Editing Punctuated equilibrium (section)

===Quantum evolution===

[[Quantum evolution]] was a controversial hypothesis advanced by [[Columbia University]] paleontologist [[George Gaylord Simpson]], regarded by Gould as "the greatest and most biologically astute paleontologist of the twentieth century."<ref>[[Stephen Jay Gould|S. J. Gould]] (2007) ''Punctuated equilibrium''. Cambridge MA: Harvard University Press, p. 26.</ref> Simpson's conjecture was that according to the geological record, on very rare occasions evolution would proceed very rapidly to form entirely new [[Family (biology)|families]], [[Order (biology)|orders]], and [[Class (biology)|classes]] of organisms.<ref name=Simpson1944>Simpson, G. G. (1944). ''[[Tempo and Mode in Evolution]]''. New York: Columbia Univ. Press, p. 206</ref><ref>Fitch, W. J. and F. J. Ayala (1995) [https://download.nap.edu/cart/download.cgi?record_id=4910 ''Tempo and mode in evolution: genetics and paleontology 50 years after Simpson''.] Washington, D.C.: National Academy Press.</ref> This hypothesis differs from punctuated equilibrium in several respects. First, punctuated equilibrium was more modest in scope, in that it was addressing evolution specifically at the [[species]] level.<ref name=Gould&Eldredge1977/> Simpson's idea was principally concerned with evolution at higher taxonomic groups.<ref name=Simpson1944/> Second, Eldredge and Gould relied upon a different mechanism. Where Simpson relied upon a [[Synergy|synergistic]] interaction between [[genetic drift]] and a shift in the [[fitness landscape|adaptive fitness landscape]],<ref>Simpson, G. G. (1953). [http://www.stephenjaygould.org/library/simpson_evolutionary-rates.html ''The Major Features of Evolution''] {{Webarchive|url=https://web.archive.org/web/20190421001618/http://www.stephenjaygould.org/library/simpson_evolutionary-rates.html |date=2019-04-21 }}. New York: Columbia Univ. Press, p. 390.</ref> Eldredge and Gould relied upon ordinary speciation, particularly Ernst Mayr's concept of allopatric speciation. Lastly, and perhaps most significantly, quantum evolution took no position on the issue of stasis. Although Simpson acknowledged the existence of stasis in what he called the bradytelic mode, he considered it (along with rapid evolution) to be unimportant in the larger scope of evolution.<ref name="Simpson1944p206">Simpson, G. G. (1944). ''[[Tempo and Mode in Evolution]]''. New York: Columbia Univ. Press, [https://books.google.com/books?id=f5qucNebo-kC&pg=PA205 pp. 205-206.]</ref> In his ''Major Features of Evolution'' Simpson stated, "Evolutionary change is so nearly the universal rule that a state of motion is, figuratively, normal in evolving populations. The state of rest, as in bradytely, is the exception and it seems that some restraint or force must be required to maintain it." Despite such differences between the two models, earlier critiques—from such eminent commentators as [[Sewall Wright]] as well as Simpson himself—have argued that punctuated equilibrium is little more than quantum evolution relabeled.<ref>{{cite journal |last=Wright |first=Sewall |date=1982 |title=Character change, speciation, and the higher taxa |journal=Evolution |doi=10.2307/2408092 |volume=56 |issue=3 |pages=427–443 |url=http://stewardshipofcreationenabler.giving.officelive.com/Documents/21_Wright1982.pdf |url-status=dead |archive-url=https://web.archive.org/web/20110828022050/http://stewardshipofcreationenabler.giving.officelive.com/Documents/21_Wright1982.pdf |archive-date=2011-08-28 |jstor=2408092 |pmid=28568042 }}</ref><ref>Simpson, G. G. (1984) ''Tempo and Mode in Evolution''. Reprint. Columbia University Press, p. xxv.</ref>