Regulatory Integration and Threshold Dynamics in Major Evolutionary Transitions: A Bioevo-Cybernetic Framework

Major evolutionary transitions—such as the emergence of multicellularity and higher-level biological organization—are often described as discrete innovations, yet the underlying dynamical mechanisms remain poorly understood. Here, we develop a continuous-time bioevo-cybernetic framework in which biological organization emerges from the coupled dynamics of energetic throughput, regulatory integration, asymmetry generation, and feedback coherence. Within this framework, all state variables evolve continuously, but their nonlinear interactions give rise to critical transitions characterized by shifts in system stability. We formalize regulatory integration as a control variable governing the coherence of feedback across biological scales. Stability analysis shows that increasing integration can induce bifurcation-like transitions, leading to the emergence of new stable organizational states. In low-integration regimes, complexity increases gradually but remains dynamically constrained, offering a mechanistic explanation for prolonged evolutionary stasis. When integration exceeds a critical threshold, the system undergoes a qualitative reorganization that supports persistent multicellular coordination and division of labor. Importantly, these transitions arise endogenously from continuous ecological and regulatory dynamics, without requiring externally imposed fitness discontinuities. The model therefore provides an integrative mechanistic framework linking gradual ecological dynamics to abrupt evolutionary change. By integrating concepts from nonlinear dynamics with evolutionary theory, this framework offers a general and testable interpretation of major evolutionary transitions as emergent properties of adaptive biological systems.