|
Undescribed Taxon
In taxonomy, an undescribed taxon is a taxon (for example, a species) that has been discovered, but not yet formally described and named. The various Nomenclature Codes specify the requirements for a new taxon to be validly described and named. Until such a description has been published, the taxon has no formal or official name, although a temporary, informal name is often used. A published scientific name may not fulfil the requirements of the Codes for various reasons. For example, if the taxon was not adequately described, its name is called a ''nomen nudum''. It is possible for a taxon to be "undescribed" for an extensive period of time, even if unofficial descriptions are published. An undescribed species may be referred to with the genus name, followed by "sp.", but this abbreviation is also used to label specimens or images that are too incomplete to be identified at the species level. In some cases, there is more than one undescribed species in a genus. In this case, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoprosopa Nondescript
''Exoprosopa'' is a large cosmopolitan genus of flies belonging to the family Bombyliidae (bee-flies), with over 325 described species. The genus parasitizes a wide range of insects, including locust and larvae of wasps. Description This genus contains the largest bee flies, of about 14 mm, sometimes larger, up to 22 mm, though a few species are as small as 6 mm. The proboscis is short. The head is large and only loosely attached to the thorax. The antenna (biology), antenna are small and well separated. Wings are large, with wingspan 40 mm, up to 64 mm in the largest species, nearly always boldly patterned; abdomen patterned (often banded) with white or pale scales on segment 6 and 7 or on each segment. Many species are sexual dimorphism, sexually dimorphic. Distribution Species are found worldwide, however Southern Africa is especially species rich with over 135 species. See also * List of Exoprosopa species References {{Taxonbar, from=Q54206 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Barcoding
DNA barcoding is a method of species identification using a short section of DNA from a specific gene or genes. The premise of DNA barcoding is that by comparison with a reference library of such DNA sections (also called " sequences"), an individual sequence can be used to uniquely identify an organism to species, just as a supermarket scanner uses the familiar black stripes of the UPC barcode to identify an item in its stock against its reference database. These "barcodes" are sometimes used in an effort to identify unknown species or parts of an organism, simply to catalog as many taxa as possible, or to compare with traditional taxonomy in an effort to determine species boundaries. Different gene regions are used to identify the different organismal groups using barcoding. The most commonly used barcode region for animals and some protists is a portion of the cytochrome ''c'' oxidase I (COI or COX1) gene, found in mitochondrial DNA. Other genes suitable for DNA barcoding a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Specimen
A biological specimen (also called a biospecimen) is a biological laboratory specimen held by a biorepository for research. Such a specimen would be taken by sampling so as to be representative of any other specimen taken from the source of the specimen. When biological specimens are stored, ideally they remain equivalent to freshly-collected specimens for the purposes of research. Human biological specimens are stored in a type of biorepository called a biobank, and the science of preserving biological specimens is most active in the field of biobanking. Quality control Setting broad standards for quality of biological specimens was initially an underdeveloped aspect of biobank growth. There is currently discussion on what standards should be in place and who should manage those standards. Since many organizations set their own standards and since biobanks are necessarily used by multiple organizations and typically are driven towards expansion, the harmonization of standa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Candidatus
In prokaryote nomenclature, ''Candidatus'' (abbreviated ''Ca.''; Latin for "candidate of Roman office") is used to name prokaryotic taxa that are well characterized but yet- uncultured. Contemporary sequencing approaches, such as 16S ribosomal RNA sequencing or metagenomics, provide much information about the analyzed organisms and thus allow identification and characterization of individual species. However, the majority of prokaryotic species remain uncultivable and hence inaccessible for further characterization in ''in vitro'' study. The recent discoveries of a multitude of candidate taxa has led to candidate phyla radiation expanding the tree of life through the new insights in bacterial diversity. Nomenclature History The initial International Code of Nomenclature of Prokaryotes (ICNP) as well as early revisions did not account for the possibility of identifying prokaryotes which were not yet cultivable. This was in apparent conflict with the ICNP's stated scope, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriology
Bacteriology is the branch and specialty of biology that studies the Morphology (biology), morphology, ecology, genetics and biochemistry of bacteria as well as many other aspects related to them. This subdivision of microbiology involves the identification, classification, and characterization of bacterial species. Because of the similarity of thinking and working with microorganisms other than bacteria, such as protozoa, fungi, and non-microorganism viruses, there has been a tendency for the field of bacteriology to extend as microbiology. The terms were formerly often used interchangeably. However, bacteriology can be classified as a distinct science. Overview Definition Bacteriology is the study of bacteria and their relation to medicine. Bacteriology evolved from physicians needing to apply the Germ theory of disease, germ theory to address the concerns relating to disease spreading in hospitals the 19th century. Identification and characterizing of bacteria being associ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Taxon
In mycology, a dark taxon (: dark taxa; or dark fungus) is a taxon that does not appear to produce any observable morphological structure and that appears impossible to cultivate in laboratory conditions. Dark taxa are chiefly detected by DNA sequencing, and in particular environmental metabarcoding. Dark taxa make up a paraphyletic group, with dark taxa appearing in every major fungal lineage. Dark taxa appear to make up a significant portion of extant fungal taxa. According to "the majority of the extant fungal diversity produces no distinguishing morphological structures that are visible or describable", and according to Martin Ryberg dark fungi "could well prove to be the dominant life style in the fungal kingdom". The naming of dark taxa is not supported by the ICN as a type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Marker
A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species. It can be described as a variation (which may arise due to mutation or alteration in the genomic loci) that can be observed. A genetic marker may be a short DNA sequence, such as a sequence surrounding a single base-pair change ( single nucleotide polymorphism, SNP), or a long one, like minisatellites. Background For many years, gene mapping was limited to identifying organisms by traditional phenotypes markers. This included genes that encoded easily observable characteristics, such as blood types or seed shapes. The insufficient number of these types of characteristics in several organisms limited the possible mapping efforts. This prompted the development of gene markers, which could identify genetic characteristics that are not readily observable in organisms (such as protein variation). Types Some commonly used types of genetic markers ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order Of Magnitude
In a ratio scale based on powers of ten, the order of magnitude is a measure of the nearness of two figures. Two numbers are "within an order of magnitude" of each other if their ratio is between 1/10 and 10. In other words, the two numbers are within about a factor of 10 of each other. For example, 1 and 1.02 are within an order of magnitude. So are 1 and 2, 1 and 9, or 1 and 0.2. However, 1 and 15 are not within an order of magnitude, since their ratio is 15/1 = 15 > 10. The reciprocal ratio, 1/15, is less than 0.1, so the same result is obtained. Differences in order of magnitude can be measured on a base-10 logarithmic scale in " decades" (i.e., factors of ten). For example, there is one order of magnitude between 2 and 20, and two orders of magnitude between 2 and 200. Each division or multiplication by 10 is called an order of magnitude. This phrasing helps quickly express the difference in scale between 2 and 2,000,000: they differ by 6 orders of magnitude. Examples o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environmental DNA
Environmental DNA or eDNA is DNA that is collected from a variety of environmental samples such as soil, seawater, snow or air, rather than directly sampled from an individual organism. As various organisms interact with the environment, DNA is expelled and accumulates in their surroundings from various sources. Such eDNA can be DNA sequencing#High-throughput methods, sequenced by environmental omics to reveal facts about the species that are present in an ecosystem — even microscopic ones not otherwise apparent or detectable. In recent years, eDNA has been used as a tool to detect endangered wildlife that were otherwise unseen. In 2020, human health researchers began repurposing eDNA techniques to track the COVID-19 pandemic. Example sources of eDNA include, but are not limited to, feces, mucus, gametes, Moulting, shed skin, Carrion, carcasses and hair. Samples can be analyzed by High throughput sequencing, high-throughput DNA sequencing methods, known as metagenomics, Mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetics, phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in Taxonomy (biology), taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identifier
An identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique ''class'' of objects, where the "object" or class may be an idea, person, physical countable object (or class thereof), or physical mass noun, noncountable substance (or class thereof). The abbreviation ID often refers to identity, identification (the process of identifying), or an identifier (that is, an instance of identification). An identifier may be a word, number, letter, symbol, or any combination of those. The words, numbers, letters, or symbols may follow an code, encoding system (wherein letters, digits, words, or symbols ''stand for'' [represent] ideas or longer names) or they may simply be arbitrary. When an identifier follows an encoding system, it is often referred to as a code or id code. For instance the ISO/IEC 11179 metadata registry standard defines a code as ''system of valid symbols that substitute for longer values'' in contrast to identifiers wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Description
A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differs from species that have been previously described or related species. For a species to be considered valid, a species description must follow established guidelines and naming conventions dictated by relevant nomenclature codes. These include the International Code of Zoological Nomenclature (ICZN) for animals, the International Code of Nomenclature for algae, fungi, and plants (ICN) for plants, and the International Committee on Taxonomy of Viruses (ICTV) for viruses. A species description often includes photographs or other illustrations of type material and information regarding where this material is deposited. The publication in which the species is described gives the new species a formal scientific name. Some 1.9 million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
