Dating the Old Rigveda: Identifying the Civilizational Transformation

This research identifies the historical context of the "Rigvedic Gradient"—the continuous civilizational transformation documented in Parikh (2026)—with the deurbanization of the Indus Valley Civilization (~1900 BCE). By synthesizing eight convergent lines of evidence, the paper argues that the "Old" Rigveda (Mandalas 2-7) was composed during the Mature Harappan period by an indigenous population. Key Evidence Layers: The Ecology Test: Rigorous computational disambiguation reveals a "Null Steppe Signature" (e.g., bhūrja/birch is shown to be a segmentation artifact) and a "Positive South Asian Signal." The supreme deity, Indra, is rendered through metaphors of lions and elephants in the most archaic strata. Genetic Anchor: Analysis of the Indus Periphery Cline and Rakhigarhi (16113) aDNA ($n=12$) shows zero Steppe ancestry in the South Asian population during the proposed composition window. Technological Constraints: Statistical analysis of vehicle vocabulary confirms a pre-spoke-wheel (pre-chariot) material profile in the Old stratum ($p=0.017$), placing it before the ~2050 BCE Sintashta innovation. Hydrographic Trajectory: The Sarasvati River’s journey from a mighty "mountains-to-ocean" river to a ritual name tracks the desiccation of the Ghaggar-Hakra system (~1900 BCE). Conclusion: The paper addresses the RUKI isogloss and satem innovation, demonstrating that these linguistic features were already 100% complete in the earliest stratum. This produces a "trifecta"—a text that is linguistically mature, technologically pre-chariot, and genetically non-Steppe—challenging the traditional model of a ~1500 BCE Steppe origin for the Vedic tradition.