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Springtails
Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called Entognatha because they have internal mouthparts, they do not appear to be any more closely related to one another than they are to all insects, which have external mouthparts. Collembolans are omnivorous, free-living organisms that prefer moist conditions. They do not directly engage in the decomposition of organic matter, but contribute to it indirectly through the fragmentation of organic matter and the control of soil microbial communities. The word ''Collembola'' is from the ancient Greek "glue" and "peg"; this name was given due to the existence of the collophore, which was previously thought to stick to surfaces to stabilize the creature. Some DNA sequence studies suggest that Collembola represent a separate evolutionary line fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orchesella Cincta
''Orchesella cincta'' is a species of springtail present in North America and Europe. They average in length, which is extremely large as most springtails don’t grow past 1 millimetre. The specific name ''cincta'' means "belted" and refers to the distinctive colouration of the third abdominal segment. Description Springtails are small, wingless relatives of insects and typically have six abdominal segments, a tubular appendage projecting ventrally from the first abdominal segment, and a forked, tail-like appendage, the Furcula (springtail), furcula, folded under the last abdominal segment, with which the animal can flip itself into the air. Members of the genus ''Orchesella'' have six antennal segments. ''Orchesella cincta'' reaches about in length and has a distinctively pigmented third abdominal segment and a dark third antennal segment. In contrast, the posterior part of the second abdominal segment and the distal part of the second antennal segments are white. The fifth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poduromorpha
The order Poduromorpha is one of the three main groups of springtails (Collembola), tiny hexapods related to insects. This group was formerly treated as a superfamily Poduroidea. They can be best distinguished from the other springtail groups by their body shape. The Symphypleona are very round animals, almost spherical and the abdominal segments are not visible. Both Entomobryomorpha and Poduromorpha are long springtails with six visible abdominal segments. While Entomobryomorpha have the first thorax segment reduced, Poduromorpha retain all three. The Poduromorpha also tend to have short legs and a plump body, but more oval in shape than the Symphypleona. Their name means ‘foot tail formed’, deriving from their short, flat, furcula. Systematics The Poduromorpha were, as Poduroidea, united with the Entomobryomorpha (then called Entomobryoidea) in a group called "Arthropleona", but this has more recently turned out to be paraphyletic. Actually the Entomobryomorpha, the P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neelipleona
Neelipleona is a name given to some hexapods of the subclass Collembola (springtails). While their taxonomic rank remains broadly settled as family Neelidae, Neelipleona has been described at order or suborder rank. Eyes are absent. Taxonomic rank Many authors consider the "Neelipleona" Symphypleona of the superfamily Sminthuroidea, family Neelidae.See references in Haaramo (2008) However, in other accounts, Neelipleona are either a distinct order from the three less controversial Springtail orders (Entomobryomorpha, Poduromorpha The order Poduromorpha is one of the three main groups of springtails (Collembola), tiny hexapods related to insects. This group was formerly treated as a superfamily Poduroidea. They can be best distinguished from the other springtail group ... and Symphypleona) or a distinct suborder of Symphypleona, or placed in the Entomobryomorpha. References Footnotes Collembola {{springtail-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arthropod cuticle, cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an exoskeleton, external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior Organ (anatomy), organs; it has an open circulatory system. Like their exteriors, the internal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Sequence
DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. The advent of rapid DNA sequencing methods has greatly accelerated biological and medical research and discovery. Knowledge of DNA sequences has become indispensable for basic biological research, DNA Genographic Projects and in numerous applied fields such as medical diagnosis, biotechnology, forensic biology, virology and biological systematics. Comparing healthy and mutated DNA sequences can diagnose different diseases including various cancers, characterize antibody repertoire, and can be used to guide patient treatment. Having a quick way to sequence DNA allows for faster and more individualized medical care to be administered, and for more organisms to be identified and cataloged. The rapid speed of sequencing attained with modern D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (evolution)
In phylogenetics, basal is the direction of the ''base'' (or root) of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a ' key innovation' implies some degree of correlation between evolutionary innovation and diversification. However, such a correlation does not make a given case predicable, so ancestral characters should not be imputed to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (biology)
In biological classification, class ( la, classis) is a taxonomic rank, as well as a taxonomic unit, a taxon, in that rank. It is a group of related taxonomic orders. Other well-known ranks in descending order of size are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order. History The class as a distinct rank of biological classification having its own distinctive name (and not just called a ''top-level genus'' ''(genus summum)'') was first introduced by the French botanist Joseph Pitton de Tournefort in his classification of plants that appeared in his ''Eléments de botanique'', 1694. Insofar as a general definition of a class is available, it has historically been conceived as embracing taxa that combine a distinct ''grade'' of organization—i.e. a 'level of complexity', measured in terms of how differentiated their organ systems are into distinct regions or sub-organs—with a distinct ''type'' of construction, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order (biology)
Order ( la, wikt:ordo#Latin, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between Family_(biology), family and Class_(biology), class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladistics
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived characteristics ( synapomorphies'')'' that are not present in more distant groups and ancestors. However, from an empirical perspective, common ancestors are inferences based on a cladistic hypothesis of relationships of taxa whose character states can be observed. Theoretically, a last common ancestor and all its descendants constitute a (minimal) clade. Importantly, all descendants stay in their overarching ancestral clade. For example, if the terms ''worms'' or ''fishes'' were used within a ''strict'' cladistic framework, these terms would include humans. Many of these terms are normally used paraphyletically, outside of cladistics, e.g. as a 'grade', which are fruitless to precisely delineate, especially when including extinct species. R ... [...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] |
Molecular Phylogenetics And Evolution
''Molecular Phylogenetics and Evolution'' is a peer-reviewed scientific journal of evolutionary biology and phylogenetics. The journal is edited by E.A. Zimmer. Indexing The journal is indexed in: *EMBiology *Journal Citation Reports *Scopus Scopus is Elsevier's abstract and citation database launched in 2004. Scopus covers nearly 36,377 titles (22,794 active titles and 13,583 inactive titles) from approximately 11,678 publishers, of which 34,346 are peer-reviewed journals in top-l ... * Web of Science External links * Elsevier academic journals Evolutionary biology journals Phylogenetics Molecular biology Publications established in 1992 Monthly journals {{biology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Evolution
Molecular evolution is the process of change in the sequence composition of cellular molecules such as DNA, RNA, and proteins across generations. The field of molecular evolution uses principles of evolutionary biology and population genetics to explain patterns in these changes. Major topics in molecular evolution concern the rates and impacts of single nucleotide changes, neutral evolution vs. natural selection, origins of new genes, the genetic nature of complex traits, the genetic basis of speciation, evolution of development, and ways that evolutionary forces influence genomic and phenotypic changes. History The history of molecular evolution starts in the early 20th century with comparative biochemistry, and the use of "fingerprinting" methods such as immune assays, gel electrophoresis and paper chromatography in the 1950s to explore homologous proteins. The field of molecular evolution came into its own in the 1960s and 1970s, following the rise of molecular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
