punctuated equilibrium


: evolution that is characterized by long periods of stability in the characteristics of an organism and short periods of rapid change during which new forms appear especially from small subpopulations of the ancestral form in restricted parts of its geographic range
also : a theory or model of evolution emphasizing this compare gradualism sense 2

Examples of punctuated equilibrium in a Sentence

Recent Examples on the Web Evolutionary biologist Stephen Jay Gould once argued that the history of life isn’t simply a gradual change in organisms, but punctuated equilibrium: Long, relatively stable periods give way to rapid speciation after some dramatic event flushes away many of Earth’s existing species. Eliot Schrefer, Discover Magazine, 11 Aug. 2020 Be it punctuated equilibrium, symbiogenesis, or epigenetics. Razib Khan, Discover Magazine, 28 Aug. 2011 The idea, called punctuated equilibrium, was originally developed by paleontologists to explain patterns in the emergence and diversification of new species, which sometimes seems to happen in sudden bursts of activity after eons of stability. Kiona N. Smith, Ars Technica, 20 Sep. 2019

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'punctuated equilibrium.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1972, in the meaning defined above

Time Traveler
The first known use of punctuated equilibrium was in 1972

Dictionary Entries Near punctuated equilibrium

Cite this Entry

“Punctuated equilibrium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/punctuated%20equilibrium. Accessed 1 Oct. 2023.

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