John Parrington examines the controversy over the cloning of human embryos.
A controversial area of science that has hardly been out of the spotlight since the birth of its leading lady - Dolly the sheep - is cloning. The recent announcement that scientists have succeeded in cloning a human embryo has reignited the simmering debate about the issue. The US biotechnology firm responsible, Advanced Cell Technology (Act) says its intention is not to produce a cloned baby. Instead it aims to produce cloned embryos as a source of human stem cells. These have the unique property of being able to mature into any cell type in the body. In theory, they could be used to treat diseases such as diabetes, stroke and Parkinson's disease. A real problem currently in transplant surgery is finding a donor whose organs will not be rejected by the immune system of the person receiving the transplant. The use of cloned stem cells could revolutionise transplant surgery as they would be a perfect match.
Many biologists are sceptical about Act's achievements. Cloned human embryos would only be useful for medical purposes if they reached a large cellular structure called a 'blastocyst'. Yet only a tiny proportion of Act's cloned embryos grew beyond a single cell, and none grew to more than a ball of six cells. Ian Wilmut, Dolly's creator, was certainly not over-impressed, arguing that 'the fact that it did not develop beyond six cells suggests it is fairly lightweight research'. It may be that cloning humans will be far more difficult than studies in animals had suggested. On the other hand, with concerted efforts in this area, it is still possible a breakthrough will occur. After all, cloning a sheep was thought to be impossible until it happened.
Certainly it is the view of every serious scientist that it would be madness for anyone to attempt to clone a person today, on the grounds of safety alone. Studies in animals as diverse as sheep, cows, pigs and mice have consistently found that only a tiny fraction of cloned animals survive to adulthood. The vast majority die in the womb. Even those animals that do survive past birth have a variety of defects and deformities. A study led by US biologist Kevin Eggan found that even when cloned animals look normal they often have hidden damage in their genes.
Cloning studies are challenging many orthodox views in genetics. A common idea is that human behaviour and even our complex society are somehow 'determined' by our genes. Socialists have always challenged this simplistic viewpoint, pointing out that humans long ago broke free of evolution. We have gone from living in caves to sending people into outer space in the space of tens of thousands of years, while our close biological cousins the chimpanzees remain the same (apart from the threat we humans pose to their survival) as they were millions of years ago. But even in animals there is a complex interaction going on between genes and the environment. Cloning studies support this, as they show that an animal can have major disruptions in its genes yet still end up looking pretty normal. This suggests that there is a great deal of plasticity in the growing embryo that still allows it to develop successfully even when a significant proportion of its genes are malfunctioning. Of course, this is not the same as saying we could ignore the effects of such abnormalities in a human. We might be missing subtle differences between superficially normal sheep, while as Eggan points out, 'Disruption in those genes in humans could cause things like mental retardation.'
There is currently a debate about whether it would be alright to clone a living human being if we could overcome all the concerns over safety. Personally I think it would be a very dangerous path to follow. First of all, could we really be sure until it was too late that we were not creating people with a range of serious abnormalities? There are already concerns that some of the techniques used in test tube baby technology have been introduced without sufficient thought as to the potential future health problems. There are all sorts of ethical issues as well. Identical twins face intense social pressure to behave in similar ways. How much more would be the pressure faced by someone growing up 20, 30 or more years after their genetic twin? It might be a very useful practical test of the importance of genes versus the environment, but would it be fair to subject a real human individual to such a test?
Assessing how serious a possibility someone attempting to clone a baby is has not been helped by the various cranks and charlatans who have been making exaggerated claims in this respect. We can probably be fairly unconcerned about Richard Seed, the failed physicist, and Clonaid, a California-based UFO cult that has vowed to produce cloned people. But there have been real fears that the maverick Italian doctor Dr Severino Antinori might seriously try to produce a cloned baby from infertile couples who are desperate for a child.
Karl Marx once compared capitalism to the sorcerer's apprentice, who unleashed amazing powers outside his control. There is no doubt that modern medicine continues to create some real marvels. Test tube baby technology has helped thousands of infertile couples and needs defending against the attacks of the same religious bigots who also want to prevent a woman's right to choose. It is a scandal that it is not freely available on the NHS.
Similarly, if applied responsibly, cloning human embryos could potentially revolutionise some areas of medicine. An increasing problem is that pioneering research findings made only after years of careful work with public funds then have their potential squandered and distorted by private interests that the public have no control over. Seizing back science and technology for the public good will be an important priority for a future socialist society.