Appendix 1
Biological Classification
Scientific classification or biological classification is how biologists group and catergorise extinct and living species of organisms. Modern classification has its roots in the work of Carolus Linnaeus, who grouped species according to shared physical characteristics. These groupings have been revised since Linnaeus to improve consistency with the Darwinian principle of common descent. Molecular systematics, which uses DNA sequences as data, has driven many recent revisions and is likely to continue to do so. Scientific classification belongs to the science of taxonomy or biological systematics.
Two examples, for the fruit fly and humans, are given below to illustrate the hierarchical nature of the classification system and the terms used.
| Taxon | Fruit fly | Human |
|---|---|---|
| Domain | Eukarya | Eukarya |
| Kingdom | Animalia | Animalia |
| Phylum or Division | Arthropoda | Chordata |
| Subphylum or subdivision | Hexapoda | Vertebrata |
| Class | Insecta | Mammalia |
| SubClass | Pterygota | Placentalia |
| Order | Diptera | Primates |
| Suborder | Brachycera | Haplorrhini |
| Family | Drosophilidae | Hominidae |
| Subfamily | Drosophilinae | Homininae |
| Genus | Drosophila | Homo |
| Species | D. melanogaster | H. sapiens |
A mnemonic for the classification hierarchy from the most to least general:
Dandy Kings Play Chess On Fancy Glass Stools (and numerous variants thereof)
= Domain Kingdom Phylum Class Order Family Genus Species.
Botanists use Domain Kingdom Division Class Order Family Tribe Genus Species to classify plants.