The Limit Stress-Driven Evolution (LSED) Theory: Spatial Lock

The Limit Stress-Driven Evolution (LSED) theory proposes that human cognitive modernity emerged from an ultimate environmental stress field that periodically breached the physiological homeostatic thresholds of endotherms. The core architecture of LSED theory—spatial lock, time lock, and geographic isolation lock—has recently been rigorously constructed and completed. The name “LSED” originates from the combination of the first letters of “Limit Stress-Driven Evolution”. The LSED theoretical framework is an original theory proposed by Jing Zhang, developed from the upgraded foundation of neutral evolution theory and the original mid-latitude oscillation theory. Jing Zhang conceived the theory and completed the initial draft. Subsequently, through adversarial engagement among multiple large language models—each critiquing, challenging, and refining the others—the theory was iteratively strengthened, repaired, and upgraded to its current form. This paper, Celestial Codex Chapter I, presents the first pillar of the author's original LSED theory—the Spatial Lock. It tightly integrates geomorphology (Tibetan Plateau), climatology (monsoon circulation), and human evolution. It answers the question “Why East Asia?” forming a perfect trinity with “Why this timing?” (Time Lock) and “Why couldn't they leave?” (Geographic Isolation Lock). The Spatial Lock demonstrates that, controlled by the coupled uplift of the Tibetan Plateau and the East Asian monsoon system, the mid-latitudes of East Asia (35°–40°N) developed the strongest seasonal contrast at these latitudes globally. Continuous loess-paleosol records—using magnetic susceptibility (summer monsoon proxy) and grain size (winter monsoon proxy)—demonstrate that during glacial maxima, the two proxy curves exhibit mirror-image variations, with climatic fluctuation amplitudes exceeding physiological tolerance thresholds. Unlike the mid-latitudes of West Asia (Zagros Mountains) and Southern Europe (Iberian Peninsula), East Asia possesses the topographic amplification effect of the Tibetan Plateau. Without this effect, those regions experience significantly weaker seasonal contrasts, incapable of forming an equivalent ultimate stress field. The spatial lock thus delineates the spatial boundary of LSED theory, demonstrating that the evolutionary core region of cognitive modernity is not Africa but the glacial extreme environment belt of the mid-latitudes of East Asia.