Putting all our eggs in one basket
Sunday Times (London)
Steve Connor is the science correspondent of The Sunday Times
STEVE CONNOR reads a controversial new study which claims that human cloning and genetic enhancement will eventually become the norm.
Bokanovsky, the fictional scientist in Aldous Huxley's Brave New World who discovers how to clone humans, finds that his invention has one limitation. He can stimulate only a maximum of 96 embryos to bud off from a single fertilised egg. "Alas, we cannot bokanovskify indefinitely," says the Director. Even science fiction, it seems, has its boundaries.
The reality of cloning, however, is another matter. Nobody knows what the true limits of the new reproductive technology will be for humans, although Lee Silver, a geneticist at Princeton University and the author of Remaking Eden: Cloning and Beyond in a Brave New World (Weidenfeld Pounds 20), believes there may be none at all. Silver has voiced some of the most extravagant claims about the likely direction of human reproduction.
In the aftermath of Dolly the sheep (the first clone of an adult mammal), many scientists have been eager to ridicule suggestions that human cloning is around the corner. Pundits have said that it is unlikely in any guise, because there is no clinical need for it, because it is technically too difficult or impossible and because people will not stand for it. Silver thinks otherwise. Not only does he believe that human cloning is inevitable, he argues that it will be combined with genetic enhancement to produce a super-race of intelligent, athletic and disease-free people. He calls them the GenRich, a gene-enriched class of DNA aristocrats. The 90% of the population who cannot afford this genetic enhancement he dubs the Naturals (no prizes for guessing how they reproduce).
One repercussion of a breeding apartheid being imposed on the human population is that eventually (after many tens of thousands of years) it could lead to the development of two separate species that would be incapable of cross-breeding even if they wanted to. This scenario has not had time to come about through Darwinian evolution. But once we start tinkering with human chromosomes directly it is easy to envisage a situation in which the GenRich and the Naturals quickly diverge. One will look upon the other with as much romantic interest as a man now views a female chimpanzee.
Such a nightmare is not as outlandish as it might seem, according to Remaking Eden. The technological framework is now being put in place for the new "reprogenetics" (as he calls the amalgam of genetics and in vitro fertilisation), to change human nature forever. "We, as human beings, have tamed the fire of life. And in so doing, we have gained the power to control the destiny of our species," he writes.
In July, it will be 20 years since the birth of Louise Brown, the world's first test-tube baby. Since then, IVF has become almost routine, and hundreds of clinics around the world have acquired the skills to perform it with varying degrees of success on thousands of infertile couples. There are still some people who rail against test-tube babies, but the vast majority of the public is in favour of the technology because it so evidently helps men and women who are desperate to have a baby.
This was not always the case. When Robert Edwards and Patrick Steptoe announced that they had "created" a baby by fertilising a human egg and sperm outside a woman's body, they were met with a wave of public outrage. Newspaper editorials called for the abandonment of IVF; the Americans thought the whole idea so bizarre that they assumed nobody would ever want it. The initial condemnation, however, gave way to gradual curiosity and grudging acceptance. Now, the idea has become almost mundane.
Silver believes that the same will happen with human cloning and genetic enhancement. Nine out of every 10 people surveyed in the week following the Dolly announcement said that human cloning should be banned. Leading ethicists, scientists and politicians were quick to condemn any suggestions that the Dolly technology could be applied to humans. Even if it was technically possible, no doctor would do it: there would be no clinical need.
"That's not what science, history, or human nature suggest to me. The cloning of Dolly broke the technological barrier. There is no reason to expect that the technology couldn't be transferred to human cells," writes Silver. There are thousands of IVF scientists with the necessary skills to apply cloning to humans, and Silver has come across at least two who privately say they are prepared to do it.
Some scientists have pointed out that Dolly was the one successful lamb out of 277 attempts. They have used such a failure rate to argue that it is too inefficient for it to be applied to humans. But Silver argues that the failure rate was, in fact, far higher in the human IVF treatment that eventually led to the successful birth of Louise Brown. Steptoe and Edwards had worked on hundreds of human eggs over more than a decade to perfect IVF, and the number of embryos they had inserted into women and had failed to implant far exceeded those that had failed in the Dolly experiment.
Silver envisages other, even more frightening ideas for tinkering with human reproduction. One, called foetal mating, involves taking the immature sex cells (those that give rise to sperm and eggs) from aborted foetuses and growing them until maturity in a test-tube. These might then be fertilised to produce a viable embryo that can be implanted back into its genetic grandmother. The result would be a baby whose mother and father had never been born. Another idea is to merge the early embryos of two mothers to create a chimera, a person with a mixture of cells from both women. Human chimeras are known to come about naturally; they are caused by the fusion of two embryos resulting from the fertilisation of two eggs ovulated simultaneously by a mother. It would be relatively easy to do this experimentally, although why anyone should want to is unclear. Silver suggests that two lesbians could use chimera technology in order to produce a baby who shares the genes of both women.
Although such concepts appear abhorrent and far-fetched at the moment, they may not always remain so. Huxley made an inspired guess over the future direction of human reproduction but, as Silver points out, he was wildly wrong about who drives the changes. Governments will not bring about cloning, it will be people, and their overwhelming desire to produce babies in their own image.