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Extinction

Extinction is the termination of a taxon by the death of its last member. A taxon may become functionally extinct before the death of its 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, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence.

"Extinct" redirects here. For other uses, see Extinct (disambiguation) and Extinction (disambiguation). For lists, see Lists of extinct species.

More than 99% of all species that ever lived on Earth, amounting to over five billion species,[1] are estimated to have died out.[2][3][4][5] It is estimated that there are currently around 8.7 million species of eukaryote globally,[6] and possibly many times more if microorganisms, like bacteria, are included.[7] Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, mammoths, ground sloths, thylacines, trilobites, and golden toads.


Through evolution, species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition. The relationship between animals and their ecological niches has been firmly established.[8] A typical species becomes extinct within 10 million years of its first appearance,[5] although some species, called living fossils, survive with little to no morphological change for hundreds of millions of years.


Mass extinctions are relatively rare events; however, isolated extinctions of species and clades are quite common, and are a natural part of the evolutionary process.[9] Only recently have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions.[10][11][12][13][14] Most species that become extinct are never scientifically documented. Some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100.[15] A 2018 report indicated that the phylogenetic diversity of 300 mammalian species erased during the human era since the Late Pleistocene would require 5 to 7 million years to recover.[16]


According to the 2019 Global Assessment Report on Biodiversity and Ecosystem Services by IPBES, the biomass of wild mammals has fallen by 82%, natural ecosystems have lost about half their area and a million species are at risk of extinction—all largely as a result of human actions. Twenty-five percent of plant and animal species are threatened with extinction.[17][18][19] In a subsequent report, IPBES listed unsustainable fishing, hunting and logging as being some of the primary drivers of the global extinction crisis.[20]


In June 2019, one million species of plants and animals were at risk of extinction. At least 571 plant species have been lost since 1750, but likely many more. The main cause of the extinctions is the destruction of natural habitats by human activities, such as cutting down forests and converting land into fields for farming.[21]


A dagger symbol (†) placed next to the name of a species or other taxon normally indicates its status as extinct.

(the last know member died circa 1768)

Steller's sea cow

(the last confirmed sighting was in 1662)

Dodo

(last seen in 2003; declared extinct in 2022)

Chinese paddlefish

(last confirmed pair was killed in the 1840s)

Great auk

(the last thylacine killed in the wild was shot in 1930; the last captive tiger lived in Hobart Zoo until 1936)

Thylacine

(last known member was heard in 1987; the entire Mohoidae family became extinct with it)

Kauai O'o

(last known members were said to live in the 1850s)

Spectacled cormorant

(last known member named Incas died in captivity in 1918; declared extinct in 1939)

Carolina parakeet

(last known member named Martha died in captivity in 1914)

Passenger pigeon

(the last claimed sighting of the emu was in 1839)

Tasmanian emu

(the last confirmed record was a juvenile specimen captured in 1974)

Japanese Sea Lion

(became extinct in the wild in 1932; the last captive deer was killed in 1938)

Schomburgk's deer

(hunted to extinction in the late 19th century; the last captive quagga died in Natura Artis Magistra in 1883)

Quagga

Examples of species and subspecies that are extinct include:

The virus is now extinct in the wild,[110] although samples are retained in laboratory settings.

smallpox

The virus, which infected domestic cattle, is now extinct in the wild.[111]

rinderpest

Pelley, Scott (1 January 2023). . CBS News.

"Scientists say planet in midst of sixth mass extinction, Earth's wildlife running out of places to live"

Committee on recently extinct organisms

series in The Guardian

The age of extinction