'In this first book of the second century of his long career, the biologist Ernst Mayr at age 100 has given us his reflections on the most interesting and important questions about life: why living things can't be understood just as very complex machines, how humans evolved, why we haven't yet communicated with any extraterrestrials, and others. Written with a clarity and vigor that shine from every page, this book is best summarized in one word: exciting!' Jared Diamond, UCLA, author of Guns, Germs and Steel (Pulitzer Prize, 1998)