Andrew Brown for Scott Rosenberg
I went to school with a clone thirty years ago, and you may well have done so too. The experience was not a memorable one: in those days they were only ever called "identical twins" —but they are completely identical genetically, whereas it is a curious fact that artificially produced clones are not genetically identical, since they do not quite share all their DNA: a few genes (about 60 out of 100,000) come from the host cell into which the nucleus to be cloned is placed. But how much does genetic identity matter? We have no difficulty in recognising identical twins as separate and distinct people: even when we cannot always tell which is which we know the distinction between them matter. Genetic identity is not personal identity, as the story of Time and Terry Twomey shows.
In 1977, Tim Twomey, a Sacramento policeman who had lost his testicles in an unfortunate developmental accident in the womb, received a testicle transplant from his identical twin brother, so that he could impregnate his wife (also a police officer, though this detail is not strictly relevant.). In 1980, Tim and his wife duly had a son, named with a worrying lack of irony Christopher Gene.
Christopher Gene’s parental genes are exactly the same as they would have been if his father had not been equipped with his brother’s spare testicle, since his father and his uncle are genetically identical. But it must have been clear to all parties in the story at every moment which distinct brother had which testicle, even though it would be impossible to tell this by genetic analysis.
It is considerations like this which go some way to explaining why the scientific world was less shocked by the cloning of Dolly last year than by the tremendous public reaction to it. There was some surprise that it had been done: the Roslin Institute in a quiet town outside Edinburgh, is not a place where cutting-edge science might be expected. But the feat seemed to most of them a technical breakthrough, not an ethical or conceptual one. Ian Wilmut, who cloned Dolly from the udder of an adult sheep, had made the real breakthrough the previous year, when he cloned two other sheep, Megan and Morag, from embryonic cells which had already started to differentiate into particular kinds of tissue. Other scientists working in the field had already produced beasts such sheep-cows, made by mixing sheep and cow embryos together, to produce a sheep with such oddities as wool patterned in black and white patches, like a cow’s hide. One sheep cloned from an adult cell seemed a logical and unsurprising development.
There were exceptions to this scientific phlegm. Lee Silver, a professor of molecular biology at Princetown, was told about Dolly by Gina Kolata of the New York Times. "It’s unbelievable!" he said. "It basically means that all of science fiction is true." She got her quote, and he got to appear on 23 chat shows in the next fourteen days. Now both of them have published books on the subject. His is Remaking Eden; hers (not a title copied from anyone else) is Clone. Kolata thanks him for his help and advice, and also reveals that an early draft of his book had a chapter explaining why cloning from adult cells was impossible.
When he had to revise that opinion, Silver appears to have abolished every other limit on his imagination. By the end of Remaking Eden, he has gone into complete raving mad scientist mode. He foresees a long term future in which humans will have fitted themselves with genetic accessories from all over the animal kingdom: they will have magnetic direction-finding systems like birds, inbuilt batteries like electric eels and, should we want them, luminous bottoms like fireflies. Of course, these are long-term plans. Before then, he tells us: "Alcohol addiction will be eliminated, along with tendencies towards mental disease and antisocial behaviour like extreme aggression. Visual and auditory acuity will be enhanced in some to improve artistic potential. And when our understanding of the genetic input into brain development has advanced, reprogenetics will provide parents with the option of enhancing various cognitive attributes as well." — and if we can do all that, we can probably fit pigs with wings, no trouble.
In is a tradition in science books of this sort to go completely doolally in the last chapter, so one should not judge his book too harshly for it. Those parts that were written before he discovered that all science fiction is true are very clear and open giddying perspectives. It was there that I discovered the story of the testicular twosome of Twomeys. Other stories make it clear that much of the future has already happened without anyone noticing; and that the excitement over cloning is simply a way to dramatise other advancements in reprogenetic technology. Almost as revealing, though, are the book’s social and political assumptions: the past does not illuminate the present nearly as much as an imagined future can.
If you just want to learn about cloning, Gina Kolata’s is the book to buy. For about half her book she describes the research that led up to Dolly’s birth with an admirable combination of clarity and detail. (the rest, unfortunately, is a reporter’s notebook dump). This is not a purely scientific story: the reasons that made cloning so unfashionable that cloning from an adult cell was finally accomplished in the middle of nowhere by a scientist few had heard of are social and financial as much as anything else. The incidental details about salary structures and conditions of employment among researchers are fascinating. One of her heroes, is a Dane named Steen Willadsen, who produced the sheep-cow chimaera, was paid $150 a month as a research fellow in Cambridge, England, later raised to 150 pounds a month. On that salary, he did ground-breaking research. When he moved to the States to work for a commercial company, he slaughtered a fatted sheep-calf, roasted and ate it in celebration; and made a lot of money from stock options in a company that cloned cattle. But he had no time for research there; worse, there was no market for their perfect cattle embryos. The venture capitalists moved out, and Willadsen ended up working in a human fertility clinic in Florida. Perhaps that he should have tried cloning race horses instead.
But humans are where the money is. Last week’s announcement by Dr Richard Seed, a Chicago surgeon, that he will clone humans just as soon as he can raise a couple of million dollars, and that he already has four couples on his waiting list for treatment, is only the latest in a long line of sensational announcements about cloning. Some notable fakes are dissected by Gina Kolata: in the 1970s, a best-selling book by a fairly reputable science journalist claimed that an eccentric millionaire had already cloned himself on a Pacific island. Even Silver in his optimistic moods believes that the cloning of humans will take more than the two years to establish that Dr Seed is projecting.
Almost everywhere outside the USA, it will of course be illegal to clone humans. The US is the only country in the world which has both the technological ability to do unlimited reprogenetics, and no national regulatory structure at all. This seems to be a paradoxical result of the strength of the religious right, which in the US is too powerful to need to compromise with the scientific establishment or to find out what is actually going on with the embryo research they find so repulsive. This has unfortunate effects. The American scientific community seems to have decided that it god has nothing to say to it, it might as well listen to Mammon,
Silver makes it very clear that there are no medical grounds to assert that a distinct human life begins at conception, or even that every child must have two identifiable parents. Early embryos can be divided and merged almost arbitrarily in the laboratory and this happens in nature, too. He offers a thought experiment to prove the point. Scientists could fertilise the sperm and eggs of ten different couples, he says, and when the resulting embryos have divided three times, and have eight cells each, they could be broken into their constituent cells and then recombined differently, so that you had ten new embryos, each made of eight cells from eight different couples. All could develop into physically normal human beings even though you could never say of any of them who was the father or mother.
But it is hard to avoid the uneasy feeling that any children born of such an experiment would be different from the usual run of crazy mixed-up kids. This unease can be felt by anyone, religious or not, who believes that human life has some intrinsic value, whenever it may be said to start. It is not ridiculous to legislate on the basis of such unease, even if the resulting laws are ineffective. The British law against human cloning, for example, forbids the introduction of nuclear material into an embryo — which is elsewhere defined in the legislation as a fertilised egg. But the law was drafted in the late Eighties, and the techniques developed since then by Willadsen and Wilmut, which would presumably form the basis for any human cloning, use unfertilised eggs, which are not embryos under the meaning of the act. So it might be legal to clone humans in this country on the basis of scientific advances made since the law was passed, though it was clearly the intention of parliament that this should not be possible.
But all this leaves aside the question of why anyone should want to be cloned. It is this question which Silver’s book answers best, partly intentionally, and partly by being such a very accurate mirror of the social and ethical assumptions that make cloning seem so fascinating and desirable, chief among them the belief that Americans have the God-given right to buy anything they can afford. He quotes a poll suggesting that five million Americans would clone themselves if given the chance.
As a practical example of people who could benefit from cloning, he suggests a couple whose children are killed after they have become sterile, though there are less dramatic possibilities: "What about another couple whose situation is not so extreme, who become sterile after having one healthy child and then want to have a second by cloning the first? The second child, of course, would be a late-born identical twin. Would this be unacceptable because the older twin is not in a position to consent to being cloned? I think not." .
Silver argues that if we were consistently condemning that sort of cloning, we should also force the mothers of identical twins to abort one of them. But the case is hugely altered because the mothers of identical twins did not plan to have them, and certainly could not ask if the twins themselves wanted to be born on those terms. It turns out that very little research has been done on the social and psychological consequences of being an identical twin, though their genetics have been closely examined. And it is very strange for anyone working in reproductive medicine to argue that whatever occurs in nature must be good, or, at worst, harmless. The largest practical use of our knowledge of genetics at the moment is to identify naturally occurring conditions for which the best treatment known to science is therapeutic abortion. I am not of course suggesting that that is how identical twins should be treated: merely pointing out that the fact that cloning occurs in nature is no argument for its desirability.
But the real meat in Silver’s book, and the part that will no doubt impress itself on the popular imagination, lies in his belief that the genetic engineering of embryos will become safe and even commonplace among the rich in the next fifty years. This is not cloning. It relies on the faith that the human genome can not merely be sequenced, but understood, so that one could study a person’s DNA and understand the character that should result from it. The logical conclusion of all this are the fantasies of completely re-engineered humans mentioned earlier with their glowing bottoms and inbuilt FM radios. But long before we reach that stage, Silver is confident that humans will be able to select among their own genes those which give desirable characters. This is deeply controversial, though he mentions these controversies on only one page out of 250.
The problem with genetic engineering in complicated beasts like humans is two-fold. One gene can affect many different areas of development; at the same time, what seem to us simple factors, like height, are affected by the interactions of many genes. When it comes to complicated and worthwhile faculties, like intelligence, the number of genes involved, their relative importance, and their detailed interactions are all a complete mystery. Dr Tom Wilkie, the head of biomedical ethics for the Wellcome Trust in London, and author of "Perilous Knowledge", another excellent guide to the subject, says "There is still a major gap in science as well as in logic between being able to clone someone and the basic problem of what genes do you stitch in to ensure better health. You don’t have to do cloning to do that. But the determinants of health are subtle and certainly polygenic to a very large degree."
It may be that this problem will be solved, and the kind of deep understanding of genetic technology that Silver anticipates will appear. And, if that happens, it may turn out to be the case that only a hundred or so genes determine intelligence, that only ten of those really matter, and that these ten can safely be modified to produce more intelligent children. But those are possibilities, not certainties.
What is certain, however, is that people will bet on them. Never mind the science: the final promise of Silver’s book is that the rich will soon be very different from you and I. They will have become a different species biologically.
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