I would rate this book, along with Dawkins' The Blind Watchmaker, as one of the most important and powerful books I've ever read. Furthermore, these two books complement each other beautifully. Diamond seems to pitch perfectly to all audiences, (I studied a biological degree, and the book has passed among many of my non-scientist friends who all claimed to have recommended it to others,) and ranges widely, (through biology, evolution & ecology, paleontology, history, sociology, and linguistics.) The whole is an unfeasibly lucid and educative rationale as to how mankind arrived to be where he was in 1991, and where he was likely to be headed. As with Dawkins, the going is rarely heavy and every page brings a satisfying feeling of having learnt something new. Sometimes uncomfortable, often funny, rarely overbearing. PLEASE read this book. Then read it to others, and recommend as widely as possible!