Evolutionary biology Allopatricspeciation from the ancient Greek allos, other Greek patra, fatherland or geographic speciation is speciation that occurs when biological populations of the same species ... , is a consequence of allopatricspeciation among island populations. Isolating mechanisms Image Speciation modes.svg right thumb 360px Comparison of allopatric , peripatric speciation peripatric , parapatric speciation parapatric and sympatric speciation sympatric speciationAllopatricspeciation may occur when a species is subdivided into two genetically isolated populations. Allopatric and allopatry ... species , such a distribution is usually the result of allopatricspeciation . Separation may be attributed ... the two groups is disrupted, speciation becomes a possibility. Allopatricspeciation in peripheral populations Main Peripatric speciation When populations become genetically isolated, heritable variations ..., fertile offspring with members of other species. Mayr, a proponent of allopatricspeciation, hypothesized that adaptive genetic changes that accumulate between allopatric populations cause negative ... p 473 ref Allopatricspeciation is thought to be the dominant mode of speciation. ref Harvnb Futuyma 1980 p 254 ref Examples Image Drosophila speciation experiment.svg right thumb 425px Allopatric ... Mayer first2 Gregory C year 1980 title Non AllopatricSpeciation in Animals journal Systematic Zoology ... last4 Moritz first4 Craig year 2005 title Reinforcement drives rapid allopatricspeciation journal ... first1 Russel year 1980 title Genetic Variation and Phenotypic Evolution During AllopatricSpeciation ... other, at which point, the genetically isolated groups have emerged as different species. Allopatric isolation is a key factor in speciation and a common process by which new species arise. ref ... not evolve as a consequence of external forces that drive populations toward speciation. Rather, the evolution of reproductive isolation, leading to speciation, is generally thought to be an incidental ... more details
, a view known as punctuated equilibrium . Allopatric Main allopatricspeciation During allopatric from ... speciation In peripatric speciation, a subform of allopatricspeciation, new species are formed in isolated ... produced in peripatric and allopatricspeciation. Ecologists refer to parapatric and peripatric ... are in fact examples of micro allopatric, or heteropatric speciation . The most widely accepted ... a form of allopatricspeciation in which repeated invasions of marine forms have subsequently differentiated ...Evolutionary biology Speciation is the evolution ary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term speciation for the splitting ... to speciation is the subject matter of much ongoing discussion. There are four geographic modes of speciation in nature, based on the extent to which speciating populations are geographically isolated from one another allopatricspeciationallopatric , peripatric speciation peripatric , parapatric speciation parapatric , and sympatric speciation sympatric . Speciation may also be induced artificially, through animal husbandry or laboratory experiments. Observed examples of each kind of speciation ... of Speciation by Joseph Boxhorn. Retrieved 8 June 2009. ref Natural speciation Image Punctuated ... and rare, relatively rapid bursts of evolutionary change. Image Speciation modes.svg right thumb 400px Comparison of allopatricspeciationallopatric , peripatric speciation peripatric , parapatric speciation parapatric and sympatric speciation All forms of natural speciation have taken place ... of each mechanism in driving biodiversity. ref cite journal title Adaptive speciation The role of natural selection in mechanisms of geographic and non geographic speciation author J.M. Baker journal ... pages 303 326 pmid 19260194 doi 10.1016 j.shpsc.2005.03.005 ref One example of natural speciation ... ice age, has undergone speciation into new freshwater colonies in isolated lakes and streams. Over ... more details
Image Speciation modes.svg right thumb 300px Comparison of allopatricspeciationallopatric , peripatric speciation peripatric , parapatric speciation parapatric and sympatric speciation sympatric speciation . Heteropatric and heteropatry are terms from biogeography , referring to organism s whose geographical ranges overlap or are even identical, so that they occur together at least in some places, but which occupy ecological niche s distinct enough to prevent frequent Hybrid biology hybridization ... being the result of heteropatric speciation . Heteropatric speciation is a special case of sympatric speciation that occurs when different ecotypes or Race biology race s of the same species geographically ... speciation is a refinement of our notion of sympatric speciation in that it represents a behavioral .... The importance of behavioral separation as a mechanism for promoting sympatric speciation in a heterogeneous ... speciation . ref J. Maynard Smith, 1966. Sympatric speciation. The American Naturalist 110 637 ... Biology 36 34 58. ref of conditions that facilitate sympatric speciation . Although some evolutionary biologists still regard sympatric speciation as a highly contentious issue, both theoretical ref D. I. Bolnick, 2006. Multispecies outcomes in a common model of sympatric speciation. Journal .... Habitat avoidance overlooking an important aspect of host specific mating and sympatric speciation. Evolution 59 1552 1559. ref studies increasingly support sympatric speciation as a likely process ... resolves the issue of sympatric speciation by reducing it to a scaling issue in terms of the way ..., the process looks sympatric, but from an individual s perspective, the process looks allopatric ... into account. See also Adaptive radiation Sympatry Allopatry Cladistics Phylogenetics speciation sympatric speciationallopatricspeciation References references speciation DEFAULTSORT Heteropatric Speciation Category Biogeography Category Speciation evolution stub ... more details
Evolutionary biology Image Speciation modes.svg left thumb 300px Comparison of allopatricspeciationallopatric , peripatric, parapatric speciation parapatric and sympatric speciation sympatric speciation . Peripatric and peripatry are terms from biogeography , referring to organism s whose ranges are closely adjacent but do not overlap, being separated where these organisms do not occur &ndash for example a wide river or a mountain range. Such organisms are usually closely related e.g. sister species , their distribution being the result of peripatric speciation . Peripatric speciation is a form of speciation , the formation of new species through evolution . In this form, new species are formed in isolated peripheral populations this is similar to allopatricspeciation in that populations are isolated and prevented from exchanging genes. However, peripatric speciation, unlike allopatricspeciation, proposes that one of the populations is much smaller than the other. One possible consequence of peripatric speciation is that a geographically widespread ancestral species becomes paraphyletic , thereby becoming a paraspecies . The concept of a paraspecies is therefore a logical consequence of the Evolutionary Species Concept, by which one species give rise to a daughter species. The evolution of the polar bear from the brown bear is a well documented example of a living species that gave ... speciation was originally proposed by Ernst Mayr , and is related to the founder effect , because ... title Ernst Mayr Genetics and speciation url http www.genetics.org cgi content full 167 3 1041 journal ... drift is often proposed to play a significant role in peripatric speciation. ref cite journal author Templeton AR title The theory of speciation via the founder principle url http www.genetics.org cgi ... pmc 1214177 ref References Reflist speciation show no evolution show no DEFAULTSORT Peripatric Speciation Category Ecology Category Evolutionary biology Category Speciation Category Scientific classification ... more details
pmid 18410292 ref Another example are ring species . See also species speciation allopatry , allopatricspeciation peripatry , peripatric speciation sympatry , sympatric speciation Adaptive radiation ... genetics cline . In parapatric speciation there is no specific extrinsic barrier to gene flow ... parapatric speciation in such cases as mining mine contamination of an area. This creates a selection ... . Similarly, a recent study provided evidence for parapatric speciation in Tennessee cave salamander ... evolibrary article 0 0 speciationmodes 04 Parapatric speciation in Understanding Evolution at evolution.berkeley.edu ... evolution 101 speciation show yes evolution show no DEFAULTSORT Parapatric Speciation Category Ecology Category Evolutionary biology Category Speciation Category Scientific classification Category Taxonomy ... more details
, B. M., J. A. Fordyce, and S. Gavrilets. 2008. What, if anything, is sympatric speciation? Journal of Evolutionary Biology 21 1452 1459. ref Allopatricspeciation is the evolution of geographically ...Evolutionary biology Sympatric speciation is the process through which new species evolve from a single ... related e.g. sister species , such a distribution may be the result of sympatric speciation . Etymological ... Society of London 1903 lxxvii cxvi. ref Sympatric speciation is one of three traditional geographic categories for the phenomenon of speciation. ref name Futuyma 2009 Futuyma, D. J ... of gene flow, which tends to keep populations genetically similar. Parapatric speciation is the evolution ... despite limited interbreeding where the two diverging groups come into contact. In sympatric speciation ... are special cases of a continuum from zero sympatric to complete allopatric spatial segregation ..., sympatric speciation is thought to be an uncommon but plausible process by which genetic divergence ... 2007 Bolnick, D. I. and B. M. Fitzpatrick. 2007. Sympatric speciation Models and empirical evidence ... of Genetics publisher Oxford University Press edition 7th year 2006 ref Evidence Image Speciation modes.svg frame left Comparison of allopatricspeciationallopatric , peripatric speciation peripatric , parapatric speciation parapatric and sympatric speciation A number of models have been proposed to account for this mode of speciation. The most popular, which invokes the disruptive selection model, was first put forward by John Maynard Smith in 1966. ref cite journal title Sympatric Speciation ... would be favoured over heterozygosity, eventually leading to speciation. Sympatric divergence ... may drive speciation because they also affect mating signals. In this case, different beak ... None ref A further well studied circumstance of sympatric speciation is when insects feed on more ... see heteropatry speciation. The apple feeding race of this species appears to have spontaneously ... more details
Speciation may refer to Speciation biology , evolutionary process by which new biological species arise Speciation chemistry , distribution of chemical elements disambig it Speciazione ... more details
Evolutionary biology Hybrid speciation is a form of speciation wherein Hybrid biology hybridization between two different closely related species leads to a novel species, reproductively isolated from the parent species. From the 1940s, reproductive isolation between hybrids and their parents was thought to be particularly difficult to achieve and thus hybrid species considered to be extremely rare. With DNA analysis becoming more accessible in the 1990s, hybrid species have been showed to be a fairly common phenomenon, particularly in plants. ref name Arnold cite book last Arnold first M.L. title ... 296. ref Hybrid speciation ecology A hybrid may have a distinct trait phenotype . This phenotype may ... of genetic variation, and can in itself facilitate speciation. There is evidence that introgression ... speciation For the hybrid individual to form have superior fitness, it will generally have to be able ... fluctuation of water level in Lake Malawi , a situation that generally favour speciation ... year 1927 volume 2 pages 311 356 ref A form of hybrid speciation that is relatively common in plants ... without change in chromosome number is called homoploid hybrid speciation. ref name Arnold This is the situation ... reduction of chromosome numbers, creating reproductive barriers and thus allowing speciation. Known cases of hybrid speciation File Heliconius mimicry.png thumb right Closely related Heliconius species ... Animals Hybrid speciation in animals is primarily homoploid . While not very common, a few animal species ... journal author Brower AVZ title Hybrid speciation in Heliconius butterflies? A review and critique ... ref Many of the crop species are hybrids, ref name Otto and hybridization is an important factor in speciation ... content 85 1 135.full.pdf accessdate 14 December 2011 ref Homoploid speciation has given rise ..., E., Salcedo, C., Jiggins, C.D. , Linares, M. 2006 Speciation by hybridization in Heliconius butterflies. Nature. speciation Category Hybridisation biology Category Genetics Category Speciation Category ... more details
Speciation of ions refers to the changing concentration of varying forms of an ion as the pH of the solution changes. Image Weak acid speciation3.png thumb 200px right The ratio of acid, AH and conjugate base, A sup &minus sup , concentrations varies as the difference between the pH and the p K sub a sub varies, in accordance with the Henderson Hasselbalch equation . The pH of a solution of a monoprotic weak acid can be expressed in terms of the extent of dissociation. After rearranging the expression defining the acid dissociation constant , and putting pH log sub 10 sub H sup sup , one obtains pH p K sub a sub log AH A sup sup This is a form of the Henderson Hasselbalch equation . It can be deduced from this expression that when the acid is 1 dissociated, that is, when AH A sup sup 100, pH p K sub a sub 2 when the acid is 50 dissociated, that is, when AH A sup sup 1, pH p K sub a sub when the acid is 99 dissociated, that is, when AH A sup sup 0.01, pH p K sub a sub 2 It follows that the range of pH within which there is partial dissociation of the acid is about p K sub a sub 2. This is shown graphically at the right. A practical application of these results is that the pH transition range of a pH indicator is approximately p K sub a sub 1 the colour of the indicator in its acid form is different from the colour of the conjugate base form. In the transition range both forms are in equilibrium, so the colour is intermediate. Outside the transition range the concentration of acid or conjugate base is less than 10 and the colour of the major species dominates. Image Citric acid speciation.png thumb 200 px Species concentrations calculated with the program http www.hyperquad.co.uk hyss.htm HySS for a 10mM solution of citric acid. p K sub a1 sub 3.13, p K sub a2 sub 4.76, p K sub a3 sub 6.40. A weak acid may be defined as an acid with p K sub a sub greater than about 2. An acid with p K sub a sub 2 would be 99 dissociated at pH 0, that is, in a 1 M HCl solution. Any acid ... more details
unreferenced date December 2007 Speciation is a process that occurs naturally in evolution and is modeled explicitly in some genetic algorithms . Speciation in nature occurs when two similar reproducing beings evolve to become too dissimilar to share genetic information effectively or correctly. In the case of living organisms , they are incapable of mating to produce offspring . Interesting special cases of different species being able to breed exist, such as a horse and a donkey mating to produce a mule . However in this case the Mule is usually infertile, and so the genetic isolation of the two parent species is maintained. In implementations of genetic search algorithms, the event of speciation is defined by some mathematical function that describes the similarity between two candidate solutions usually described as individuals in the population. If the result of the similarity is too low, the chromosomal crossover crossover Operation mathematics operator is disallowed between those individuals. See also DEFAULTSORT Speciation Genetic Algorithm Category Evolutionary algorithms Category Genetic algorithms ... more details
Unreferenced date April 2008 Expert subject Genetics date April 2008 A genetic isolate is population of organisms that has little genetic mixing with other organisms within the same species. This may result in speciation , but this is not necessarily the case. Genetic isolates may form new species in several ways allopatric speciation , in which two populations of the same species are geographically isolated from one another by an extrinsic barrier, and evolve intrinsic genetic reproductive isolation peripatric speciation , in which a small group of a population is separated from the main population, and experiences genetic drift parapatric speciation , in which zones of two diverging populations are separate, but do overlap somewhat partial separation is afforded by geography, so individuals of each species may come in contact from time to time, but selection for specific behaviours or mechanisms may prevent breeding between the two groups. sympatric speciation , a contentious method of speciation in which species diverge while inhabiting the same place. Human influences on genetic isolates include restricted Dog breeding breeding of dogs , or a community living secluded away from others such as Tristan da Cunha or Pitcairn Islands . A far larger and less secluded human genetic isolate is the ethnic Finns , natives of Finland see Finnish disease heritage . See also Language isolate Linkage disequilibrium DEFAULTSORT Genetic Isolate Category Speciation ... more details
Scripta 2011 40 4 350 363. ref References references See also Biological species Allopatricspeciation Parapatric speciation Sympatric speciation Category Evolutionary biology Category Population genetics Category Speciation ca Esp cies bessones de Zwillingsart es Especies gemelas it Sibling species ... more details
changes in response to their varying environments. These may drive allopatricspeciation , which is arguably the dominant mode of speciation. Evolving definitions and controversy The lack of geographic ... a common range exemplifies sympatric speciation . Such speciation may be a product of reproductive ... gene flow that results in genetic divergence. Sfn Futuyma 2009 p 241 Sympatric speciation does not imply secondary contact, which is speciation or divergence in allopatry followed by range expansions ... occurs and allopatric species, which occur in entirely distinct ranges that are neither adjacent nor overlapping. Sfn Futuyma 2009 pp 487 490 Allopatric species isolated from one another by geographical ... in complete speciation until recently, many researchers considered it nonexistent, doubting that selection ... Karen McCoy suggested that sympatry can act as a mode of speciation only when the probability ... the range of the population during the period of reproduction. ref name Sympatric speciation ... speciation in parasites what is sympatry? author McCoy, K.D. publisher Trends year 2003 pages 400 404 ref . In essence, sympatric speciation does require very strong forces of natural selection to be acting ..., recent research has begun to indicate that sympatric speciation is not as uncommon as was once assumed. Sympatric speciation Image Speciation modes.svg thumb 360px Different modes of speciation Main Sympatric speciation The lack of geographic constraint in isolating sympatric populations implies that the emerging species avoid interbreeding via other mechanisms. Before speciation is complete, two diverging populations may still produce viable offspring. As speciation progresses, isolating mechanisms ... closely related species than do allopatric groups. This is shown in the study of hybrid zone hybrid ... formation of a viable zygote in both sympatric and allopatric populations. There are two main ... speciation. If hybrid offspring are either sterile or less fit than non hybrid offspring, mating ... more details
italictitle Taxobox name Paraplesiops image Paraplesiops bleekeri.jpg image caption Paraplesiops bleekeri regnum Animalia phylum Chordata classis Actinopterygii ordo Perciformes familia Plesiopidae genus Paraplesiops genus authority Pieter Bleeker Bleeker , 1875 synonyms Bleeckeria small Castelnau, 1873 small Ruppelia small Castelnau, 1873 small Acanthogonia small Ogilby, 1918 small Paraplesiops is a genus containing five largely Allopatric speciation allopatric species of fish es in the longfin, or roundhead, family Plesiopidae , commonly known as blue devils, bluedevils or blue devilfish because of their colouration. The genus is most similar to the tropical genera Plesiops and Fraudella . It is restricted to subtropical and temperate rocky and coral reefs in Australia n waters. Its species are mostly cryptic, occurring in submarine caves, crevices and under rocky ledges. ref name ram cite journal author Hoese, Douglass F. & Kuiter, Rudie H. year 1984 title A revision of the Australian plesiopid fish genus Paraplesiops , with notes on other Australian genera. journal Records of the Australian Museum volume 36 issue 1 pages 7 18 url http australianmuseum.net.au Uploads Journals 17631 322 complete.pdf doi 10.3853 j.0067 1975.36.1984.322 ref Species Paraplesiops poweri small James Douglas Ogilby Ogilby , 1908 small , Northern Blue Devil ref name ram Paraplesiops bleekeri small Albert G nther G nther , 1861 small , Eastern Blue Devil ref name ram Paraplesiops meleagris small Wilhelm Peters Peters , 1869 small , Southern Blue Devil ref name ram Paraplesiops alisonae small Hoese and Rudie Kuiter Kuiter , 1984 small , Alison s Blue Devil ref name ram Paraplesiops sinclairi small Hutchins, 1987 small , Western Blue Devil ref cite journal author Hutchins, J.B. year 1987 title Description of a new plesiopid fish from south western Australia, with a discussion of zoogeography of Paraplesiops . journal Records of the Western Australian Museum volume 13 issue 2 pages 231 240 u ... more details
italictitle Taxobox name Drosophila pseudoobscura regnum Animal ia phylum Arthropod a classis Insect a ordo Fly Diptera familia Drosophilidae genus Drosophila subgenus Sophophora species group Drosophila obscura species group obscura group species subgroup Drosophila pseudoobscura species subgroup pseudoobscura subgroup species D. pseudoobscura binomial Drosophila pseudoobscura binomial authority Frolova & Astaurov, 1929 ref ITIS id 146332 taxon Drosophila pseudoobscura ref Drosophila pseudoobscura is a species of Drosophilidae fruit fly , used extensively in lab studies of speciation . In 2005, D. pseudoobscura was the second Drosophila species to have its genome sequenced, after the model organism Drosophila melanogaster . ref cite journal author S. Richards year 2005 title Comparative genome sequencing of Drosophila pseudoobscura Chromosomal, gene, and cis element evolution journal Genome Research journal Genome Research volume 15 pages 1 18 url http www.genome.org cgi content full 15 1 1 pmid 15632085 doi 10.1101 gr.3059305 issue 1 pmc 540289 author separator , author2 Y. Liu display authors 2 last3 Bettencourt first3 BR last4 Hradecky first4 P last5 Letovsky first5 S last6 Nielsen first6 R last7 Thornton first7 K last8 Hubisz first8 MJ last9 Chen first9 R ref Allopatric speciation has been induced by reproductive isolation in D. pseudoobscura after only eight generations using different food types, starch and maltose. ref cite journal author D. M. B. Dodd year 1989 title Reproductive isolation as a consequence of adaptive divergence in Drosophila pseudoobscura journal Evolution journal Evolution volume 43 pages 1308 1311 url http www.eebweb.arizona.edu Courses Ecol525 Readings Dodd 1989.pdf doi 10.2307 2409365 issue 6 ref References reflist Wikispecies Drosophila pseudoobscura Category Drosophilidae Category Sequenced genomes Diptera stub fr Drosophila pseudoobscura vi Drosophila pseudoobscura simple Drosophila pseudoobscura ... more details
italic title Tempo and Mode in Evolution 1944 was George Gaylord Simpson George Gaylord Simpson s seminal contribution to the modern evolutionary synthesis evolutionary synthesis , which integrated the facts of paleontology with those of genetics and natural selection . Simpson argued that the microevolution of population genetics was sufficient in itself to explain the patterns of macroevolution observed by paleontology . Simpson also highlighted the distinction between tempo and mode. Tempo encompasses evolutionary rates . . . their acceleration and deceleration, the conditions of exceptionally slow or rapid evolutions, and phenomena suggestive of inertia and momentum. While mode embraces the study of the way, manner, or pattern of evolution, a study in which tempo is a basic factor, but which embraces considerably more than tempo. Simpson s Tempo and Mode attempted to draw out several distinct generalizations That evolution s tempo can impart information about its mode. That multiple tempos can be found in the fossil record bradytelic, tachytelic, horotelic . That the facts of paleontology are consistent with the Neo Darwinism genetical theory of natural selection . Moreover, that theories such as orthogenesis , Lamarckism , mutation pressures, and Hopeful Monster macromutations are either false or play little to no role. Most evolution& 151 nine tenths & 151 occurs by the steady phyletic transformation of whole lineages anagenesis . In contrast to Ernst Mayr Ernst Mayr s interpretation of speciation by splitting, particularly Allopatric speciation allopatric and Peripatric speciation peripatric speciation. The lack of evidence for evolutionary transitions in the fossil record is best accounted for, first, by the poorness of the geological record, and secondly as a consequence of quantum evolution which is responsible for the origin taxonomic units of relatively high rank, such as families, orders, and classes. . Quantum evolution built upon Sewall Wright Sewall ... more details
even though the parent species surrounds the daughter species so there is no Allopatricspeciation geographic isolation . The speciation in the early stages would depend on assortative mating in which ... Assortative mating has been invoked to explain sympatric speciation . For some populations there are two .... Goby fish Positive assortative mating is believed to be the cause of the speciation of a daughter .... Dudgeon 2004 . Evidence for sympatric speciation by host shift in the sea. Current Biology 14 16 , pp ... natural selection Hypergamy speciation Category Reproduction Category Sexual selection Category Demography ... more details
Taxobox name Gymnophaps image Papuan Mountain Pigeon 3.jpg image caption Papuan Mountain Pigeon regnum Animalia phylum Chordata classis Aves ordo Columbiformes familia Columbidae genus Gymnophaps genus authority Tommaso Salvadori Salvadori , 1874 Gymnophaps is a genus of bird in the pigeon family Columbidae it includes three species , all called Mountain pigeons. Mountain pigeons live in the forested hills and mountains of certain islands in eastern Indonesia and in the region of Melanesia . They are tree dwellers and eat fruit. A remarkable aspect of these pigeons is that they have bright red skin around the eyes. Otherwise, they are dark gray on the back and wings, with paler heads and undersides. Males and females look mostly alike, though the female Papuan Mountain Pigeon has a grayer belly than the male. Mountain pigeons move around a lot and are often seen flying, usually in Flock birds flocks of at least ten or as many as a hundred or more birds. They are not known to do a lot of loud cooing, rather their vocalizations are muted or wheezy when they make any noise at all. The ranges of the three species do not overlap, so this genus is an example of probable allopatric speciation . Two species are island Endemism endemics the Buru Mountain Pigeon is endemic to the Maluku Islands , and the Pale Mountain Pigeon is endemic to the Solomon Islands archipelago Solomon Islands . The Papuan Mountain Pigeon has a range in between the others it lives on the island of New Guinea and on nearby smaller islands. Species Papuan Mountain Pigeon , Gymnophaps albertisii Buru Mountain Pigeon , Gymnophaps mada Pale Mountain Pigeon , Gymnophaps solomonensis References cite book last1 Gibbs first1 David last2 Barnes first2 Eustace last3 Cox first3 John title Pigeons and Doves A Guide to the Pigeons and Doves of the World publisher Yale University Press year 2001 pages 168 169, 577 580 isbn 0 300 07886 2 Category Columbidae Columbiformes stub ca Gymnophaps de Bergtauben eo Montokolo ... more details
The Bateson Dobzhansky Muller Model ref http www.ncbi.nlm.nih.gov pmc articles PMC1207686 pdf ge14441331.pdf Dobzhansky, Bateson, and the genetics of speciation. ref is a model of the evolution of genetic incompatibility. The theory was first described by William Bateson in 1909 ref cite journal last Batson first William title Heredity and variation in modern lights journal Darwin and Modern Science year 1909 pages 85 81 ref , then independently described by Theodosius Dobzhansky in 1934 ref cite journal last Dobzhansky first Theodosius title Studies on Hybrid Sterility . I. Spermatogenesis in pure and hybrid Drosophila pseudoobscura journal Zeitschrift f r Zellforschung und mikroskopische Anatomie year 1934 volume 21 pages 169 221 url http resources.metapress.com pdf preview.axd?code k8473n7380186x54&size largest ref , and later elaborated by Hermann Joseph Muller Herman Muller . The model attempts to explain how incompatibilities between closely related species develop without either of them going through an Fitness landscape adaptive valley . In its simplest form the model shows that changes in at least two loci are required to cause hybrid incompatibility, or at least a decrease in fitness between individuals from two ancestrally identical, but Allopatry allopatric populations. This is based on the idea that a new allele which has arisen at one locus in one population should not cause decreased fitness when placed into the identical except for one allele genetic background of the second population. Therefore another allele at a second locus which is incompatible with the first must have arisen. See Also William Bateson Theodosius Dobzhansky Hermann Joseph Muller References reflist Category Evolutionary biology tr Bateson Dobzhansky Muller Modeli ... more details
Wikify date December 2011 Pierre Tr maux 20 July 1818 12 March 1895 was a French architect, orientalist and photographer, and author of numerous scientific and ethnographic publications. His 1865 work Origine et transformations de l homme et des autres tres was a predecessor and precursor to the theory of punctuated equilibrium Wilkins and Nelson, 2008 . ref Wilkins, J.S and Nelson, G.J. 2008 . Tr maux on species A theory of allopatric speciation and punctuated equilibrium before Wagner. Archives of Philosophy of the Science. University of Pittsburgh USA . pdf http philsci archive.pitt.edu 3881 1 Tremaux on species.pdf. Published online as pre print format in this digital library and definitively published in History and Philosophy of the Life Sciences Hist. Philos. Life Sci, 2008, 30 179 206 . ref References for instructions on creating citations using ref ref see http en.wikipedia.org wiki Wikipedia Footnotes Reflist External links http fr.wikipedia.org wiki Pierre Tr C3 A9maux Pierre Tr maux in French Wikipedia http books.google.co.uk books?id qAFAAAAAIAAJ&printsec frontcover&dq pierre tremaux origine&hl en&sa X&ei vLP3TtiuM4G8 QbXjf3zAg&sqi 2&ved 0CDoQ6AEwAA v onepage&q&f false Origine et transformations de l homme et des autres tres Hachette, 1865 available on Google books Persondata Metadata see Wikipedia Persondata . NAME Tremaux, Pierre ALTERNATIVE NAMES SHORT DESCRIPTION French architect DATE OF BIRTH 20 July 1818 PLACE OF BIRTH DATE OF DEATH 12 March 1895 PLACE OF DEATH DEFAULTSORT Tremaux, Pierre Category 1818 births Category 1895 deaths Category French architects Category French orientalists Category French photographers Category Ethnographers France architect stub France scientist stub es Pierre Tr maux fr Pierre Tr maux ... more details
italictitle Taxobox name Spermophilus pallidicauda image status LC status system iucn3.1 status ref ref name iucn http www.iucnredlist.org apps redlist details 136231 0 full IUCN Red List ref regnum Animalia phylum Chordata classis Mammal ia ordo Rodent ia familia Sciuridae genus Spermophilus species S. pallidicauda binomial Spermophilus pallidicauda binomial authority Konstantin Alekseevich Satunin Satunin , 1903 synonyms The pallid ground squirrel , Spermophilus pallidicauda , is a species of rodent in the Sciuridae family. It is found in Mongolia and the adjacent Nei Mongol autonomous region. ref http www.bucknell.edu msw3 browse.asp?id 12401054 Mammal Species of the World ref A generic revision of the genus was undertaken in 2007 which helped resolve the uncertainty as to whether this species should be considered a subspecies of Spermophilus erythrogenys . A phylogeny based on molecular sequence data determined that S. pallidicauda was indeed a separate species from S. erythrogenys , and from the other similar species in the genus, S. brevicauda and S. alashanicus . ref Harrison, R. G. , S. M. Bogdanowicz , R. S. Hoffmann , E. Yensen , and P. W. Sherman . 2003. Phylogeny and evolutionary history of the ground squirrels Rodentia Marmotinae . Journal of Mammalian Evolution 10 249 276. ref Distribution The pallid ground squirrel is found in Mongolia near Lake Khulu Nur and the Baidarak River and in Ullyn Bulyk, the Mongolian and the Gobi Altai Mountains . ref Ellerman, J. R. and T. C. S. Morrison Scott . 1966. Checklist of Palearctic and Indian mammals , 1758 1946. 2nd ed. Trustees of the British Museum Natural History , London, United Kingdom. ref The closely related species, Alashan ground squirrel Spermophilus alashanicus from the Alxa League Alashan Desert and Spermophilus brevicauda , found in eastern Kazakhstan and in Tian Shan mountain range, are Allopatric speciation allopatric in distribution as they are largely separated by geographic boundaries. ref name ... more details
forests in which populations become allopatric. Over time, this led to speciation populations of the same ... of speciation and used it to explain population patterns in other areas of the world, such as Africa ... may have been a refugium. But this model of speciation remains highly controversial. Citation needed ... Reflist Coyne, Jerry A. and H. Allen Orr. 2004. Speciation . Sunderland Sinauer Associates, Inc. ISBN 0 87893 091 4 Haffer, Jurgen. 1969. Speciation in Amazonian Forest Birds. Science . Vol. 165 131 ... more details
be reserved for those occasions where allopatricspeciationallopatric , or geographically isolated, speciation occurred and varieties are best used in cases where sympatric speciation is suspected ... more details
examples of both intraspecific and interspecific hybridisation. Topics related to speciation Species problem Allopatric vs. sympatric speciation Sexual selection and speciation Islands as natural laboratories for exploring speciation Species concepts biological vs. phylogenetic Instant speciation via polyploidy etc. Ecological vs. genetics genetic speciation Punctuated equilibrium evolution and speciation ... Ciconiiformes An introduction to Speciation http www.uwyo.edu dbmcd molmark lect2a.html Speciation and Hybridization ... more details
. Speciation Genetic analysis performed on this species suggest that it evolved directly from Layia glandulosa in what may be an example of both allopatricspeciation and peripatric speciation . ref ... more details
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