Developmental biology is seemingly well understood, with development widely accepted as being a series of programmed changes through which an egg turns into an adult organism, or a seed matures into a plant. However, the picture is much more complex than that: is it all genetically controlled or does environment have an influence? Is the final adult stage the target of development and everything else just a build-up to that point? Are developmental strategies the same in plants as in animals? How do we consider development in single-celled organisms? In this concise, engaging volume, Alessandro Minelli, a leading developmental biologist, addresses these key questions. Using familiar examples and easy-to-follow arguments, he offers fresh alternatives to a number of preconceptions and stereotypes, awakening the reader to the disparity of developmental phenomena across all main branches of the tree of life.