Ernst Haeckel Quote

In the course of individual development, inherited characters appear, in general, earlier than adaptive ones, and the earlier a certain character appears in ontogeny, the further back must lie in time when it was acquired by its ancestors.

Allgemeine Entwickelungsgeschichte der Organismen (1866), Vol. 2, 298. Trans. Stephen Jay Gould, Ontogeny and Phylogeny (1977)