Andrew Purvis (Food Magazine, 15th May) refers to human nutritional physiology having been shaped by wild foods. He is of course dead right; what else could have shaped it?{}
The Human and other animal Genome Projects have brought much hope of being able to solve genetic disorders in mankind. One interesting spin off is the incredible conservation of the genetic code across huge gulfs of evolutionary time. For example, the sequencing of the genetic code for the puffer fish shows that its blood clotting factors are essentially identical to those of Humans although our last common ancestor lived 450 million years ago! Moreover 98.5% of our genome is shared with the chimpanzee: hence our physiological link to a diet of wild food. The current and very recent epidemic of thrombotic disease cannot be due to a change in our genome. It must be due to changing environment including most importantly changing diets operating on ancient genes.

Professor Ted Tuddenham,

MRC Haemostasis and Thrombosis Research Group,

Imperial College Hammersmith Campus, London.