In ten weeks, one female fruit fly can produce more descendants than there are people on Earth. Some fruit flies are born without genitals - scientists call these mutants 'Ken and Barbie' - whereas others are born with their legs on their heads. They can be trained by punishment and reward, and have a work-and-rest schedule based on the 24-hour clock. They can become addicted to crack cocaine. Males have toxic semen, which is bad news for females: too much sex can kill them. And there are more than 1,000 species living in Hawaii. The amazing fruit fly is, in fact, an unsung hero in the history of science. No popular account exists of the fruit fly or its pioneering role in many of this century's greatest discoveries. This book corrects this poor public image by telling the story of modern biology - from genetics to evolution, physiology to ecology, medicine to psychology - through the life of the fly. In a highly original and entertaining style, Martin Brookes takes us through successive stages in the life cycle of the fly, each illustrating an important concept in biology. From the incredible journey from embryo to adult, to the nature of memory and learning and theories of ageing, this book reveals how one short and seemingly insignificant life has informed almost every aspect of human existence. The result is a broad introduction to biology, evolution and genetics based around the personality of the fly, and a 'warts and all' insight into the practical realities of science. Often dismissed as irrelevant, the fruit fly will, through this unique synthesis, come to be recognised for what it really is: an icon of modern science and a window on our own biological world.