Letter: Brought to book

Sir: It would be an exaggeration to suggest that Lewis Wolpert had merely skimmed my book, The Engineer in the Garden, before reviewing it (17 November). He cannot have done more than flick its edges.

That Jurassic park is science fiction is not, as Professor Wolpert tells us, 'contrary to Tudge's view'. In fact I spend some pages explaining why it would be extremely difficult to recreate a dinosaur, even if the DNA was complete, and why it is theoretically impossible if it is incomplete (as is bound to be the case).

I do not 'fail to understand just how difficult it will be to create any life form he could imagine'. Rather I discuss what the concept of 'life' entails and ask whether life is simply 'a process' that can in theory be replicated by any mechanical system of appropriate design or whether it depends upon the chemistry of carbon.

Neither do I 'play the Frankenstein card'. I do not suggest that the problems raised by escaped organisms that contain foreign genes are of a quite different order from present problems. I point out that escaped transgenic organisms are merely a special case of escapes of 'exotics' in general. But I do point out that the introduction of exotics is probably second only to habitat loss as a cause of extinction of native species; and that the presence of 'foreign' genes within exotics adds another layer of uncertainty since it is impossible to predict the true potential of novel genes until several generations have passed.

Professor Wolpert has not reviewed my book. He has merely knocked over a few Aunt Sallys that have been around for about 20 years.

Yours faithfully,

COLIN TUDGE

London, SE21