117 Sentences With "punctuated equilibrium"

So I would argue that we've entered a moment of punctuated equilibrium in retail.

Republicans have experienced what evolutionary biologists might call punctuated equilibrium, a rapid evolution caused by an environmental crisis.

JAMES COULTER: Well, I think I've learned that you have to look for that moment of punctuated equilibrium.

Instead I see this idea of punctuated equilibrium will come back to the term moving across industries and across sectors.

So if you think about industries that are going through this moment of punctuated equilibrium, one of the markets is the media business.

But in some instances, when environmental conditions are particularly severe and attritional, selectional processes accelerate the process—an evolutionary phenomenon dubbed "punctuated equilibrium" by the late evolutionary biologist Stephen Jay Gould.

Many years ago, the late evolutionary biologist Stephen Jay Gould proposed a concept he called "punctuated equilibrium," in which species undergo rapid bursts of evolution in reaction to a sudden environmental change.

Maybe instead of an ever-crescendoing parabolic rise in machine learning we should hope for a kind of punctuated equilibrium, periods of hypergrowth alternating with AI winters, giving us time to reflect and adjust.

And to that point: Research published today in Science suggests that populations of great tits (Parus major) are in the midst of a punctuated equilibrium phase thanks to the relatively recent introduction of backyard feeders.

James: You know we haven't invested in airlines for a number of years in part because we invested during the 90s early 2000s when we were in this moment of punctuated equilibrium where there was a series of airline mergers and changes in service et cetera.

And fashion tends to advance on the punctuated equilibrium model proposed by the paleontologist Stephen Jay Gould: A house moseys along under one designer in one aesthetic until he or she leaves or is fired, at which point environmental stress is created, a new designer comes in with a new idea, and the brand heads off in a different direction.

Much confusion has arisen over what proponents of punctuated equilibrium actually argued, what mechanisms they advocated, how fast the punctuations were, what taxonomic scale their theory applied to, how revolutionary their claims were intended to be, and how punctuated equilibrium related to other ideas like saltationism, quantum evolution, and mass extinction.Gould, S. J. (1992) "Punctuated equilibrium in fact and theory." In Albert Somit and Steven Peterson The Dynamics of Evolution. New York: Cornell University Press. pp. 54–84.

At the same time, social scientific applications of the punctuated equilibrium concept have been criticized for losing sight of a core idea in the original biological theory of punctuated equilibrium: the notion that geographic location plays a significant role in determining which populations are subject to abrupt changes at a given time.

206Fitch, W. J. and F. J. Ayala (1995) Tempo and mode in evolution: genetics and paleontology 50 years after Simpson. Washington, D.C.: National Academy Press. This hypothesis differs from punctuated equilibrium in several respects. First, punctuated equilibrium was more modest in scope, in that it was addressing evolution specifically at the species level.

Phyletic gradualism vs. punctuated equilibrium: applicability of neontological data. Paleobiology, 6(3), 271-275. There will always be variance in environments.

Punctuated Equilibrium is the first solo album by American singer/guitarist Scott "Wino" Weinrich, released in January 2009 on Southern Lord.

He was a critic of gradualism and the punctuated equilibrium theory of evolution.Lambert, David. (1988). Neo-Darwinism: An Emperor With No Clothes.

New York: Oxford University Press, pp. 97-116.Geary, Dana (2008). "The Legacy of Punctuated equilibrium." In Warren D. Allmon et al.

Falconer was originally a creationist who denied the fact of evolution.Gould, Stephen Jay. (2007). Punctuated Equilibrium. Harvard University Press. pp. 14–18.

At college, he was roommates with the paleontologist, Niles Eldredge, who proposed the theory of punctuated equilibrium in 1972, in Carman Hall.

Cultural evolution follows punctuated equilibrium which Gould and Eldredge developed for biological evolution. BloomfieldBloomfield, Masse (1993). Mankind in Transition, Masefield Books.Bloomfield, Masse (1995).

Niles Eldredge (; born August 25, 1943) is an American biologist and paleontologist, who, along with Stephen Jay Gould, proposed the theory of punctuated equilibrium in 1972.

Punctuated equilibrium postulates that evolutionary change is concentrated during a geologically short speciation phase, which is followed by evolutionary stasis that persists until the species goes extinct. The prevalence of evolutionary stasis through most of the existence time of species is a major argument for the relevance of species selection in shaping the evolutionary history of clades. However, punctuated equilibrium is neither a macroevolutionary model of speciation, nor is it a prerequisite for species selection.

Some critics jokingly referred to the theory of punctuated equilibrium as "evolution by jerks",Turner, John (1984). "Why we need evolution by jerks." New Scientist 101 (Feb. 9): 34–35.

Punctuated equilibrium has also been cited as contributing to the hypothesis that species are Darwinian individuals, and not just classes, thereby providing a stronger framework for a hierarchical theory of evolution.

Punctuated equilibrium is often portrayed to oppose the concept of gradualism, when it is actually a form of gradualism.Dawkins, Richard (1996). The Blind Watchmaker. New York: W. W. Norton & Co., Chapter 9. (p.

He believed that evolution had occurred "by gradual steps at remote irregular periods." This has been compared to the concept of punctuated equilibrium. He also held that the same processes apply to humans.

Cross, W. C., Graham, T. A., & Wright, N. A. (2016). New paradigms in clonal evolution: punctuated equilibrium in cancer. The Journal of pathology, 240(2), 126-136. A study looks at breast cancer.

CIP Press (English translation). His hypothesis of frozen plasticity is an extension of Niles Eldredge and Stephen Jay Gould's theory of punctuated equilibrium,Flegr, Jaroslav (1999). Frozen Evolution, pp. 141-146, 149-156.

London: > John Murray. 5th edition, pp. 121-122. Thus punctuated equilibrium is incongruous with some of Darwin's ideas regarding the specific mechanisms of evolution, but generally accords with Darwin's theory of evolution by natural selection.

London: John Murray. 5th edition, p. 551. Thus punctuationism in general is consistent with Darwin's conception of evolution. According to early versions of punctuated equilibrium, "peripheral isolates" are considered to be of critical importance for speciation.

The study directly challenges phyletic gradualism and punctuated equilibrium. It shows how many factors can come into play when comparing the two modes of evolution.Johnson, J. G. (1982). Occurrence of phyletic gradualism and punctuated equilibria through geologic time.

The punctuated equilibrium model of policy change was first presented by Frank Baumgartner and Bryan Jones in 1993, and has increasingly received attention in historical institutionalism.Pierson, Paul. (2004). Politics in Time: History, Institutions, and Social Analysis. Princeton: Princeton University Press.

While the traditional model of paleontology, the phylogenetic model, posits that features evolved slowly without any direct association with speciation, the relatively newer and more controversial idea of punctuated equilibrium claims that major evolutionary changes don't happen over a gradual period but in localized, rare, rapid events of branching speciation. Punctuated gradualism is considered to be a variation of these models, lying somewhere in between the phyletic gradualism model and the punctuated equilibrium model. It states that speciation is not needed for a lineage to rapidly evolve from one equilibrium to another but may show rapid transitions between long-stable states.

Punctuated equilibrium in social theory is a conceptual framework for understanding the process of change in complex social systems. The approach studies the evolution of policy change,Baumgartner, Frank and Bryan D. Jones (1993). Agendas and Instability in American Politics. Chicago: University of Chicago Press.

Donald Ross Prothero (February 21, 1954) is an American geologist, paleontologist, and author who specializes in mammalian paleontology and magnetostratigraphy, a technique to date rock layers of the Cenozoic era and its use to date the climate changes which occurred 30-40 million years ago. He is the author or editor of more than 30 books and over 300 scientific papers, including at least 5+ geology textbooks. Stephen Jay Gould cited Prothero's research on the lack of response to climate change in mammals from the Eocene, Oligocene and Pleistocene epochs to support the punctuated equilibrium model of evolution. He called Prothero “the best punctuated equilibrium researcher on the West Coast”.

Modeling modes of evolution: Comparing phyletic gradualism & punctuated equilibrium. The American Biology Teacher, 56(6), 354-360. Another related study focuses on the extent of undefined area when trying to compare the two modes of evolution making it difficult to isolate one model.Ricklefs, R. E. (1980).

Eldredge and Stephen Jay Gould proposed punctuated equilibria in 1972. Punctuated equilibrium is a refinement to evolutionary theory. It describes patterns of descent taking place in "fits and starts" separated by long periods of stability. Eldredge went on to develop a hierarchical vision of evolutionary and ecological systems.

Before punctuated equilibrium, most evolutionists considered stasis to be rare or unimportant.Gould, S. J. 2002. The Structure of Evolutionary Theory. Cambridge MA: Harvard University Press, p. 875. The paleontologist George Gaylord Simpson, for example, believed that phyletic gradual evolution (called horotely in his terminology) comprised 90% of evolution.

The basis for advancing the multiregional interpretation stems from his skepticism of punctuated equilibrium (the idea evolution typically proceeds with long static periods and abrupt changes, instead of gradual modification during speciation) as an accurate model for Pleistocene humanity, noting that speciation played a role earlier in human evolution.

Dr Anne Dambricourt-Malassé (born 1959) is a paleoanthropologist at the French National Centre for Scientific Research (CNRS). She has advocated a highly controversial non-Darwinian view of human evolution with theories similar to punctuated equilibrium, auto-organization and dissipative structures, with natural selection not being the exclusive method of evolution.

Some scholars have questioned the revolutionary character of an evolution through four centuries.; Clifford Rogers has suggested that the military revolution can best be compared with the concept of "punctuated equilibrium evolution" (a theory originating in biology), meaning short bursts of rapid military innovation followed by longer periods of relative stagnation.

He published his first paper on dinosaur endothermy in 1968. His seminal work, The Dinosaur Heresies, was published in 1986. He revealed the first evidence of parental care at nesting sites for Allosaurus. He also observed evidence in support of Eldredge and Gould's theory of punctuated equilibrium in dinosaur populations.

Punctuated gradualism is a microevolutionary hypothesis that refers to a species that has "relative stasis over a considerable part of its total duration [and] underwent periodic, relatively rapid, morphologic change that did not lead to lineage branching". It is one of the three common models of evolution. While the traditional model of palaeontology, the phylogenetic model, states that features evolved slowly without any direct association with speciation, the relatively newer and more controversial idea of punctuated equilibrium claims that major evolutionary changes don't happen over a gradual period but in localized, rare, rapid events of branching speciation. Punctuated gradualism is considered to be a variation of these models, lying somewhere in between the phyletic gradualism model and the punctuated equilibrium model.

Chicago: University of Illinois Press, pp. 64-97. The theory posits that most social systems exist in an extended period of stasis, which may be punctuated by sudden shifts leading to radical change. The theory was largely inspired by the evolutionary biology theory of punctuated equilibrium developed by paleontologists Niles Eldredge and Stephen Jay Gould.

The Academy of Management Review 16(1): 10-36 As some researchers have noted, the biological applications of punctuated equilibrium have rejuvenated a new "theory about change within entities."Arrow, H., M. S. Poole, K. B. Henry, S. Wheelan, and R. Moreland (2004). "Time, change, and development: The temporal perspective on groups." Small Group Research 35 (1): 73-105.

Nevertheless, they found a readiness for critics to "seize upon" key statements and portray punctuated equilibrium, and exercises associated with it, such as public exhibitions, as a "Marxist plot". In his account of one ad hominem absurdity, Gould states on p. 984 "I swear that I do not exaggerate" regarding the accusations of a Marxist plot.

Although such punctuated-equilibrium behaviour can be "designed" or "hard-coded", it should be stressed that this is an emergent effect of the negative-component- selection principle fundamental to the algorithm. EO has primarily been applied to combinatorial problems such as graph partitioning and the travelling salesman problem, as well as problems from statistical physics such as spin glasses.

Connie JG Gersick 1991 "Revolutionary Change Theories: A Multilevel Exploration of the Punctuated Equilibrium Paradigm" The Academy of Management Review, Vol. 16, No. 1 pp. 10-36 1 These processes of rapidly emerging new form appear to take place by complex learning within the systems themselves, which when observable, display curves of changing rates that accelerate and decelerate.

337 In 1972 Niles Eldredge and Stephen Jay Gould used fossil evidence to advocate the theory of punctuated equilibrium, which maintains that evolution is characterized by long periods of relative stasis and much shorter periods of relatively rapid change.Eldredge, Niles and S. J. Gould (1972). "Punctuated equilibria: an alternative to phyletic gradualism" In T.J.M. Schopf, ed., Models in Paleobiology.

When a habitat changes, the resident population typically moves to more suitable places; this is the typical response of flying insects or oceanic organisms, which have wide (though not unlimited) opportunity for movement. This common response is called habitat tracking. It is one explanation put forward for the periods of apparent stasis in the fossil record (the punctuated equilibrium theory).

Jean-Paul Gaster has played and recorded with the rock band Five Horse Johnson. He appears on the albums The Mystery Spot and The taking of Blackheart. In 2007, Jean-Paul Gaster collaborated with Opeth keyboardist Per Wiberg and Kamchatka guitarist Thomas Andersson on a project called King Hobo. During 2008, Jean-Paul Gaster played drums on Maryland doom legend guitarist Scott Weinrich's solo album, Punctuated Equilibrium.

In a diagram from the book The Automated Society, Bloomfield, Masse, The Automated Society, Masefield Books, 1995. Bloomfield defines the history of humanity beginning over two million years ago and ending over a hundred thousand years in the future. The diagram is base on biological punctuated equilibrium and a parallel cultural evolution. The predictions of the future follow what has happened in the past.

In the 1980s, the American palaeontologists Stephen Jay Gould and Niles Eldredge argued for an extended synthesis based on their idea of punctuated equilibrium, the role of species selection shaping large scale evolutionary patterns and natural selection working on multiple levels extending from genes to species.Gould, Stephen Jay. (1980). Is a New and General Theory of Evolution Emerging? Paleobiology. Vol. 6, No. 1. pp. 119-130.

Alternative explanations for the punctuated pattern of evolution observed in the fossil record. Both macromutation and relatively rapid episodes of gradual evolution could give the appearance of instantaneous change, since 10,000 years seldom registers in the geological record. The punctuational nature of punctuated equilibrium has engendered perhaps the most confusion over Eldredge and Gould's theory. Gould's sympathetic treatment of Richard Goldschmidt,Gould, S. J. (1976).

However, the punctuational equilibrium model may still be inferred from both the observation of stasis and examples of rapid and episodic speciation events documented in the fossil record. Dawkins also emphasizes that punctuated equilibrium has been "oversold by some journalists",Dawkins, Richard (1996). The Blind Watchmaker, p. 250-251. but partly due to Eldredge and Gould's "later writings".Dawkins, Richard (1996). The Blind Watchmaker, p. 241.

In his book Darwin's Dangerous Idea, philosopher Daniel Dennett is especially critical of Gould's presentation of punctuated equilibrium. Dennett argues that Gould alternated between revolutionary and conservative claims, and that each time Gould made a revolutionary statement—or appeared to do so—he was criticized, and thus retreated to a traditional neo-Darwinian position.Dennett, Daniel (1995). Darwin's Dangerous Idea. New York: Simon & Schuster, pp. 282-299.

In linguistics, R. M. W. Dixon has proposed a punctuated equilibrium model for language histories,Dixon, R.M.W. (1997). The rise and fall of languages Cambridge: Cambridge University Press. with reference particularly to the prehistory of the indigenous languages of Australia and his objections to the proposed Pama–Nyungan language family there. Although his model has raised considerable interest, it does not command majority support within linguistics.

Hugh Falconer MD FRS (29 February 1808 – 31 January 1865) was a Scottish geologist, botanist, palaeontologist, and paleoanthropologist. He studied the flora, fauna, and geology of India, Assam, and Burma, and was the first to suggest the modern evolutionary theory of punctuated equilibrium. He was the first to discover the Siwalik fossil beds, and may also have been the first person to discover a fossil ape.

A year before he had privately sent the work to Darwin who was delighted to read it. In the work he observed long periods of evolutionary stasis in fossil mammals with short periods of rapid evolutionary change throughout geological time. This research shows great foresight. Niles Eldredge and Stephen Jay Gould developed the same basic theory a century later, a theory known as punctuated equilibrium.

Nearly all species undergo true extinction under the model of punctuated equilibrium. Charles Darwin proposed the idea of stasis in his book, On the Origin of Species. He suggested that species spend the majority of their evolutionary lifespan in the same form, having undergone very little morphological or genetic change. Another concept of species on the tree of life is the composite species concept.

The edge of chaos is a borderline region that lies between complete anarchy or randomness and a state of punctuated equilibrium. The agile enterprise ideally operates in this region, needing the tension between constant change and the constraints that weaken change efforts to keep the organization perturbed enough for innovation and success. In other words, the edge of chaos is the space in which self- organizing and co-evolution flourish.

Anatomical comparison of the skulls of anatomically modern humans (left) and Homo neanderthalensis (right) The emergence of archaic humans is sometimes used as an example of punctuated equilibrium. This occurs when a species undergoes significant biological evolution within a relatively short period. Subsequently, the species undergoes very little change for long periods until the next punctuation. The brain size of archaic humans expanded significantly from in erectus to .

Alfred A. Knopf, New York, 2000. Eldredge's interpretation of the Phacops fossil record was that the aftermaths of the lens changes, but not the rapidly occurring evolutionary process, were fossilized. This and other data led Stephen Jay Gould and Niles Eldredge to publish their seminal paper on punctuated equilibrium in 1971. Synchrotron X-ray tomographic analysis of early Cambrian bilaterian embryonic microfossils yielded new insights of metazoan evolution at its earliest stages.

Connie Gersick's research on the evolution of organizational systems (1988, 1991) revealed patterns of change mirroring those in biological species. Gersick examined models of change in six domains - developmental patterns of adults, groups and organizations, the history of science, physical science, and biological evolution - and found evidence for punctuated equilibria (as opposed to steady, incremental change) across those disparate systems.Gersick, Connie (1991). "Revolutionary Change Theories: A Multilevel Exploration of the Punctuated Equilibrium Paradigm".

Mammals and land bridges. Journal of the Washington Academy of Sciences 30: 137163. See Charles H. Smith's website for full text: He anticipated such concepts as punctuated equilibrium (in Tempo and mode) and dispelled the myth that the evolution of the horse was a linear process culminating in the modern Equus caballus. He coined the word hypodigm in 1940, and published extensively on the taxonomy of fossil and extant mammals. p. 418.

Quantum evolution was a controversial hypothesis advanced by Columbia University paleontologist George Gaylord Simpson, who was regarded by Gould as "the greatest and most biologically astute paleontologist of the twentieth century."Gould, S. J. (2007) Punctuated equilibrium. Cambridge MA: Harvard University Press, p. 26. Simpson's conjecture was that according to the geological record, on very rare occasions evolution would proceed very rapidly to form entirely new families, orders, and classes of organisms.

Allyn's play "Buying In" was a Semifinalist for the 2017 Eugene O'Neill National Playwrights Conference. His play Commencement was selected for the Baltimore Playwrights Festival. and won a Writers Digest award. His play Punctuated Equilibrium received a staged reading by the Hangar Theatre Lab in Ithaca, NY. His play Writers Colony appeared in the Fresh Fruit Festival in New York City, and Baptizing Adam won the James H. Wilson Award for Best-Full Length Play.

The Automated Society, Masefield Books. has written that human societies follow punctuated equilibrium which would mean first, a stable society, and then a transition resulting in a subsequent stable society with greater complexity. This model would claim mankind has had a stable animal society, a transition to a stable tribal society, another transition to a stable peasant society and is currently in a transitional industrial society. The status of a human society rests on the productivity of food production.

Phyletic gradualism, top, would consist of steady evolutionary change in small steps, in contrast to punctuated equilibrium Apparently sudden changes can be explained either by macromutation or by relatively rapid episodes of gradual evolution, since 10,000 years barely registers in the fossil record. Phyletic gradualism is a model of evolution which theorizes that most speciation is slow, uniform and gradual.Eldredge, N. and S. J. Gould (1972). "Punctuated equilibria: an alternative to phyletic gradualism" In T.J.M. Schopf, ed.

To the contrast, niche conservation pulls individuals toward ancestral ecological traits in an evolutionary tug-of-war. Also, nature tends to have a 'jump on the band wagon' perspective when something beneficial is found. This can lead to the opposite occurring with disruptive selection eventually selecting against the average; when everyone starts taking advantage of that resource it will become depleted and the extremes will be favored. Furthermore, gradualism is a more realistic view when looking at speciation as compared to punctuated equilibrium.

He describes human evolutionary history as a step function of punctuated equilibrium, with long periods of stability interrupted with short periods of transition. He argues that humans are now in a period of transition from a stable agrarian society through a transitional industrial and/or information society becoming a stable automated society. Each stable society has its own social organization. The animal society has a dominant male and everyone else; the tribal society has a chief, a medicine man, hunters and everyone else.

Berlin: Borntraeger. found in the fossil record. Mayr later complimented Eldredge and Gould's paper, stating that evolutionary stasis had been "unexpected by most evolutionary biologists" and that punctuated equilibrium "had a major impact on paleontology and evolutionary biology." A year before their 1972 Eldredge and Gould paper, Niles Eldredge published a paper in the journal Evolution which suggested that gradual evolution was seldom seen in the fossil record and argued that Ernst Mayr's standard mechanism of allopatric speciation might suggest a possible resolution.

88) (The judge ruled that "intelligent design is not science and is essentially religious in nature".)Kitzmiller v. Dover Area School District 6: Conclusion, section H According to the theory of evolution, genetic variations occur without specific design or intent. The environment "selects" the variants that have the highest fitness, which are then passed on to the next generation of organisms. Change occurs by the gradual operation of natural forces over time, perhaps slowly, perhaps more quickly (see punctuated equilibrium).

Thus, the transition itself can only be illustrated and corroborated by transitional fossils, but it will never be known in detail. Progressing research and discovery managed to fill in several gaps and continues to do so. Critics of evolution often cite this argument as being a convenient way to explain off the lack of 'snapshot' fossils that show crucial steps between species. The theory of punctuated equilibrium developed by Stephen Jay Gould and Niles Eldredge is often mistakenly drawn into the discussion of transitional fossils.

Instead, these groups have evolved by expanding into empty ecological niches. In the punctuated equilibrium model of environmental and biological change, the factor determining survival is often not superiority over another in competition but ability to survive dramatic changes in environmental conditions, such as after a meteor impact energetic enough to greatly change the environment globally. The main land dwelling animals to survive the K-Pg impact 66 million years ago had the ability to live in tunnels, for example. In 2010 Sahney et al.

In some variants blood or grease may fall from the wounded animal, in an Iroquois version the blood causes leaves to change color in autumn. Sometimes the hunters are also placed in the firmament, represented by the stars of the Big Dipper's handle. The original prototype of the myth must have been invented at least 15,000 years ago for it to have diffused across the Bering land bridge. It has been suggested to provide evidence for punctuated equilibrium as a system for myth evolution.

Ancient lakes allow scientists to study the mechanisms of environmental changes over glacial- interglacial timescales. Evolutionary characteristics including sexual selection, adaptive radiation and punctuated equilibrium are studied in ancient lakes due to their prolonged existence and general geographic isolation. Most of the research has been associated with the endemic fauna and diatoms that exists in these isolated lakes, concentrating on Lake Baikal, the Caspian Sea and the African Great Lakes. Information is derived from the associations of the fluvial-lacustrine, fluctuating profundal and evaporative facies.

The 1970s witnessed an explosion in the understanding of solid-state physics, driven by the development of the integrated circuit, and the laser. Stephen Hawking developed his theories of black holes and the boundary-condition of the universe at this period with his theory called Hawking radiation. The biological sciences greatly advanced, with molecular biology, bacteriology, virology, and genetics achieving their modern forms in this decade. Biodiversity became a cause of major concern as habitat destruction, and Stephen Jay Gould's theory of punctuated equilibrium revolutionized evolutionary thought.

He also suggested that as soon as life emerged it would gradually grow in complexity. Consistent with evolutionary theories of punctuated equilibrium, Marxists believe that new forms in nature are not the result of gradual change but that quantitative multiplication gradually builds up momentum for a "leap" in nature which produces a change or a new species. They believe that incidental to one of these leaps (and leap may be regarded as a set of genetic mutations) the phenomenon of consciousness emerged. The creature became aware of the forces which were playing on it.

Ahmadi Muslims do not take all the Quranic and Biblical creation narratives literally, but understand some of the passages metaphorically.Guided evolution and punctuated equilibrium Darwinian evolution as well as intelligent design models are rejected as are certain aspects of Islamic creationism that some modernist religious bodies have postulated. Instead they propound the concept of "guided evolution" (analogous, or identical, to the doctrine of theistic evolution or evolutionary creationism). Mirza Tahir Ahmad favored the perspective that the human race was created gradually via evolution under the supervision of God.

Press, pp. 205-206. In his Major Features of Evolution Simpson stated, "Evolutionary change is so nearly the universal rule that a state of motion is, figuratively, normal in evolving populations. The state of rest, as in bradytely, is the exception and it seems that some restraint or force must be required to maintain it." Despite such differences between the two models, earlier critiques—from such eminent commentators as Sewall Wright as well as Simpson himself—have argued that punctuated equilibrium is little more than quantum evolution relabeled.

Bryan D. Jones is an American political scientist and public policy scholar. He holds the J. J. "Jake" Pickle Regents Chair in Congressional Studies at the University of Texas. He is an Academic Director of the Comparative Agendas Project, which has received more than $2,650,000 of National Science Foundation grant funding. Jones's work includes the development of punctuated equilibrium in social theory and budget theory, and he has published academic articles in the American Political Science Review, the Journal of Politics, the American Journal of Political Science, the Policy Studies Journal, and others.

Products lines can be seen to incrementally change and branch over time following the principle of phyletic gradualism. Or they can be seen to have periods of stasis followed by disruptive innovation. This follows the principle of punctuated equilibrium Ecosystem Theory provides a conceptual framework that helps designers and others understand the mechanisms underpinning product innovation in a tangible and visual way. Technology change is one of the environmental variables that provide both opportunity and threat for products in much the same way that environmental variables such as climate provide opportunity and threat for species.

A uniformitarian perspective was adopted for biological changes. Such a view can seem to contradict the fossil record, which often shows evidence of new species appearing suddenly, then persisting in that form for long periods. In the 1970s palaeontologists Niles Eldredge and Stephen Jay Gould developed a theoretical model that suggests that evolution, although a slow process in human terms, undergoes periods of relatively rapid change (ranging between 50,000 and 100,000 years) alternating with long periods of relative stability. Their theory is called punctuated equilibrium and explains the fossil record without contradicting Darwin's ideas.

This distanced his theory from Lamarckian laws of inevitable progress. It has been argued that this anticipated the punctuated equilibrium hypothesis, but other scholars have preferred to emphasise Darwin's commitment to gradualism. He cited Richard Owen's findings that the earliest members of a class were a few simple and generalised species with characteristics intermediate between modern forms, and were followed by increasingly diverse and specialised forms, matching the branching of common descent from an ancestor. Patterns of extinction matched his theory, with related groups of species having a continued existence until extinction, then not reappearing.

Smaller populations on the other hand, which are isolated from the parental stock, are decoupled from the homogenizing effects of gene flow. In addition, pressure from natural selection is especially intense, as peripheral isolated populations exist at the outer edges of ecological tolerance. If most evolution happens in these rare instances of allopatric speciation then evidence of gradual evolution in the fossil record should be rare. This hypothesis was alluded to by Mayr in the closing paragraph of his 1954 paper: Although punctuated equilibrium generally applies to sexually reproducing organisms,Eldredge, Niles and S. J. Gould (1997).

The most significant and rapid genetic reorganization occurs in extremely small populations that have been isolated (as on islands). His theory of peripatric speciation (a more precise form of allopatric speciation which he advanced), based on his work on birds, is still considered a leading mode of speciation, and was the theoretical underpinning for the theory of punctuated equilibrium, proposed by Niles Eldredge and Stephen Jay Gould. Mayr is sometimes credited with inventing modern philosophy of biology, particularly the part related to evolutionary biology, which he distinguished from physics due to its introduction of (natural) history into science.

Therefore, these living things did not necessarily evolve through a gradual process of natural selection. Rather, he posited, the process of evolution experiences jumps in complexity (such as the emergence of a self-reflective universe, or noosphere), in a sort of qualitative punctuated equilibrium. Finally, the complexification of human cultures, particularly language, facilitated a quickening of evolution in which cultural evolution occurs more rapidly than biological evolution. Recent understanding of human ecosystems and of human impact on the biosphere have led to a link between the notion of sustainability with the "co-evolution" and harmonization of cultural and biological evolution.

Pseudoextinction is an event that occurs much more frequently under the assumption of a Phyletic gradualism model of evolution, under which speciation is slow, uniform and gradual. The majority of speciation would occur through anagenesis under this model, resulting in a majority of species undergoing Pseudoextinction. However, the model of punctuated equilibrium is more widely accepted, with the proposal that most species remain in stasis, a state of very little evolutionary change, for a large proportion of the species' lifespan. This would result in increased cases of speciation through cladogenesis and true extinction, with fewer cases of Pseudoextinction.

A phylogenetic tree showing the three- domain system. Eukaryotes are colored red, archaea green, and bacteria blue One of the most prominent debates arising during the 1970s was over the theory of punctuated equilibrium. Niles Eldredge and Stephen Jay Gould proposed that there was a pattern of fossil species that remained largely unchanged for long periods (what they termed stasis), interspersed with relatively brief periods of rapid change during speciation. Improvements in sequencing methods resulted in a large increase of sequenced genomes, allowing the testing and refining of evolutionary theories using this huge amount of genome data.

Based on a careful historical comparative analysis, Dixon questions the concept of Pama–Nyungan languages for which he argues sufficient evidence has never been provided. He also proposes a new "punctuated equilibrium" model, based on the theory of the same name in evolutionary biology, which is more appropriate for numerous language regions, including the Australian languages. Dixon puts forth his theory in The Rise and Fall of Languages, refined in his monograph Australian Languages: their nature and development (2002). Dixon is the author of a number of other books including Australian Languages: Their Nature and Development and Ergativity.

Self- organized criticality (SOC) is a statistical physics concept to describe a class of dynamical systems that have a critical point as an attractor. Specifically, these are non-equilibrium systems that evolve through avalanches of change and dissipations that reach up to the highest scales of the system. SOC is said to govern the dynamics behind some natural systems that have these burst-like phenomena including landscape formation, earthquakes, evolution, and the granular dynamics of rice and sand piles. Of special interest here is the Bak–Sneppen model of SOC, which is able to describe evolution via punctuated equilibrium (extinction events) – thus modelling evolution as a self-organised critical process.

This is obviously at odds with genetic algorithms, the quintessential evolutionary computation algorithm that selects good solutions in an attempt to make better solutions. The resulting dynamics of this simple principle is firstly a robust hill climbing search behaviour, and secondly a diversity mechanism that resembles that of multiple-restart search. Graphing holistic solution quality over time (algorithm iterations) shows periods of improvement followed by quality crashes (avalanche) very much in the manner as described by punctuated equilibrium. It is these crashes or dramatic jumps in the search space that permit the algorithm to escape local optima and differentiate this approach from other local search procedures.

Sudden jumps with apparent gaps in the fossil record have been used as evidence for punctuated equilibrium. Such jumps can be explained either by macromutation or simply by relatively rapid episodes of gradual evolution by natural selection, since a period of say 10,000 years barely registers in the fossil record. "Missing link" is still a popular term, well recognized by the public and often used in the popular media. It is, however, avoided in the scientific press, as it relates to the concept of the great chain of being and to the notion of simple organisms being primitive versions of complex ones, both of which have been discarded in biology.

The basic Tierra model has been used to experimentally explore in silico the basic processes of evolutionary and ecological dynamics. Processes such as the dynamics of punctuated equilibrium, host-parasite co-evolution and density-dependent natural selection are amenable to investigation within the Tierra framework. A notable difference between Tierra and more conventional models of evolutionary computation, such as genetic algorithms, is that there is no explicit, or exogenous fitness function built into the model. Often in such models there is the notion of a function being "optimized"; in the case of Tierra, the fitness function is endogenous: there is simply survival and death.

Then the climbing will take place on the green curve, which is even more smoothed out. Because the hollows to the right of B and C have now disappeared, the process may continue up to the peaks at D. But of course the landscape puts a limit on the disorder or variability. Besides -- dependent on the landscape -- the process may become very jerky, and if the ratio between the time spent by the process at a local peak and the time of transition to the next peak is very high, it may as well look like a punctuated equilibrium as suggested by Gould (see Ridley).

The word phyletic derives from the Greek φυλετικός phūletikos, which conveys the meaning of a line of descent.φυλετικός phūletikos originates from φυλέτης phūletēs "one of the same tribe," from φυλή phulē, "clan, race, people", derived from φύεσθαι phuesthai, "to descend, to originate." Phyletic gradualism contrasts with the theory of punctuated equilibrium, which proposes that most evolution occurs isolated in rare episodes of rapid evolution, when a single species splits into two distinct species, followed by a long period of stasis or non-change. These models both contrast with variable-speed evolution ("variable speedism"), which maintains that different species evolve at different rates, and that there is no reason to stress one rate of change over another.

While the details of his work are in scientific disrepute, the concept of catastrophic change (extinction event and punctuated equilibrium) has gained acceptance in recent decades. The term heresy is used not only with regard to religion but also in the context of political theory. The term heresy is also used as an ideological pigeonhole for contemporary writers because, by definition, heresy depends on contrasts with an established orthodoxy. For example, the tongue- in-cheek contemporary usage of heresy, such as to categorize a "Wall Street heresy" a "Democratic heresy" or a "Republican heresy," are metaphors that invariably retain a subtext that links orthodoxies in geology or biology or any other field to religion.

Much of his research includes testing evolutionary models in the fossil record, particularly the theory of punctuated equilibrium. His research is focused on the systematics and morphometrics of late Mesozoic and Cenozoic bryozoans found in deposits located in the Caribbean, especially the Dominican Republic, Panama, Costa Rica, and Venezuela, and the Gulf coast of the United States, particularly Florida, Alabama, and Mississippi. He has also worked extensively on Cenozoic bryozoans in England and southern Scandinavia and was a contributor to the Deep Sea Drilling Project on Cenozoic bryozoans recovered from the Atlantic and Pacific oceans. In April 1997 Cheetham was awarded the Raymond C. Moore Medal for Excellence in Paleontology by the Society for Sedimentary Geology.

The extended evolutionary synthesis consists of a set of theoretical concepts argued to be more comprehensive than the earlier modern synthesis of evolutionary biology that took place between 1918 and 1942. The extended evolutionary synthesis was called for in the 1950s by C. H. Waddington, argued for on the basis of punctuated equilibrium by Stephen Jay Gould and Niles Eldredge in the 1980s, and was reconceptualized in 2007 by Massimo Pigliucci and Gerd B. Müller. The extended evolutionary synthesis revisits the relative importance of different factors at play, examining several assumptions of the earlier synthesis, and augmenting it with additional causative factors. It includes multilevel selection, transgenerational epigenetic inheritance, niche construction, evolvability, and several concepts from evolutionary developmental biology.

Political scientist Francis Fukuyama has asserted that humans imbue intrinsic value on the rules they enact and follow, especially in the larger societal institutions that create order and stability. Despite rapid social change and increasing institutional problems, the value placed on an institution and its rules can mask how well an institution is functioning as well as how that institution could be improved. The inability to change an institutional mindset is supported by the theory of punctuated equilibrium, long periods of deleterious governmental policies punctuated by moments of civil unrest. After decades of economic decline the United Kingdom's referendum to leave to EU was seen as an example of the dramatic movement after a long period of governmental inertia.

Using uniformitarianism, which states that one cannot make an appeal to any force or phenomenon which cannot presently be observed (see catastrophism), Darwin theorized that the evolutionary process must occur gradually, not in saltations, since saltations are not presently observed, and extreme deviations from the usual phenotypic variation would be more likely to be selected against. Gradualism is often confused with the concept of phyletic gradualism. It is a term coined by Stephen Jay Gould and Niles Eldredge to contrast with their model of punctuated equilibrium, which is gradualist itself, but argues that most evolution is marked by long periods of evolutionary stability (called stasis), which is punctuated by rare instances of branching evolution.Eldredge, Niles, and S. J. Gould (1972).

The study of Paleozoic trilobites in the Welsh-English borders by Niles Eldredge was fundamental in formulating and testing punctuated equilibrium as a mechanism of evolution. Reprinted in Identification of the 'Atlantic' and 'Pacific' trilobite faunas in North America and Europe implied the closure of the Iapetus Ocean (producing the Iapetus suture), thus providing important supporting evidence for the theory of continental drift. Trilobites have been important in estimating the rate of speciation during the period known as the Cambrian explosion because they are the most diverse group of metazoans known from the fossil record of the early Cambrian. Trilobites are excellent stratigraphic markers of the Cambrian period: researchers who find trilobites with alimentary prosopon, and a micropygium, have found Early Cambrian strata.

Initially introduced in educational and behavioral psychology, the term has acquired a broader interpretation over time, and expressions such as "experience curve", "improvement curve", "cost improvement curve", "progress curve", "progress function", "startup curve", and "efficiency curve" are often used interchangeably. In economics the subject is rates of "development", as development refers to a whole system learning process with varying rates of progression. Generally speaking all learning displays incremental change over time, but describes an "S" curve which has different appearances depending on the time scale of observation. It has now also become associated with the evolutionary theory of punctuated equilibrium and other kinds of revolutionary change in complex systems generally, relating to innovation, organizational behavior and the management of group learning, among other fields.

Stephen Jay Gould's popular 1989 account of this work, Wonderful Life, brought the matter into the public eye and raised questions about what the explosion represented. While differing significantly in details, both Whittington and Gould proposed that all modern animal phyla had appeared almost simultaneously in a rather short span of geological period. This view led to the modernization of Darwin's tree of life and the theory of punctuated equilibrium, which Eldredge and Gould developed in the early 1970s and which views evolution as long intervals of near-stasis "punctuated" by short periods of rapid change. Other analyses, some more recent and some dating back to the 1970s, argue that complex animals similar to modern types evolved well before the start of the Cambrian.

Alternative explanations of the pattern of evolution observed in the fossil record. While apparently instantaneous change may look like macromutation, gradual evolution by natural selection could readily give the same effect, since 10,000 years barely registers in the fossil record. The fossil record of an evolutionary progression typically consists of punctuated equilibrium, with species that suddenly appear, as if by macromutation, and ultimately disappear, in many cases close to a million years later, without any change in external appearance. This is compatible with evolution by smaller mutational steps because periods of a few tens of thousands of years can barely be distinguished in the fossil record: relatively rapid evolution will always appear as a sudden change in a sequence of fossils.

Top left: retouched image of Opabinia (Walcott Cambrian Geology and Paleontology II by Charles Doolittle Walcott) Opabinia made it clear how little was known about soft-bodied animals, which do not usually leave fossils. When Whittington described it in the mid-1970s, there was already a vigorous debate about the early evolution of animals. Preston Cloud argued in 1948 and 1968 that the process was "explosive", and and in the early 1970s Niles Eldredge and Stephen Jay Gould developed their theory of punctuated equilibrium, which views evolution as long intervals of near-stasis "punctuated" by short periods of rapid change. On the other hand, around the same time Wyatt Durham and Martin Glaessner both argued that the animal kingdom had a long Proterozoic history that was hidden by the lack of fossils.

Pinpointing the extinction (or pseudoextinction) of a species requires a clear definition of that species. If it is to be declared extinct, the species in question must be uniquely distinguishable from any ancestor or daughter species, and from any other closely related species. Extinction of a species (or replacement by a daughter species) plays a key role in the punctuated equilibrium hypothesis of Stephen Jay Gould and Niles Eldredge.See: Niles Eldredge, Time Frames: Rethinking of Darwinian Evolution and the Theory of Punctuated Equilibria, 1986, Heinemann Skeleton of various extinct dinosaurs; some other dinosaur lineages still flourish in the form of birds In ecology, extinction is often used informally to refer to local extinction, in which a species ceases to exist in the chosen area of study, but may still exist elsewhere.

The existence of the biblical Kingdom of Edom was proved by archaeologists led by Ezra Ben-Yosef and Tom Levy, using a methodology called the punctuated equilibrium model in 2019. Archaeologists mainly took copper samples from the Timna Valley and Faynan in Jordan's Arava valley dated to 1300–800 BCE. According to the results of the analyses, the researchers thought that Pharaoh Shoshenk I of Egypt (the Biblical "Shishak"), who attacked Jerusalem in the 10th century BC, encouraged the trade and production of copper instead of destroying the region. Tel Aviv University professor Ben-Yosef reported “Our new findings contradict the view of many archaeologists that the Arava was populated by a loose alliance of tribes, and they’re consistent with the biblical story that there was an Edomite kingdom here”.

Moreover, his commitment to the principle of the correlation of parts caused him to doubt that any mechanism could ever gradually modify any part of an animal in isolation from all the other parts (in the way Lamarck proposed), without rendering the animal unable to survive. In his Éloge de M. de Lamarck (Praise for M. de Lamarck), Cuvier wrote that Lamarck's theory of evolution Instead, he said, the typical form makes an abrupt appearance in the fossil record, and persists unchanged to the time of its extinction. Cuvier attempted to explain this paleontological phenomenon he envisioned (which would be readdressed more than a century later by "punctuated equilibrium") and to harmonize it with the Bible. He attributed the different time periods he was aware of as intervals between major catastrophes, the last of which is found in Genesis.

Canalisation of a large set of genotypes into a limited phenotypic space has been suggested as a mechanism for the accumulation, in a neutral manner, of mutations that could otherwise be deleterious. Genetic canalisation could allow for evolutionary capacitance, where genetic diversity accumulates in a population over time, sheltered from natural selection because it does not normally affect phenotypes. This hidden diversity could then be unleashed by extreme changes in the environment or by molecular switches, releasing previously cryptic genetic variation that can then contribute to a rapid burst of evolution, a phenomenon termed decanalisation. Cycles of canalization- decanalization could explain the alternating periods of stasis, where genotypic diversity accumulates without morphological changes, followed by rapid morphological changes, where decanalization releases the phenotypic diversity and becomes subject to natural selection, in the fossil record, thus providing a potential developmental explanation for the punctuated equilibrium.

Spirit Caravan put out two albums Jug Fulla Sun (1999) and Elusive Truth (2001) and the Dreamwheel EP (1999) before disbanding in 2002. Weinrich joined ex-Pentagram guitarist Victor Griffin in his outfit, Place of Skulls, for one album, With Vision (2003) before leaving to start his most recent band, The Hidden Hand. The Hidden Hand released a 7", three studio albums, one DVD/CDEP, and a split 12" with Wooly Mammoth before he disbanded the group in August 2007. Weinrich performing with Saint Vitus, 2011 He was a member of a project called Shrinebuilder featuring Al Cisneros (Om and Sleep), Scott Kelly of Neurosis and Dale Crover (Melvins and Altamont) and during 2008 recorded an album of solo material entitled Punctuated Equilibrium featuring Jean-Paul Gaster of Clutch (drums) and Jon Blank of Rezin (bass guitar), which was released in January 2009 on Southern Lord records.

The paper considers that the number of habitable planets may fluctuate wildly with time due to the unpredictable timing of catastrophic events, thereby creating a punctuated equilibrium in which habitable planets are more likely at some times than at others. Based on the results of Monte Carlo simulations on a toy model of the Milky Way, the team found that the number of habitable planets is likely to increase with time, though not in a perfectly linear pattern. Subsequent studies saw more fundamental revision of the old concept of the galactic habitable zone as an annulus. In 2008, a study by Nikos Prantzos revealed that, while the probability of a planet escaping sterilization by supernova was highest at a distance of about 10 kpc from the galactic center, the sheer density of stars in the inner galaxy meant that the highest number of habitable planets could be found there.

One of the tenets of population genetics since its inception has been that macroevolution (the evolution of phylogenic clades at the species level and above) was solely the result of the mechanisms of microevolution (changes in gene frequency within populations) operating over an extended period of time. During the last decades of the 20th century some paleontologists raised questions about whether other factors, such as punctuated equilibrium and group selection operating on the level of entire species and even higher level phylogenic clades, needed to be considered to explain patterns in evolution revealed by statistical analysis of the fossil record. Near the end of the 20th century some researchers in evolutionary developmental biology suggested that interactions between the environment and the developmental process might have been the source of some of the structural innovations seen in macroevolution, but other evo-devo researchers maintained that genetic mechanisms visible at the population level are fully sufficient to explain all macroevolution.

Smocovitis, Unifying Biology, chapter 5; see also: Mayr and Provine (eds.), The Evolutionary Synthesis In the second half of the century the ideas of population genetics began to be applied in the new discipline of the genetics of behavior, sociobiology, and, especially in humans, evolutionary psychology. In the 1960s W.D. Hamilton and others developed game theory approaches to explain altruism from an evolutionary perspective through kin selection. The possible origin of higher organisms through endosymbiosis, and contrasting approaches to molecular evolution in the gene-centered view (which held selection as the predominant cause of evolution) and the neutral theory (which made genetic drift a key factor) spawned perennial debates over the proper balance of adaptationism and contingency in evolutionary theory.Gould, The Structure of Evolutionary Theory, chapter 8; Larson, Evolution, chapter 12 In the 1970s Stephen Jay Gould and Niles Eldredge proposed the theory of punctuated equilibrium which holds that stasis is the most prominent feature of the fossil record, and that most evolutionary changes occur rapidly over relatively short periods of time.Larson, Evolution, pp 271–283 In 1980 Luis Alvarez and Walter Alvarez proposed the hypothesis that an impact event was responsible for the Cretaceous–Paleogene extinction event.