Replies

"Nobody seriously doubts that the sudden appearance in the fossil record of numerous marine animal groups of both familiar and enigmatic type close to the base of the Cambrian reflects one of the important events in the history of the biosphere." (R.A. Fortey, D.E.G. Briggs, M.A. Wills "The Cambrian evolutionary cexplosion': decoupling cladogenesis from morphological disparity," Biological Journal of the Linnean Society, Vol. 57: 13-33 (1996), emphasis added.)

"Beautifully preserved organisms from the Lower Cambrian Maotianshan Shale in central Yunnan, southern China, document the sudden appearance of diverse metazoan body plans at phylum or subphylum levels, which were either short-lived or have continued to the present day." (J.Y. Chen, "The sudden appearance of diverse animal body plans during the Cambrian explosion," International Journal of Developmental Biology, Vol. 53: 733-51 (2009), emphasis added.)

"...the sudden expansion in phyla of the Cambrian explosion" (Lynn Helena Caporale, "Putting together the pieces: evolutionary mechanisms at work within genomes," BioEssays, Vol. 31: 700-702 (2009), emphasis added.)

A college-level invertebrate biology textbook states: "Most of the animal phyla that are represented in the fossil record first appear, "fully formed" and identifiable as to their phylum, in the Cambrian .... The fossil record is therefore of no help with respect to understanding the origin and early diversification of the various animal phyla..." (R. S. K. Barnes, P. Calow, P. J. W. Olive, D. W. Golding, and J. I. Spicer, The Invertebrates: A New Synthesis, 3rd ed. (Malden, MA: Blackwell Scientific Publications, 2001), pp. 9-10, emphasis added.)

"...the sudden appearance of a near complete diversity of animal body plans in the fossil record around 530-520 million years ago" (T. Vavouri and B. Lehner, "Conserved noncoding elements and the evolution of animal body plans," BioEssays, Vol. 31: 727-735 (July 31, 2009), emphasis added.)

"...the profound morphological gaps among the major groups, set against the background of sudden appearances in the fossil record of many novel taxa and the absence of easily recognizable transitional forms" (Richard K. Grosberg, "Out on a Limb: Arthropod Origins," Science, Vol. 250: 632-633 (November 2, 1990), emphasis added.)

"Darwin recognized that the sudden appearance of animal fossils in the Cambrian posed a problem for his theory of natural selection. ... Recent geochronological studies have reinforced the impression of a 'big bang of animal evolution' by narrowing the temporal window of apparent divergences to just a few million years." (Gregory A. Wray, Jeffrey S. Levinton, Leo H. Shapiro, "Molecular Evidence for Deep Precambrian Divergences," Science, Vol. 74: 568-573 (October 25, 1996), emphasis added.)

"The apparently sudden origin of animal phyla has contributed to the view that phyla represent a fundamental level of organization." (Lindell Bromham, "What can DNA Tell us About the Cambrian Explosion?," Integrative and Comparative Biology, Vol. 43: 148-156 (2003), emphasis added.)

"The fossil record of metazoa shows a sudden expansion at around 550-530 million years ago." (Science, Vol. 288: 929 (May 12, 2000), emphasis added.)

"This paucity of metazoan fossils in the strata of Earth is broken by the sudden appearance of highly developed metazoan fossils in the Cambrian, a pattern colloquially referred to as the Cambrian evolutionary 'explosion'." (Christopher W. Wheat and Niklas Wahlberg, "Phylogenomic Insights into the Cambrian Explosion, the Colonization of Land and the Evolution of Flight in Arthropoda," Systematic Biology, Vol. 62: 93-109 (2013), emphasis added.)

"[T]he fossil record displays the sudden appearance of intracellular detail and the 32 phyla." (Michael A. Crawford, C. Leigh Broadhurst, Martin Guest, Atulya Nagar, Yiqun Wang, Kebreab Ghebremeskel, Walter F. Schmidt, "A quantumtheory for the irreplaceable role of docosahexaenoic acid in neural cell signalling throughout evolution," Prostaglandins, Leukotrienes and Essential Fatty Acids, Vol. 88: 5-13 (2013), emphasis added.)

"The Cambrian explosion in animal evolution during which all the diverse body plans appear to have emerged almost in a geological instant is a highly publicized enigma." (Eugene V. Koonin, "The Biological Big Bang model for the major transitions in evolution," Biology Direct, Vol. 2: 21 (2007), emphasis added.)

"At the beginning of the Cambrian, however, life took a sudden turn toward the complex. In a few million years -- the equivalent of a geological instant -- an ark's worth of sophisticated body types filled the seas. This biological burst, dubbed the Cambrian explosion, produced the first skeletons and hard shells, antennae and legs, joints and jaws. It set the evolutionary stage for all that followed by giving rise to most of the major phyla known on Earth today. Even our own chordate ancestors got their start during this long-past era." (Richard Monastersky, Science News, Vol. 146 (9) (August 27, 1994), emphasis added.)

-From: How "Sudden" Was the Cambrian Explosion?