This text provides a general overview of how plants and animals made the transition from water to land. It presents integrated summaries of the evidence from both fossils and living organisms, and from molecular to organismic levels. The authors consider when and where these transitions occurred; which groups of organisms were involved; and in what environments and environmental conditions they took place. They also discuss the biochemical, physiological, morphological, behavioural and ecological properties that permitted the organisms to make these transitions, and the changes that occurred as the transitions took place. The work gives equal emphasis to palaeobiology and neobiology, and incorporates the latest information relevant to water-land transitions, deriving from recent applications of micropalaeontological and molecular methods to classical issues.