The disgrace of Professor Hwang Woo-suk will go down in the annals as one of the great scientific reversals of our time. Professor Hwang, of South Korea's Seoul National University, resigned last week after much of his pioneering work on cloning and stem cells was exposed as a sham. He offered a public apology for the "shock and disappointment" he had caused.
"Shock" and "disappointment" were especially well-chosen words for a context that extends far beyond Korea. Professor Hwang's speciality is currently lionised as one of the most promising fields of medical research - if not the most promising of all. It draws the most capable and ambitious young scientists; it attracts billions of dollars in funding; and it is sustained by a lavish investment of popular hope. If wishful thinking alone were the driving force of medical science, stem cells would have been produced from cloned embryos, injected into humans and be curing all manner of dread conditions already.
Until it is established how much of Professor Hwang's research is discredited, the field is effectively in suspension. Those who have cited the professor's flawed results to support their own research will have to revisit their conclusions. The flow of funding towards stem-cell research may slow. These are dark and uncertain days for the burgeoning community of stem-cell researchers.
Yet it is high time that a long second look was taken at this whole area of science. Researchers have talked up the potential benefits of stem cells to the point where swaths of lay opinion now regard them as a panacea. So often have they told us that they are the "building blocks of life" or some such that we have come to believe them.
And how can we not? When relatives and friends are afflicted with conditions that could, we are told, be cured so simply in future, what qualifications do we non-scientists have for doubt?
My own aversion to conventional wisdom may predispose me to be unduly negative about the embrace of stem-cell technology as the cure-all of the future. But it is a fact that cut-throat competition for funding encourages research departments to advertise their prospects more optimistically than they might have done in the past. Investors, not unreasonably, want the promise of high returns before they risk an initial outlay. What might be all too easily becomes what already is. The hype needs to be banished from stem-cell research; Professor Hwang's public admission of mistakes may in this respect be a salutary development for his discipline.
But there is another reason, too, why the field of stem-cell research and cloning so urgently needs this pause for reflection. And it has to do not with the possibility of expensive failure, but with the distinctly ambiguous implications of success.
Stem-cell research has been very convincingly presented by its proponents as being all about curing diseases that are at present incurable. And in part, of course, it is. Who would begrudge treatment to children with defective immune systems - its most successful application so far - or to those with diseases such as multiple sclerosis or Parkinson's? There need be no real debate here. The controversy in the US relates not to the treatment as such, but to the use of aborted or cloned foetuses to produce the stem cells.
The great hope of stem-cell research, however - and the precise area in which Professor Hwang was working - is that it will be possible to grow and implant cells that are genetically matched to individual patients. This would mean not just that inherited diseases could be screened for in the womb, as in some cases they are already, but that all manner of genetic "faults" could be corrected.
It is at this point that "treatment" mutates all too easily into "improvement" - and gene therapy, the term that is fast entering our vocabulary, into a word that has been in ideological exile for half a century: "eugenics".
What constitutes a genetic "fault" may depend on culture or context. Is genetic susceptibility to a disease detected in a foetus grounds for treatment or abortion? And what price then health insurance? At present, insurers are not permitted to require genetic testing, not even in the United States, where private health insurance is the rule. But the pressure is there; it makes commercial sense for the insurers and it will surely prove irresistible. The result will be either large groups of people whose genetic make-up renders them uninsurable or the end of private health insurance. Politicians will have to choose.
And what of supposedly desired characteristics? It is sufficient to scan a few US fertility services on the internet to realise how far the exercise of parental choice has already advanced. That one biological parent's high IQ, sporty physique, blonde hair and blue eyes may not guarantee a child that is precisely to specification is a separate issue. The scale of this society's genetic preferences are all too apparent. Science increasingly makes it possible for them to be realised. Sex selection is already being broached in this country as a procedure that could become as routine as amniocentesis for testing the health of the foetus. Could selection for other features follow?
The implications do not stop at birth. If there is no censure attached to selecting certain characteristics in children, what will be the lot of those children who do not conform, whether by appearance or intellect? When society regards it largely as the luck of the draw that people turn out as they do, there must be a tolerance of difference. Once it becomes possible to select or change any of these elements, tolerance is likely to decline. Individuals will be held responsible for choosing or not choosing "treatment". This is not 1984 or Brave New World, it is basic and brutal common sense.
Until now, the stem-cell pioneers and gene-therapy proponents have been extraordinarily successful in ignoring all links between their research and the early 20th century pursuit of eugenics. If you want to split hairs, you could say that the quest then was to improve the human race, whereas now it is to improve each individual, one by one. But the implications are surely the same: the exclusion, demonising or destruction of those who do not, or cannot be made to, fit.
The 60-year taboo that banished eugenics from our vocabulary may also have expunged the knowledge of what it led to when it became part of a national ethos of supremacy. Perhaps that taboo was too complete. If the disgrace of a South Korean professor makes us all - scientists and non-scientists alike - stop and think, his overzealous pursuit of scientific glory will have had a welcome and salutary effect.Reuse content