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Cordyceps Unilateralis
''Ophiocordyceps unilateralis'', commonly known as zombie-ant fungus, is an insect-pathogenic fungus, discovered by the British naturalist Alfred Russel Wallace in 1859, and currently found predominantly in tropical forest ecosystems. ''O. unilateralis'' infects ants of the tribe Camponotini, with the full pathogenesis being characterized by alteration of the behavioral patterns of the infected ant. Infected hosts leave their canopy nests and foraging trails for the forest floor, an area with a temperature and humidity suitable for fungal growth; they then use their mandibles to attach themselves to a major vein on the underside of a leaf, where the host remains after its eventual death. The process leading to mortality takes 4–10 days, and includes a reproductive stage where fruiting bodies grow from the ant's head, rupturing to release the fungus's spores. ''O. unilateralis'' is, in turn, also susceptible to fungal infection itself, an occurrence that can limit its impact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis René Tulasne
Louis René Étienne Tulasne, a.k.a. Edmond Tulasne (12 September 1815 – 22 December 1885) was a French botanist and mycologist born in Azay-le-Rideau. He originally studied law at Poitiers, but his interest later turned to botany. As a young man he assisted botanist Auguste de Saint-Hilaire (1779–1853) with studies of Brazilian flora. From 1842 until 1872 he worked as a naturalist at the Muséum national d'histoire naturelle in Paris. In 1854 he succeeded Adrien-Henri de Jussieu (1797–1853) as a member of the Académie des sciences. He died in Hyères on 22 December 1885, age 70. Tulasne's specialized study was the science of mycology. His microscopic investigation of fungi, particularly parasitic species, contributed much to the understanding on the complexities of their nature and development. He is credited with introducing the concept of " pleomorphy" in regard to fungi. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clavicipitaceae
The Clavicipitaceae are a family of fungi within the order Hypocreales. A 2008 estimate placed 43 genera in the family, but recent work has increased this number to 97. Phylogeny Molecular phylogenetic analysis of multigene DNA sequence data indicates the taxon Clavicipitaceae is paraphyletic, and consists of three well-defined clades, at least one of which is shared with members of another fungal family (Hypocreaceae). The evolution within the Clavicipitaceae is marked by interkingdom host jumping, and the range of this large and heterogeneous fungal group spans mutualistic plant symbionts, as well as parasites of plants, insects, and other fungi. Significance Many of its members produce alkaloids toxic to animals and humans. One of its most infamous species is ''Claviceps purpurea'', which has historical significance as the cause of St. Anthony's fire, also known as ergotism. Ergotism is caused by ergot alkaloids, such as ergotamine and ergocristine, which are chemical d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septation
In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interatrial septum, the wall of tissue that is a sectional part of the left and right atria of the heart * Interventricular septum, the wall separating the left and right ventricles of the heart * Lingual septum, a vertical layer of fibrous tissue that separates the halves of the tongue. *Nasal septum: the cartilage wall separating the nostrils of the nose * Alveolar septum: the thin wall which separates the alveoli from each other in the lungs * Orbital septum, a palpebral ligament in the upper and lower eyelids * Septum pellucidum or septum lucidum, a thin structure separating two fluid pockets in the brain * Uterine septum, a malformation of the uterus * Vaginal septum, a lateral or transverse partition inside the vagina * Intermuscular sep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascoma
An ascocarp, or ascoma (), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascocarps are most commonly bowl-shaped (apothecia) but may take on a spherical or flask-like form that has a pore opening to release spores (perithecia) or no opening (cleistothecia). Classification The ascocarp is classified according to its placement (in ways not fundamental to the basic taxonomy). It is called ''epigeous'' if it grows above ground, as with the morels, while underground ascocarps, such as truffles, are termed ''hypogeous''. The structure enclosing the hymenium is divided into the types described below (apothecium, cleistothecium, etc.) and this character ''is'' important for the taxonomic classification of the fungus. Apothecia can be relatively large and fleshy, whereas the others are microscopic—about the size of flecks of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myrmecophilous
Myrmecophily ( , ) is the term applied to positive interspecies associations between ants and a variety of other organisms, such as plants, other arthropods, and fungi. Myrmecophily refers to mutualistic associations with ants, though in its more general use, the term may also refer to commensal or even parasitic interactions. The term "myrmecophile" is used mainly for animals that associate with ants. An estimated 10,000 species of ants (Formicidae) are known, with a higher diversity in the tropics.B. Holldobler and E.O. Wilson, The Ants, Cambridge, Massachusetts: The Belknap Press of Harvard University Press, 1990. In most terrestrial ecosystems, ants are ecologically and numerically dominant, being the main invertebrate predators. As a result, ants play a key role in controlling arthropod richness, abundance, and community structure.K. Fiedler, B. Holldobler, and P. Seufert, "Butterflies and ants: The communicative domain," Cellular and molecular life sciences, vol. 52, 1996 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clades
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between organisms t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speciation
Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book ''On the Origin of Species''. He also identified sexual selection as a likely mechanism, but found it problematic. There are four geographic modes of speciation in nature, based on the extent to which speciating populations are isolated from one another: allopatric speciation, allopatric, peripatric speciation, peripatric, parapatric speciation, parapatric, and sympatric speciation, sympatric. Speciation may also be induced artificially, through animal husbandry, agriculture, or laboratory experiments of speciation, laboratory experiments. Whether genetic drift is a minor or major contributor to speciation is the subject of much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive Isolation
The mechanisms of reproductive isolation are a collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation. They prevent members of different species from producing offspring, or ensure that any offspring are sterile. These barriers maintain the integrity of a species by reducing gene flow between related species.Strickberger, M. 1978. ''Genética''. Omega, Barcelona, España, p.: 874-879. .Futuyma, D. 1998. ''Evolutionary biology'' (3ª edición). Sinauer, Sunderland. The mechanisms of reproductive isolation have been classified in a number of ways. Zoologist Ernst Mayr classified the mechanisms of reproductive isolation in two broad categories: pre-zygotic for those that act before fertilization (or before mating in the case of animals) and post-zygotic for those that act after it.Mayr, E. 1963. ''Animal species and evolution''. Harvard University Press, Cambridge. The mechanisms are genetically controlled and can appear in species whose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Complex
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each other, further blurring any distinctions. Terms that are sometimes used synonymously but have more precise meanings are cryptic species for two or more species hidden under one species name, sibling species for two (or more) species that are each other's closest relative, and species flock for a group of closely related species that live in the same habitat. As informal taxonomic ranks, species group, species aggregate, macrospecies, and superspecies are also in use. Two or more taxa that were once considered conspecific (of the same species) may later be subdivided into infraspecific taxa (taxa within a species, such as bacterial strains or plant varieties), that is complex but it is not a species complex. A species complex is in most cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensu
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular concept, but it also appears in expressions that indicate the convention or context of the usage. Common qualifiers ''Sensu'' is the ablative case of the noun ''sensus'', here meaning "sense". It is often accompanied by an adjective (in the same case). Three such phrases are: *''sensu stricto'' – "in the strict sense", abbreviation ''s.s.'' or ''s.str.''; *''sensu lato'' – "in the broad sense", abbreviation ''s.l.''; *''sensu amplo'' – "in a relaxed, generous (or 'ample') sense", a similar meaning to ''sensu lato''. Søren Kierkegaard uses the phrase ''sensu eminenti'' to mean "in the pre-eminent r most important or significantsense". When appropriate, comparative and superlative adjectives may also be used to convey the meaning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stroma (tissue)
Stroma () is the part of a tissue or organ with a structural or connective role. It is made up of all the parts without specific functions of the organ - for example, connective tissue, blood vessels, ducts, etc. The other part, the parenchyma, consists of the cells that perform the function of the tissue or organ. There are multiple ways of classifying tissues: one classification scheme is based on tissue functions and another analyzes their cellular components. Stromal tissue falls into the "functional" class that contributes to the body's support and movement. The cells which make up stroma tissues serve as a matrix in which the other cells are embedded. Stroma is made of various types of stromal cells. Examples of stroma include: * stroma of iris * stroma of cornea * stroma of ovary * stroma of thyroid gland * stroma of thymus * stroma of bone marrow * lymph node stromal cell * multipotent stromal cell (mesenchymal stem cell) Structure Stromal connective tissues are fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tolypocladium
''Tolypocladium'' is a genus of fungi within the family Ophiocordycipitaceae. It includes species that are parasites of other fungi, insect pathogens, rotifer pathogens and soil inhabiting species with uncertain ecological roles. ''Tolypocladium'' was originally circumscribed as a genus containing anamorphic fungi. It was later determined that some ''Cordyceps''-like teleomorphic fungi were the teleomorphs of ''Tolypocladium'' species. These species were considered to belong in the genus ''Cordyceps'' until molecular phylogenetics studies found these species to be more closely related to ''Ophiocordyceps'' and were considered to belong in that genus before they were transferred to the new genus ''Elaphocordyceps'' by Sung and colleagues in 2007. However, under the ICN's 2011 " one fungus, one name" principle, fungi can not have different names for their anamorphic and teleomorphic stages if they are found to be the same taxon. Quandt and colleagues formally synonymized ''Tolypocl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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