Evolution
Main article: Evolution of fungi
In contrast to plants and animals, the early fossil record of the fungi is meager. Factors that likely contribute to the under-representation of fungal species among fossils include the nature of fungal fruiting bodies, which are soft, fleshy, and easily degradable tissues and the microscopic dimensions of most fungal structures, which therefore are not readily evident. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble extant fungi. Often recovered from a permineralized plant or animal host, these samples are typically studied by making thin-section preparations that can be examined with light microscopy or transmission electron microscopy. Researchers study compression fossils by dissolving the surrounding matrix with acid and then using light or scanning electron microscopy to examine surface details. # ISO certification in India
Prototaxites milwaukeensis (Penhallow, 1908)—a Middle Devonian fungus from Wisconsin
The earliest fossils possessing features typical of fungi date to the Paleoproterozoic era, some 2,400 million years ago (Ma); these multicellular benthic organisms had filamentous structures capable of anastomosis. Other studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups. For much of the Paleozoic Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant chytrids in having flagellum-bearing spores. The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization. Studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times. # ISO certification in India
In May 2019, scientists reported the discovery of a fossilized fungus, named Ourasphaira giraldae, in the Canadian Arctic, that may have grown on land a billion years ago, well before plants were living on land. Pyritized fungus-like microfossils preserved in the basal Ediacaran Doushantuo Formation (~635 Ma) have been reported in South China. Earlier, it had been presumed that the fungi colonized the land during the Cambrian (542–488.3 Ma), also long before land plants. Fossilized hyphae and spores recovered from the Ordovician of Wisconsin (460 Ma) resemble modern-day Glomerales, and existed at a time when the land flora likely consisted of only non-vascular bryophyte-like plants. Prototaxites, which was probably a fungus or lichen, would have been the tallest organism of the late Silurian and early Devonian. Fungal fossils do not become common and uncontroversial until the early Devonian (416–359.2 Ma), when they occur abundantly in the Rhynie chert, mostly as Zygomycota and Chytridiomycota. At about this same time, approximately 400 Ma, the Ascomycota and Basidiomycota diverged, and all modern classes of fungi were present by the Late Carboniferous (Pennsylvanian, 318.1–299 Ma). # ISO certification in India
Lichens formed a component of the early terrestrial ecosystems, and the estimated age of the oldest terrestrial lichen fossil is 415 Ma; this date roughly corresponds to the age of the oldest known sporocarp fossil, a Paleopyrenomycites species found in the Rhynie Chert. The oldest fossil with microscopic features resembling modern-day basidiomycetes is Palaeoancistrus, found permineralized with a fern from the Pennsylvanian. Rare in the fossil record are the Homobasidiomycetes (a taxon roughly equivalent to the mushroom-producing species of the Agaricomycetes). Two amber-preserved specimens provide evidence that the earliest known mushroom-forming fungi (the extinct species Archaeomarasmius leggetti) appeared during the late Cretaceous, 90 Ma. # ISO certification in India
Some time after the Permian–Triassic extinction event (251.4 Ma), a fungal spike (originally thought to be an extraordinary abundance of fungal spores in sediments) formed, suggesting that fungi were the dominant life form at this time, representing nearly 100% of the available fossil record for this period. However, the relative proportion of fungal spores relative to spores formed by algal species is difficult to assess,[ the spike did not appear worldwide, and in many places it did not fall on the Permian–Triassic boundary. # ISO certification in India
Sixty-five million years ago, immediately after the Cretaceous–Paleogene extinction event that famously killed off most dinosaurs, there was a dramatic increase in evidence of fungi; apparently the death of most plant and animal species led to a huge fungal bloom like “a massive compost heap”. # ISO certification in India
Taxonomy
Although commonly included in botany curricula and textbooks, fungi are more closely related to animals than to plants and are placed with the animals in the monophyletic group of opisthokonts. Analyses using molecular phylogenetics support a monophyletic origin of fungi. The taxonomy of fungi is in a state of constant flux, especially due to research based on DNA comparisons. These current phylogenetic analyses often overturn classifications based on older and sometimes less discriminative methods based on morphological features and biological species concepts obtained from experimental matings. # ISO certification in India
There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards. Efforts among researchers are now underway to establish and encourage usage of a unified and more consistent nomenclature. Until relatively recent (2012) changes to the International Code of Nomenclature for algae, fungi and plants, fungal species could also have multiple scientific names depending on their life cycle and mode (sexual or asexual) of reproduction. Web sites such as Index Fungorum and MycoBank are officially recognized nomenclatural repositories and list current names of fungal species (with cross-references to older synonyms).
The 2007 classification of Kingdom Fungi is the result of a large-scale collaborative research effort involving dozens of mycologists and other scientists working on fungal taxonomy. It recognizes seven phyla, two of which—the Ascomycota and the Basidiomycota—are contained within a branch representing subkingdom Dikarya, the most species rich and familiar group, including all the mushrooms, most food-spoilage molds, most plant pathogenic fungi, and the beer, wine, and bread yeasts. The accompanying cladogram depicts the major fungal taxa and their relationship to opisthokont and unikont organisms, based on the work of Philippe Silar, “The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research” and Tedersoo et al. 2018. The lengths of the branches are not proportional to evolutionary distances. # ISO certification in India
| Zoosporia | RozellomycetaRozellomycotaRozellomycetesMicrosporidiomycotaMitosporidiumParamicrosporidiumNucleophagaMetchnikovelleaMicrosporeaAphelidiomycetaAphelidiomycotaAphelidiomycetesEumycotaChytridiomycetaNeocallimastigomycotaNeocallimastigomycetesChytridiomycotaMonoblepharomycotinaHyaloraphidiomycetesMonoblepharidomycetesSanchytriomycetesChytridiomycotinaMesochytriomycetesChytridiomycetesBlastocladiomycetaBlastocladiomycotaBlastocladiomycetesPhysodermatomycetesAmastigomycotaZoopagomycetaBasidiobolomycotaBasidiobolomycetesOlpidiomycetesEntomophthoromycotaNeozygitomycetesEntomophthoromycetesKickxellomycotaZoopagomycotinaZoopagomycetesKickxellomycotinaDimargaritomycetesKickxellomycetesMortierellomycotaMortierellomycetesMucoromycetaCalcarisporiellomycotaCalcarisporiellomycetesMucoromycotaUmbelopsidomycetesMucoromycetesSymbiomycotaGlomeromycotaParaglomeromycetesArchaeosporomycetesGlomeromycetesDikaryaEntorrhizomycotaEntorrhizomycetesBasidiomycotaAscomycota |
| Basidiomycota | PucciniomycotinaTritirachiomycetesMixiomycetesAgaricostilbomycetesCystobasidiomycetesClassiculaceaeMicrobotryomycetesCryptomycocolacomycetesAtractiellomycetesPucciniomycetesOrthomycotinaUstilaginomycotinaMonilielliomycetesMalasseziomycetesUstilaginomycetesExobasidiomycetesAgaricomycotina?Geminibasidiomycetes?WallemiomycetesBartheletiomycetesTremellomycetesDacrymycetesAgaricomycetes |
| Ascomycota | TaphrinomycotinaNeolectomycetesTaphrinomycetesSchizosaccharomycetaArchaeorhizomycetesPneumocystidomycetesSchizosaccharomycetesSaccharomycetaSaccharomycotinaSaccharomycetesPezizomycotina?Thelocarpales?Vezdaeales?Lahmiales?TriblidialesOrbiliomycetesPezizomycetesLeotiomycetaSordariomycetaXylonomycetesGeoglossomycetesLeotiomycetesLaboulbeniomycetesSordariomycetesDothideomycetaConiocybomycetesLichinomycetesEurotiomycetesLecanoromycetesCollemopsidiomycetesArthoniomycetesDothideomycetes |