368 THE STRUCTURE OF EVOLUTIONARY THEORY
But earlier versions of Cope's views (and Hyatt's opinion throughout his life)
posit an evolutionary mechanism diametrically opposed to this later
functionalism—an internal dynamic yielding an orthogenetic phylogeny of
predetermined stages, with the source of predictable novelty inherent in ontogeny
itself. This history of lineages unfolds along a "grand potential ontogeny" much
longer than the realized portion of early species in a phyletic series. The adult stage
of the initiating species does not reach beyond an early phase of the potential
sequence. (Suppose, for example, that the full series includes 100 stages, ending in
predictable extinction. The ancestral species may only progress from stages 1 to 10
in its own ontogeny, leaving 90 available steps for successive terminal additions in
the phylogeny of subsequent species.) This concept of an extended potential
ontogeny as the source of predictable phyletic additions became the most powerful
version within a class of non-Darwinian theories generally regarded today as
purely fanciful or falsely analogic, and without conceivable mechanism—the idea
of racial ontogenies and life cycles. But the concept of a genealogical ontogeny,
however indefensible by modern standards, once possessed an interesting rationale
in this recapitulatory context. *
- As a small footnote in the logic of evolutionary theory and the history of
Darwinian arguments, this notion of "phyletic life cycles" provides the best
historiographic refutation of