Living fossil

[[File:Coelacanth.png|thumb|right|Coelacanths have changed quite a bit since ''{{wpl|Styloichthys}}''. The claim that they have remained completely unchanged is simply untrue.]]{{evolution}}[[File:Lingula-Ozamis-1.JPG|thumb|right|A living ''Lingula'' that's actually similar to its ancestors 450 million years ago.]]
A '''living fossil''' is a species (or sometimes a [[Taxonomy|higher group]]) that has an extensive [[fossil record]] but also retains known living specimens. [[Creationism|Creationists]] love them as they believe that such things appear to deny [[evolution]], not realising that morphological adaptations are not selected in a stable environment. Living fossils are sometimes {{wpl|Lazarus taxa}}, ''i.e.'' they disappear from the fossil record and are presumed extinct but are later found alive.

==Selected examples==

* The '''[[coelacanth]]''' is said to be a living fossil that has not changed at all between its fossil form and the living fish we know today,<ref>http://www.creationtips.com/coelacanth.html</ref> but this is a wildly inaccurate assessment.<ref name="Casane">Casane D and Laurenti P. "Why Coelacanths are not "Living fossils" : a Review of Molecular and Morphological Data" ''Bioessays'' 2013 Feb 4, doi|10.1002/bies.201200145</ref> The most common misconception about the coelacanth is that the living ''Latimeria'' is of the same sort as the Palaeozoic and Mesozoic coelacanth. Although it is related to an ''order'' of much smaller fish from millions of years ago, coelacanths make up an entire order (Coelacanthiformes) of which the ''Latimeria'' is the sole living survivor. (By comparison, the order that humans belong to is the primates, so claiming coelacanths haven't changed in all those years is like claiming that humans are identical to early monkeys.) The gap throughout the Cenozoic is because the coelacanth's current habitat is in deep water, where fossilisation rarely happens. 
* The '''dawn redwood''' ''Metasequoia'' was thought to be extinct, until a grove of them was found in [[China]] in the mid-20th century. It is related to similar species that lived until about 5 million years ago.
* One sort of brachiopod, the '''''{{wpl|Lingula||''''',}} has a fossil record extending to the Ordovician, with close relatives going all the way to the [[Cambrian]].
* The {{wpl|horseshoe crab||,}} virtually unchanged in 250 million years. Or perhaps not, what with ''{{wpl|Austrolimulus}}'' looking more like the head of a trident than a modern horseshoe crab.

==History of term==
[[Charles Darwin]] coined the term "living fossil" in ''[[The Origin of Species]]''.  In reference to several genera of fresh water fish, he noted:

{{quotebox|These anomalous forms may almost be called '''living fossils'''; they have endured to the present day, from having inhabited a confined area, and from having thus been exposed to less severe competition.
<ref>"[http://darwin.thefreelibrary.com/The-Origin-of-Species/4-1-2 Chapter IV.-NATURAL SELECTION (Page 2)]," The Free Library.</ref>}}

Note that Darwin also provides an explanation as to why living fossils do not contradict the tenets of evolution.

Since then, creationists have latched onto living fossils, believing they provide [[evidence]] against evolution.  [[Harun Yahya]] explains it:

{{quotebox|Countless living things have remained unchanged for millions of years, and their current anatomical structures are [[bullshit|exactly the same]] as they were millions of years ago. The fossil record is almost complete with both animal and plant specimens demonstrating this. It definitively and [[not even wrong|scientifically refutes]] evolution. <ref>"[http://www.living-fossils.com/4_1.php Living Fossils Refute Evolution]," living-fossils.com.</ref>}}

This [[Creationist claims|claim]] fails to recognise that, although evolution [[Prediction|predicts]] that species can change, it does not require that species must change. <ref>See [[Talk.origins|Talk Origins]]' page on [http://www.talkorigins.org/indexcc/CB/CB930.html fossil species still living].</ref>  This is due in part to a misunderstanding of how evolution resulted in the development of new species.  Yahya further explains:

{{quotebox|According to the theory, all living things have descended from various "ancestral" forms. A living species that existed before gradually turned into another species, and every present species emerged in this way. According to the theory, this transition took place slowly over hundreds of millions of years and progressed in stages. That being the case, countless numbers of "intermediate forms" must have emerged and lived over the long process of transition in question. <ref>"[http://www.living-fossils.com/1_1.php The Origin of Species According to the Fossil Records]."</ref>}}

This interpretation assumes that the tempo of evolution is gradual and steady.  Contrary to this assumption, the mode of evolution proposed by Darwin, while incremental, is not equivalent to [[phyletic gradualism]]. <ref>Douglas, Theobald (2001).  "[https://www.molevo.org/PE.html All you need to know about Punctuated Equilibrium (almost)]."</ref>  Thus it is unlikely that diversification took place because one species "gradually turned into another species."  As indicated by the fossil evidence, most new species probably developed by rapidly branching from ancestral species followed by long periods of evolutionary stasis. 

Today, the mechanism is known: when selection pressure is lessened, or favors traits the organism already possesses to be successful in the current niche, {{wpl|stabilizing selection|stabilizing selection}} occurs, which favors the existing, successful body plan; stabilizing selection is the opposite of {{wpl|Disruptive selection|disruptive selection}}.

Some living fossils like [[lungfish]] can be problematic for creationists.

==Elvis taxon==

An Elvis taxon is a species or higher group that has been misidentified as reappearing after presumed [[extinction]]. These examples may appear to have some similarities with older and/or extinct species&mdash;but unlike other [[living fossil]]s are not actual descendants of them. The similarities are just coincidental, most likely due to [[convergent evolution]], making the Elvis taxon polyphyletic with its extinct "ancestor".

The term comes from [[Elvis Presley]], and references the countless Elvis impersonators that have cropped up since his death. They may look like Elvis, but they're not actually related to him.

==Zombie taxon==
A related phenomenon, a zombie taxon is a reworked fossil that was washed out of the original rocks and re-deposited in later sediments. The name is a play on the fact that the fossil moved after the animals death kinda like a zombie.<ref>Archibald, David. Zombie Origins ''[[New Scientist]]'' '''193''' 27 2007-03-24 2596 [https://www.newscientist.com/article/mg19325961.300-zombie-origins.html url] doi:10.1016/s0262-4079(07)60736-2 [https://web.archive.org/web/20200401033719/https://www.newscientist.com/article/mg19325961.300-zombie-origins.html archive url]</ref>

==Lazarus taxon==
A Lazarus taxon (plural taxa) is a taxon that disappears for one or more periods from the fossil record, only to appear again later (either later in the fossil record or alive today). The term is exclusively used to refer to gaps in the fossil record wherein the taxon is believed to have become extinct at one point only to be found in later strata afterwards.
The term refers to the story in the Christian biblical Gospel of John, in which Jesus Christ raised Lazarus from the dead. The gap between the Lazarus taxon and the last previous known member is referred to as a ghost lineage, although the term ghost lineage can refer to any gap in the record. 

The coelacanth is an example of a Lazarus taxon. The longest ghost lineage is the {{wpl|Monoplacophora}}, a class of molluscs that were originally believed to have become extinct 388 million years ago before living members were described from deep waters of Costa Rica in 1952 with Pleistocene fossils being recovered in the late 80s early 90s. 

==See also==
*[[Fossil]]
*[[How come there are still monkeys?]]
*[[Linnaean taxonomy]]
*[[Punctuated equilibrium]]
*[[Cryptozoology]] — most of which are completely fake, but a few of which are for alleged sightings of [[extinct]] animals: ''[[Basilosaurus]]'', ''[[Gigantopithecus]]'', and [[thylacine]]

==External links==
* Neyman, Greg (April 13, 2005).  "[http://www.answersincreation.org/livingfossil.htm Creation Science Rebuttals:  Living Fossils]."  Answers in Creation.
* [http://creationwiki.org/Living_fossil Living Fossil] on CreationWiki
* Morris, Henry.  "[http://www.icr.org/index.php?module=articles&action=view&ID=774 The Profusion of Living Fossils]."  Institute for Creation Research.  (suggests dinosaurs were living fossils "called dragons")

==References==
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[[Category:Evolution]]
[[Category:Creationism]]

Categories: Evolution, Creationism