Darwin's Doubt: The Explosive Origin of Animal Life and the Case for Intelligent Design

by Stephen C. Meyer

Sedgwick emphasized that these Cambrian animal fossils appeared to pop out of nowhere into the geological column. But he also stressed what he viewed as a broader reason to doubt Darwin’s evolutionary model: the sudden appearance of the Cambrian animals was merely the most outstanding instance of a pattern of discontinuity that extends throughout the geologic column. Where in the Ordovician strata, for instance, are many of the families of the trilobites and brachiopods present in the Cambrian just below it?15 These creatures along with numerous other types suddenly disappear. But just as suddenly one finds newcomers in the Ordovician strata like the eurypterans (sea scorpions), starfish, and tetracorals (see Fig. 1.5).16 In a later Paleozoic period called the Devonian, the first amphibians (e.g., Ichthyostega) arise. Much later, many staples of the Paleozoic era (which encompasses the Cambrian, Ordovician, and four subsequent periods) suddenly go extinct in a period called the Permian.17 Then, in the Triassic period that follows, completely novel animals such as turtles and dinosaurs emerge.18 Such discontinuity, Sedgwick argued, is not the exception, but the rule.