Our plunge into the gene pool: Biological knowledge is about to change the world as we know it. So let the moral argument begin

ALMOST 40 years ago, the double helix structure of the DNA molecule was deciphered in Cambridge. In July, the Steven Spielberg movie Jurassic Park opens in Britain. The film is about the re-creation of dinosaurs using DNA from blood found inside a mosquito preserved in amber. It is based on the single most startling and, maybe, poetic insight that DNA appears to provide - that all of life with rare exceptions is connected by a single, fabulously competent, chemical messenger. Spielberg is evidently moved by this holistic vision. In his film ET, the cry goes up from one scientist trying to revive the dying alien: 'He's got DNA]' We are one with the universe, the messenger tells us, nobody is a stranger here.

Popular culture says many things; most are trivial, but this time it is on to the big one. Forty years down the line from Watson and Crick it is clear that biology possesses the most powerful knowledge of the age. Physics made this century, transforming the electromechanical culture of the 19th into the electromagnetic one of the 20th. And, for the moment, physics remains the scientific market leader. The most popularly evocative science stories are still about physics. Big Science still means gigantic particle colliders or space telescopes. These are the paraphernalia of our creation myths.

But now Big Science also means the multinational, multi-billion pound project to 'sequence' the human genome; the effort to plot the entire genetic structure of human DNA. This project has poetry for the movies, but it also has something that the weird speculations of high physics do not have - immediate practical impact. Some version of human destiny in the form of susceptibility to disease, longevity, intelligence and, maybe, character, seem to be at least partially encoded in the chemistry of the genome. The physicists may be able to claim that somewhere in those ripples lies the clue to our 'ultimate' origin. But biologists can potentially claim so much more: a clear, direct, useable narrative about our existence.

As a result, physics, it is now commonly stated, is dead. Long live biology. The bizarre and frequently inept excursions by the popularisers of physics into the realms of the theological and the philosophical are symptoms of its decadence and its impending decline. They are about to be usurped. The 21st century will be dominated by the impact of this new knowledge and its accompanying technology. Science will take on a new human intimacy as it finally crosses the barrier at which it has always faltered - the barrier of the self.

The 'future shock' associated with this development has not yet been felt. Perhaps we are still too enmeshed in the disorientations of the physics culture - nuclear weapons may have been adequately sublimated, but the information revolution arising, ultimately, from quantum theory is still being slowly and uneasily absorbed. And the huge changes promised by biology are still in the future. Sequencing the genome may, for example, point us to the specific gene that causes cystic fibrosis or muscular dystrophy, but further knowledge and technologies are required before we can act upon this information.

Yet the first developments are definitely with us in the form of some limited applications of gene therapy and in the artificial production of substances such as human growth hormone - a development that has already moved from the therapeutic to the cosmetic. It has been offered as a treatment, not just for dwarfism but also for people who feel they are unattractively short. And it is absolutely clear that momentous developments are on the way; that we are to be confronted with a whole new realm of choice.

'The availability of so many options,' writes my colleague Tom Wilkie in his massively informative book on the subject, 'is something very new in human experience.'

We know where we are heading and consequently, as the philosopher Bernard Williams has pointed out, it is wrong for us to relax our moral guard just because some things are not possible now. 'It is a requirement on moral argument,' Williams has said, 'that it shouldn't simply stop at mere technical fact and say that the question does not yet arise.'

But where to start? The scope of the moral argument may be said to be as vast as the genome itself; there are as many subtleties as there are 'base pairs' in human DNA - three billion. We may feel relaxed about curing cystic fibrosis with gene therapy, but what about designing our babies, or perhaps even curing cystic fibrosis or Aids by 'germ-line' therapy that involves intervening permanently and perhaps unpredictably in the human gene pool?

There are many issues, but, really, there is only one: eugenics, whose bland dictionary presence states that it is 'the study of methods of improving the quality of the human race'. For most people the very word is tainted. There was much toying with the idea - by, among others, Churchill - in the technologically confident early decades of this century. The fear among the educated was that the poor were breeding too quickly and, as a result, the quality of the general stock of humanity would deteriorate. The crude prescriptions included government control of fertility and marriage; a strategy whose one redeeming feature was that it inspired a brilliant, book-length condemnation from G K Chesterton.

'They can offer us nothing,' he wrote of the eugenicists in Eugenics and Other Evils, 'but the same stuffy science, the same bullying bureaucracy and the same terrorism by tenth-rate professors that have led the German Empire to its recent conspicuous triumph.'

That was in 1922. In the event, the Germans were to make Chesterton's case for him even more conclusively. Nazism embraced eugenics, and controlling human fertility in the name of social engineering ceased to be a

respectable option.

But, in anticipation of the coming sovereignty of biology, eugenics is quietly becoming respectable again. Moral philosophers such as John Harris at Manchester University are attempting to see beyond the gut loathing the word provokes. After all, he points out, it only means planning for better offspring in a better world and who could object to that? Parents use money and other wiles to improve the condition of their children, why should they not also employ biology? Furthermore, although germ-line technology for eradicating Aids may hold risks for future generations, will there not come a point when those risks are outweighed by the risks of doing nothing?

Harris is right to ask these questions. Recoiling in historically aware horror from all this is not an option. Eugenics will arrive through the marketplace, if not through legislation. The offering of growth hormone as a cosmetic treatment is but one portent. Designing all kinds of characteristics into babies will unquestionably soon be possible and, if the eugenically inclined rich cannot find such services in this country, they will obtain them elsewhere. They may be disappointed - no serious biologist would claim that genetics is the full story of our destiny and they would know that the impact of environment and upbringing is at least as important - but the option to gamble would be on offer. But, as Chesterton saw, rigging the game for the living is one thing, rigging it for the unborn is quite another. He wrote of selecting a wife on the basis of her breeding capacities: 'The baby that does not exist can be considered even before the wife who does.' This is the point: biology will offer us the power to be conceptually and morally implicated in the nature of future generations. This may be perfectly rational, but we are not likely to be good at it. Horrible mistakes are certain to be made as they invariably are when technological ambition outstrips sensible caution.

The real point, however, is nothing to do with such rationality. It is again captured by Chesterton when he muses that 'Keats died young; but he had more pleasure in a minute than a Eugenist gets in a month'. The uncertainty and ultimately indefinable nature of our experience is fundamental to our conception of what it is to be human. A consumptive genius is a phenomenon we like to feel is beyond any rational balancing of probabilities and, crazy as it may seem, it is natural occasionally to muse that the aborted foetus or the child unconceived because of wise genetic counselling could have been Keats. Biologists will say they are not threatening any of that, they are simply pursuing knowledge. This is true, but inadequate, for knowledge changes things and, now, it is about to change everything.

'Perilous Knowledge: The Human Genome Project and its Implications' by Tom Wilkie (Faber & Faber, pounds 14.99).