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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 ...
Reinforcement favoring reproductive isolation is required for both parapatric and sympatric speciation. Without reinforcement, the geographic area of contact between different forms of the same species, called their "hybrid zone", will not develop into a boundary between the different species.
The Bak–Sneppen model is a simple model of co-evolution between interacting species. It was developed to show how self-organized criticality may explain key features of the fossil record, such as the distribution of sizes of extinction events and the phenomenon of punctuated equilibrium. It is named after Per Bak and Kim Sneppen.
In evolutionary biology, punctuated equilibrium (also called punctuated equilibria) is a theory that proposes that once a species appears in the fossil record, the population will become stable, showing little evolutionary change for most of its geological history.
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.
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 ...
However, as physical disturbances grow in magnitude and size, the sloshes will result in large amounts of water spilling out, representing the extinction and speciation of the organisms present. An example Eldredge uses is the dinosaurs, which were the prevalent life form on earth for 150 million years, [ 6 ] surviving smaller sloshes in the ...
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]