China Shandong Evolution Model Chapter 7:The Physical Lockdown of Evolutionary Morphology and Population Strategy — Triple Constraints of Geometric Thermodynamics, Energy Budget, and Minimum Entropy Production

Abstract The morphological traits and survival strategies of Late Pleistocene East Asian archaic humans have long been attributed to “adaptive narratives” or “genetic innovations,” while neglecting the hard constraints of geometry, energy conservation, and the second law of thermodynamics to which organisms, as physical systems, must conform. Based on the LSED (Latitudinal Stress-Energy Dynamics) theoretical framework, this chapter systematically demonstrates, through three progressively nested physical constraints, that East Asian archaic human evolution is not a free search in open morphological space, but rather a necessary solution to physical boundary value problems. Constraint I — Geometric Thermodynamics: Under glacial low-temperature conditions, the rate of heat loss per unit volume scales with mass as M⁻¹/³. Coupling this with metabolic scaling laws ( B ∝ M ³/⁴ ) yields a minimum sustainable body size threshold M ≥ (C·ΔT/k)12/13. Individuals below this threshold cannot maintain core body temperature regardless of genotype. The high ΔT of East Asian glacial periods enforced a robust physique — not as “genetic innovation”, but as geometric necessity. Appendix Abstract The Nihewan Basin, a key Early Pleistocene archaeological locality in East Asia, has been invoked to challenge the “Luxi Thermodynamic Anchor”—a core proposition of the LSED (Late Pleistocene Shandong–Hebei Refugium) model, which posits that the Luxi sector served as a geothermal refugium during extreme glacial intervals. Critics argue that Nihewan’s ~2 Ma record of continuous hominin activity, apparently unaccompanied by pronounced geothermal expression, negates Luxi’s purported thermal necessity. This paper demonstrates that this objection rests on incomplete premises: the Nihewan Basin proper (encompassing the Yuxian and Yangyuan sub-basins) hosts confirmed geothermal systems—karst-fault conductive types (38–42°C) in Yuxian and mantle-plume-influenced medium–high temperature systems (>90°C bottom-hole) in Yangyuan. Rather than contradicting the LSED framework, Nihewan affirms it: geothermal resources, irrespective of mechanism, underpinned long-term glacial survival. The critical distinction lies not in geothermal presence but in visibility. Nihewan’s basin geomorphology naturally exposes cultural horizons; Luxi’s occupation surfaces lie buried beneath Late Pleistocene–Holocene Yellow River alluvium. Nihewan thus functions as a “visible reference” validating the pattern; Luxi as a “concealed test case” awaiting verification. Together they form a complementary evidentiary structure: Nihewan demonstrates that East Asia was persistently inhabited across glacial cycles; Luxi offers a candidate mechanism explaining how populations endured the harshest intervals.