Neurally Driven Evolution: Behavior, Niche Construction, and the Acceleration of Variation Structure

The nervous system invents no new evolutionary mechanism. It accelerates and complexifies an existing one. The first paper in this series showed that autocatalytic systems generate, through their history of perturbations, a structured variation space whose topology makes certain variations more probable than others. The present paper extends this thesis to the level of neural systems. The nervous system is not a fourth inheritance system in Jablonka's sense, but a possibility-space generator operating on a dramatically shortened timescale, which acts on the perturbation structure of offspring through niche construction, without leaving the causal architecture of the basic mechanism. Three empirically grounded channels connect neural processes to heritable variation structure: activity-dependent gene expression inscribed into the somatic genome of neurons; neuroendocrine axes transmitting chronic neural integration states to the germline; and niche construction as the primary indirect channel through which behavior shapes the perturbation environment of successive generations. The Weismann barrier remains intact throughout. The category error committed by Jablonka's behavioral inheritance system is avoided by maintaining strict causal-level distinctions.