Echoes of Spain_C: Chalcolithic Lives

Across the sweep of northern and eastern Iberia, Spain_C emerges amid the long shadow of Neolithic farming and the dawn of metal use. Archaeological deposits dated between 3800 and 3000 BCE at sites such as Atapuerca (El Mirador Cave), La Chabola de la Hechicera (Álava) and Paris Street (Cerdanyola, Barcelona) record continued reliance on domesticated crops and herds, while monumental burial architecture and cave interments show complex social memory.

Material culture indicates local trajectories rather than a single migration event: megalithic tombs and collective burials persist alongside innovations—copper objects, specialized flint, and new ceramic styles—first appearing in the late 4th to early 3rd millennium BCE. Archaeological data indicates connections along the Atlantic façade and Mediterranean coast, suggesting exchange networks that carried raw materials, ideas, and possibly people.

Genetic evidence complements this picture by revealing a mixed ancestry mosaic — persistent Neolithic farmer lineages, signatures associated with Mesolithic hunter‑gatherers, and later arriving components. Limited evidence suggests some regional continuity, particularly in the Basque‑adjacent valleys, but the balance of ancestries shifts through time as new cultural practices spread. Uncertainty remains about the pace and social mechanics of these changes; ongoing sampling and contextual excavation are refining the narrative.

Spain_C is notable for a relatively large dataset (117 individuals) spanning 3800–1700 BCE from diverse locations—Basque Country (Álava sites: El Sotillo, Alto de la Huesera, Las Yurdinas II; La Chabola de la Hechicera), Burgos (El Mirador Cave, Arroyal I), Murcia (Camino del Molino), Barcelona (Paris Street), Madrid (Camino de las Yeseras), and Tarragona (Galls Carboners). This spatial spread allows robust inference about population structure and change.

Y‑chromosome results show a plurality of haplogroup I (31 individuals), with notable counts of G (11) and R (10), plus smaller numbers of F and P. Mitochondrial diversity is characterized by U (25), K (23), J (18), H (14) and a subclade H3 (8). This pattern reflects a layered ancestry: mtDNA K and J are common in early European farmers, while U and Y‑chromosome I point to enduring hunter‑gatherer contributions. The presence of R lineages—found in a minority—may signal the initial appearance or local adoption of lineages associated elsewhere with Steppe‑derived ancestry, particularly in later individuals of the time range.

Genetic data indicate regional heterogeneity rather than a uniform population: some valleys show stronger hunter‑gatherer‑linked signals, while coastal and southern samples retain robust farmer ancestry. With 117 samples the picture is stronger than most regional studies, but temporal sampling gaps mean that the timing of shifts—such as any increase in Steppe‑related ancestry—remains imprecise. Ongoing chronologically dense sampling and radiocarbon calibration are needed to resolve the tempo of genetic change.