The Third Mechanism: Evidence from the Genetic Code for a Generative Property of Dissipative Cycling

Evolutionary theory invokes two mechanisms: random mutation produces variation; natural selection shapes it. This paper proposes a third: a generative property intrinsic to dissipative cycling, in which each passage through a cycle of structural stabilisation and functional interaction produces higher informational order than the one before. We present chemical evidence from the genetic code showing that codon structure is organised by exactly two operations — structural stabilisation and functional interaction — in a mandatory cyclic order, invariant across all 37 known genetic code variants in 4 billion years of evolution. We then show that three independent lines of published evidence — spontaneous gene duplication rates exceeding degradation, the one-directional ratchet of Constructive Neutral Evolution, and continuing fitness generation in the Lenski Long-Term Evolution Experiment — are unified by this property. The third mechanism does not replace mutation or selection. It explains what neither can: why neutral cycling produces complexity rather than noise, why relaxed selection increases rather than decreases organisational depth, and why the genetic code has the specific structure it has.