We can now determine, easily and relatively cheaply, the detailed chemical architecture of genes; and we can trace the products of these genes (enzymes and proteins) as they influence the course of embryology. In so doing we have made the astounding discovery that all complex animal phyla - arthropods and vertebrates in particular - have retained, despite their half-billion years of evolutionary independence, an extensive set of common genetic blueprints for building bodies.

"Brotherhood by Inversion", p. 330 - Leonardo's Mountain of Clams and the Diet of Worms (1998)