Evolution as a Constrained Generative System: Structural Derivation of Evolutionary Necessity from Three Axioms

We derive the structural properties of evolution from the three axioms of constrained generative systems without presupposing biological theory. The evolutionary pixel is the ordered pair (rep₁, rep₂) of consecutive replicative acts: the first configuration in which a difference becomes classifiable as heritable under a finite constraint L (heritability compatible with lineage continuity). The consumption type is T3, the regime R2. Evolution is intrinsically multi-family: three Q-readings (E/Q21 conservation, G/Q28 compression, F/Q20 directionality) are simultaneously active, a structural necessity, not a biological accident. The derivation establishes that uniform randomness of variation is structurally excluded by Axiom 3 (observable iteration): in a trajectory-consumptive system, classification is history-dependent, and identical variations receive different classifications depending on the accumulated lineage. The fact that DNA instantiates three Q-families simultaneously is not a biological accident but a structural necessity derivable from the axioms. Nineteenth verified domain.