英和和英

出典:『Wikipedia』 (2010/07/22 04:18 UTC 版)

英語による解説

引用

Quantum evolution is a component of George Gaylord Simpson's multi-tempoed theory of evolutionary change, proposed to explain the rapid emergence of higher taxonomic groups. According to Simpson, evolutionary rates differ from group to group and even among closely related lineages. These different rates of evolutionary change were designated by Simpson as horotelic (medium tempo), bradytelic (slow tempo), and tachytelic (rapid tempo). Quantum evolution differed from these styles of change in that it involved a drastic shift in the adaptive zones of certain classes of animals. The word "quantum" therefore refers to an "all-or-none reaction," where transitional forms are particularly unstable, and perished rapidly and completely. Although quantum evolution may happen at any taxonomic level (1953, 389), it plays a much larger role in "the origin taxonomic units of relatively high rank, such as families, orders, and classes." (1944, 206)