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15 Ιαν 2021 · Punctuated equilibrium is a theory that states that evolution occurs primarily through short bursts of intense speciation, followed by lengthy periods of stasis or equilibrium. The model postulates that nearly 99% of a species’ time on earth is spent in stasis, and change happens very quickly.
30 Αυγ 2016 · Reviews both the assertions of the punctuated equilibrium model and proposed mechanisms for gradualism, rapid speciation, and stasis as fossil patterns. Shows that a wide variety of species-level patterns are found in empirical fossil studies.
To ensure a good understanding of the punctuated equilibrium model, it is necessary to briefly describe the context of its emergence in the United States. This model is rooted in pluralism, an approach that has dominated American political science for nearly a hundred years.
10 Δεκ 2021 · Gradualism states that evolution occurred slowly, while punctuated equilibrium posits that it occurred rapidly followed by long periods of no change.
31 Οκτ 2023 · In the gradual speciation model, species diverge gradually over time in small steps. In the punctuated equilibrium model, a new species changes quickly from the parent species and then remains largely unchanged for long periods of time afterward.
Phyletic gradualism and punctuated equilibrium represent the opposite extremes of a continuum. There are classic examples inferred from the fossil record for both patterns (see MacFadden, 1986) and (Chaline and Laurin, 1986) for phyletic gradualism; (Williamson, 1981) and (Cheetham, 1987) for punctuated equilibrium.
THE model of punctuated equilibrium has given new impetus to evolutionary think ing, raising significant questions concern ing both the nature of the fossil record and the mechanism of the...
