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English: Alternative explanations of the punctuated equilibrium pattern of evolution observed in the fossil record. Both macromutation and relatively rapid episodes of gradual evolution by natural selection could give the effect of apparently instantaneous change, since 10,000 years barely registers in the fossil record.
Punctuated equilibrium is commonly contrasted with phyletic gradualism, the idea that evolution generally occurs uniformly by the steady and gradual transformation of whole lineages . [2] In 1972, paleontologists Niles Eldredge and Stephen Jay Gould published a landmark paper developing their theory and called it punctuated equilibria. [1]
The punctuated equilibrium model of policy change was first presented by Frank Baumgartner and Bryan Jones in 1993, [1] and has increasingly received attention in historical institutionalism. [3] The model states that policy generally changes only incrementally due to several restraints, namely the "stickiness" of institutional cultures, vested ...
Also, members of older groups tended to perceive their groups to have more of the characteristics of Stage-3 and Stage-4 groups and to be more productive. Based on these results, Wheelan's position supports the traditional linear models of group development and casts doubt on the cyclic models and Gersick's punctuated equilibrium model.
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. Around this ...
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. [30] [31] [32] [33]
It was Gould who coined the term "punctuated equilibria" though the theory was originally presented by Eldredge in his doctoral dissertation on Devonian trilobites and his article published the previous year on allopatric speciation. [41] According to Gould, punctuated equilibrium revised a key pillar "in the central logic of Darwinian theory."
The court jester hypothesis builds upon the punctuated equilibrium theory of Stephen Gould (1972) [8] by providing a primary mechanism for it. [2] The 2001 paper by Barnosky that is one of the first to use the term appropriate for the Court Jester side of the debate: the Stability hypothesis of Stenseth and Maynard Smith (1984), Vrba's Habitat Theory (1992), Vrba's Turn-over pulse hypothesis ...