The Variety of Life achieves in one volume what most people would think impossible. It introduces all the principal groups of creatures that are now believed to have existed in the history of the Earth. It reveals their astonishing range of form and lifestyle, showing in passing that animals and plants are really very similar, compared to many (or most) of the rest. Yet it shows how all earthly creatures are related to all the others, despite the vast differences between them. The Variety of Life also explains how biologists have arrived at their present understanding of life's diversity, describing and assessing the state of our knowledge as the new millennium begins.