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Supraprimates
Euarchontoglires (synonymous with Supraprimates) is a clade and a superorder of mammals, the living members of which belong to one of the five following groups: rodents, lagomorphs, treeshrews, colugos, and primates. Evolutionary affinities within mammals The Euarchontoglires clade is based on DNA sequence analyses and retrotransposon markers that combine the clades Glires (Rodentia + Lagomorpha) and Euarchonta (Scandentia + Primates + Dermoptera). It is usually discussed without a taxonomic rank but has been called a cohort, magnorder, or superorder. Relations among the four cohorts (Euarchontoglires, Xenarthra, Laurasiatheria, Afrotheria) and the identity of the placental root remain controversial. So far, few, if any, distinctive anatomical features have been recognized that support Euarchontoglires; nor does any strong evidence from anatomy support alternative hypotheses. Although both Euarchontoglires and diprotodont marsupials are documented to possess a vermiform app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glires
Glires (, Latin ''glīrēs'' 'dormice') is a clade (sometimes ranked as a grandorder) consisting of rodents and lagomorphs (rabbits, hares, and pikas). The hypothesis that these form a monophyletic group has been long debated based on morphological evidence. Two morphological studies, published in 2001 and 2003, strongly support the monophyly of Glires. In particular, the 2003 study reported the discovery of fossil material of basal members of Glires, particularly the genera ''Mimotona'', ''Gomphos'', '' Heomys'', '' Matutinia'', '' Rhombomylus'', and '' Sinomylus''. Their description, in 2005, helped to bridge the gap between more typical rodents and lagomorphs. Data published in 2001, based on nuclear DNA, supported Glires as a sister of Euarchonta to form Euarchontoglires, but some genetic data from both nuclear and mitochondrial DNA have been less supportive. A study, published in 2007, investigating retrotransposon Retrotransposons (also called Class I transposable element ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primatomorpha
The Primatomorpha are a proposed mirorder of mammals containing the flying lemurs (order Dermoptera or colugos) and lemurs (Strepsirrhini, adapiformes and lemuriformes). However, notably, the haplorhini are sister to the lemurs, together forming the primate (Plesiadapiformes and descendents) order within this group. Primatomorpha is sister to Scandentia, together forming the Euarchonta. The term "Primatomorpha" first appeared in the general scientific literature in 1991 (K.C. Beard) and 1992 (Kalandadze, Rautian). Major DNA sequence analyses of predominantly nuclear sequences (Murphy et al., 2001) support the Euarchonta hypothesis, while a major study investigating mitochondrial sequences supports a different tree topology (Arnason et al., 2002). A study investigating retrotransposon presence/absence data has claimed strong support for Euarchonta (Kriegs et al., 2007). Some interpretations of the molecular data link Primates and Dermoptera in a clade (mirorder) known as Prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euarchonta
The Euarchonta are a proposed grandorder of mammals: the order Scandentia (treeshrews), and its sister Primatomorpha mirorder, containing the Dermoptera or colugos and the primates (Plesiadapiformes and descendents). The term "Euarchonta" (meaning "true rulers") appeared in 1999, when molecular evidence suggested that the morphology-based Archonta should be trimmed down to exclude Chiroptera. Further DNA sequence analyses supported the Euarchonta hypothesis. Despite multiple papers pointing out that some mitochondrial sequences showed unusual properties (particularly murid rodents and hedgehogs) and were likely distorting the overall tree, and despite earlier studies showing near total congruence of mtDNA-based and nuclear-based trees when such sequences were excluded, some authors continued to produce misleading trees. A study investigating retrotransposon presence/absence data has claimed strong support for Euarchonta. Some interpretations of the molecular data link Primates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treeshrew
The treeshrews (or tree shrews or banxrings) are small mammals native to the tropical forests of South and Southeast Asia. They make up the entire order Scandentia, which split into two families: the Tupaiidae (19 species, "ordinary" treeshrews), and the Ptilocercidae (one species, the pen-tailed treeshrew). Though called 'treeshrews', and despite having previously been classified in Insectivora, they are not true shrews, and not all species live in trees. They are omnivores; among other things, treeshrews eat fruit. Treeshrews have a higher brain to body mass ratio than any other mammal, including humans, but high ratios are not uncommon for animals weighing less than . Among orders of mammals, treeshrews are closely related to primates, and have been used as an alternative to primates in experimental studies of myopia, psychosocial stress, and hepatitis. Name The name '' Tupaia'' is derived from ''tupai'', the Indonesian word for squirrel, and was provided by Sir Stamfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Rat
The brown rat (''Rattus norvegicus''), also known as the common rat, street rat, sewer rat, wharf rat, Hanover rat, Norway rat, Norwegian rat and Parisian rat, is a widespread species of common rat. One of the largest muroids, it is a brown or grey rodent with a head and body length of up to long, and a tail slightly shorter than that. It weighs between . Thought to have originated in northern China and neighbouring areas, this rodent has now spread to all continents except Antarctica, and is the dominant rat in Europe and much of North America. With rare exceptions, the brown rat lives wherever humans live, particularly in urban areas. Selective breeding of the brown rat has produced the fancy rat (rats kept as pets), as well as the laboratory rat (rats used as model organisms in biological research). Both fancy rats and laboratory rats are of the domesticated subspecies ''Rattus norvegicus domestica''. Studies of wild rats in New York City have shown that populations livi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primate
Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including humans). Primates arose 85–55 million years ago first from small terrestrial mammals, which adapted to living in the trees of tropical forests: many primate characteristics represent adaptations to life in this challenging environment, including large brains, visual acuity, color vision, a shoulder girdle allowing a large degree of movement in the shoulder joint, and dextrous hands. Primates range in size from Madame Berthe's mouse lemur, which weighs , to the eastern gorilla, weighing over . There are 376–524 species of living primates, depending on which classification is used. New primate species continue to be discovered: over 25 species were described in the 2000s, 36 in the 2010s, and three in the 2020s. Primates have large bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrotransposon
Retrotransposons (also called Class I transposable elements or transposons via RNA intermediates) are a type of genetic component that copy and paste themselves into different genomic locations (transposon) by converting RNA back into DNA through the reverse transcription process using an RNA transposition intermediate. Through reverse transcription, retrotransposons amplify themselves quickly to become abundant in eukaryotic genomes such as maize (49–78%) and humans (42%). They are only present in eukaryotes but share features with retroviruses such as HIV, for example, discontinuous reverse transcriptase-mediated extrachromosomal recombination. These retrotransposons are regulated by a family of short non-coding RNAs termed as PIWI -element induced wimpy testisinteracting RNAs (piRNAs). piRNA is a recently discovered class of ncRNAs, which are in the length range of ~24-32 nucleotides. Initially, piRNAs were described as repeat-associated siRNAs (rasiRNAs) because of thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrotransposon Marker
Retrotransposon markers are components of DNA which are used as cladistic markers. They assist in determining the common ancestry, or not, of related taxa. The "presence" of a given retrotransposon in related taxa suggests their orthologous integration, a derived condition acquired via a common ancestry, while the "absence" of particular elements indicates the plesiomorphic condition prior to integration in more distant taxa. The use of presence/absence analyses to reconstruct the systematic biology of mammals depends on the availability of retrotransposons that were actively integrating before the divergence of a particular species. Details The analysis of SINEs – Short INterspersed Elements – LINEs – Long INterspersed Elements – or truncated LTRs – Long Terminal Repeats – as molecular cladistic markers represents a particularly interesting complement to DNA sequence and morphological data. The reason for this is that retrotransposons are assumed to represent powerf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomic Rank
In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species, genus, family (biology), family, order (biology), order, class (biology), class, phylum (biology), phylum, kingdom (biology), kingdom, domain (biology), domain. While older approaches to taxonomic classification were phenomenological, forming groups on the basis of similarities in appearance, organic structure and behaviour, methods based on genetic analysis have opened the road to cladistics. A given rank subsumes under it less general categories, that is, more specific descriptions of life forms. Above it, each rank is classified within more general categories of organisms and groups of organisms related to each other through inheritance of phenotypic trait, traits or features from common ancestors. The rank of any ''species'' and the description of its ''genus'' is ''basic''; which means that to iden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenarthra
Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and armadillos. Extinct xenarthrans include the glyptodonts, pampatheres and ground sloths. Xenarthrans originated in South America during the late Paleocene about 60 million years ago. They evolved and diversified extensively in South America during the continent's long period of isolation in the early to mid Cenozoic Era. They spread to the Antilles by the early Miocene and, starting about 3 Mya, spread to Central and North America as part of the Great American Interchange. Nearly all of the formerly abundant megafaunal xenarthrans became extinct at the end of the Pleistocene. Xenarthrans share several characteristics not present in other placental mammals, which suggest their ancestors were subterranean diggers for insects. The name Xenarthra de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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