ABSTRACT This study presents a Bayesian time-calibrated phylogenetic analysis of Satpuda Bhoyari's divergence within the Western Indo-Aryan macro-family, using three complementary computational historical linguistics frameworks: (1)...
moreABSTRACT
This study presents a Bayesian time-calibrated phylogenetic analysis of Satpuda Bhoyari's divergence within the Western Indo-Aryan macro-family, using three complementary computational historical linguistics frameworks: (1) BEAST2 Bayesian phylogenetic inference with a Relaxed Lognormal Clock and Binary Covarion substitution model; (2) Bayesian Posterior Predictive Checking (PPC) for model adequacy assessment; and (3) Approximate Bayesian Computation (ABC) for independent divergence time validation. The input data is a 200-item binary cognate matrix constructed from the authenticated Satpuda Bhoyari Lokgeet corpus and lexical dataset across six taxa (Bhoyari, Marwari, Mewadi, Rangdi, Malvi, Bundeli). Historical calibration priors are anchored to documented Western Indo-Aryan attestation dates.
BEAST2 analysis estimates Bhoyari divergence from Core Rajasthani at a posterior mean of 700 years before present (≈ 1325 CE), with a 95% Highest Posterior Density (HPD) interval of 575–825 BP (≈ 1200–1450 CE). Posterior node probability at the Proto-Bhoyari node is 0.92 — strong phylogenetic support. The relaxed clock identifies a three-phase trajectory: Proto-Bhoyari founding (~1300–1400 CE), Malwa contact phase (~1500–1700 CE), and Satpuda stabilization (~1700 CE onward). The Bayesian Skyline model shows a population proxy dip at founding, followed by gradual expansion during the Malwa phase and stabilization plateau post-1700 CE.
PPC confirms adequate model fit: all three summary statistics (mean pairwise Hamming distance, homoplasy index, normalized tree height) fall within the 95% simulated range. ABC independently confirms the divergence estimate: posterior mean ≈ 680 BP, with Model A (~1300 CE split) receiving posterior probability 0.71 vs Model B (~1500 CE split, P=0.19) and Model C (~1700 CE split, P=0.10). SplitsTree5 phylogenetic network analysis reveals moderate reticulation (δ = 0.21) confirming Malwa contact influence without altering primary Rajasthani inheritance. Five independent computational methods converge on a single conclusion: Satpuda Bhoyari diverged from Core Rajasthani ~1300–1400 CE and was never derived from Malvi.
Satpuda Bhoyari (Pawari) exhibits lexical and phonological similarities with Malvi as a result of an extended Malwa contact phase lasting approximately 250–300 years during historical migration and settlement processes. However, these similarities are primarily superficial and arise from areal convergence rather than genetic affiliation.
Subsequent linguistic surveys and regional classifications, relying largely on such surface features, placed Bhoyari within the Malvi subgroup. Nevertheless, a deeper structural analysis—particularly of its phonology, morphology, and core grammatical system—reveals a significantly closer alignment with the Core Rajasthani linguistic group.
Therefore, Bhoyari is more appropriately understood as a southern extension of the Rajasthani dialect continuum, and its classification under Malvi represents a case of contact-induced misclassification rather than true linguistic derivation.
Results
The present linguistic and computational analysis not only establishes the phylogenetic position of Satpuda Bhoyari (Pawari) but also provides strong indirect historical evidence regarding the migration trajectory of the Bhoyar Pawar community.
Results
The convergence of five independent Bayesian methods—BEAST2, Bayesian Skyline, Posterior Predictive Checking, Approximate Bayesian Computation, and SplitsTree5—confirms that Bhoyari diverged from the Core Rajasthani linguistic group around 1300–1400 CE. This linguistic divergence is not merely a structural phenomenon; it reflects a real historical separation of a speech community from the Rajasthani region.
Crucially, the presence of a prolonged Malwa contact phase (approximately 250–300 years), supported by measurable contact parameters (δ ≈ 0.21), lexical borrowing patterns, and demographic expansion signals, indicates that this migrating population did not move directly to the Satpuda region. Instead, it passed through and remained in the Malwa region for several generations, allowing significant but surface-level linguistic interaction with Malvi.
This sequence—Rajasthani origin → Malwa contact → Satpuda stabilization—is not an assumption but a model consistently supported by multiple independent datasets and analytical frameworks.
Therefore, the linguistic evidence aligns closely with and strongly supports the historical migration narrative of the Bhoyar Pawar community:
Rajasthani Origin (~1300 CE):
The divergence of Bhoyari from Core Rajasthani indicates that the ancestral Bhoyar Pawar population was originally part of the Rajasthani linguistic and cultural sphere.
Malwa Phase (~1400–1700 CE):
The statistically detectable Malwa contact phase demonstrates a prolonged period of settlement or interaction in the Malwa region, during which linguistic convergence with Malvi occurred.
Satpuda Settlement (~1700 CE onwards):
The stabilization phase marks the final establishment of the community in the Satpuda region (the Betul–Chhindwara zone), where Bhoyari developed into its present form.
Importantly, this linguistic reconstruction provides independent scientific validation of the community’s migration history, separate from oral traditions, genealogies, or historical texts. In other words, the language itself preserves the migration pathway.
Key Inference
The Bhoyari language functions as a linguistic record of migration: it indicates that the Bhoyar Pawar community originated in Rajasthan, underwent a significant Malwa phase, and later settled in the Satpuda region.
Thus, this study goes beyond classification. It establishes that:
Bhoyari is structurally Rajasthani, confirming its origin.
Malvi influence is contact-based, confirming the Malwa phase.
Final linguistic stabilization occurred in Satpuda, confirming settlement.
Final Statement
Language here is not merely a medium of communication—it is historical evidence.
In the case of Bhoyari, it preserves and reflects the Rajasthan → Malwa → Satpuda migration pathway of the Bhoyar Pawar community.
Five methods | One conclusion: Bhoyari ← Core Rajasthani ~1300 CE | NOT from Malvi | But Classified under Malvi | Satpuda stabilization ~1700 CE | PP = 0.92