Overview
I1g (BY151) represents a minor but phylogenetically coherent branch within haplogroup I1, with a core distribution spanning the Baltic coastline and northern continental Europe. The lineage likely emerged during the Late Bronze Age from populations linked to the southern Scandinavian interaction zone. Unlike the more expansive I1a or I1b lineages, I1g maintained more localized growth and reflects the micro-differentiation that accompanied early Germanic and pre-Germanic communities across the Baltic shores.
Geographic distribution
Modern carriers appear primarily in Sweden, Denmark, northern Germany, Poland, Estonia and Latvia. Low-level presence in Britain and the Netherlands is attributed to medieval and early modern migrations. The Baltic-centered distribution suggests continuity with early coastal cultures.
Ancient DNA
- A limited number of Iron Age and early medieval remains from the southern Baltic region show affinity to BY151-associated lineages.
- Some Viking Age individuals with Scandinavian-Baltic cultural signatures cluster near basal I1g branches.
- Late Nordic Bronze Age genomes contain broader Z58-related ancestry ancestral to I1g.
Phylogeny & subclades
I1g fits within the Z58 > Z138 > BY151 phylogenetic chain. It forms a separate minor branch not part of the major I1b (Z58 > Z63) or I1c (Z58 > Z2041) radiations, marking it as a distinct continental sub-expansion of I1.
- I1-Y51867
- I1-BY153
- Basal BY151* microclades
Notes & context
I1g is useful for reconstructing the fine-scale structure of early northern European populations. Its restricted range highlights the microregional differentiation within the broader I1 landscape.
References & external links