Classification is the categorization of living organisms into a hierarchical series of groups. Based on the work of Carl Linnaeus during the eighteenth century, classification was devised to organize scientific discussion of plants and animals. Its universal acceptance and use has done much to further science. One aim of modern classification is to show evolutionary relationships between organisms. All organisms are divided into one of five kingdoms and then into successively more exclusive groups. After the kingdom is the phylum (the term division is sometimes used instead of phylum for plants), then class, order, family, genus, and the smallest commonly used grouping is the species. Each grouping can be recognized by shard characters, the more characters in common the closer to the rank of species the organisms are. For example all animals are in the same kingdom, all animals with a backbone and notochord are in the phylum...