Glossary
Species
The basic unit of classification: a group of organisms treated as one kind and given a two-part scientific name.
A species is the rank at which an animal gets its own page on this site. Biologists use several definitions; the most familiar is a group of animals that can breed with one another and produce fertile young.
Where to draw the line between two species is sometimes revised as evidence changes, which is why names and counts shift between editions of a classification.
Related terms
- Scientific name
- The formal two-part name of a species, written in italics: the genus, then the species.
- Genus
- A rank below family: a group of closely related species. It is the first word of a scientific name.
- Subspecies
- A named population within a species that differs consistently from others, usually by region.
- Taxon
- Any named group in a classification, at any rank: a species, a family, a class.