Quantum evolution
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- For the alternative non-standard theory see: Quantum evolution (alternative).
Quantum evolution was a component of George Gaylord Simpson's (1902-1984) multi-tempoed theory of evolutionary change. According to Simpson (1944), some lineages in the fossil record evolved with extraordinary slowness, others more rapidly. Simpson observed that in most phyletic lines evolution occurred in a moderate and steady manner, while others showed fluctuating patterns of evolutionary descent. The most rapid of these tempos was dubbed "quantum evolution."
Quantum evolution relied heavily on Sewall Wright's theory of random genetic drift. Simpson believed that major evolutionary transitions would arise when small populations—isolated and limited from gene flow—would fixate upon unusual gene combinations. This "inadaptive phase" (by genetic drift) would then (by natural selection) drive a deme population from one stable "adaptive peak" to another on the adaptive landscape.
Simpson considered quantum evolution his crowning achievement, being "perhaps the most important outcome of [my] investigation, but also the most controversial and hypothetical." (1944, p. 206). Simpson later downplayed the significance of quantum evolution in his popular volume The Major Features of Evolution (1953) in favor of a strict adaptationist view (see Gould 1980, 1983).
[edit] References
- Eldredge, N. (1995) Reinventing Darwin. New York: John Wiley & Sons. pp. 20-26.
- Gould, S. J. (1980) "G. G. Simpson, Paleontology and the Modern Synthesis." In E. Mayr and W. B. Provine, eds., The Evolutionary Synthesis. Cambridge MA: Harvard University Press, pp. 153-172.
- Gould, S. J. (1983) "The hardening of the Modern Synthesis" In Marjorie Grene, ed., Dimensions of Darwinism. Cambridge UK: Cambridge University Press, pp. 71-93.
- Gould, S. J. (1994) "Tempo and mode in the macroevolutionary reconstruction on Darwinism" PNAS USA 91(15):6764-71.
- Gould, S. J. (2002) The Structure of Evolutionary Theory Cambridge MA: Harvard Univ. Press. pp. 529-31.
- Mayr, E. (1976) Evolution and the Diversity of Life. Cambridge MA: Belknap Press. p. 206.
- Mayr, E. (1982) The Growth of Biological Thought. Cambridge MA: Belknap Press. pp. 555, 609-10.
- Simpson, G. G. (1944) Tempo and Mode in Evolution. New York: Columbia Univ. Press.
