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709:, 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. These models both contrast with variable-speed evolution ("variable speedism"), which maintains that different species evolve at different rates, and that there is no reason to stress one rate of change over another.
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762:, Darwin wrote that "the periods during which species have undergone modification, though long as measured in years, have probably been short in comparison with the periods during which they retain the same form".
817:φυλετικός phūletikos originates from φυλέτης phūletēs "one of the same tribe," from φυλή phulē, "clan, race, people", derived from φύεσθαι phuesthai, "to descend, to originate."
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is among the few brachiopods surviving today but also known from fossils over 500 million years old. In the fifth edition of
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is slow, uniform and gradual. When evolution occurs in this mode, it is usually by the steady transformation of a whole
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argues that constant-rate gradualism is not present in the professional literature, thereby the term serves only as a
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Phyletic gradualism, top, would consist of steady evolutionary change in small steps, in contrast to
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differs but little from the living species of this genus".
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himself was not a constant-rate gradualist, as suggested by
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Apparently sudden changes can be explained either by
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808:. San Francisco: Freeman Cooper. p. 84.
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681:occurs. The theory is contrasted with
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665:which theorizes that most
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427:Evolutionary anthropology
407:Applications of evolution
863:On the origin of species
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826:Dawkins, Richard. 1996.
743:On the Origin of Species
728:, Dawkins observes that
462:Evolutionary linguistics
457:Evolutionary game theory
432:Evolutionary computation
804:In T.J.M. Schopf, ed.,
575:Objections to evolution
482:Evolutionary psychology
477:Evolutionary physiology
422:Evolutionary aesthetics
401:Fields and applications
383:History of paleontology
878:Charles Darwin, 1869.
861:Charles Darwin, 1859.
806:Models in Paleobiology
772:Punctuated equilibrium
713:Evolutionary biologist
707:punctuated equilibrium
683:punctuated equilibrium
507:Speciation experiments
487:Experimental evolution
442:Evolutionary economics
264:Recent human evolution
122:Processes and outcomes
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25:punctuated equilibrium
880:The Origin of Species
777:Punctuated gradualism
760:The Origin of Species
467:Evolutionary medicine
412:Biosocial criminology
378:History of speciation
291:Evolutionary taxonomy
254:Timeline of evolution
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928:Evolutionary biology
908:at Wikimedia Commons
829:The Blind Watchmaker
725:The Blind Watchmaker
437:Evolutionary ecology
51:Evolutionary biology
906:Phyletic gradualism
659:Phyletic gradualism
539:Social implications
527:Universal Darwinism
517:Island biogeography
452:Evolutionary ethics
417:Ecological genetics
363:Molecular evolution
301:Transitional fossil
129:Population genetics
45:Part of a series on
570:Theistic evolution
502:Selective breeding
214:Parallel evolution
179:Adaptive radiation
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933:Rate of evolution
904:Media related to
782:Quantum evolution
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347:Origin of Species
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512:Sociobiology
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281:Biogeography
276:Biodiversity
194:Coextinction
184:Co-operation
159:Polymorphism
84:Introduction
522:Systematics
331:Renaissance
209:Convergence
199:Contingency
189:Coevolution
922:Categories
788:References
703:phūletikos
701:φυλετικός
675:anagenesis
667:speciation
296:Cladistics
219:Extinction
204:Divergence
174:Speciation
154:Adaptation
68:John Gould
850:Evolution
720:straw-man
693:The word
679:splitting
663:evolution
555:Dysgenics
271:Phylogeny
169:Gene flow
139:Diversity
134:Variation
766:See also
695:phyletic
619:Category
545:Eugenics
387:timeline
368:Evo-devo
326:Overview
144:Mutation
106:Evidence
101:Glossary
755:Lingula
748:Lingula
689:History
671:species
111:History
94:Outline
884:p. 551
867:p. 313
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341:Darwin
699:Greek
79:Index
834:ISBN
736:and
89:Main
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