Law as a Primary Adaptive Platform: Generalized Darwinism, Extended Phenotype Theory, and the Methodological Foundations of Evolutionary Jurisprudence

Existing evolutionary approaches to law and institutions treat legal systems as enabling infrastructure for economic processes: the rule of law as a condition of possibility for markets, not as an object of evolutionary analysis in its own right. This paper challenges that assumption through three connected methodological claims. First, evolutionary legal theory satisfies the methodological conditions for genuine Darwinian analysis established by Hodgson and Knudsen: legal systems exhibit identifiable units of replication, documented variation mechanisms, and measurable retention mechanisms. Second, law functions as a primary adaptive platform, not merely as institutional infrastructure; the autonomous evolutionary dynamics of legal systems can block structural reform even when sustained economic pressure strongly favors it, a finding demonstrated through the Constitutional Lock-in Index (CLI), validated across four jurisdictions with scores ranging from 0.24 (Chile) to 0.89 (Argentina). Third, legal evolution operates simultaneously at three distinct levels of intentionality, corresponding to bureaucratic routines, strategic agency, and architectural constraints; only a framework that integrates all three levels can explain the characteristic pattern of reform failure documented in 23 consecutive failed Argentine labor reform attempts between 1983 and 2023. The paper also introduces Heteronomous Bayesian Updating (HBU) as the individual-level cognitive mechanism that translates macro-level institutional retention into individual norm internalization. Together, CLI and HBU constitute the empirical core of a research program in evolutionary jurisprudence that generates falsifiable predictions, not biological metaphors. The paper closes with an argument for the genealogical coherence of the Dawkins-Hayek synthesis on which the broader program rests.