1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Tree model
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In historical linguistics, the tree model is a model of the evolution of languages analogous to the concept of a family tree, particularly a phylogenetic tree in the biological evolution of species. As with species, each language is assumed to have evolved from a parent or mother language. Popularized by the German linguist August Schleicher in 1853, the model has always been a common method of describing genetic relationships between languages since the first attempts to do so. The wave model was developed in 1872 by Schleichers student Johannes Schmidt as an alternative to the model that incorporates horizontal transmission. According to the Genesis narrative, the descendants of Noah gathered together in the land of Shinar, in response to their over-reaching God decided to confound their language, that they may not understand one anothers speech and scattered them abroad from thence upon the face of the earth. In other words, if languages were given by God, then they did not evolve, in all he identified 72 nations, tribal founders and languages. The confusion and dispersion occurred in the time of Peleg, son of Heber, son of Shem, most of the 72 languages, however, date to many generations after Heber. St. Augustine solves this first problem by supposing that Heber, St. Augustines hypothesis stood without major question for over a thousand years. Then, in a series of tracts, published in 1684, expressing skepticism concerning various beliefs, especially Biblical, Sir Thomas Browne wrote, yet whether, after a large dispersion, and the space of sixteen hundred years, men maintained so uniform a language in all parts. By then, discovery of the New World and exploration of the Far East had brought knowledge of numbers of new languages far beyond the 72 calculated by St. Augustine. Citing the native American languages, Browne suggests the confusion of tongues at first fell only upon those present in Sinaar at the work of Babel, for those about the foot of the hills, whereabout the ark rested. Their primitive language might in time out into several parts of Europe. This is an inkling of a tree, in Brownes view, simplification from a larger aboriginal language than Hebrew could account for the differences in language. He suggests ancient Chinese, from which the others descended by confusion, admixtion and corruption, later he invokes commixture and alteration. Verstegan made no doubt that he could contrive a letter that might be understood by the English, Dutch, the confusion at the Tower of Babel was thus removed as an obstacle by setting it aside. Attempts to find similarities in all languages were resulting in the uncovering of an ancient master language from which all the other languages derive. Browne undoubtedly did his writing and thinking well before 1684, now the High Dutch or Teutonick Tongue, is one of the prime and most spacious Maternal Languages of Europe. It was the language of the Goths and Vandals, and continueth yet of the greatest part of Poland and Hungary, some of her writers would make this world believe that she was the language spoken in paradise
3.
Family tree
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A family tree, or pedigree chart, is a chart representing family relationships in a conventional tree structure. The more detailed family trees used in medicine and social work are known as genograms, genealogical data can be represented in several formats, for example as a pedigree or ancestry chart. Family trees are presented with the oldest generations at the top. An ancestry chart, which is a showing the ancestors of an individual, will more closely resemble a tree in shape. In some ancestry charts, a appears on the left. A descendancy chart, which all the descendants of an individual will be narrowest at the top. Family trees can have many themes, one might encompass all direct descendants of a single figure, or all known ancestors of a living person. Another might include all members of a particular surname, yet another approach is to construct a tree including all holders of a certain office, such as kings of Germany. This relies on dynastic marriage to hold together the links between dynasties, the image of the tree probably originated with one in medieval art of the Tree of Jesse, used to illustrate the Genealogy of Christ in terms of a prophecy of Isaiah. Fan charts depict paternal and maternal ancestors, however, because a parent must be born before their child is born, a person cannot be their own ancestor, and thus there are no loops, so ancestry forms a directed acyclic graph. The graphs of matrilineal descent and patrilineal descent are trees however, assuming no common ancestor, an ancestry chart is a perfect binary tree, as each person has exactly one mother and one father, for two parents, these thus have a regular structure. A descendancy chart, on the hand, does not in general have a regular structure, as a person can have any number of children. The longest family tree in the world is that of the Chinese philosopher and educator Confucius, the tree spans more than 80 generations from him, and includes more than 2 million members. An international effort involving more than 450 branches around the world was started in 1998 to retrace, a new edition of the Confucius genealogy was printed in September 2009 by the Confucius Genealogy Compilation Committee, to coincide with the 2560th anniversary of the birth of the Chinese thinker. This latest edition is expected to include some 1.3 million living members who are scattered around the world today, the 1999 edition of the Guinness Book of Records recorded the Lurie family in the longest lineage category as oldest-known living family in the world today. In Europe, the pedigree of Niall Noígíallach would be contender for the longest, the author Pete Frame is notable for having produced family trees of rock bands. In this instance, the entries represent membership of certain groups, several books have been produced with his family trees, which in turn have led to a BBC television series about them, including interviews from the bands depicted in the trees
4.
Arabic
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Arabic is a Central Semitic language that was first spoken in Iron Age northwestern Arabia and is now the lingua franca of the Arab world. Arabic is also the language of 1.7 billion Muslims. It is one of six languages of the United Nations. The modern written language is derived from the language of the Quran and it is widely taught in schools and universities, and is used to varying degrees in workplaces, government, and the media. The two formal varieties are grouped together as Literary Arabic, which is the language of 26 states. Modern Standard Arabic largely follows the standards of Quranic Arabic. Much of the new vocabulary is used to denote concepts that have arisen in the post-Quranic era, Arabic has influenced many languages around the globe throughout its history. During the Middle Ages, Literary Arabic was a vehicle of culture in Europe, especially in science, mathematics. As a result, many European languages have borrowed many words from it. Many words of Arabic origin are found in ancient languages like Latin. Balkan languages, including Greek, have acquired a significant number of Arabic words through contact with Ottoman Turkish. Arabic has also borrowed words from languages including Greek and Persian in medieval times. Arabic is a Central Semitic language, closely related to the Northwest Semitic languages, the Ancient South Arabian languages, the Semitic languages changed a great deal between Proto-Semitic and the establishment of the Central Semitic languages, particularly in grammar. Innovations of the Central Semitic languages—all maintained in Arabic—include, The conversion of the suffix-conjugated stative formation into a past tense, the conversion of the prefix-conjugated preterite-tense formation into a present tense. The elimination of other prefix-conjugated mood/aspect forms in favor of new moods formed by endings attached to the prefix-conjugation forms, the development of an internal passive. These features are evidence of descent from a hypothetical ancestor. In the southwest, various Central Semitic languages both belonging to and outside of the Ancient South Arabian family were spoken and it is also believed that the ancestors of the Modern South Arabian languages were also spoken in southern Arabia at this time. To the north, in the oases of northern Hijaz, Dadanitic and Taymanitic held some prestige as inscriptional languages, in Najd and parts of western Arabia, a language known to scholars as Thamudic C is attested
5.
Comparative method (linguistics)
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The comparative method was developed over the 19th century. Key contributions were made by the Danish scholars Rasmus Rask and Karl Verner, the comparative method aims to prove that two or more historically attested languages are descended from a single proto-language by comparing lists of cognate terms. From them, regular sound correspondences between the languages are established, and a sequence of sound changes can then be postulated. Relation is deemed certain only if at least a partial reconstruction of the ancestor is feasible. For example, a chain of speakers across the centuries links Vulgar Latin to all of its modern descendants. Two languages are related if they descended from the same ancestor language. For example, Italian and French both come from Latin and therefore belong to the family, the Romance languages. However, it is possible for languages to have different degrees of relatedness, English, for example, is related to both German and Russian, but is more closely related to the former than it is to the latter. Although all three share a common ancestor, Proto-Indo-European, English and German also share a more recent common ancestor, Proto-Germanic. Therefore, English and German are considered to belong to a different subgroup, shared retentions from the parent language are not sufficient evidence of a sub-group. For example, German and Russian both retain from Proto-Indo-European a contrast between the case and the accusative case, which English has lost. Languages have been compared since antiquity, the Scythian theory was further developed by Andreas Jäger and William Wotton, who made first forays to reconstruct this primitive common language. In 1710 and 1723, Lambert ten Kate first formulated the regularity of sound laws, introducing among others, the root vowel. ”The comparative method developed out of attempts to reconstruct the proto-language mentioned by Jones, which he did not name. The first professional comparison between the Indo-European languages known then was made by the German linguist Franz Bopp in 1816, though he did not attempt a reconstruction, he demonstrated that Greek, Latin and Sanskrit shared a common structure and a common lexicon. Both Rask and Grimm were unable to explain apparent exceptions to the laws that they had discovered. This Neogrammarian Hypothesis led to application of the method to reconstruct Proto-Indo-European. Linguists working with other families followed suit, and the comparative method quickly became the established method for uncovering linguistic relationships. The abbreviated summary below is based on their concepts of how to proceed and this step involves making lists of words that are likely cognates among the languages being compared
6.
August Schleicher
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August Schleicher was a German linguist. His great work was A Compendium of the Comparative Grammar of the Indo-European Languages, to show how Indo-European might have looked, he created a short tale, Schleichers fable, to exemplify the reconstructed vocabulary and aspects of Indo-European society inferred from it. Schleicher was born in Meiningen, in the Duchy of Saxe-Meiningen and he died from tuberculosis at the age of 47 in Jena, in the Duchy of Saxe-Weimar-Eisenach, in present-day Thuringia. Schleicher was educated at the University of Bonn and taught at the Charles University in Prague and he began his career studying theology and Oriental languages, especially Arabic, Hebrew, Sanskrit and Persian. Influenced by Georg Wilhelm Friedrich Hegel, he formed the theory that a language is an organism, with periods of development, maturity, in 1850, Schleicher completed a monograph systematically describing European languages, Die Sprachen Europas in systematischer Übersicht. He explicitly represented languages as perfectly natural organisms that could most conveniently be described using terms drawn from biology, genus, species, Schleicher claimed that he himself had been convinced of the natural descent and competition of languages before he had read Darwin’s Origin of Species. He invented a system of classification that resembled a botanical taxonomy, tracing groups of related languages. His model, the Stammbaumtheorie, was a development in the study of Indo-European languages. He first introduced a representation of a Stammbaum in an article published in 1853 entitled Die ersten Spaltungen des indogermanischen Urvolkes. By the time of the publication of his Deutsche Sprache he had begun to use trees to illustrate language descent, Schleicher is commonly recognized as the first linguist to portray language development using the figure of a tree. Largely in reaction to this, Johannes Schmidt later proposed his Wave Theory as an alternative model, Schleicher believed that languages pass through a life cycle, similar to that of living beings. They start simpler than they will become, Language declines both in sound and in form. The transition from the first to the period is one of slower progress. Schleicher was an advocate of the polygenesis of languages, since languages are continually dying out, whilst no new ones practically arise, there must have been originally many more languages than at present. The number of languages was therefore certainly far larger than has been supposed from the still-existing languages. Schleichers ideas on polygenesis had long-lasting influence, both directly and via their adoption by the biologist Ernst Haeckel, in 1866, August Leskien, a pioneer of research into sound laws, began studying comparative linguistics under August Schleicher at the University of Jena. Bonn, H. B. Koenig Linguistische Untersuchungen, part 2, Die Sprachen Europas in systematischer Uebersicht. Koenig, new ed. by Konrad Koerner, Amsterdam, John Benjamins Formenlehre der kirchenslavischen Sprache, Die ersten Spaltungen des indogermanischen Urvolkes
7.
Dialect continuum
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That happens, for example, across large parts of India or the Maghreb. Historically, it happened in various parts of Europe such as between Portugal, southern Belgium and southern Italy, and between Flanders and Austria. Leonard Bloomfield used the dialect area. It is analogous to a species in evolutionary biology. Dialect continua typically occur in long-settled agrarian populations, as innovations spread from their various points of origin as waves, in this situation, hierarchical classifications of varieties are impractical. Instead, dialectologists map variation of language features across a dialect continuum. The influential Atlas linguistique de la France pioneered the use of a trained fieldworker and these atlases typically consist of display maps, each showing local forms of a particular item at the survey locations. Secondary studies may include maps, showing the areal distribution of various variants. A common tool in these maps is an isogloss, a line separating areas where different variants of a particular feature predominate, in a dialect continuum, isoglosses for different features are typically spread out, reflecting the gradual transition between varieties. A bundle of coinciding isoglosses indicate a stronger dialect boundary, as might occur at geographical obstacles or long-standing political boundaries, in other cases, intersecting isoglosses and more complex patterns are found. Standard varieties may be developed and codified from one or more locations in a continuum, in such cases the local variety is said to be dependent on, or heteronomous with respect to, the standard variety. The Scandinavian languages, Danish, Norwegian and Swedish, are cited as examples. Conversely, a defined in this way may include local varieties that are mutually unintelligible. The choice of standard is determined by a political boundary. As a results, speakers on either side of the boundary may use almost identical varieties, but treat them as dependent on different standards, the choice may be a matter of national, regional or religious identity, and may be controversial. In the Yugoslav republic of Macedonia, a standard was developed from local varieties within a continuum with Serbia to the north, the standard was deliberately based on varieties from the west of the republic that were most different from standard Bulgarian. Now known as Macedonian, it is the standard of the independent Republic of Macedonia. Europe provides several examples of dialect continua, the largest of which involve the Germanic, Romance and Slavic branches of the Indo-European language family
8.
Phylogenetic tree
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The taxa joined together in the tree are implied to have descended from a common ancestor. Phylogenetic trees are central to the field of phylogenetics, 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 phylogenetic comparative methods. Unrooted trees illustrate only the relatedness of the nodes and do not require the ancestral root to be known or inferred. The idea of a tree of life arose from ancient notions of a progression from lower to higher forms of life. Charles Darwin also produced one of the first illustrations and crucially popularized the notion of a tree in his seminal book The Origin of Species. Over time, species classification has become static and more dynamic. A rooted phylogenetic tree is a tree with a unique node corresponding to the most recent common ancestor of all the entities at the leaves of the tree. 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, unrooted trees illustrate the relatedness of 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, both rooted and unrooted phylogenetic trees can be either bifurcating or multifurcating, and either labeled or unlabeled. 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. A labeled tree has specific values assigned to its leaves, while a tree, sometimes called a tree shape. The last distinction is the most biologically relevant, it arises because there are places on an unrooted tree to put the root. For labeled bifurcating trees, there are,2 n −2. for n ≥2 total rooted trees and. 2 n −3. for n ≥3 total unrooted trees, among labeled bifurcating trees, the number of unrooted trees with n leaves is equal to the number of rooted trees with n −1 leaves. A dendrogram is a term for the diagrammatic representation of a phylogenetic tree. A cladogram is a phylogenetic tree formed using cladistic methods and this type of tree only represents a branching pattern, i. e. its branch spans do not represent time or relative amount of character change
9.
Clade
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A clade is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single branch on the tree of life. The common ancestor may be an individual, a population, a species, 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, 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, the term clade was coined in 1957 by the biologist Julian Huxley to refer to the result of cladogenesis, a concept Huxley borrowed from Bernhard Rensch. Many commonly named groups are clades, for example, rodents or insects, because in each case, their name refers to a common ancestor with all its descendant branches. Rodents, for example, are a branch of mammals that split off after the end of the period when the clade Dinosauria stopped being the dominant terrestrial vertebrates 66 million years ago, the original population and all its descendants are a clade. The rodent clade corresponds to the order Rodentia, and insects to the class Insecta and these clades include smaller clades, such as chipmunk or ant, each of which consists of even smaller clades. The clade rodent is in included in the mammal, vertebrate. The phenomenon of convergent evolution is, however, responsible for cases where there are misleading similarities in the morphology of groups that evolved from different lineages. The publication of Darwins theory of evolution in 1859 gave this view increasing weight, thomas Henry Huxley, an early advocate of evolutionary theory, proposed a revised taxonomy based on clades. For example, he grouped birds with reptiles, based on fossil evidence, german biologist Emil Hans Willi Hennig is considered to be the founder of cladistics. Taxonomists have increasingly worked to make the taxonomic system reflect evolution, when it comes to naming, however, this principle is not always compatible with the traditional rank-based nomenclature. For these and other reasons, phylogenetic nomenclature has been developed, a clade is by definition monophyletic, meaning that it contains one ancestor and all its descendants. The ancestor can be known or unknown, any and all members of a clade can be extant or extinct, the science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics, the latter term coined by Ernst Mayr, derived from clade. The results of analyses are tree-shaped diagrams called cladograms, they. Three methods of defining clades are featured in phylogenetic nomenclature, node-, stem-, the relationship between clades can be described in several ways, A clade located within a clade is said to be nested within that clade. In the diagram, the clade, i. e. the apes. Two clades are sisters if they have a common ancestor
10.
Monophyly
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In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it consists of an ancestral species and all its descendants. The term is synonymous with the uncommon term holophyly, monophyletic groups are typically characterized by shared derived characteristics. Monophyly is contrasted with paraphyly and polyphyly, as shown in the second diagram, a paraphyletic group consists of all of the descendants of a common ancestor minus one or more monophyletic groups. These definitions have taken time to be accepted. When the cladistic school of thought became mainstream in the 1960s, indeed, taxonomists sometimes used terms without defining them, leading to confusion in the early literature, a confusion which persists. On the broadest scale, definitions fall into two groups, willi Hennig defined monophyly as groups based on synapomorphy. Some authors have sought to define monophyly to include paraphyly as any two or more groups sharing a common ancestor, however, this broader definition encompasses both monophyletic and paraphyletic groups as defined above. Therefore, most scientists today restrict the term monophyletic to refer to groups consisting of all the descendants of one common ancestor, however, when considering taxonomic groups such as genera and species, the most appropriate nature of their common ancestor is unclear. Assuming that it would be one individual or mating pair is unrealistic for sexually reproducing species, some argue that using a broader definition, such as a species and all its descendants, does not really work to define a genus. According to D. M. Glossary of scientific naming Clade Paraphyly Polyphyly Crown group Abbey, graphical explanation of basic phylogenetic terms. Carr, Steven M. Concepts of monophyly, polyphyly & paraphyly
11.
Speech community
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A speech community is a group of people who share a set of linguistic norms and expectations with regard to how their language should be used. Exactly how to define speech community is debated in the literature and it has also been assumed that within a community a homogeneous set of norms should exist. Each speech community has different norms that tend to share only partially. Communities may be de-localized and unbounded rather than local, and they often comprise different sub-communities with differing speech norms, such groups can be villages, countries, political or professional communities, communities with shared interests, hobbies, or lifestyles, or even just groups of friends. Speech communities may share both particular sets of vocabulary and grammatical conventions, as well as styles and genres, and also norms for how. The adoption of the concept of the community as a unit of linguistic analysis emerged in the 1960s. Dialectologists rather realized that traits spread through diffusion and that social factors were decisive in how this happened. They also realized that traits spread as waves from centers and that several competing varieties would exist in some communities. This could be done by focusing on the aspect of language. This definition gives equal importance to the structural and interactional layers, the community is a group of people that frequently interact with each other. This is not a definition of a group because frequency of interaction is relative and graduated. The definition of the system is also not exclusive because it is defined as being set off from other systems by significant differences in usage. Here Gumperz again identifies two important components of the community, its members share both a set of linguistics forms and a set of social norms that govern the use of those forms. Gumperz also sought to set up a framework for describing how linguistic systems can be in use within a single speech community. Where Gumperz formulation was designed to incorporate heterogeneity, by focusing on shared norms of language use rather than a linguistic system. Like that of Gumperz, Labovs formulation stressed that a community was defined more by shared norms than by shared linguistic forms. But like Chomsky, Labov also saw each of the formally distinguished linguistic varieties within a community as homogeneous, invariant. Probably because of their considerable power, Labovs and Chomskys understandings of the speech community became widely influential in linguistics
