… development of taxonomic hierarchy (see figure 2). That is, natural processes predict that over time they will first produce a proliferation of species, which, in much more time, will produce a proliferation of genera—and so on until one or more phyla finally appear.
Figure 2: Hierarchical Classification of the Body Structures of OrganismsCredit: Wikimedia Commons
The problem with these predictions is that the fossil record reveals the opposite: a top-down hierarchy. As paleontologists Douglas Erwin, James Valentine, and John Sepkoski have observed with respect to the Avalon and Cambrian explosions, “The major pulse of diversification of phyla occurs