Robert May: Think of the benefits, Mr Meacher. An apple, say, that helps people slim

GM technology could clear our countryside of its wildlife diversity, creating an ever more silent spring

Michael Meacher, the former environment minister, attempted in these pages last week to rekindle public anxieties over the safety of GM foods. What is more disappointing than his lack of regard for the weight of evidence on this issue is that he is overlooking what I believe is the far more important question of how GM crops might affect the UK countryside and the intensification of agricultural practices.

Mr Meacher speculated about a number of worries over GM food safety, flying in the face of findings of the Food Standards Agency, the Advisory Committee on Novel Foods and Processes, the expert opinions of a host of independent national and international bodies, the conclusions of numerous scientific conferences, and the experience of the populations of countries such as the United States which have been eating GM foods for many years without any evidence of harm.

The highly selective references in Mr Meacher's article to last year's Royal Society report on GM foods exhibited just the kind of political spin that he accuses the Government of. Only someone ideologically opposed to GM would ignore our principal conclusion that there is no scientific reason to believe genetic modification makes foods inherently less safe than their conventional counterparts. Our report noted that humans have been consuming large amounts of DNA from a wide variety of sources, including bacteria, throughout their evolutionary history. Hence, eating a GM DNA sequence in a crop, which has usually been transferred from some other plant species, is unlikely to have an ill effect on human health.

Mr Meacher branded the principle of "substantial equivalence", in which the assessment of all new foods begins with a comparison against existing foodstuffs, as "scientifically vacuous". His view is not shared by bodies such as the World Health Organisation, the Organisation for Economic Co-operation and Development and the Royal Society, all of which have examined this in detail.

It is true, as the Royal Society report emphasises, that the application of "substantial equivalence" needs to be refined, and made consistent between EU member states, but it is currently the only practical way of evaluating the safety of any novel foods, GM or otherwise.

Nowhere in his article did Mr Meacher acknowledge that genetic modification may be used in the future to improve the quality of food. This is the biggest problem with the current debate. If products were available that offered the consumer benefits, say allergy-free nuts or even a golden GM apple the eating of which makes you thin and witty, the public could weigh these up against the possible risks, in much the same way that they do with mobile phones, for instance.

However, Mr Meacher appears uninterested in considering how the public might benefit nutritionally from GM. Instead his article dwelt on the conceivable unintended adverse impacts that we identified in our report. He was right that our report highlighted babies as being particularly vulnerable to any changes in the nutritional content of their food. If and when GM ingredients are proposed for inclusion in infant formula, UK and EU regulations need to be rigorous enough to deal with this special case.

The list of half-truths in Mr Meacher's article goes on. His assertion that a rise in allergies may be linked to GM foods does not stand up to systematic analysis, such as that carried out by the United States Centre for Disease Control. And his opening warning about the uncertainties of transferring specific DNA sequences lacks credibility because he fails to point out that conventional cross-breeding shuffles far greater numbers of genes, in a more uncontrolled way.

But perhaps the most disappointing aspect of Mr Meacher's article was that it missed the opportunity to consider what role GM crops might play in the future of the UK countryside. The intensification of agriculture through conventional practices has had demonstrable adverse effects on the diversity of wildlife species over the past couple of decades, with the well-documented decline of wildflower and farmland bird populations. Depending on how we use it to grow crops, GM technology could make this situation better or worse.

Like so many applications of science, GM technology is a double-edged sword. It offers us, on the one hand, the chance of a "Doubly Green Revolution", in which we grow our food efficiently but in ways that work with the grain of nature. On the other hand, it could offer us the opportunity to ramp up the intensification of agriculture, wrenching the environment into a form that suits our needs and in doing so clearing our countryside of its rich diversity of wild animal and plant species, creating an ever more silent spring.

Making a choice between such options involves values and beliefs, set against the background of a realistic understanding of the possibilities that tomorrow's agricultural biotechnology may offer. That is the debate we should be having, Mr Meacher.

Lord May of Oxford is President of the Royal Society