Book excerpt: This illustrated book describes how some finned vertebrates acquired limbs, giving rise to more than 25,000 extant terrapod species. Michel Laurin uses paleontological, geological, physiological, and comparative anatomical data to describe this monumental event. Along with discussing the evolutionary pressures that may have led vertebrates onto dry land, the author also shows how extant vertebrates yield clues about the conquest of land and how scientists uncover evolutionary history.--[book cover].