Overview
H3b is the southern and Deccan oriented counterpart to H3a. It occupies a geographic domain centered on the southern Indian peninsula and displays genetic signatures consistent with early Holocene settlement patterns and long term regional continuity. The lineage has a more pronounced presence in Dravidian speaking populations and tribal groups of the central and southern Western Ghats.
Like H3a, H3b did not undergo the large-scale expansions seen in H1 lineages, instead maintaining smaller, localized microbranches reflective of stable regional demography. Its position in the H3 topology helps clarify the structure of H3 as a dual-centered South Asian lineage.
Geographic distribution
H3b occurs primarily in southern India, especially Tamil Nadu, Karnataka, Andhra Pradesh and Kerala. Additional occurrences appear in Sri Lankan communities with deep South Indian connections. The lineage is often found among tribal populations in the Western and Eastern Ghats.
Outside South Asia, H3b is virtually absent, emphasizing its insulation within peninsular populations.
Ancient DNA
- Deccan and southern Indian Neolithic sites occasionally reveal upstream H-associated markers compatible with ancestral H3b.
- Iron Age individuals from peninsular India sometimes show profiles aligning with downstream H3 expansions.
- No extra-regional ancient H3b individuals have been identified.
Phylogeny & subclades
H3b sits opposite H3a in the H3 structure. It includes several shallow microbranches, each tied to specific regions of southern India. Like H3a, its internal diversity reflects regional founder effects rather than large demographic pulses.
- H3b* basal
- Western Ghats microbranches
- Sri Lankan H3b clusters
Notes & context
H3b provides the southern complement to H3a and completes the internal H3 structure within the atlas. It highlights the deeply rooted paternal history of peninsular India.
References & external links