Editing Fluorescence (section)

==== Evolutionary origins ====
The incidence of fluorescence across the [[tree of life]] is widespread, and has been studied most extensively in cnidarians and fish. The phenomenon appears to have evolved multiple times in multiple [[Taxon|taxa]] such as in the anguilliformes (eels), gobioidei (gobies and cardinalfishes), and tetradontiformes (triggerfishes), along with the other taxa discussed later in the article. Fluorescence is highly genotypically and phenotypically variable even within ecosystems, in regards to the wavelengths emitted, the patterns displayed, and the intensity of the fluorescence. Generally, the species relying upon camouflage exhibit the greatest diversity in fluorescence, likely because camouflage may be one of the uses of fluorescence.<ref name="sparks">{{Cite journal | last1 = Sparks | first1 = J. S. | last2 = Schelly | first2 = R. C. | last3 = Smith | first3 = W. L. | last4 = Davis | first4 = M. P. | last5 = Tchernov | first5 = D. | last6 = Pieribone | first6 = V. A. | last7 = Gruber | first7 = D. F. | editor1-last = Fontaneto | editor1-first = Diego | title = The Covert World of Fish Biofluorescence: A Phylogenetically Widespread and Phenotypically Variable Phenomenon | doi = 10.1371/journal.pone.0083259 | journal = PLOS ONE| volume = 9 | issue = 1 | pages = e83259 | year = 2014 | pmid =  24421880| pmc = 3885428|bibcode = 2014PLoSO...983259S | doi-access = free }}</ref>

[[File:Observed occurrences of green and red biofluorescence in Actinopterygii - journal.pone.0083259.g002.png|thumb|alt=Observed occurrences of green and red biofluorescence in Actinopterygii|Fluorescence has multiple origins in the tree of life. This diagram displays the origins within actinopterygians (ray finned fish).]]

It is suspected by some scientists that [[Green fluorescent protein|GFPs]] and GFP-like proteins began as electron donors activated by light. These electrons were then used for reactions requiring light energy. Functions of fluorescent proteins, such as protection from the sun, conversion of light into different wavelengths, or for signaling are thought to have evolved secondarily.<ref name="Biology of underwater fluorescence">{{cite web|last1=Beyer|first1=Steffen|title=Biology of underwater fluorescence|url=https://translate.google.com/translate?sl=de&tl=en&prev=_t&hl=en&ie=UTF-8&u=http://www.fluopedia.org/publications/deutsch/biologie/|website=Fluopedia.org|access-date=19 January 2022|archive-date=30 July 2020|archive-url=https://web.archive.org/web/20200730070159/https://translate.google.com/translate?sl=de&tl=en&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.fluopedia.org%2Fpublications%2Fdeutsch%2Fbiologie%2F|url-status=live}}</ref>