I am a great fan of Ian Stewart, and an avid reader of 'popular science' novels such as this one. However, I think Ian has made a mistake with his audience on this one. He is a mathematician, not a biologist, and as such he describes simple A-level biological phenomenon as if it was all new, excitingand in great depth. Then rushes onto the mathematics that just leave you stumped wanting more explanation. The first half of the book is a boring re-hash of biology text-books. Written (it seems) to bring the knowledge of his reader up to a fundamental level of understanding in order to pile the mathematics on top, later in the book. As a biologist I was left bored churning through the first bit and then a bit lost in places on the second bit (Seriously multi-dimensional mathematics gets about half a chapter, and no nuts and bolts explanation as with the biology, I would of much preferred half a book on this!). If your a mathematician that has never looked at life sciences, then you will probably enjoy it. If your a life scientist looking for a mathematicians take on your subject, then that is basically what you get, but be prepared to read around some of the concepts elsewhere as they are not included in sufficient clarity within the book. Despite this, Ian is an engrossing and enjoyable author and usually his books are a triumph of learining and reasoning. Maybe I am too close to one of the subjects to appreciatte it, but I was disapointed with this title.