Editing Symbiosis (section)

==Major examples of co-evolutionary relationships== 

=== Mycorrhiza ===

About 80% of [[vascular plants]] worldwide form symbiotic relationships with fungi, in particular in [[arbuscular mycorrhiza]]s.<ref name="Schüßler-2001">{{cite journal |last1=Schüβler |first1=Arthur |last2=Schwarzott |first2=Daniel |last3=Walker |first3=Christopher |title=A new fungal phylum, the Glomeromycota: phylogeny and evolution |journal=Mycological Research |date=December 2001 |volume=105 |issue=12 |pages=1413–1421 |doi=10.1017/S0953756201005196 }}</ref> The mutualism evolved due to the limitation of plant root capacity for absorbing soil nutrients, especially phosphate and nitrogen, which are crucial for plant growth.<ref>{{Cite journal |last=Lee |first=Soon-Jae |date=2025-02-01 |title=Plants Are Not Independent Organisms: Introducing the Role of Mycorrhizal Fungi in Plant Roots with a Safe Method for Visualization |url=https://online.ucpress.edu/abt/article/87/2/139/206658/Plants-Are-Not-Independent-OrganismsIntroducing |journal=The American Biology Teacher |volume=87 |issue=2 |pages=139–144 |doi=10.1525/abt.2025.87.2.139 |issn=0002-7685|doi-access=free }}</ref><!--better source needed-->

=== Pollination ===

[[File:Hummingbird hawkmoth a.jpg|upright|thumb|Pollination is a mutualism between [[flowering plant]]s and their animal pollinators.]]

{{Further|Entomophily|Ornithophily|Reproductive coevolution in Ficus}}

[[Flowering plant]]s and the animals that [[pollinate]] them have co-evolved. Many plants that are pollinated by [[insect]]s (in [[entomophily]]), [[bat]]s, or [[bird]]s (in [[ornithophily]]) have highly specialized flowers modified to promote pollination by a specific pollinator that is correspondingly adapted. The first flowering plants in the fossil record had relatively simple flowers. Adaptive [[speciation]] quickly gave rise to many diverse groups of plants, and, at the same time, corresponding speciation occurred in certain [[Insect ecology#Symbiosis|insect groups]]. Some groups of plants developed nectar and large sticky pollen, while insects evolved more specialized morphologies to access and collect these rich food sources. In some taxa of plants and insects, the relationship has become dependent,<ref>{{Harvnb|Harrison|2002}}</ref> where the plant species can only be pollinated by one species of insect.<ref>{{Harvnb|Danforth|Ascher|1999}}</ref>

[[File:Ant - Pseudomyrmex species, on Bull Thorn Acacia (Acacia cornigera) with Beltian bodies, Caves Branch Jungle Lodge, Belmopan, Belize - 8505045055.jpg|thumb|''Pseudomyrmex'' ant on bull thorn acacia (''[[Vachellia cornigera]]'') with Beltian bodies that provide the ants with protein<ref name="Hölldobler-1990">{{cite book |last1=Hölldobler |first1=Bert |last2=Wilson |first2=Edward O. |author2-link=E. O. Wilson |url=https://archive.org/details/ants0000hlld |title=The Ants |publisher=Harvard University Press |year=1990 |isbn=978-0-674-04075-5 |pages=[https://archive.org/details/ants0000hlld/page/532 532]–533 |url-access=registration}}</ref>]]

=== Acacia ants and acacias ===

{{main|Pseudomyrmex ferruginea}}

The [[acacia ant]] (''Pseudomyrmex ferruginea'') is an obligate plant ant that protects at least five species of "Acacia" (''[[Vachellia]]''){{efn|The acacia ant protects at least 5 species of "Acacia", now all renamed to ''Vachellia'': ''[[Vachellia chiapensis|V. chiapensis]]'', ''[[Vachellia collinsii|V. collinsii]]'', ''[[Vachellia cornigera|V. cornigera]]'', ''[[Vachellia hindsii|V. hindsii]]'' and ''[[Vachellia sphaerocephala|V. sphaerocephala]]''.}} from preying insects and from other plants competing for sunlight, and the tree provides nourishment and shelter for the ant and its larvae.<ref name="Hölldobler-1990" /><ref>{{cite web|last=National Geographic|title=Acacia Ant Video|url=http://video.nationalgeographic.com/video/player/animals/bugs-animals/ants-and-termites/ant_acaciatree.html|url-status=dead|archive-url=https://web.archive.org/web/20071107085438/http://video.nationalgeographic.com/video/player/animals/bugs-animals/ants-and-termites/ant_acaciatree.html|archive-date=2007-11-07}}</ref>

=== Seed dispersal ===

{{Main|Seed dispersal syndrome}}

Seed dispersal is the movement, spread or transport of [[seed]]s away from the parent plant. Plants have limited mobility and rely upon a variety of [[dispersal vector]]s to transport their propagules, including both [[abiotic]] vectors such as the wind and living ([[Biotic component|biotic]]) vectors like birds. In order to attract animals, these plants evolved a set of morphological characters such as [[fruit]] colour, mass, and persistence correlated to particular seed dispersal agents.<ref>{{cite journal |last1=Tamboia|first1=Teri|last2=Cipollini|first2=Martin L.|last3=Levey|first3=Douglas J. |title=An evaluation of vertebrate seed dispersal syndromes in four species of black nightshade (Solanum sect. Solanum) |journal=Oecologia |volume=107 |issue=4 |pages=522–532 |date=September 1996 |pmid=28307396 |doi=10.1007/bf00333944 |bibcode=1996Oecol.107..522T }}</ref> For example, plants may evolve conspicuous fruit colours to attract avian frugivores, and birds may learn to associate such colours with a food resource.<ref>{{Cite journal |last1=Lim |first1=Ganges |last2=Burns |first2=Kevin C. |date=2021-11-24 |title=Do fruit reflectance properties affect avian frugivory in New Zealand? |journal=New Zealand Journal of Botany |volume=60 |issue=3 |pages=319–329 |doi=10.1080/0028825X.2021.2001664 }}</ref><!--need other examples here, preferably as subsections-->

=== Nitrogen fixation in legumes ===

{{further|Rhizobia}}

[[File:Soybean-root-nodules (cropped).jpg|thumb|upright=1.1|[[Root nodule]]s, each containing billions of ''[[Rhizobiaceae]]'' bacteria, fix nitrogen in symbiosis with a [[legume]]. ]]

'''Rhizobia''' are [[bacteria]] that [[Nitrogen fixation|fix nitrogen]] inside the [[root nodule]]s of [[legume]]s such as [[bean]]s and [[clover]]. To express genes for nitrogen fixation, rhizobia require a plant [[Host (biology)|host]]; they cannot independently fix nitrogen.<ref name="Zahran1999">{{Cite journal |last=Zahran |first=Hamdi Hussein |date=1999-12-01 |title=Rhizobium-legume symbiosis and nitrogen fixation under severe conditions and in an arid climate |journal=Microbiology and Molecular Biology Reviews |volume=63 |issue=4 |pages=968–989, table of contents |doi=10.1128/MMBR.63.4.968-989.1999 |pmc=98982 |pmid=10585971}}</ref> 
Rhizobia infect the legume's roots and produce nodules where they fix nitrogen gas (N<sub>2</sub>) from the atmosphere, turning it into a more readily useful form of nitrogen. From here, the nitrogen is exported and used for growth in the legume.<ref name="Herridge2013">{{cite journal |last=Herridge |first=David |title=Rhizobial Inoculants |journal=GRDC |date=2013}}</ref>

=== Lichens ===

{{main|Lichen}}

A '''lichen''' is a hybrid [[colony (biology)|colony]] of [[algae]] or [[cyanobacteria]] living symbiotically among the [[hypha|hyphal filaments]] of multiple species of [[fungus|fungi]] and other micro-organisms embedded in the outer layer or cortex, in a mutualistic relationship. Lichens are able to flourish in harsh environments such as bare rocks.<ref>{{Cite journal |last1=Grube |first1=Martin |last2=Cardinale |first2=Massimiliano |last3=de Castro |first3=João Vieira |last4=Müller |first4=Henry |last5=Berg |first5=Gabriele |date=1 September 2009 |title=Species-specific structural and functional diversity of bacterial communities in lichen symbioses |url=https://academic.oup.com/ismej/article/3/9/1105/7588287 |journal=The ISME Journal |volume=3 |issue=9 |pages=1105–1115 |doi=10.1038/ismej.2009.63 |pmid=19554038 |bibcode=2009ISMEJ...3.1105G}}</ref><ref>{{Cite journal |last1=Grube |first1=Martin |last2=Berg |first2=Gabriele |date=August 2009 |title=Microbial consortia of bacteria and fungi with focus on the lichen symbiosis |url=https://linkinghub.elsevier.com/retrieve/pii/S1749461309000219 |journal=Fungal Biology Reviews |language=en |volume=23 |issue=3 |pages=72–85 |doi=10.1016/j.fbr.2009.10.001|bibcode=2009FunBR..23...72G }}</ref><ref>{{Cite journal |last1=Spribille |first1=Toby |last2=Tuovinen |first2=Veera |last3=Resl |first3=Philipp |last4=Vanderpool |first4=Dan |last5=Wolinski |first5=Heimo |last6=Aime |first6=M. Catherine |last7=Schneider |first7=Kevin |last8=Stabentheiner |first8=Edith |last9=Toome-Heller |first9=Merje |date=2016-07-21 |title=Basidiomycete yeasts in the cortex of ascomycete macrolichens |journal=Science |doi=10.1126/science.aaf8287 |pmid=27445309 |pmc=5793994 |volume=353 |issue=6298 |pages=488–492 |bibcode=2016Sci...353..488S}}</ref>