Species

A species is a group of organisms of the same type. The term species is one of the seven major classification groups that biologists use to identify and categorize living things. These seven groups are hierarchical or range in order of size. Species is the last and smallest complete group. The classification scheme for all living things is: kingdom, phylum, class, order, family, genus, and species.

Species can be considered the basic unit of scientific classification. It is used to describe a group of closely related, physically similar organisms that can breed with one another. Members of the same species often are so close in features that it is difficult to tell them apart. For example, although a wolf and a dog look similar, they do not belong to the same species. The wolf belongs to the species lupus (Canis lupus), while the dog to the species familiaris (Canis familiaris). Some organisms, however, are more difficult to differentiate. This is the case with sunflowers of different species. Some species of organisms may differ very little in their conspicuous features, shape, behavior, and habitat. However, only members of the same species will share a common gene pool.

The only correct way to identify one species from another is by the binomial (two-word) scientific name. For example, the correct way to distinguish between two species of seabirds would be to use their binomial names: Sula sula and Sula nebouxii. In these examples, Sula is the genus name, while sula and nebouxii are the species names. (The species name is always the lowercase Latin word that follows the uppercase Latin genus word.) Very often, however, it is the common name for the species that is most used to refer to one particular type. So, for the example above, most people would refer to the two species of seabirds as the red-footed booby and the blue-footed booby instead of using the binomial scientific name.

[See alsoClass; Classification; Family; Genus; Kingdom; Order; Phylum ]