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

by Stephen C. Meyer

classification dispenses with taxonomic ranks and hierarchies. In their system, there is no “top” and no “down.” Nevertheless, advocates of phylogenetic classification do acknowledge that different combinations of “character” states (characteristics or features of organisms) can mark either bigger or smaller morphological differences between clades (closely related groups of organisms that presumably share a common ancestor). And some leading advocates of phylogenetic classification have noted that the fossil record exhibits a pattern in which a few character traits marking large morphological differences between clades arise first, followed later in each clade by the addition of other combinations of characters that mark smaller differences within those clades. Larger differences between clades arise first, smaller differences within them arose later—the themes precede the variations.