Evolutionary Systems Thinking -- From Equilibrium Models to Open-Ended Adaptive Dynamics

TL;DR

This paper proposes a new non-equilibrium framework called Stability-Driven Assembly (SDA) for modeling evolutionary dynamics, emphasizing endogenous selection and feedback mechanisms that enable open-ended evolution beyond traditional equilibrium models.

Contribution

Introduction of SDA as a minimal, non-equilibrium model that captures endogenous selection and feedback, enabling open-ended evolution without predefined fitness functions.

Findings

Equilibrium models cannot produce open-ended evolution.

SDA demonstrates how stability-driven feedback leads to structural emergence.

Population-dependent, non-stationary dynamics are essential for evolution.

Abstract

Complex change is often described as "evolutionary" in economics, policy, and technology, yet most system dynamics models remain constrained to fixed state spaces and equilibrium-seeking behavior. This paper argues that evolutionary dynamics should be treated as a core system-thinking problem rather than as a biological metaphor. We introduce Stability-Driven Assembly (SDA) as a minimal, non-equilibrium framework in which stochastic interactions combined with differential persistence generate endogenous selection without genes, replication, or predefined fitness functions. In SDA, longer-lived patterns accumulate in the population, biasing future interactions and creating feedback between population composition and system dynamics. This feedback yields fitness-proportional sampling as an emergent property, realizing a natural genetic algorithm driven solely by stability. Using SDA, we demonstrate why equilibrium-constrained models, even when simulated numerically, cannot exhibit open-ended evolution: evolutionary systems require population-dependent, non-stationary dynamics in which structure and dynamics co-evolve. We conclude by discussing implications for system dynamics, economics, and policy modeling, and outline how agent-based and AI-enabled approaches may support evolutionary models capable of sustained novelty and structural emergence.