LSED Framework: Limiting Stress-triggered Evolutionary Dynamics (LSED) — Evolutionary Rules on the Survival Threshold

Traditional Neo-Darwinism emphasizes gradual change, yet the Pleistocene hominin fossil record shows punctuated morphological change. Gradualism cannot explain: why do peak evolutionary rates occur in specific spatiotemporal windows (35°–40° N, Middle–Late Pleistocene)? Why did tropical African hominin brain size stagnate (~1300 cc)? Why is Neanderthal introgression closely associated with the modern human cognitive leap? This paper proposes the Limiting Stress-triggered Evolutionary Dynamics (LSED) framework to fill these gaps. LSED has three core mechanisms: (1) stress filtering and leap; (2) gradient displacement; (3) oscillation tempering. Global hominin habitats are classified into three types: the Stable Zone (S = 0.2–0.4, stasis), the Tempering Zone (35°–40° N, S = 0.6–0.8, accelerated leaps), and the Death Zone (S > 0.9, population collapse). The LGM North Africa Death Zone [1] provides empirical validation of the Death Zone category. LSED generates five independently testable predictions and specifies explicit falsification conditions, satisfying Popperian criteria for a scientific theory [2]. This preprint is the companion piece to “The LGM North Africa Death Zone” [1], together forming a “refutation + replacement” theoretical dyad. References in this version are independently numbered and fully verified.