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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. [70] Dawkins also emphasizes that punctuated equilibrium has been "oversold by some journalists", [71] but partly due to Eldredge and Gould's "later writings ...
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 ...
Gersick's study of naturally occurring groups departs from the traditionally linear models of group development. Her punctuated equilibrium model (Gersick, 1988, 1989, 1991) suggests that groups develop through the sudden formation, maintenance, and sudden revision of a "framework for performance".
The punctuated equilibrium model (above) consists of morphological stability followed by episodic bursts of evolutionary change via rapid cladogenesis. It is contrasted (below) to phyletic gradualism , a more gradual, continuous model of evolution.
Gould's initial work on punctuated equilibrium was coauthored with Niles Eldredge. [20] Gould's model of punctuated equilibrium drew attention to episodic bursts of evolutionary change followed by periods of morphological stability. He challenged the conventional model of gradual, continuous change - called phyletic gradualism. [21]
The word phyletic derives from the Greek φυλετικός phūletikos, which conveys the meaning of a line of descent. [2] 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.
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 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.