Human Cloning: The Least Interesting Application of Cloning Technology
One of the most powerful methods of applying life’s machinery involves harnessing biology’s own reproductive mechanisms in the form of cloning. Cloning will be a key technology—not for cloning actual humans but for life extension purposes, in the form of “therapeutic cloning.” This process creates new tissues with “young” telomere-extended and DNA-corrected cells to replace without surgery defective tissues or organs.
All responsible ethicists, including myself, consider human cloning at the present time to be unethical. The reasons, however, for me have little to do with the slippery-slope issues of manipulating human life. Rather, the technology today simply does not yet work reliably. The current technique of fusing a cell nucleus from a donor to an egg cell using an electric spark simply causes a high level of genetic errors.57 This is the primary reason that most of the fetuses created by this method do not make it to term. Even those that do make it have genetic defects. Dolly the Sheep developed an obesity problem in adulthood, and the majority of cloned animals produced thus far have had unpredictable health problems.58
Scientists have a number of ideas for perfecting cloning, including alternative ways of fusing the nucleus and egg cell without use of a destructive electrical spark, but until the technology is demonstrably safe, it would be unethical to create a human life with such a high likelihood of severe health problems. There is no doubt that human cloning will occur, and occur soon, driven by all the usual reasons, ranging from its publicity value to its utility as a very weak form of immortality. The methods that are demonstrable in advanced animals will work quite well in humans. Once the technology is perfected in terms of safety, the ethical barriers will be feeble if they exist at all.
Cloning is a significant technology, but the cloning of humans is not its most noteworthy usage. Let’s first address its most valuable applications and then return to its most controversial one.
Why Is Cloning Important? The most immediate use for cloning is improved breeding by offering the ability to directly reproduce an animal with a desirable set of genetic traits. A powerful example is reproducing animals from transgenic embryos (embryos with foreign genes) for pharmaceutical production. A case in point: a promising anticancer treatment is an antiangiogenesis drug called aaATIII, which is produced in the milk of transgenic goats.59
Preserving Endangered Species and Restoring Extinct Ones. Another exciting application is re-creating animals from endangered species. By cryopreserving cells from these species, they never need become extinct. It will eventually be possible to re-create animals from recently extinct species. In 2001 scientists were able to synthesize DNA for the Tasmanian tiger, which had then been extinct for sixty-five years, with the hope of bringing this species back to life.60 As for long-extinct species (for example, dinosaurs), it is highly doubtful that we will find the fully intact DNA required in a single preserved cell (as they did in the movie Jurassic Park). It is likely, however, that we will eventually be able to synthesize the necessary DNA by patching together the information derived from multiple inactive fragments.
Therapeutic Cloning. Perhaps the most valuable emerging application is therapeutic cloning of one’s own organs. By starting with germ-line cells (inherited from the eggs or sperm and passed on to offspring), genetic engineers can trigger differentiation into diverse types of cells. Because differentiation takes place during the prefetal stage (that is, prior to implantation of a fetus), most ethicists believe this process does not raise concerns, although the issue has remained highly contentious.61
Human Somatic-Cell Engineering. This even more promising approach, which bypasses the controversy of using fetal stem cells entirely, is called trans-differentiation; it creates new tissues with a patient’s own DNA by converting one type of cell (such as a skin cell) into another (such as a pancreatic islet cell or a heart cell).62 Scientists from the United States and Norway have recently been successful in reprogramming liver cells into becoming pancreas cells. In another series of experiments, human skin cells were transformed to take on many of the characteristics of immune-system cells and nerve cells.63
Consider the question, What is the difference between a skin cell and any other type of cell in the body? After all, they all have the same DNA. As noted above, the differences are found in protein signaling factors, which include short RNA fragments and peptides, which we are now beginning to understand.64 By manipulating these proteins, we can influence gene expression and trick one type of cell into becoming another.
Perfecting this technology would not only defuse a sensitive ethical and political issue but also offer an ideal solution from a scientific perspective. If you need pancreatic islet cells or kidney tissues—or even a whole new heart—to avoid autoimmune reactions, you would strongly prefer to obtain these with your own DNA rather than the DNA from someone else’s germ-line cells. In addition, this approach uses plentiful skin cells (of the patient) rather than rare and precious stem cells.
Transdifferentiation will directly grow an organ with your genetic makeup. Perhaps most important, the new organ can have its telomeres fully extended to their original youthful length, so that the new organ is effectively young again.65 We can also correct accumulated DNA errors by selecting the appropriate skin cells (that is, ones without DNA errors) prior to transdifferentiation into other types of cells. Using this method an eighty-year-old man could have his heart replaced with the same heart he had when he was, say, twenty-five.
Current treatments for type 1 diabetes require strong antirejection drugs that can have dangerous side effects.66 With somatic-cell engineering, type 1 diabetics will be able to make pancreatic islet cells from their own cells, either from skin cells (transdifferentiation) or from adult stem cells. They would be using their own DNA, and drawing upon a relatively inexhaustible supply of cells, so no antirejection drugs would be required. (But to fully cure type 1 diabetes, we would also have to overcome the patient’s autoimmune disorder, which causes his body to destroy islet cells.)
Even more exciting is the prospect of replacing one’s organs and tissues with their “young” replacements without surgery. Introducing cloned, telomereextended, DNA-corrected cells into an organ will allow them to integrate themselves with the older cells. By repeated treatments of this kind over a period of time, the organ will end up being dominated by the younger cells. We normally replace our own cells on a regular basis anyway, so why not do so with youthful rejuvenated cells rather than telomere-shortened error-filled ones? There’s no reason why we couldn’t repeat this process for every organ and tissue in our body, enabling us to grow progressively younger.
Solving World Hunger. Cloning technologies even offer a possible solution for world hunger: creating meat and other protein sources in a factory without animals by cloning animal muscle tissue. Benefits would include extremely low cost, avoidance of pesticides and hormones that occur in natural meat, greatly reduced environmental impact (compared to factory farming), improved nutritional profile, and no animal suffering. As with therapeutic cloning, we would not be creating the entire animal but rather directly producing the desired animal parts or flesh. Essentially, all of the meat—billions of pounds of it—would be derived from a single animal.
There are other benefits to this process besides ending hunger. By creating meat in this way, it becomes subject to the law of accelerating returns—the exponential improvements in price-performance of information-based technologies over time—and will thus become extremely inexpensive. Even though hunger in the world today is certainly exacerbated by political issues and conflicts, meat could become so inexpensive that it would have a profound effect on the affordability of food.
The advent of animal-less meat will also eliminate animal suffering. The economics of factory farming place a very low priority on the comfort of animals, which are treated as cogs in a machine. The meat produced in this manner, although normal in all other respe
cts, would not be part of an animal with a nervous system, which is generally regarded as a necessary element for suffering to occur, at least in a biological animal. We could use the same approach to produce such animal by-products as leather and fur. Other major advantages would be to eliminate the enormous ecological and environmental damage created by factory farming as well as the risk of prion-based diseases, such as mad-cow disease and its human counterpart, vCJD.67
Human Cloning Revisited. This brings us again to human cloning. I predict that once the technology is perfected, neither the acute dilemmas seen by ethicists nor the profound promise heralded by enthusiasts will predominate. So what if we have genetic twins separated by one or more generations? Cloning is likely to prove to be like other reproductive technologies that were briefly controversial but rapidly accepted. Physical cloning is far different from mental cloning, in which a person’s entire personality, memory, skills, and history will ultimately be downloaded into a different, and most likely more powerful, thinking medium. There’s no issue of philosophical identity with genetic cloning, since such clones would be different people, even more so than conventional twins are today.
If we consider the full concept of cloning, from cell to organisms, its benefits have enormous synergy with the other revolutions occurring in biology as well as in computer technology. As we learn to understand the genome and proteome (the expression of the genome into proteins) of both humans and animals, and as we develop powerful new means of harnessing genetic information, cloning provides the means to replicate animals, organs, and cells. And that has profound implications for the health and well-being of both ourselves and our evolutionary cousins in the animal kingdom.
NED LUDD: If everyone can change their genes, then everyone will choose to be “perfect” in every way, so there’ll be no diversity and excelling will become meaningless.
RAY: Not exactly. Genes are obviously important, but our nature—skills, knowledge, memory, personality—reflects the design information in our genes, as our bodies and brains self-organize through our experience. This is also readily evident in our health. I personally have a genetic disposition to type 2 diabetes, having actually been diagnosed with that disease more than twenty years ago. But I don’t have any indication of diabetes today because I’ve overcome this genetic disposition as a result of reprogramming my biochemistry through lifestyle choices such as nutrition, exercise, and aggressive supplementation. With regard to our brains, we all have various aptitudes, but our actual talents are a function of what we’ve learned, developed, and experienced. Our genes reflect dispositions only. We can see how this works in the development of the brain. The genes describe certain rules and constraints for patterns of interneuronal connections, but the actual connections we have as adults are the result of a self-organizing process based on our learning. The final result—who we are—is deeply influenced by both nature (genes) and nurture (experience).
So when we gain the opportunity to change our genes as adults, we won’t wipe out the influence of our earlier genes. Experiences prior to the gene therapy will have been translated through the pretherapy genes, so one’s character and personality would still be shaped primarily by the original genes. For example, if someone added genes for musical aptitude to his brain through gene therapy, he would not suddenly become a music genius.
NED: Okay, I understand that designer baby boomers can’t get away completely from their predesigner genes, but with designer babies they’ll have the genes and the time to express them.
RAY: The “designer baby” revolution is going to be a very slow one; it won’t be a significant factor in this century. Other revolutions will overtake it. We won’t have the technology for designer babies for another ten to twenty years. To the extent that it is used, it would be adopted gradually, and then it will take those generations another twenty years to reach maturity. By that time, we’re approaching the Singularity, with the real revolution being the predominance of nonbiological intelligence. That will go far beyond the capabilities of any designer genes. The idea of designer babies and baby boomers is just the reprogramming of the information processes in biology. But it’s still biology, with all its profound limitations.
NED: You’re missing something. Biological is what we are. I think most people would agree that being biological is the quintessential attribute of being human.
RAY: That’s certainly true today.
NED: And I plan to keep it that way.
RAY: Well, if you’re speaking for yourself, that’s fine with me. But if you stay biological and don’t reprogram your genes, you won’t be around for very long to influence the debate.
Nanotechnology: The Intersection of Information and the Physical World
The role of the infinitely small is infinitely large.
—LOUIS PASTEUR
But I am not afraid to consider the final question as to whether, ultimately, in the great future, we can arrange the atoms the way we want; the very atoms, all the way down!
—RICHARD FEYNMAN
Nanotechnology has the potential to enhance human performance, to bring sustainable development for materials, water, energy, and food, to protect against unknown bacteria and viruses, and even to diminish the reasons for breaking the peace [by creating universal abundance].
—NATIONAL SCIENCE FOUNDATION NANOTECHNOLOGY REPORT
Nanotechnology promises the tools to rebuild the physical world—our bodies and brains included—molecular fragment by molecular fragment, potentially atom by atom. We are shrinking the key feature size of technology, in accordance with the law of accelerating returns, at the exponential rate of approximately a factor of four per linear dimension per decade.68 At this rate the key feature sizes for most electronic and many mechanical technologies will be in the nanotechnology range—generally considered to be under one hundred nanometers—by the 2020s. (Electronics has already dipped below this threshold, although not yet in three-dimensional structures and not yet self-assembling.) Meanwhile rapid progress has been made, particularly in the last several years, in preparing the conceptual framework and design ideas for the coming age of nanotechnology.
As important as the biotechnology revolution discussed above will be, once its methods are fully mature, limits will be encountered in biology itself. Although biological systems are remarkable in their cleverness, we have also discovered that they are dramatically suboptimal. I’ve mentioned the extremely slow speed of communication in the brain, and as I discuss below (see p. 253), robotic replacements for our red blood cells could be thousands of times more efficient than their biological counterparts.69 Biology will never be able to match what we will be capable of engineering once we fully understand biology’s principles of operation.
The revolution in nanotechnology, however, will ultimately enable us to redesign and rebuild, molecule by molecule, our bodies and brains and the world with which we interact.70 These two revolutions are overlapping, but the full realization of nanotechnology lags behind the biotechnology revolution by about one decade.
Most nanotechnology historians date the conceptual birth of nanotechnology to physicist Richard Feynman’s seminal speech in 1959, “There’s Plenty of Room at the Bottom,” in which he described the inevitability and profound implications of engineering machines at the level of atoms:
The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It would be, in principle, possible . . . for a physicist to synthesize any chemical substance that the chemist writes down. . . . How? Put the atoms down where the chemist says, and so you make the substance. The problems of chemistry and biology can be greatly helped if our ability to see what we are doing, and to do things on an atomic level, is ultimately developed—a development which I think cannot be avoided.71
An even earlier conceptual foundation for nanotechnology was formulated by the information theorist John von Neumann in the early 1950s with his model of a self-replicating
system based on a universal constructor, combined with a universal computer.72 In this proposal the computer runs a program that directs the constructor, which in turn constructs a copy of both the computer (including its self-replication program) and the constructor. At this level of description von Neumann’s proposal is quite abstract—the computer and constructor could be made in a great variety of ways, as well as from diverse materials, and could even be a theoretical mathematical construction. But he took the concept one step further and proposed a “kinematic constructor”: a robot with at least one manipulator (arm) that would build a replica of itself from a “sea of parts” in its midst.73
It was left to Eric Drexler to found the modern field of nanotechnology, with a draft of his landmark Ph.D. thesis in the mid-1980s, in which he essentially combined these two intriguing suggestions. Drexler described a von Neumann kinematic constructor, which for its sea of parts used atoms and molecular fragments, as suggested in Feynman’s speech. Drexler’s vision cut across many disciplinary boundaries and was so far-reaching that no one was daring enough to be his thesis adviser except for my own mentor, Marvin Minsky. Drexler’s dissertation (which became his book Engines of Creation in 1986 and was articulated technically in his 1992 book, Nanosystems) laid out the foundation of nanotechnology and provided the road map still being followed today.74
Drexler’s “molecular assembler” will be able to make almost anything in the world. It has been referred to as a “universal assembler,” but Drexler and other nanotechnology theorists do not use the word “universal” because the products of such a system necessarily have to be subject to the laws of physics and chemistry, so only atomically stable structures would be viable. Furthermore, any specific assembler would be restricted to building products from its sea of parts, although the feasibility of using individual atoms has been shown. Nevertheless, such an assembler could make just about any physical device we would want, including highly efficient computers and subsystems for other assemblers.