Cambrian explosion
Language: English
Part of speech: name
Pronunciation: ipa: /ˈkam.bɹɪ.ən ɪkˈspləʊ.ʒən/
ipa: /ˈkæm.bɹi.ən ɛkˈsploʊ.ʒən/
Forms: form: Cambrian explosions
Etymology: Of unclear origin, inspired by George Gaylord Simpson's description of "explosive" evolution. The earliest known use is in a BSCS high school biology textbook written in 1961 under the direction of paleobotanist Wilson Steward.
Senses: examples: text: Alternatively, if animals had a relatively long Precambrian history, why do so many kinds appear abruptly and more or less synchronously in the fossil record during Early Cambran time? Was there an external environmental factor that either prevented animals from becoming fossilizable (i.e., large muscular, and/or mineralized) prior to the beginning of the Cambrian, or did some biological or environmental event trigger the metazoan radiation? Hypotheses that have been advanced to explain these questions tend to focus on either an external environmental control on, or an internal property of, the organisms that participated in the Cambrian explosion.
ref: 1992, “Evolution of the Earliest Animals”, in J[ames] William Schopf, editor, Major Events in the History of Life [Proceedings from a Symposium Convened by the IGPP Center for the Study of Evolution and the Origin of Life at the University of California, Los Angeles, Held January 11, 1991], Sudbury, Mass.; London: Jones and Bartlett Publishers, →ISBN, page 87:
text: A major adaptive radiation took place during the Cambrian Period that resulted in the evolution of most of the known phyla (broad groupings of organisms) as well as other phyla that have since become extinct. This geologically rapid appearance of diverse multicellular life is referred to as the Cambrian explosion, and is best documented in the fauna of the Burgess Shale (Middle Cambrian-age Stephan Formation) of British Columbia.
ref: 2008 May, “Affected Environment”, in Draft Programmatic Environmental Impact Statement for Geothermal Leasing in the Western United States (DES 08-22), volume I (Programmatic Analysis), [Washington, D.C.]: US Department of the Interior, Bureau of Land Management; US Department of Agriculture, United States Forest Service, →OCLC, paragraph 3.5.4, pages 3-49–3-50:
text: Evidence of transitional stages is missing both in the living world and in the "Cambrian explosions" at Burgess Shale in the Canadian Rockies and at the Chengjiang site in China. It is only proper at this point that we demand hard evidence of transitional stages. To wait millions of years for it to appear is simply a scientism of the gaps.
ref: 2011, Michael Ebifegha, “Introduction”, in Creation or Evolution?: Origin of Species in Light of Science’s Limitations and Historical Records, Bloomington, Ind.: iUniverse, →ISBN, page 7:
text: A few worlds may have made this giant leap, invented sex (or some equivalent), and produced planets with sponge-like organisms to filter-clean their seas as a precedent to the evolution of more complex life. Here and there, and likely very rarely, a few planets may have undergone their own Cambrian explosions.
ref: 2014, Jan Zalasiewicz, Mark R. F. Williams, “Water in the Cosmos”, in Ocean Worlds, Oxford: Oxford University Press, →ISBN:
text: [T]hese cliffs, cut over the millennia by the Kotuikan as it winds toward the Arctic Ocean, record one of Earth history's great turning points. As well as any rocks known anywhere, they document the remarkable diversification of animal life popularly known as the Cambrian Explosion. In the broadest possible sense, the Kotuikan cliffs record the beginnings of the modern world, a world in which animals swim, crawl, or walk beneath an atmosphere of breathable air. That's really what brought us here.
ref: 2015, Andrew H[erbert] Knoll, “In the Beginning?”, in Life on a Young Planet: The First Three Billion Years of Evolution on Earth, new Princeton Science Library paperback edition, Princeton, N.J.; Woodstock, Oxfordshire: Princeton University Press, →ISBN, page 8:
text: Brocks said the new study suggested the Ediacaran biota “already contained some of the creatures that gave rise to the [Cambrian] explosion, to the rise of modern animals”. The Cambrian explosion, also called the biological big bang, was a period about 538.8m years ago when almost all major animal groups started to appear in the fossil record.
ref: 2022 November 22, Donna Lu, “The real paleo diet: researchers find traces of world’s oldest meal in 550m-year-old fossil”, in The Guardian:
synonyms: biological big bang
qualifier: evolutionary biology
glosses: The relatively rapid appearance, during the Cambrian Period around 541 million years ago, of most major animal phyla, as demonstrated in the fossil record.