Subspecies

From EvoWiki

Subspecies is the taxonomic rank immediately subordinate to a species. It is a taxonomic group which is less distinct than the primary stock or species from which it originates. The characteristics attributed to subspecies are generally derived from changes that have taken place or evolved as a result of geographical distribution or isolation from the primary species or nominate form (see below), also called nominate subspecies. In layman's terms, a subspecies may also be described as a diversification of the primary species since a subspecies always has the nominate form or primary species as its common ancestor, i.e. it always originates from a common ancestral stock.