Editing Homology (biology) (section)

===Homology vs. analogy===
[[File:Acer pseudoplatanus MHNT.BOT.2004.0.461.jpg|thumb|upright=0.7|[[Sycamore maple]] fruits have wings [[Convergent evolution|analogous]] but not homologous to an insect's wings.]]
{{further|Convergent evolution}}

The opposite of homologous organs are analogous organs which do similar jobs in two taxa that were not [[Phylogenetic tree|present in their most recent common ancestor]] but, rather, [[convergent evolution|evolved separately]]. For example, the [[insect wing|wings of insects]] and birds evolved independently in [[Phylum|widely separated groups]], and converged functionally to support powered [[flight]], so they are analogous. Similarly, the wings of a [[sycamore maple]] seed and the wings of a bird are analogous but not homologous, as they develop from quite different structures.<ref>{{cite web |title=Secret Found to Flight of 'Helicopter Seeds' |url=http://www.livescience.com/3672-secret-flight-helicopter-seeds.html |publisher=LiveScience |access-date=2 March 2017 |date=11 June 2009}}</ref><ref>{{cite journal |last1=Lentink, D. |last2=Dickson, W. B. |last3=van Leeuwen, J. L. |last4=Dickinson, M. H. |title=Leading-Edge Vortices Elevate Lift of Autorotating Plant Seeds |journal=Science |date=12 June 2009 |volume=324 |issue=5933 |pages=1438–1440 |doi=10.1126/science.1174196 |pmid=19520959 |bibcode=2009Sci...324.1438L |s2cid=12216605 |url=http://authors.library.caltech.edu/14781/2/Lentink2009p4415Science_supp.pdf }}</ref> A structure can be homologous at one level, but only analogous at another. [[Pterosaur]], [[Bird flight|bird]] and [[bat wing]]s are analogous as wings, but homologous as forelimbs because the organ served as a forearm (not a wing) in the last common ancestor of [[tetrapod]]s, and evolved in different ways in the three groups. Thus, in the pterosaurs, the "wing" involves both the forelimb and the hindlimb.<ref name=Scotland2010>{{Cite journal | last=Scotland | first=R. W. | title=Deep homology: A view from systematics | doi=10.1002/bies.200900175 | journal=BioEssays | volume=32 | issue=5 | pages=438–449 | year=2010 | pmid=20394064| s2cid=205469918 }}</ref> Analogy is called [[homoplasy]] in [[cladistics]], and [[convergent evolution|convergent or parallel evolution]] in evolutionary biology.<ref>Cf. Butler, A. B.: ''Homology and Homoplasty.'' In: Squire, Larry R. (Ed.): ''Encyclopedia of Neuroscience'', Academic Press, 2009, pp. 1195–1199.</ref><ref>{{cite web |url=http://explainry.com/difference-between/homologous-analogous-structures/ |title=Homologous structure vs. analogous structure: What is the difference? |access-date=27 September 2016}}</ref>