The ambitious project of sequencing the DNA in the human genome released its first draft three years ago. At the time it was often portrayed as `reading the book of life’, but what is only recently being understood is how appropriate this metaphor really is. The jargon of molecular biology is scattered with terms borrowed from linguistics, such as transcribe, translate and code. The parallels between these two fields run much deeper than this though, and it has been discovered that both DNA and the proteins that it codes for have a grammatical structure like language. This has lead to the very productive swapping of ideas and techniques between biologists and linguists. For example, `authorship tests’ have been applied to unknown DNA sequences and `evolutionary trees’ have been constructed of old texts. But first, in what ways are DNA and proteins so profoundly similar to language? Continue reading →