Even so, this is a remarkable achievement. But is this possible in humans, and if so, what are the barriers.
The first item to note is that the frog experiments utilized nuclei from a developing tadpole. Embryonic tissue is still actively dividing. Using a nucleus from a dividing cell is crucial to the success of these experiments. Non-dividing cells such as adult bone and neural cells have had the cell division portions of their genes turned off by a variety of molecular mechanisms. That is why the use of most adult cells would be impossible in these experiments. They wouldn't work. It also explains why DNA from long dead cells such as from a mummy, or even a dinosaur as in Jurassic Park is totally impractical.
Some cells in the adult body are actively dividing, such as skin fibroblasts. These cells continually supply new skin cells to replace those which sluff off. In fact it was skin fibroblasts that were purportedly used for cloning a man in David Rorvik's fictional book, In His Image: The Cloning of a Man, back in the late seventies. But there are difficulties here too. Skin cells have had many genes switched off. These are skin cells, not liver cells, or eye cells, or bone cells. All of the genes needed to produce the unique proteins required by all these specialized cells have been switched off by a variety of molecular mechanisms. Many of these mechanisms are unknown; consequently, we do not know how to unlock them. Nor do we know how to get them expressed in the correct sequence necessary for embryological development.
There are so many roadblocks to the successful cloning of an adult human that I don't expect it any time soon. However, I am afraid our current culture will pursue this possibility as long as there is potential profit and a perceived scientific benefit.
© 1994 Probe Ministries International