The ability of species of nudibranch to incorporate the cells of completely separate species could have profound implications for humanity, says Drew Harvell While they may be outnumbered and outweighed by insects, the terrestrial world is really the kingdom of the vertebrates. Mammals, birds, reptiles and amphibians dominate most ecosystems. Yet, as Drew Harvell points out in her fascinating new book, the seeming diversity of the terrestrial vertebrates is deceptive. In fact all are contained