The Limits of Cloning
Ian Wilmut, professor at the Roslin Institute in Scotland, is the father of Dolly, the cloned sheep. Dr. Wilmut spoke with NPQ editor Nathan Gardels in Switzerland in 1999.
Davos--It is unfortunate that so much of the public attention concerning cloning has been concentrated on the idea of copying people, which I do not favor for any reason at all. Some of the hype has been just crazy: copying dictators like Saddam Hussein, or armies of bad guys, or the opposite--clones of saints like Mother Teresa.
If the clone of Saddam was brought up by Saddam, he would no doubt, like most of the rest of us, revolt against his father and be a good guy. This kind of thing just isn't going to happen.
Cloning technology will mainly be useful as a way to treat human diseases by producing proteins, by producing organs from animals which can be transplanted into human patients and by producing new human cells that can replace damaged cells.
Once the genomes of humans and certain animals are identified and located, we will be able to know which regions of DNA cause heart disease, stroke or cancer. Targeted drugs and genetic modification--along with lifestyle changes--will enable us then to reduce these risks.
To take but one example, by cloning sheep that carry the extra gene that encodes the production of a protein which causes clotting in human blood, we can mass produce those proteins for clinical use for hemophiliacs or during surgery. Other proteins with other functions can also be made in the same way.
Cloning can also be used to reproduce animal organs like hearts and kidneys for transplant into human patients. This is a pressing issue because 200,000 people die each year before an organ becomes available from a donor.
Pigs are the most likely animals to clone organs from, though with today's technology those organs are normally destroyed when implanted because they are rejected by the human immunological response. In the future, however, I'm sure we will be able to change this situation by genetically modifying what it is in the pig's genes that set off the human reaction. With ever greater knowledge of the genetic blueprints of pigs and humans, we will be able, as it were, to close the gap of differences between species that makes transplants problematic.
The most controversial issue today is the idea of producing human cells to treat disease. This is very promising because diseases like Parkinson's, Type One Diabetes or AIDS involve cells that cannot repair or replace themselves when damaged.
The idea is controversial because the only way you can do this at present is to produce a human embryo from which you could then derive "stem cells" in a tissue culture dish in the lab. Embryonic stem cells retain the ability to differentiate into all the various tissues of the human body. If the new cells taken from the embryo, such as the eyelet cells of diabetes, are then transplanted into the person with the disease to replace damaged cells, there would be no immune reaction because the cells are immunologically the same.
The controversial point is whether that embryo is a human being, or only a ball of cells with human potential.
The "embryo" would comprise about 250 cells, but with almost no differentiation into cells with specific functions. At that stage of growth there is no evidence of a nervous system that could register pain or any other way in which that embryo could be conscious or aware.
In this important sense, the embryo is not a "person." It is only a potential person.
To me, using that embryo as the basis for developing differentiated cells in a tissue culture dish is no different than transplanting the organs of a dead person into a living one. Most people are now comfortable with that.
NPQ | Among those not comfortable with organ transplants, and thus cloning of cells, are the Japanese. Echoing the traces of Shintoism still present in Japanese culture, the belief is that the soul and being exist not only in the nervous system and the brain, as Western science sees it, but in all things, from trees to stones to kidneys. Pope John Paul II also opposes cloning because it breaks the "unified totality" of the person that comes from the link between sexuality and procreation. Some Muslims accept using stem cells if done before the soul (ruh) enters the embryo 40 days after it begins to grow.
Can there be global standards that govern genetic modification of species?
Ian Wilmut | I fully understand that cloning cells, like organ transplants, is offensive to some like the Japanese.
Ultimately, society has to decide if we go this path or not. The scientists, the companies and the patients are too closely involved, too self-interested, to make the proper decision.
The United Kingdom has been well-served by the Special Commission on Human Fertilization and Embryology which recommended an authority be set up to regulate everything done with the human embryo and assisted reproduction.
That commission was chaired by a philosopher and included a theologian, a developmental biologist and lay people.
The authority also must take into account public opinion. A recent survey showed a large majority of the UK was against copying people; a small majority favored producing embryos from which cells could be grown.
Obviously, the United States, disposed to a greater degree of individual freedom and responsibility than in Europe, is less disposed to regulate cloning. I hope this is a passing aberration.
After all, through the Federal Drug Administration, irresponsible companies are prevented from selling preparations laced with alcohol. And adoption--a practice far less intrusive on family and child life than cloning--is strongly regulated in the US.
NO MINI-ME | There are three reasons usually given for producing children who are copies of an existing person--to treat infertility, to replace a lost child and selective breeding. Though I at least understand the motivation of the first two reasons, the third escapes me completely.
For a variety of reasons, an ordinary heterosexual couple may not be able to have children, even with the current treatments for infertility. As sad as that may be, will cloning really give them what they seek?
You have to look at the family. What would have happened, let's say 20 years ago, if my wife and I had discovered we were infertile and, through cloning, had produced a replica of me? Certainly, the person born would have been genetically identical to me, but born at a different time and to a different mother. Physically, he would look just like me because the genetic control of physical development is fairly tight.
But personality is only partly determined by genes. It is also determined by environment--being and circumstance as the philosophers say. It is probably half and half.
How would my wife respond, in time, to a teenager who looks exactly like I did when she met me? How would I react?
We know that parents impose limits and expectations on their children as it is. Wouldn't I be even more domineering toward an exact copy of myself? Or, perhaps, completely disengaged because I couldn't emotionally handle reliving my teens?
Also, by the time the child was 20, he would be able to look at his 55-year-old father and know exactly what he would look like 35 years hence. And how would my replica cope when he saw his father die of a specific gene-related disease? In short, how will a cloned child cope with knowing his future before it unfolds?
I, for one, would not produce a child that would have to live under these circumstances.
Then there are those parents who have lost a child and want him or her back. Unless you have lost a child, you cannot imagine the horror. But to try to replace that child is a big illusion. In the first place, you would have to be absolutely certain that the natural child did not die from any genetically related disease--or was genetically disposed to a disease that had not yet manifested itself.
What you will get is a genetically identical copy, but lots of emotional trauma. What happens when the clone becomes older than the child that died? How will you deal with that? If that natural child was musically or athletically talented, inevitably parents will expect the cloned child to be the same. But did the natural child die before his personality was fully formed, in which case it wouldn't be known how he ultimately turned out?
In the end, I suspect it is easier to say no to everybody who wants to clone a child for this purpose rather than to try to draw a hypothetical point at which personality develops.
My wife and I have two daughters and would have liked to have a son. But we achieved that through a very old-fashioned technology, adoption.
Finally, I do not understand the motivation of selective breeding. I know, of course, that out in California there are sperm banks supposedly full of the genes of brilliant and beautiful people so that copies can be made of great philosophers and movie stars. That is totally unacceptable and an abuse of science.
NPQ | In history, where there is a will and a means, there is always a way. Someone, surely, will ultimately clone a human. The technology is nearly there, the money is there and the culture is obsessed with health and longevity.
Wilmut | The technology being "nearly there" is not good enough. It is not widely understood that a significant proportion of animals produced by cloning die soon after birth. Many fetuses never make it to the full term of the pregnancy. That is about 10 times higher than normal birth and reproduction.
It is awful if you think about it. Even so, if you left it to desperate couples who want children, they would take the chance. I think they shouldn't be allowed to. If the cloned child died, it might be a blessing. We don't know yet what deformity or problems it might have had in the future. We just don't yet have enough experimental data on sheep, let alone humans.
NPQ | What are the dangers of using cloned organs from animals? One fear is that using pig organs, for example, may transmit viruses the human immune system cannot handle.
Wilmut | Cloning technology will be used to produce proteins that are put into patients, organs from pigs into patients and, perhaps, human cells into patients. The question is what do we need to know about the proteins, organs or cells before we implant them?
Perhaps they will cause an increased risk of cancer? Some pig diseases, caused by damage to their genes at some point in their evolution, lay dormant in the pig. But might they quicken inside the human body?
We just don't know. Current tests that involve passing human blood through pig tissue show, so far, no evidence of viral release.
I think society, generally, should demand that we are cautious in the way in which we use these new technologies. Before anything is tried on humans, there needs to be very ambitious research.
Only after years of open use where it affected the public, for example, did we learn that the pesticide DDT would cause cancer.
NPQ | To be cautious, some propose adopting the "irreversibility principle"--don't do anything to the human gene pool that cannot be reversed and therefore itself becomes part of the genome.
Wilmut | I would not agree to that. If it were possible to eliminate Huntington's disease or cystic fibrosis from the germ line by changing the human genetic code, then I would do it. But that would only be because we have absolute knowledge of the genes that cause those abnormalities.
But would I intervene to increase intelligence, for example? I would be more restrictive here because one simply cannot know the effect on the child of making such a genetic change. We should not experiment on children.
NPQ | In 100 years, will we have enough knowledge of DNA to know what each gene does, and thus be more confident in our manipulation of the genetic code of our own species?
Wilmut | How do we know what genes do? We experiment on animals. In a hundred years, therefore, we may know a lot about animal models, but not so much more about human traits, which are far more complex. If we play around with those human genes about which we do not have absolute knowledge, who knows the effects?
Fifteen years ago I discussed with colleagues doing genetic experiments with animals. We all had a very naïve optimism. Now, with the cloning of Dolly, some of that imagination has materialized positively--but some didn't.
I was horrified to recently hear colleagues talking about children exactly the same way we talked about animals 15 years ago. You certainly have to be careful about animals, but you have to be far more careful about what you are doing to a person.