The animal world is immensely diverse, and our understanding of it has been greatly enhanced by analysis of DNA and the study of evolution and development ('evo-devo'). In this Very Short Introduction Peter Holland presents a modern tour of the animal kingdom. Beginning with the definition of animals (not obvious in biological terms), he takes the reader through the high-level groupings of animals (phyla) and new views on their evolutionary relationships based on
molecular data, together with an overview of the biology of each group of animals.