There is a quiet revolution going on in the world of cloning. Very few have heard of it, but its potential power is astonishing. Imagine a radical new way to clone that can not only create exact carbon copies of adults, but also allows the generation of important genetic improvements. Another you, but smarter, healthier, and maybe a bit better looking.
The birth of Dolly the sheep fifteen years ago shocked the world. We learned it is possible to replace the genes of an egg with those from an adult, and in a few cases the egg would proceed to make a viable clone, like Dolly. And the debates began! Should we allow human cloning? Was this a useful new reproductive option for childless couples? Or was it a crime against nature? Would clones have a soul? Were we moving towards a Brave New World future, with armies of clones fighting our wars and working in our factories?
The gene replacement technology used to make Dolly, however, was severely flawed. Only about one in a hundred eggs with genes from an adult survives. This procedure clearly should not be applied to people. For every birth there would be 99 aborted monstrosities, and even the rare clones surviving to birth are not really normal when examined carefully.
But recently we’ve seen a perfect storm of incredible advances in biology that changes everything. It is now possible to take adult cells, from the skin for example, and to transform them into stem cells, which can then be converted into complete individuals. It works quite well for mice, and there is every reason to think it would also work for humans.
How is this cloning through stem cells accomplished? The breakthrough was Shinya Yamanaka’s discovery that it is possible to treat adult cells with a special gene expression cocktail that turns them into the functional equivalent of embryonic stem cells. Stem cells, as the name suggests, are able to branch in many different developmental directions, to give rise to heart, nerve, liver, or other cell types. In the field of medicine, this is like the ancient alchemist somehow succeeding in turning lead into gold. Stem cells offer great promise in the regeneration and repair of diseased or damaged organs. Historically, the most powerful stem cells – those able to give rise to all of the different cell types of the body – were made from embryos. Hence the ethical controversy, since it was necessary to kill human embryos to make embryonic stem cells.
Adult derived stem cells made by the Yamanaka procedure, however, are as powerful as those made from embryos. They too can give rise to all of the cell types of the body. Indeed, it is possible to take adult derived mouse stem cells, grown in a plastic dish in the laboratory, and to turn them into complete mice. The controversy over human embryonic stem cells should now be officially over because we can make equally potent stem cells from adults, without sacrificing embryos.
Stem cell cloning, however, opens a Pandora’s box of possibilities. It is much more efficient than the gene replacement approach used to make Dolly. In addition, stem cells are extremely genetically malleable. Nobel prize winning genetic engineering technology works very well with them. It is therefore now feasible to clone not only exact copies, but also improved versions of people.
With the technical objections rapidly fading, it is now time to revisit the ethical issues of cloning. First, is it morally wrong to have multiple people with the same, or nearly the same, genes? Of course identical twins, triplets, quadruplets, and so on have long existed as a product of nature. But there are some differences between clones and twins. Twins are the same age, while a clone would be younger than its single parent. In addition, there is a limit on the number of genetically identical individuals that can be made by natural reproduction, but in theory a hundred or more clones could be made from one person. It makes most of us uncomfortable to think that a wealthy person could now make many young copies of him or herself.
Another issue is procreation without sex. Some people find the laboratory creation of human offspring repugnant, thinking it degrades and cheapens the process of reproduction. Are we heading towards a shopping catalog selection of our children? Nevertheless, the current methods of in vitro fertilization involve mixing eggs and sperm in the test tube, thereby creating human embryos for otherwise infertile couples. About one percent of all births in the U.S. are now the result of in vitro fertilization. Cloning technology is similar in principle, but using only one parent to make embryos instead of two. Does that difference make it morally wrong?
Our science and technology are marching forward at an ever accelerating pace. The topic could not be more important. We are talking about the nature of our children, and in the long run, our species. Genetic enhancement could lead to improved intelligence, and exceptionally long and healthy lives. Or a hellish dystopia. We must move into the future with great care.
About the Author: Steve Potter is a Professor of Pediatrics, in the Division of Developmental Biology, at Children’s Hospital Medical Center in Cincinnati. He is the author of Designer Genes: A New Era in the Evolution of Man, published by Random House, 2010. In addition he has written over one hundred science papers, and co-authored the third edition of the medical school textbook, Larsen’s Human Embryology.
Eveloce: A term coined in Designer Genes: A New Era in the Evolution of Man. It refers to self accelerating evolution. For example, in the not too distant future people will be able to genetically engineer offspring with increased intelligence, who in turn will be better equipped to make offspring that are still smarter. It is easy to see how this kind of evolution could go explosive.
There are incorrect information in this article.
It is not necessarily to kill an embryo to obtain embryonic cells. Only the the inner cell mass will develop into a fetus. The out cells layers are also embryonic cells some of which will perish and others become part of the placenta. These can be used for cloning.
In addition, cloning means identical. Therefore, the clones cannot be more or less intelligent than the stem cell made from somatic cells of an individual from which the clones originate.
It is possible however that genetic enhancement (?? meaning) can be done by inserting or deleting genes from the stem cells, in theory.
I believe we leave human cloning alone. But, clone animals who can help to improve human health such as for medicinal uses. That is Eveloce for non-human only.
Yes, it really is necessary to kill an embryo in order to derive embryonic stem cells. Otherwise there would be no ethical controversy. Only the inner cell mass cells, which would make the person, can give rise to embryonic stem cells. Of course any cell can be used for the nuclear transfer type of cloning used to make Dolly. Unfortunately Mr. Lee is confusing this process with the production of embryonic stem cells.
Second, Mr. Lee states that clones are exact copies, and hence cannot be more intelligent than the individual they are derived from. But in the blog I state that we are talking about not making exact carbon copies, but versions with significant improvements. I think this is clear enough.
I really appreciate free, succcint, reliable data like this.
Thanks for this. I’m going to get your book.
So. How do we proceed? The genetic enhancement gurus tell us all we need is to make sure we really understand what we’re doing–that the only problems are technical and the ethicists are just wringing their hands. But history shows us that the scientists *always* believe that now, at last, they understand the biology well enough to proceed with a program of human engineering. Charles Davenport believed it. HJ Muller believed it. Jim Watson believed it. Craig Venter believes it. Medical genetics has always been about two things: relief of suffering and human improvement.
So far, it has always turned out that it’s more complicated than we think–it’s easy to over-hype the technology and underestimate the “unknown unknowns.” We are still probably some distance from the kinds of marquis genetic enhancements you discuss, but they are clearly getting closer, and the future has a way of sneaking up on one.
I’m interested in your take, as a pediatrician, on where the medical begins and ends. Since the beginning of the last century, preventive medicine advocates have been promoting a science of health rather than a science of disease.
Should these new technologies be the province of doctors? If so, are doctors equipped to tease out the ethical tangles you raise? Or will they inevitably end up in the sticky hands of entrepreneurs more interested in their own wealth than the public good? Or, possibly worse, in the hands of a short-sighted public that drives large segments of the population rapidly into evolutionary debacles, for the sake of some momentarily fashionable trait?