Fractal Series - Paper 6: Fractal Bipedality- Chromosome 2 Fusion and Entropic Reorganization

Title Fractal Series — Paper 6: Fractal Bipedality — Chromosome 2 Fusion and Entropic Reorganization Author Juan F. Culajay Type Preprint / Report Language English License Creative Commons Attribution 4.0 International (CC BY 4.0) Description / Abstract Obligate bipedality represents one of the most consequential and irreversible commitments in hominin evolution. Unlike facultative or transient upright postures observed across multiple vertebrate lineages, hominins evolved a fully stabilized bipedal architecture while retaining manipulative forelimbs and cranial expansion. This paper proposes that the human-specific fusion of ancestral chromosomes 2p and 2q acted as an internal developmental perturbation, displacing the hominin lineage from a prior thermodynamic stability basin and necessitating large-scale entropic reorganization across gene regulation, morphology, and locomotor mechanics. Within the E³ Framework (Energy, Environment, Entropy), chromosome 2 fusion is interpreted not as a gradual selective optimization but as a boundary-condition collapse that forced genome-wide chromatin reconfiguration. The loss of a telomeric boundary altered long-range regulatory topology, particularly affecting HOX cluster coordination and axial patterning constraints. This displacement required millions of years of entropic filtering to restore organismal equilibrium, expressed phenotypically as pelvic restructuring, spinal curvature, lower-limb elongation, and irreversible commitment to upright gait. Fractal Bipedality reframes natural selection as a post-perturbation stabilizing process rather than a creative driver, positioning bipedality as a thermodynamically enforced outcome of internal genomic reorganization. This model integrates genomics, developmental biology, and evolutionary biomechanics into a unified stability-based account of hominin uprightness. Keywords Fractal bipedality; chromosome 2 fusion; human evolution; obligate bipedalism; entropic reorganization; developmental constraints; HOX regulation; chromatin topology; E³ framework; thermodynamic stability Communities (optional) Evolutionary Biology; Theoretical Biology; Systems Biology; Biophysics; Human Evolution Funding None. Related identifiers (part of Fractal Series) Culajay, J. (2025). Fractal Series — Paper 0: Fractal Overview — The Origin of Entropy. Zenodo. https://doi.org/10.5281/zenodo.17780671 Culajay, J. (2025a). Fractal Series — Paper 1: Fractal Entropy — The Dimensional Architecture of Entropic Regulation. Zenodo. https://doi.org/10.5281/zenodo.17507973 Culajay, J. (2025b). Fractal Series — Paper 2: Fractal Equilibrium — A Thermodynamic Framework for Nested Stability in Living Systems. Zenodo. https://doi.org/10.5281/zenodo.17509557 Culajay, J. (2025c). Fractal Series — Paper 3: Fractal Genesis — The Mineral Precursors to Biology. Zenodo. https://doi.org/10.5281/zenodo.17509846 Culajay, J. F. (2025d). Fractal Series — Paper 4: Fractal Evolution — A Thermodynamic Model for the Development of Life. Zenodo. https://doi.org/10.5281/zenodo.17509924 Culajay, J. (2025e). Fractal Series — Paper 5: Fractal Mechanics — The E³ Model in Action for Molecular Evolution. Zenodo. https://doi.org/10.5281/zenodo.17518356 Culajay, J. (2025e2). Fractal Series — Paper 6: Fractal Bipedality — Chromosome 2 Fusion and Entropic Reorganization. https://zenodo.org/records/18451705 Culajay, J. F. (2025f). Fractal Series — Paper 7: Fractal Sapience — The Recurrence of Sapience Across Epochs. Zenodo. https://doi.org/10.5281/zenodo.17532753 Culajay, J. (2025g). Fractal Series — Paper 8: Fractal Consciousness — The Thermodynamic Architecture of Awareness. Zenodo. https://doi.org/10.5281/zenodo.17780027 Culajay, J. (2025h). Fractal Series — Paper 9: Fractal Learning — Entropy as Universal Optimizer: The Physics of Retention. Zenodo. https://doi.org/10.5281/zenodo.17779799 Culajay, J. (2025i). Fractal Series — Paper 10: Fractal Morality — The Thermodynamics of Social Coherence. Zenodo. https://doi.org/10.5281/zenodo.17778975 Culajay, J. (2025j). Fractal Series — Paper 11: Fractal Spacetime and Scale‑Echo Symmetry (SES). Zenodo. https://doi.org/10.5281/zenodo.17778646 Culajay, J. (2025k). Fractal Series — Paper 12: Conclusion — Stability(x) and the Geometry of Meaning. Zenodo. https://doi.org/10.5281/zenodo.17777921 Culajay, J. (2026l). Fractal Series — Paper 13:Fractal Mythology: The Geometry of Balance in Ancient Cosmologies. Zenodo. https://doi.org/10.5281/zenodo.18451062 Notes for Zenodo record This preprint is part of a multi‑paper Fractal Series developing the E³ Framework (Energy, Environment, Entropy) as a unified thermodynamic ontology spanning molecular biology, development, evolution, cognition, and cosmology. Paper 6 focuses on bipedality as a stability‑driven outcome of internal genomic reorganization rather than gradual adaptive optimization. Open Review Policy This publication is part of an open scientific dialogue. Researchers and readers are encouraged to contribute constructive reviews, critiques, or replication insights related to Fractal Sapience and the broader Fractal Series. Valuable feedback may be acknowledged in future versions or derivative works.