BIOLOGY Volume 1 - A Guide to General Biology - 2004

2. DIVERSITY OF LIFE ON EARTH

2.1. Classification

2.1.2. Taxonomy

Taxonomy is divided into two branches: the first deals with assigning names to organisms, which is nomenclature, while the second deals with grouping organisms, which is systematics. Systematics is based on the Similarities and differences among organisms.

Biological nomenclature is based on the binomial system, pioneered by the Swedish naturalist Carl Linnaeus (1707–1778). In the binomial system, every Organism is assigned two Latin names: a generic name and a specific name. The generic name begins with a capital letter, while the specific name begins with a lowercase letter. Humans, for example, are designated as Homo sapiens, where Homo is the generic name and sapiens is the specific name. Both the genus and species Latin names are written in italics. Alternatively, they may be written in standard font, in which case they must be underlined, such as Homo sapiens. This convention must always be observed when writing the Latin name of an organism. The generic name may be abbreviated to its initial capital letter, as in H. sapiens. (Abbreviation is only permissible if the full name of the organism has been explicitly stated immediately beforehand.) Scientific Latin names are universally accepted worldwide. This prevents the confusion caused by regional common names. For instance, the plant Ficus carica is commonly known by several names: fig, common fig, and edible fig. The snow leopard, Uncia uncia, is also known as the ounce, while the bighorn sheep, Ovis canadensis, has alternative common names such as the Rocky Mountain bighorn. Equal confusion arises when a single common name is used to refer to more than one species. For example, the common name 'hellebore' may refer to plants of the genus Helleborus (family Ranunculaceae) as well as plants of the genus Veratrum (family Melanthiaceae).