Misplaced Pages

#457542

55-882: See text Nassarius , common name nassa mud snails (USA) or dog whelks (UK), is a genus of minute to medium-sized sea snails , marine gastropod molluscs in the family Nassariidae . They are scavengers. The name is derived from the Latin word "nassa", meaning a wickerbasket with a narrow neck, for catching fish. Nassarius would then mean "someone who uses such a wickerbasket for catching fish". Species within this genus are found worldwide. These snails usually live on mud flats or sand flats, intertidally or subtidally. Most Nassarius species are very active scavengers , feeding on crabs and carrion as dead fish , etc. They often burrow into marine substrates and then wait with only their siphon protruding, until they smell nearby food. The shells of species in this genus have

110-769: A flora of his homeland Sweden, Flora Svecica (1745), and in this, he recorded the Swedish common names, region by region, as well as the scientific names. The Swedish common names were all binomials (e.g. plant no. 84 Råg-losta and plant no. 85 Ren-losta); the vernacular binomial system thus preceded his scientific binomial system. Linnaean authority William T. Stearn said: By the introduction of his binomial system of nomenclature, Linnaeus gave plants and animals an essentially Latin nomenclature like vernacular nomenclature in style but linked to published, and hence relatively stable and verifiable, scientific concepts and thus suitable for international use. The geographic range over which

165-464: A tree of life arose from ancient notions of a ladder-like progression from lower into higher forms of life (such as in the Great Chain of Being ). Early representations of "branching" phylogenetic trees include a "paleontological chart" showing the geological relationships among plants and animals in the book Elementary Geology , by Edward Hitchcock (first edition: 1840). Charles Darwin featured

220-424: A basal tooth. The foot is large, expanded and bifurcate at its posterior extremity. The operculum is ovate, the margin serrated or entire. The shell is ovate and ventricose. The body whorl is variously sculptured. The aperture is ovate, with a short reflected truncated anterior canal. The inner lip is smooth, often widely spread over with enamel, with a posterior callosity or blunt dentiform plait. The outer lip

275-814: A combination of genes that come from different genomic sources (e.g., from mitochondrial or plastid vs. nuclear genomes), or genes that would be expected to evolve under different selective regimes, so that homoplasy (false homology ) would be unlikely to result from natural selection. When extinct species are included as terminal nodes in an analysis (rather than, for example, to constrain internal nodes), they are considered not to represent direct ancestors of any extant species. Extinct species do not typically contain high-quality DNA . The range of useful DNA materials has expanded with advances in extraction and sequencing technologies. Development of technologies able to infer sequences from smaller fragments, or from spatial patterns of DNA degradation products, would further expand

330-620: A diagrammatic evolutionary "tree" in his 1859 book On the Origin of Species . Over a century later, evolutionary biologists still use tree diagrams to depict evolution because such diagrams effectively convey the concept that speciation occurs through the adaptive and semirandom splitting of lineages. The term phylogenetic , or phylogeny , derives from the two ancient greek words φῦλον ( phûlon ), meaning "race, lineage", and γένεσις ( génesis ), meaning "origin, source". A rooted phylogenetic tree (see two graphics at top)

385-427: A function of the number of tips. For 10 tips, there are more than 34 × 10 6 {\displaystyle 34\times 10^{6}} possible bifurcating trees, and the number of multifurcating trees rises faster, with ca. 7 times as many of the latter as of the former. A dendrogram is a general name for a tree, whether phylogenetic or not, and hence also for the diagrammatic representation of

440-609: A more suitable metaphor than the tree . Indeed, phylogenetic corals are useful for portraying past and present life, and they have some advantages over trees ( anastomoses allowed, etc.). Phylogenetic trees composed with a nontrivial number of input sequences are constructed using computational phylogenetics methods. Distance-matrix methods such as neighbor-joining or UPGMA , which calculate genetic distance from multiple sequence alignments , are simplest to implement, but do not invoke an evolutionary model. Many sequence alignment methods such as ClustalW also create trees by using

495-536: A number of different formats, all of which must represent the nested structure of a tree. They may or may not encode branch lengths and other features. Standardized formats are critical for distributing and sharing trees without relying on graphics output that is hard to import into existing software. Commonly used formats are Although phylogenetic trees produced on the basis of sequenced genes or genomic data in different species can provide evolutionary insight, these analyses have important limitations. Most importantly,

550-485: A particularly common name is used varies; some common names have a very local application, while others are virtually universal within a particular language. Some such names even apply across ranges of languages; the word for cat , for instance, is easily recognizable in most Germanic and many Romance languages . Many vernacular names, however, are restricted to a single country and colloquial names to local districts. Some languages also have more than one common name for

605-441: A phylogenetic tree. A cladogram only represents a branching pattern; i.e., its branch lengths do not represent time or relative amount of character change, and its internal nodes do not represent ancestors. A phylogram is a phylogenetic tree that has branch lengths proportional to the amount of character change. A chronogram is a phylogenetic tree that explicitly represents time through its branch lengths. A Dahlgrenogram

SECTION 10

#1732852637458

660-469: A relatively high cyrtoconoid (approaching a conical shape but with convex sides) spire and a siphonal notch . (Described as Aciculina ) The shell is turreted, polished, smooth or longitudinally plicate. The inner lip shows the callus sharp, straight, defined. The outer lip is produced in the middle, variced externally. (Described as Nassa ) The eyes are situated on the middle of the tentacles. The lingual teeth are arched and pectinated. The uncini show

715-447: A specific time. In other words, it is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. In evolutionary biology, all life on Earth is theoretically part of a single phylogenetic tree, indicating common ancestry . Phylogenetics is the study of phylogenetic trees. The main challenge

770-445: A tree shape, defines a topology only. Some sequence-based trees built from a small genomic locus, such as Phylotree, feature internal nodes labeled with inferred ancestral haplotypes. The number of possible trees for a given number of leaf nodes depends on the specific type of tree, but there are always more labeled than unlabeled trees, more multifurcating than bifurcating trees, and more rooted than unrooted trees. The last distinction

825-399: Is a directed tree with a unique node — the root — corresponding to the (usually imputed ) most recent common ancestor of all the entities at the leaves of the tree. The root node does not have a parent node, but serves as the parent of all other nodes in the tree. The root is therefore a node of degree 2, while other internal nodes have a minimum degree of 3 (where "degree" here refers to

880-604: Is a diagram representing a cross section of a phylogenetic tree. A phylogenetic network is not strictly speaking a tree, but rather a more general graph , or a directed acyclic graph in the case of rooted networks. They are used to overcome some of the limitations inherent to trees. A spindle diagram, or bubble diagram, is often called a romerogram, after its popularisation by the American palaeontologist Alfred Romer . It represents taxonomic diversity (horizontal width) against geological time (vertical axis) in order to reflect

935-548: Is dentated, internally crenulated. The animal has a long siphon. Several beads made from Nassarius gibbosulus shells are thought to be the earliest known forms of personal adornment, or even jewelry . Two shell beads found in Skhul Cave on the slopes of Mount Carmel , Israel , are thought to be 100,000 years old, whilst another found at Oued Djebbana , Algeria , is believed to be 90,000 years old. A further group of pierced shells, some with red ochre , has been recovered from

990-461: Is in these remarks from a book on marine fish: In scientific binomial nomenclature, names commonly are derived from classical or modern Latin or Greek or Latinised forms of vernacular words or coinages; such names generally are difficult for laymen to learn, remember, and pronounce and so, in such books as field guides, biologists commonly publish lists of coined common names. Many examples of such common names simply are attempts to translate

1045-506: Is most true of genetic material that is subject to lateral gene transfer and recombination , where different haplotype blocks can have different histories. In these types of analysis, the output tree of a phylogenetic analysis of a single gene is an estimate of the gene's phylogeny (i.e. a gene tree) and not the phylogeny of the taxa (i.e. species tree) from which these characters were sampled, though ideally, both should be very close. For this reason, serious phylogenetic studies generally use

1100-650: Is the Cape dikkop (or "gewone dikkop", not to mention the presumably much older Zulu name "umBangaqhwa"); Burhinus vermiculatus is the "water dikkop". The thick joints in question are not even, in fact, the birds' knees, but the intertarsal joints —in lay terms the ankles. Furthermore, not all species in the genus have "thick knees", so the thickness of the "knees" of some species is not of clearly descriptive significance. The family Burhinidae has members that have various common names even in English, including " stone curlews ", so

1155-539: Is the most biologically relevant; it arises because there are many places on an unrooted tree to put the root. For bifurcating labeled trees, the total number of rooted trees is: For bifurcating labeled trees, the total number of unrooted trees is: Among labeled bifurcating trees, the number of unrooted trees with n {\displaystyle n} leaves is equal to the number of rooted trees with n − 1 {\displaystyle n-1} leaves. The number of rooted trees grows quickly as

SECTION 20

#1732852637458

1210-458: Is to find a phylogenetic tree representing optimal evolutionary ancestry between a set of species or taxa. Computational phylogenetics (also phylogeny inference) focuses on the algorithms involved in finding optimal phylogenetic tree in the phylogenetic landscape. Phylogenetic trees may be rooted or unrooted. In a rooted phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and

1265-605: The Aterian levels at the Taforalt site in Morocco; these Nassarius gibbosulus beads have been securely dated to about 82,000 years ago. All these examples predate several 75,000-year-old Nassarius kraussianus beads which were found at Blombos Cave , South Africa (including some colored with red ochre ). These beads had previously been thought to be the oldest examples of jewelry. From A.D. 1130 to 1275, shell beads were manufactured by

1320-515: The ICZN has formal rules for biological nomenclature and convenes periodic international meetings to further that purpose. The form of scientific names for organisms, called binomial nomenclature , is superficially similar to the noun-adjective form of vernacular names or common names which were used by non-modern cultures. A collective name such as owl was made more precise by the addition of an adjective such as screech . Linnaeus himself published

1375-581: The Nassarius is considered nearly indispensable for keeping sand beds clean and healthy, as these snails tend to burrow and plow through the upper layer in a conch-like fashion, keeping algae and detritus from building up visibly on the surface. The shells of various species of Nassarius are popular with shell collectors, and are sometimes used in jewelry and other forms of decoration. The genus Nassarius has traditionally been subdivided into several subgenera, based on differences in shell morphology, especially

1430-690: The World Register of Marine Species (WoRMS): Common name In chemistry , IUPAC defines a common name as one that, although it unambiguously defines a chemical, does not follow the current systematic naming convention, such as acetone , systematically 2-propanone , while a vernacular name describes one used in a lab, trade or industry that does not unambiguously describe a single chemical, such as copper sulfate , which may refer to either copper(I) sulfate or copper(II) sulfate. Sometimes common names are created by authorities on one particular subject, in an attempt to make it possible for members of

1485-406: The sculpture : Aciculina , Alectrion , Allanassa , Nassodonta , Niotha , Plicarcularia , Profundinassa , Pygmaeonassa , Telasco , and Zeuxis . However, this division is difficult to define, resulting in much confusion. Even phylogenetic analysis shows that the division into these subgenera appears to be uncertain and unreliable. There seem to be two groups within the genus Nassarius with

1540-572: The Hebrew Language publish from time to time short dictionaries of common name in Hebrew for species that occur in Israel or surrounding countries e.g. for Reptilia in 1938, Osteichthyes in 2012, and Odonata in 2015. Phylogeny A phylogenetic tree , phylogeny or evolutionary tree is a graphical representation which shows the evolutionary history between a set of species or taxa during

1595-683: The SSAR switched to an online version with a searchable database. Standardized names for the amphibians and reptiles of Mexico in Spanish and English were first published in 1994, with a revised and updated list published in 2008. A set of guidelines for the creation of English names for birds was published in The Auk in 1978. It gave rise to Birds of the World: Recommended English Names and its Spanish and French companions. The Academy of

1650-524: The Secretariat for the AFNC. SSA is an accredited Standards Australia (Australia's peak non-government standards development organisation) Standards Development The Entomological Society of America maintains a database of official common names of insects, and proposals for new entries must be submitted and reviewed by a formal committee before being added to the listing. Efforts to standardize English names for

1705-501: The amphibians and reptiles of North America (north of Mexico) began in the mid-1950s. The dynamic nature of taxonomy necessitates periodical updates and changes in the nomenclature of both scientific and common names. The Society for the Study of Amphibians and Reptiles (SSAR) published an updated list in 1978, largely following the previous established examples, and subsequently published eight revised editions ending in 2017. More recently

Nassarius - Misplaced Pages Continue

1760-509: The author introduced into it so many new English names, that are to be found in no dictionary, and that do not preclude the necessity of learning with what Latin names they are synonymous. A tolerable idea may be given of the danger of too great a multiplicity of vulgar names, by imagining what geography would be, or, for instance, the Post-office administration, supposing every town had a totally different name in every language. Various bodies and

1815-493: The authors of many technical and semi-technical books do not simply adapt existing common names for various organisms; they try to coin (and put into common use) comprehensive, useful, authoritative, and standardised lists of new names. The purpose typically is: Other attempts to reconcile differences between widely separated regions, traditions, and languages, by arbitrarily imposing nomenclature, often reflect narrow perspectives and have unfortunate outcomes. For example, members of

1870-408: The choice of the name "thick-knees" is not easy to defend but is a clear illustration of the hazards of the facile coinage of terminology. For collective nouns for various subjects, see a list of collective nouns (e.g. a flock of sheep, pack of wolves). Some organizations have created official lists of common names, or guidelines for creating common names, hoping to standardize

1925-442: The closest relationship between the subgenera Zeuxis and Telasco . Even the species within the subgenus Plicarcularia do not belong to a single clade . In the end, the molecular phylogeny did not match the previous morphological phylogeny. In the course of time, more than 1,000 names have been allocated to species in the genus Nassarius , most of which have become synonyms. The following species are accepted names according to

1980-455: The edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed. Trees are useful in fields of biology such as bioinformatics , systematics , and phylogenetics . Unrooted trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to be known or inferred. The idea of

2035-449: The form of an unrooted binary tree , a free tree with exactly three neighbors at each internal node. In contrast, a rooted multifurcating tree may have more than two children at some nodes and an unrooted multifurcating tree may have more than three neighbors at some nodes. Both rooted and unrooted trees can be either labeled or unlabeled. A labeled tree has specific values assigned to its leaves, while an unlabeled tree, sometimes called

2090-464: The general public (including such interested parties as fishermen, farmers, etc.) to be able to refer to one particular species of organism without needing to be able to memorise or pronounce the scientific name. Creating an "official" list of common names can also be an attempt to standardize the use of common names, which can sometimes vary a great deal between one part of a country and another, as well as between one country and another country, even where

2145-517: The genus Burhinus occur in Australia, Southern Africa, Eurasia, and South America. A recent trend in field manuals and bird lists is to use the name " thick-knee " for members of the genus. This, in spite of the fact that the majority of the species occur in non-English-speaking regions and have various common names, not always English. For example, "Dikkop" is the centuries-old South African vernacular name for their two local species: Burhinus capensis

2200-582: The inhabitants of the Exhausted Cave near the Clear Creek Ruins. A Southern Sinagua site in Verde Valley , Arizona where "shell played a major role in the economic system of this culture." Nassarius vibex is a species which is often selected for marine aquaria . It is often confused with Nassarius obsoletus , a cooler water snail less suited to tropical marine aquarium temperatures. In aquaria,

2255-409: The leaf nodes without making assumptions about ancestry. They do not require the ancestral root to be known or inferred. Unrooted trees can always be generated from rooted ones by simply omitting the root. By contrast, inferring the root of an unrooted tree requires some means of identifying ancestry. This is normally done by including an outgroup in the input data so that the root is necessarily between

Nassarius - Misplaced Pages Continue

2310-706: The modern (now binding) International Code of Nomenclature for algae, fungi, and plants contains the following: Art. 68. Every friend of science ought to be opposed to the introduction into a modern language of names of plants that are not already there unless they are derived from a Latin botanical name that has undergone but a slight alteration. ... ought the fabrication of names termed vulgar names, totally different from Latin ones, to be proscribed. The public to whom they are addressed derives no advantage from them because they are novelties. Lindley's work, The Vegetable Kingdom, would have been better relished in England had not

2365-439: The optimal tree using many of these techniques is NP-hard , so heuristic search and optimization methods are used in combination with tree-scoring functions to identify a reasonably good tree that fits the data. Tree-building methods can be assessed on the basis of several criteria: Tree-building techniques have also gained the attention of mathematicians. Trees can also be built using T-theory . Trees can be encoded in

2420-452: The outgroup and the rest of the taxa in the tree, or by introducing additional assumptions about the relative rates of evolution on each branch, such as an application of the molecular clock hypothesis . Both rooted and unrooted trees can be either bifurcating or multifurcating. A rooted bifurcating tree has exactly two descendants arising from each interior node (that is, it forms a binary tree ), and an unrooted bifurcating tree takes

2475-405: The range of DNA considered useful. Phylogenetic trees can also be inferred from a range of other data types, including morphology, the presence or absence of particular types of genes, insertion and deletion events – and any other observation thought to contain an evolutionary signal. Phylogenetic networks are used when bifurcating trees are not suitable, due to these complications which suggest

2530-484: The same animal. For example, in Irish, there are many terms that are considered outdated but still well-known for their somewhat humorous and poetic descriptions of animals. w/ literal translations of the poetic terms Common names are used in the writings of both professionals and laymen . Lay people sometimes object to the use of scientific names over common names, but the use of scientific names can be defended, as it

2585-576: The same language is spoken in both places. A common name intrinsically plays a part in a classification of objects, typically an incomplete and informal classification, in which some names are degenerate examples in that they are unique and lack reference to any other name, as is the case with say, ginkgo , okapi , and ratel . Folk taxonomy , which is a classification of objects using common names, has no formal rules and need not be consistent or logical in its assignment of names, so that say, not all flies are called flies (for example Braulidae ,

2640-402: The scientific name into English or some other vernacular. Such translation may be confusing in itself, or confusingly inaccurate, for example, gratiosus does not mean "gracile" and gracilis does not mean "graceful". The practice of coining common names has long been discouraged; de Candolle's Laws of Botanical Nomenclature , 1868, the non-binding recommendations that form the basis of

2695-417: The simpler algorithms (i.e. those based on distance) of tree construction. Maximum parsimony is another simple method of estimating phylogenetic trees, but implies an implicit model of evolution (i.e. parsimony). More advanced methods use the optimality criterion of maximum likelihood , often within a Bayesian framework , and apply an explicit model of evolution to phylogenetic tree estimation. Identifying

2750-407: The so-called "bee lice") and not every animal called a fly is indeed a fly (such as dragonflies and mayflies ). In contrast, scientific or biological nomenclature is a global system that attempts to denote particular organisms or taxa uniquely and definitively , on the assumption that such organisms or taxa are well-defined and generally also have well-defined interrelationships; accordingly

2805-410: The total number of incoming and outgoing edges). The most common method for rooting trees is the use of an uncontroversial outgroup —close enough to allow inference from trait data or molecular sequencing, but far enough to be a clear outgroup. Another method is midpoint rooting, or a tree can also be rooted by using a non-stationary substitution model . Unrooted trees illustrate the relatedness of

SECTION 50

#1732852637458

2860-411: The tree before hybridisation takes place, and conserved sequences . Also, there are problems in basing an analysis on a single type of character, such as a single gene or protein or only on morphological analysis, because such trees constructed from another unrelated data source often differ from the first, and therefore great care is needed in inferring phylogenetic relationships among species. This

2915-529: The trees that they generate are not necessarily correct – they do not necessarily accurately represent the evolutionary history of the included taxa. As with any scientific result, they are subject to falsification by further study (e.g., gathering of additional data, analyzing the existing data with improved methods). The data on which they are based may be noisy ; the analysis can be confounded by genetic recombination , horizontal gene transfer , hybridisation between species that were not nearest neighbors on

2970-800: The use of common names. For example, the Australian Fish Names List or AFNS was compiled through a process involving work by taxonomic and seafood industry experts, drafted using the CAAB (Codes for Australian Aquatic Biota) taxon management system of the CSIRO , and including input through public and industry consultations by the Australian Fish Names Committee (AFNC). The AFNS has been an official Australian Standard since July 2007 and has existed in draft form (The Australian Fish Names List) since 2001. Seafood Services Australia (SSA) serve as

3025-404: The variation of abundance of various taxa through time. A spindle diagram is not an evolutionary tree: the taxonomic spindles obscure the actual relationships of the parent taxon to the daughter taxon and have the disadvantage of involving the paraphyly of the parental group. This type of diagram is no longer used in the form originally proposed. Darwin also mentioned that the coral may be

#457542