A species (pl.: species) is a population of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring...

An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction...

An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological...

introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a...

In zoological nomenclature, a type species (species typica) is the species name with which the name of a genus or subgenus is considered to be permanently...

On the Origin of Species (or, more completely, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle...

precise meanings are cryptic species for two or more species hidden under one species name, sibling species for two (or more) species that are each other's closest...

last member if it loses the capacity to reproduce and recover. Because a species' potential range may be very large, determining this moment is difficult...

the IUCN Red List of Threatened Species identified 5220 (2754 animals, 1 fungus, 2464 plant, 1 protist) endangered species, subspecies and varieties, stocks...

number of lists of fictional species: List of fictional extraterrestrials (by media type) Lists of fictional alien species: A, B, C, D, E, F, G, H, I,...