Testing the Cambrian explosion hypothesis by using a molecular dating technique.
Molecular studies have the potential to shed light on the origin of the animal phyla by providing independent estimates of the divergence times, but have been criticized for failing to account adequately for variation in rate of evolution. A method of dating divergence times from molecular data addresses the criticisms of earlier studies and provides more realistic, but wider, confidence intervals. The data are not compatible with the Cambrian explosion hypothesis as an explanation for the origin of metazoan phyla, and provide additional support for an extended period of Precambrian metazoan diversification.
Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom. LBromham@zoology.uq.edu.au
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Bromham
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Rambaut
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Fortey
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Cooper
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Penny
D000818:Animals; D005075:Biological Evolution; D016001:Confidence Intervals; D016013:Likelihood Functions; D008954:Models, Biological; D012335:RNA, Ribosomal / Q000235:genetics
D012335:RNA, Ribosomal