An Evolutionary Significant Unit (ESU) is a group that is considered distinct for purposes of conservation under the Endangered Species Act. This term can apply to any species, subspecies, geographic race, or population. To qualify as an ESU, a population must 1) be substantially reproductively isolated from other conspecific populations, and 2) represent an important component in the evolutionary legacy of the biological species (Waples 1991). The conservation ethic is an ethic of resource use, allocation, exploitation, and protection. ... [[Image:{{npov}} {{expert-subject|Law}} The Endangered Species Act (, et seq. ... In biology, a species is one of the basic units of biodiversity. ... In zoology, as in other branches of biology, subspecies is the rank immediately subordinate to a species. ...

Equivalent terms

The equivalent term used by COSEWIC is Wildlife Species, or for brevity just species, which is used to refer to species, subspecies, varieties, or geographically or genetically distinct populations of organisms. [1]

References

Waples, R. S. 1991. Pacific salmon, Oncorhynchus spp., and the definition of "species" under the Endangered Species Act. Mar. Fish. Rev. 53(3):11-22.