Redefining Homo sapiens: The Dual Cognitive Gene Code and Taxonomic Revision

Traditional classification of Homo sapiens relies primarily on morphological features. However, morphological similarity may arise from shared ancestral retention, parallel evolution under similar pressures, or coincidental overlap—not genuine evolutionary lineage relationships. Synthesizing paleogenomic and fossil anatomical evidence, this paper proposes a new taxonomic criterion: whether the key cognitive genes introgressed from Neanderthals and Denisovans are present. Neanderthal‑derived genes such as NRG1, CADPS2, and CNTNAP2 are closely associated with neurodevelopment, synaptic plasticity, and language ability. Their frequencies in modern Eurasian populations (1.5–2.6%) are significantly higher than in African populations (<0.5%). The Denisovan‑derived gene EPAS1 reaches a frequency of ~80% in Tibetan populations, representing a key high‑altitude adaptation. The Xuchang crania (~105–125 ka, cranial capacity ~1800 cc) from China exhibit a mosaic of Neanderthal robusticity and Sapiens‑like high vault morphology, providing anatomical evidence for early admixture in True Sapiens. Drawing on Darwin’s principle of natural selection and Zhou Benxiong’s (1978) southern‑limit logic of the mammoth, this paper formalizes three evolutionary mechanisms and establishes a “Three‑Lock” constraint framework. Accordingly, isolated African populations are classified as Homo sapiens similis (Sapiens‑like), while populations that underwent mid‑latitude climatic tempering and genetic admixture constitute Homo sapiens verus (True Sapiens).