Editing Lichen (section)

==History==
[[File:Haeckel Lichenes.jpg|thumb|"Lichenes" fancifully drawn by [[Ernst Haeckel]] to emphasize his ideas of symmetry in his ''[[Kunstformen der Natur|Artforms of Nature]]'', 1904]]

Although lichens had been recognized as organisms for quite some time, it was not until 1867, when Swiss botanist [[Simon Schwendener]] proposed his dual theory of lichens, that lichens are a combination of fungi with algae or cyanobacteria, whereby the true nature of the lichen association began to emerge.<ref name=Honegger2000/> Schwendener's hypothesis, which at the time lacked experimental evidence, arose from his extensive analysis of the anatomy and development in lichens, algae, and fungi using a [[light microscopy|light microscope]]. Many of the leading lichenologists at the time, such as [[James Mascall Morrison Crombie|James Crombie]] and [[William Nylander (botanist)|Nylander]], rejected Schwendener's hypothesis because the consensus was that all living organisms were autonomous.<ref name=Honegger2000/>

Other prominent biologists, such as [[Heinrich Anton de Bary]], [[Albert Bernhard Frank]], [[Beatrix Potter]], [[Melchior Treub]] and [[Hermann Hellriegel]], were not so quick to reject Schwendener's ideas and the concept soon spread into other areas of study, such as microbial, plant, animal and human pathogens.<ref name=Honegger2000/><ref name=Treub1873/><ref>{{Cite book|last=Wakeford|first=Tom|url=http://worldcat.org/oclc/922973303|title=Liaisons of Life : From Hornworts to Hippos, How the Unassuming Microbe Has Driven Evolution.|date=2002|publisher=John Wiley & Sons, Incorporated|isbn=978-0-470-24400-5|oclc=922973303}}</ref> When the complex relationships between pathogenic microorganisms and their hosts were finally identified, Schwendener's hypothesis began to gain popularity. Further experimental proof of the dual nature of lichens was obtained when [[Eugen Thomas]] published his results in 1939 on the first successful re-synthesis experiment.<ref name=Honegger2000/>

In the 2010s, a new facet of the fungi–algae partnership was discovered. [[Toby Spribille]] and colleagues found that many types of lichen that were long thought to be [[ascomycota|ascomycete]]–algae pairs were actually ascomycete–[[basidiomycota|basidiomycete]]–algae trios. The third symbiotic partner in many lichens is a basidiomycete yeast.<ref name="pmid_27445309"/><ref name="Yong_2016-07-21">{{Citation |last=Yong |first=Ed |author-link=Ed Yong |date=2016-07-21 |title=How a guy from a Montana trailer park overturned 150 years of biology |journal=The Atlantic |url=https://www.theatlantic.com/science/archive/2016/07/how-a-guy-from-a-montana-trailer-park-upturned-150-years-of-biology/491702/ |access-date=2017-07-23 |postscript=. |archive-url=https://web.archive.org/web/20170723161812/https://www.theatlantic.com/science/archive/2016/07/how-a-guy-from-a-montana-trailer-park-upturned-150-years-of-biology/491702/ |archive-date=23 July 2017 |url-status=live }}</ref>