In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and environmental conditions, though this is not always so. Killer whales (orcas) are among the most widely known cosmopolitan species on the planet, as they maintain several different resident and transient populations in every major oceanic body on Earth, from the Arctic Circle to Antarctica and every coastal and open-water region in-between. Such a taxon is said to have a cosmopolitan distribution, or exhibit cosmopolitanism, as a species; another example, the rock dove, in addition to having been bred domestically for centuries, now occurs in most urban areas around the world.