Balkan Chalcolithic Echoes

The Balkan Chalcolithic unfolds across long-lived tell settlements and necropoleis from the late sixth millennium through the early second millennium BCE. Archaeological horizons sampled here span key sites in present-day Bulgaria, Serbia and Croatia — Yunatsite, Tell Ezero (South Central Bulgaria), Kazanlak, Smyadovo, Sushina, Podlokanj (Serbia) and Dakovo–Franjevac (Croatia) — each preserving stratified sequences of domestic architecture, craft production and burial practice. Material culture shows regional continuity with Neolithic farming traditions and simultaneous innovation: copper artefacts and new pottery forms appear alongside older local house plans.

Stratigraphic data indicate that these communities emerged from long-standing Neolithic farmer populations, with episodic reorganization of settlement patterns during the later Chalcolithic. Radiocarbon determinations from the sampled contexts fall between 5468 and 2000 BCE, a broad interval that captures both late Chalcolithic florescence and transitions into the Early Bronze Age in Bulgaria.

Archaeological data indicate shifting social networks across river valleys and coastal corridors: trade in raw copper and exotic goods suggests wider connections across the Balkans and into the Carpathian Basin. Limited evidence suggests that some demographic change occurred near the end of the sequence, consistent with broader regional transformations around 3000–2000 BCE. Given the spatial spread of the sampled sites, interpretations emphasize mosaic continuity and change rather than a single migration event.

Genome-wide and uniparental data from 40 individuals sampled across multiple sites provide a regional view of ancestry in the Balkan Chalcolithic. Mitochondrial haplogroups are dominated by U (8), K (6), H (4), T (3) and HV (2) — a profile consistent with persistence of Neolithic farmer‑associated maternal lineages alongside haplogroups common in earlier European hunter‑gatherers. Such mtDNA diversity supports continuity of local maternal ancestry through the Chalcolithic.

Y‑chromosome diversity is more variable: haplogroups I (4) and R (3) are present along with F (2), G (2) and H (1). The presence of I suggests local Mesolithic‑derived paternal lines, while R — recorded here without subclade resolution — may reflect incoming steppe‑related male ancestry that becomes more prominent in later Bronze Age contexts. Haplogroups G and F are often associated with early farmer or Near Eastern lineages and their occurrence here aligns with archaeological evidence for long‑term Neolithic continuity. Because some Y lineages are represented by small counts (many <10), conclusions about sex‑biased admixture should be treated as provisional.

Autosomal patterns across the cohort indicate a mixture of local Anatolian‑Neolithic farmer ancestry, remnant European hunter‑gatherer input, and increasing steppe‑related ancestry toward the end of the sampled interval. With a sample size of 40, these signals are meaningful at a regional scale, but site‑by‑site heterogeneity and small counts for particular haplogroups warrant cautious, iterative interpretation as more data accrue.