Changes

==Etymology==

==Etymology==

[http://nordan.daynal.org/wiki/index.php?title=English#ca._1100-1500_.09THE_MIDDLE_ENGLISH_PERIOD Middle English], from [[Latin]] exstinctus, past participle of exstinguere

[https://nordan.daynal.org/wiki/index.php?title=English#ca._1100-1500_.09THE_MIDDLE_ENGLISH_PERIOD Middle English], from [[Latin]] exstinctus, past participle of exstinguere

*Date: [http://www.wikipedia.org/wiki/15th_Century 15th century]

*Date: [https://www.wikipedia.org/wiki/15th_Century 15th century]

==Definitions==

==Definitions==

*1 a : no longer burning  

*1 a : no longer burning  

:b : having no qualified claimant <an extinct title>

:b : having no qualified claimant <an extinct title>

==Description==

==Description==

In [[biology]] and [[ecology]], '''extinction''' is the end of an [[organism ]] or [[group]] of [http://en.wikipedia.org/wiki/Taxon taxa]. The [[moment]] of extinction is generally [[considered]] to be the [[death]] of the last [[individual]] of that [[species]] (although the capacity to [[Reproduction|breed]] and recover may have been lost before this point). 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 [http://en.wikipedia.org/wiki/Lazarus_taxon Lazarus taxa], where a [[species]] presumed extinct abruptly "re-appears" (typically in the [http://en.wikipedia.org/wiki/Fossil fossil record]) after a period of [[apparent]] [[absence]].

In [[biology]] and [[ecology]], '''extinction''' is the end of an [[organism ]] or [[group]] of [https://en.wikipedia.org/wiki/Taxon taxa]. The [[moment]] of extinction is generally [[considered]] to be the [[death]] of the last [[individual]] of that [[species]] (although the capacity to [[Reproduction|breed]] and recover may have been lost before this point). 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 [https://en.wikipedia.org/wiki/Lazarus_taxon Lazarus taxa], where a [[species]] presumed extinct abruptly "re-appears" (typically in the [https://en.wikipedia.org/wiki/Fossil fossil record]) after a period of [[apparent]] [[absence]].

Through [[evolution]], new [[species]] arise through the [[process]] of [http://en.wikipedia.org/wiki/Speciation speciation]—where new varieties of [[organisms]] arise and thrive when they are able to find and exploit an [http://en.wikipedia.org/wiki/Ecological_niche ecological niche]—and species become extinct when they are no longer able [[to]] survive in changing conditions or against superior [[competition]]. A typical species becomes extinct within 10 million years of its first [[appearance]], although some [[species]], called [http://en.wikipedia.org/wiki/Living_fossil living fossils], [[survive]] virtually unchanged for hundreds of millions of years. Extinction, though, is usually a [[natural]] [[phenomenon]]; it is estimated that 99.9% of all species that have ever lived are now extinct.

Through [[evolution]], new [[species]] arise through the [[process]] of [https://en.wikipedia.org/wiki/Speciation speciation]—where new varieties of [[organisms]] arise and thrive when they are able to find and exploit an [https://en.wikipedia.org/wiki/Ecological_niche ecological niche]—and species become extinct when they are no longer able [[to]] survive in changing conditions or against superior [[competition]]. A typical species becomes extinct within 10 million years of its first [[appearance]], although some [[species]], called [https://en.wikipedia.org/wiki/Living_fossil living fossils], [[survive]] virtually unchanged for hundreds of millions of years. Extinction, though, is usually a [[natural]] [[phenomenon]]; it is estimated that 99.9% of all species that have ever lived are now extinct.

[http://en.wikipedia.org/wiki/Extinction_event Mass extinctions] are [[relatively]] rare [[events]]; however, isolated extinctions are quite common. Only recently have extinctions been [[recorded]] and [[scientists]] have become alarmed at the high rates of recent extinctions. It is estimated most [[species]] that go extinct have never been [[documented]] by scientists. Some scientists estimate that up to half of presently existing species may become extinct by 2100.[http://en.wikipedia.org/wiki/Extinction]

[https://en.wikipedia.org/wiki/Extinction_event Mass extinctions] are [[relatively]] rare [[events]]; however, isolated extinctions are quite common. Only recently have extinctions been [[recorded]] and [[scientists]] have become alarmed at the high rates of recent extinctions. It is estimated most [[species]] that go extinct have never been [[documented]] by scientists. Some scientists estimate that up to half of presently existing species may become extinct by 2100.[https://en.wikipedia.org/wiki/Extinction]

[[Category: Biology]]

[[Category: Biology]]