Hydro-Genetic Dynamics: Fluvial Corridors as Selective Sorting Vectors and Channels for Geogenetic Evolution in the Bengal Basin and Himalayan Foothills

Overview & Summary This manuscript introduces the paradigm of Geogenetic Evolution to challenge standard isotropic, flat-plane diffusion models in human landscape genetics. By employing a mechanical sieve heuristic, the study models how active, deep-time river dynamics, deltaic land formation, and paleochannel avulsions dictate long-term human settlement, enforce regional endogamy, and structure paternal genetic lineages across centuries. Focusing on the northern sub-continental alluvial plain ("Green Zone" axis), the radiating catchments of the Himalayan foothills, and the hyper-alluvial Ganges–Brahmaputra delta (Bengal Basin), this research integrates macro-scale continental drainage analysis with high-resolution deltaic distributary modeling. Published empirical Y-DNA frequency data (Haplogroups H, P/R1a, and O) are spatially mapped onto ancestral river networks and correlated with classical ethnonyms and historical geography (such as Gangaridai, Vanga, Pundra, Suhma, and Harikela). Key Highlights & Findings Macro-Scale Alternating Columns: Parallel river networks exiting the Hindu Kush-Himalayan (HKH) mass organize expanding human streams into alternating, longitudinal genetic corridors (e.g., sub-continental P/R1a vs. trans-Himalayan O). Micro-Scale Sorting (Varendra Sieve Network): Elevated clay uplands (Barind Tract) and intersecting floodplains in North Bengal act as a sorting grid, partitioning the indigenous baseline (Haplogroup H) and incoming western riverine lineages (P/R1a) via distinct channels (Mahananda, Teesta–Karatoya, and the Baral River transverse conduit). Central Micro-Fractal Layout: Parallel deltaic rivers near central Bengal (Sitalakhya, Buriganga, Dhaleswari) act as strict socio-ecological troughs, preserving distinct population sub-structures over short physical distances. Tripartite Deltaic Symmetry: Lower Bengal forms a symmetrical "genetic sandwich"—a central southern H-spine (Old Brahmaputra–Tetulia axis) flanked by western (Mahananda–Hooghly) and eastern (Surma–Kushiyara/Chittagong) P-lineage wings. Historical Geography Synthesis: Ancient kingdom boundaries recorded in classical Puranic, epigraphic, and Greco-Roman texts align directly with deep-time hydro-geographic boundaries rather than arbitrary borders. Empirical Data Gaps: Identifies targeted, unstudied coastal estuarine zones (Lower Tetulia axis, Meghna Estuary) and provides testable predictions for future micro-evolutionary and ancient DNA (aDNA) sampling.