Bronze Age Voices of Croatian Caves

The Middle to Late Bronze Age occupation represented by the Bezdanjača Cave assemblage (Croatia, c. 2000–800 BCE) sits at a crossroads of long-standing local traditions and pan-European transformations. Archaeological data indicates intensified metalworking, changing burial practices, and broader exchange networks in the western Balkans during this interval. Material culture and stratigraphy at Bezdanjača and nearby sites show continuity with earlier Neolithic and Eneolithic communities while also exhibiting traits similar to contemporaneous Urnfield and regional Bronze Age horizons.

Genetically, 38 analysed individuals provide a window into maternal line continuity and incoming influences: mtDNA haplogroups dominated by U, T and H suggest a mixture of deep local maternal lineages and more widespread Bronze Age maternal types. Limited Y‑chromosome information prevents firm statements about paternal continuity or male-biased migration here. Archaeological context—burials, grave goods, and metallurgy—implies social changes that may reflect mobility, marriage networks, and exchange across the Adriatic and Danubian corridors.

Limited evidence suggests the population at Bezdanjača was neither wholly isolated nor entirely replaced; rather, it was part of a mosaic of communities adapting technologies and identities across the Bronze Age Balkans. Further excavation and broader genomic sampling across neighbouring sites are needed to refine timelines of arrival and interaction.

The genetic snapshot from 38 individuals dated to c. 2000–800 BCE at Bezdanjača Cave emphasizes maternal diversity and regional admixture patterns typical of Bronze Age Europe. Observed mtDNA counts—U (8), T (7), H (5), HV (3), H5r (2)—indicate a predominance of lineages that are common across Neolithic farmers, Mesolithic foragers, and Bronze Age populations. Haplogroup U is often associated with deep European maternal ancestry, while H and T are widespread among Neolithic and later groups; the presence of HV and H5r, though limited, adds nuance to maternal continuity.

Crucially, Y‑chromosome haplogroups are not consistently reported or are sparse for this dataset, so paternal lineage patterns remain unresolved. This limits conclusions about sex-biased migration (for example, steppe-associated male influxes) specific to these samples. Nevertheless, genome-wide studies of nearby Bronze Age contexts generally document increased Steppe-related ancestry starting in the 3rd–2nd millennium BCE, layered onto earlier Anatolian farmer and Western hunter-gatherer ancestries. The Bezdanjača maternal profile fits a model of regional admixture: local maternal continuity with incoming genetic components.

Interpretations must remain cautious: 38 samples are informative but represent a single locality. Broader sampling across the Croatian Bronze Age is required to test whether these mitochondrial patterns reflect local persistence, selective burial practices, or wider demographic shifts.