Proto-Indo-European as a Field Invariant: Anchors, Registers, and a Layered Mesh Model for Indo-European Chronology

Proto-Indo-European (PIE) is conventionally modeled as a temporally prior spoken proto-language from which Indo-European languages diverged via branching descent. Recent hybridBayesian phylogenetic analyses, most notably Heggarty et al. (2023), challenge this assump-tion by demonstrating that early Indo-European evolution is non-tree-like and that few ancientwritten languages function as direct ancestors of modern clades.This paper argues that the ≈8120 years before present horizon recovered by such models doesnot represent the birth of a discrete language, but rather the emergence of a linguistic field: along-duration interaction zone characterized by overlapping dialect continua, lateral transmis-sion, and coexisting registers. Under these conditions, comparative reconstruction recovers not ahistorical ancestor but a field invariant—a constraint set abstracted from preserved structure.We show that reliable reconstruction under a field model requires early stabilized anchorregisters. Vedic Sanskrit uniquely fulfills this role through explicit phonetic, metrical, ped-agogical, and grammatical preservation mechanisms. For Sanskrit to preserve high-resolutionIndo-European constraints, stabilization must precede major vernacular drift, implying a pre-5000 BCE stabilization horizon (target window 7000–5000 BCE; sensitivity analyses extendinto the early third millennium BCE). This requirement is structural, not cultural, and conflictswith chronologies that date Sanskrit via Indo-Iranian split estimates.Using network phylogenetics, information-theoretic reasoning, and identifiability analysis, weargue, and outline testable diagnostics showing, that traditional Indo-Iranian “splits” arise fromtree-forcing artifacts and circular dating dependencies. Reclassifying these as later registeralignments resolves persistent conflicts between linguistics, archaeology, and genetics, whilerepositioning Bronze-Age steppe horizons as downstream accelerators rather than linguisticorigins.PIE remains methodologically indispensable for comparative reconstruction but must bereclassified ontologically as an invariant abstraction derived from preserved structure, not as atemporally prior speech community. In short, reconstruction still targets a coherent system, butthat system is a field-derived invariant rather than a single ancestral tongue.