Editing Quantum evolution (section)

{{short description|Evolution where transitional forms are particularly unstable and do not last long}}
{{evolutionary biology}}
'''Quantum evolution''' is a component of [[George Gaylord Simpson]]'s multi-tempoed theory of [[evolution]] proposed to explain the rapid emergence of higher [[Taxonomy (biology)|taxonomic groups]] in the [[fossil record]]. According to Simpson, [[Rate of evolution|evolutionary rates]] differ from group to group and even among closely related lineages. These different rates of evolutionary change were designated by Simpson as ''bradytelic'' (slow tempo), ''horotelic'' (medium tempo), and ''tachytelic'' (rapid tempo). 

Quantum evolution differed from these styles of change in that it involved a drastic shift in the [[Evolutionary landscape|adaptive zones]] of certain classes of animals. The word "[[Atomic electron transition|quantum]]" therefore refers to an "all-or-none reaction", where transitional forms are particularly unstable, and thereby perish rapidly and completely.<ref>[[Gould, S. J.]] (1980). [https://books.google.com/books?id=NV5HcU9B2kQC&pg=PA153 "G. G. Simpson, Paleontology and the Modern Synthesis."] In [[Ernst Mayr|E. Mayr]] and [[Will Provine|W. B. Provine]], eds., ''The Evolutionary Synthesis''. Cambridge MA: Harvard University Press, pp. [https://books.google.com/books?id=Jd0yGJ3nF9EC&pg=PA160 153–172.]</ref> Although quantum evolution may happen at any taxonomic level,<ref>Simpson, G. G. (1953). ''[http://www.stephenjaygould.org/library/simpson_evolutionary-rates.html The Major Features of Evolution]''. New York: Columbia Univ. Press, p. 389.</ref> it plays a much larger role in "the origin taxonomic units of relatively high rank, such as [[Family (biology)|families]], [[Order (biology)|orders]], and [[Class (biology)|classes]]."<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=PA206 p. 206.]</ref>