From Keith Tritton
Stephen Strauss is right when he says that terms like “blueprint” and “book of life” are poor metaphors for the way that DNA functions (21 February, p 22). I think that a gene works more like a knitting pattern. Both contain instructions which, if followed correctly, result in the assembly of a structure that is both complex and useful – on the one hand a protein, on the other a sweater.
Sandy, Bedfordshire, UK
