| Animal Species and Their Evolution Long before Charles Darwin undertook his first voyage, animal taxonomists had begun the scientific classification of animals, plants, and minerals. In the mid-1950s, taxonomist A. J. Cain summarized the state of knowledge about the structure of the living world in his major book Animal Species and Their Evolution . His work remains remarkably current today. Here Cain explains each of the terms by which scientists now classify all animals--from species through genus, family, order, class, and phylum. |