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Willi Hennig
Emil Hans Willi Hennig (20 April 1913 – 5 November 1976) was a Germans, German biologist and zoologist who is considered the founder of Phylogenesis, phylogenetic systematics, otherwise known as cladistics. In 1945 as a POWs in World War II, prisoner of war, Hennig began work on his theory of cladistics, which he published in German in 1950, with a substantially revised English translation published in 1966. With his works on evolution and systematics he revolutionised the view of the natural order of beings. As a Taxonomy (biology), taxonomist, he specialised in dipterans (true flies). Hennig coined the key terms synapomorphy, Plesiomorphy and symplesiomorphy, symplesiomorphy, and paraphyly. He also asserted, in his "auxiliary principle", that "the presence of apomorphous characters in different species 'is always reason for suspecting kinship [i.e., that species belong to a monophyletic group], and that their origin by convergence should not be presumed a priori' (Hennig, 195 ... [...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] |
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] |
Dürrhennersdorf
Dürrhennersdorf ( hsb, Suche Hendrichecy) is a municipality in the district Görlitz (district), Görlitz, in Saxony, Germany. Notable people * Wolfgang Böhmer (born 1936), politician * Willi Hennig (1913–1976) biologist and founder of cladistics References Populated places in Görlitz (district) {{Görlitz-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POWs In World War II
A prisoner of war (POW) is a person who is held captive by a belligerent power during or immediately after an armed conflict. The earliest recorded usage of the phrase "prisoner of war" dates back to 1610. Belligerents hold prisoners of war in custody for a range of legitimate and illegitimate reasons, such as isolating them from the enemy combatants still in the field (releasing and repatriating them in an orderly manner after hostilities), demonstrating military victory, punishing them, prosecuting them for war crimes, exploiting them for their labour, recruiting or even conscripting them as their own combatants, collecting military and political intelligence from them, or indoctrinating them in new political or religious beliefs. Ancient times For most of human history, depending on the culture of the victors, enemy fighters on the losing side in a battle who had surrendered and been taken as prisoners of war could expect to be either slaughtered or enslaved. Earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dresden
Dresden (, ; Upper Saxon: ''Dräsdn''; wen, label=Upper Sorbian, Drježdźany) is the capital city of the German state of Saxony and its second most populous city, after Leipzig. It is the 12th most populous city of Germany, the fourth largest by area (after Berlin, Hamburg and Cologne), and the third most populous city in the area of former East Germany, after Berlin and Leipzig. Dresden's urban area comprises the towns of Freital, Pirna, Radebeul, Meissen, Coswig, Radeberg and Heidenau and has around 790,000 inhabitants. The Dresden metropolitan area has approximately 1.34 million inhabitants. Dresden is the second largest city on the River Elbe after Hamburg. Most of the city's population lives in the Elbe Valley, but a large, albeit very sparsely populated area of the city east of the Elbe lies in the West Lusatian Hill Country and Uplands (the westernmost part of the Sudetes) and thus in Lusatia. Many boroughs west of the Elbe lie in the foreland of the Ore Mounta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Stalingrad
The Battle of Stalingrad (23 August 19422 February 1943) was a major battle on the Eastern Front of World War II where Nazi Germany and its allies unsuccessfully fought the Soviet Union for control of the city of Stalingrad (later renamed to Volgograd) in Southern Russia. The battle was marked by fierce close-quarters combat and direct assaults on civilians in air raids, with the battle epitomizing urban warfare. The Battle of Stalingrad was the deadliest battle to take place during the Second World War and is one of the bloodiest battles in the history of warfare, with an estimated 2 million total casualties. Today, the Battle of Stalingrad is universally regarded as the turning point in the European Theatre of war, as it forced the '' Oberkommando der Wehrmacht'' (German High Command) to withdraw considerable military forces from other areas in occupied Europe to replace German losses on the Eastern Front, ending with the rout of the six field armies of Army G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fritz Rudolf Hennig
Fritz originated as a German nickname for Friedrich, or Frederick (''Der Alte Fritz'', and ''Stary Fryc'' were common nicknames for King Frederick II of Prussia and Frederick III, German Emperor) as well as for similar names including Fridolin and, less commonly, Francis. Fritz (Fryc) was also a name given to German troops by the Entente powers equivalent to the derogative Tommy. Other common bases for which the name Fritz was used include the surnames Fritsche, Fritzsche, Fritsch, Frisch(e) and Frycz. Below is a list of notable people with the name "Fritz." Surname *Amanda Fritz (born 1958), retired registered psychiatric nurse and politician from Oregon *Al Fritz (1924–2013), American businessman *Ben Fritz (born 1981), American baseball coach *Betty Jane Fritz (1924–1994), one of the original players in the All-American Girls Professional Baseball League *Clemens Fritz (born 1980), German footballer *Edmund Fritz (before 1918–after 1932), Austrian actor, film director, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Lusatia
Upper Lusatia (german: Oberlausitz ; hsb, Hornja Łužica ; dsb, Górna Łužyca; szl, Gōrnŏ Łużyca; pl, Łużyce Górne or ''Milsko''; cz, Horní Lužice) is a historical region in Germany and Poland. Along with Lower Lusatia to the north, it makes up the region of Lusatia, named after the Slavic ''Lusici'' tribe. Both parts of Lusatia are home to the West Slavic minority group of the Sorbs. The major part of Upper Lusatia is part of the German federal state of Saxony, roughly comprising Bautzen district and Görlitz district. The northwestern extremity, around Ruhland and Tettau, is incorporated into the Oberspreewald-Lausitz district of the state of Brandenburg. The eastern part of Upper Lusatia is in Poland, east of the Neisse (''Nysa'') river, in Lower Silesian Voivodeship. A small strip of land in the north around Łęknica is incorporated into Lubusz Voivodeship, along with the Polish part of Lower Lusatia. The historic capital of Upper Lusatia is Bautzen/ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Inference
Computational phylogenetics is the application of computational algorithms, methods, and programs to phylogenetic"origin,_source,_birth")_is_the_study_of_the_evolutionary_his_... "origin, source, birth") is the study of the evolutionary his ... "origin, source, birth") is the study of the evolutionary his ... "origin, source, birth") is the study of the evolutionary his ... "origin, source, birth") is the study of the evolutionary his ... "tribe, clan, race", and wikt:γενετικός, γενετικός [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle Of Parsimony
Occam's razor, Ockham's razor, or Ocham's razor ( la, novacula Occami), also known as the principle of parsimony or the law of parsimony ( la, lex parsimoniae), is the problem-solving principle that "entities should not be multiplied beyond necessity". It is generally understood in the sense that with competing theories or explanations, the simpler one, for example a model with fewer parameters, is to be preferred. The idea is frequently attributed to English Franciscan friar William of Ockham (), a scholastic philosopher and theologian, although he never used these exact words. This philosophical razor advocates that when presented with competing hypotheses about the same prediction, one should select the solution with the fewest assumptions, and that this is not meant to be a way of choosing between hypotheses that make different predictions. Similarly, in science, Occam's razor is used as an abductive heuristic in the development of theoretical models rather than as a rigorou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyly
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic group (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term was coined by Willi Hennig to apply to well-known taxa like Reptilia ( reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor, including all extant reptiles as well as the extinct synapsids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiomorphy And Symplesiomorphy
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and synapomorphy, all mean a trait shared between species because they share an ancestral species. Apomorphic and synapomorphic characteristics convey much information about evolutionary clades and can be used to define taxa. However, plesiomorphic and symplesiomorphic characteristics cannot. The term ''symplesiomorphy'' was introduced in 1950 by German entomologist Willi Hennig. Examples A backbone is a plesiomorphic trait shared by birds and mammals, and does not help in placing an animal in one or the other of these two clades. Birds and mammals share this trait because both clades are descended from the same far distant ancestor. Other clades, e.g. snakes, lizards, turtles, fish, frogs, all have backbones and none are either birds nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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