BOOK REVIEW / The genesis of fear: The engineer in the garden - Colin Tudge: Jonathan Cape, pounds 17.99

MARY Shelley understood something very profound about our fears of 'monsters', for the image of Frankenstein and his creation is proving very hard to remove from any discussion of genetic engineering.

Yet genetic engineering offers great promise for solving major medical, agricultural and environmental problems. Part of the difficulty is that people's fantasies have little to do with reality. There is a common belief that cloning of humans has either already been achieved or is just round the corner. Even Colin Tudge, a good science journalist who should know better, thinks it will be possible, sooner or later, to grow humans by placing some cells in culture under appropriate conditions. There is not the slightest evidence that this can be done for any animal and, while one cannot predict the future, at present it is almost as unlikely as building a time machine.

A valuable feature of the book is the attention given to plants and agriculture. Genetic engineering could have an enormous impact on farming in poor countries, but Tudge believes it is impossible to deliver the new technologies to the people who need them most without compromising their autonomy. Western farmers, in their search for efficiency, have bred cattle which have more muscle than the skeleton can carry. So Tudge is appalled by the sight of modern beef bulls 'lumbering around the show barely able to pick up their feet', and crippled broiler birds. While recognising that genetic engineering when applied to farm animals need not be intrinsically worse, he fears it will enable breeders to progress even more rapidly to even more grotesque forms. It is, however, no help to talk about animal technology going mad and farmers being driven by greed. Are farmers trying to improve productivity more greedy than authors trying to sell their books? The question is not one of greed, but the difficult issue of our relationship with animals. Why is it acceptable to kill animals for food, but not acceptable to breed forms which some may find distasteful? Such questions require analysis, not instant critical judgements.

An important feature of modern evolutionary theory (well covered here) is the evolutionary stable strategy developed by John Maynard Smith to account for animal conflicts - hawklike and dovelike behaviour. Tudge unwisely tries to extend this idea to include human behaviour, and argues that Christ's view of an all-dove society is not possible because of the inevitable rise of hawks. Sociobiology should, however, be applied to humans with extreme care. The scientific community itself provides a clear counter-example of peaceful competition and cooperation.

The weakness of the book lies in its treatment of molecular biology. This is a complex topic which is poorly explained - the absence of diagrams making it even more so. And there is no mention of the cell. Discussing the implications of molecular biology for development, neurobiology, ageing and the origin of life without talking about cells is a bit like trying to play tennis without a ball. The cell is the true miracle of evolution. Failure to understand its complexity leads Tudge to make silly suggestions about how embryos might develop. He also fails to understand just how difficult it will be to create any life form he could imagine. Prediction of the effect of changing even one protein in the early embryo will be beyond our capacity for a very long time. Jurassic Park, contrary to Tudge's view, is science fiction.

Genetic engineering raises few new ethical problems. There has already been extensive discussion of the dangers. It is hard to think of any aspect of science that has been so exposed to public discussion. Introducing genes into the germline which would then be passed on to future generations is already banned, as are most experiments on human embryos. There are problems relating to the patenting of animals, confidentiality and the release of new organisms into the environment, but it would be a great loss if exaggerated fears prevented its potential for good being fully exploited. Informed public debate is the best way forward. But the continual playing of the Frankenstein card is not helpful.