Isotopic insights into long-term socio-economic transformations in prehistoric Kuyavia, Poland

This study investigates long-term socio-economic transformations in prehistoric Kuyavia, Poland, through stable isotope analysis of human, animal and plant remains, combined with radiocarbon dating. A total of 84 human individuals, spanning from the Middle Neolithic to the Middle Bronze Age (around 4100–1230 cal BC), were analysed to reconstruct ancient diet and subsistence strategies, and their implications to reveal possible social stratification. Isotopic values from cattle provide insights into changing herding strategies and adaptations to diverse environments, while analyses of charred cereals contextualise plant-based dietary contributions and crop management practices, including varying levels of manuring. The results indicate marked dietary and economic variability: Middle and Late Neolithic farming groups relied primarily on cereals and cattle, while early Corded Ware communities appear to have occupied marginal ecological niches with distinctive herding strategies. From the Middle Bronze Age, isotopic evidence demonstrates the first substantial incorporation of millet into the human diet, representing the earliest widespread use of a C4 crop in the region. Variability in nitrogen isotope values suggests differential access to animal protein and possible social inequalities, particularly during the Early Bronze Age. Together, these findings highlight both continuity and transformation in prehistoric economies over more than two millennia, offering a refined archaeological perspective on cultural evolution in East-Central Europe and demonstrating the potential of stable isotope analysis and radiocarbon dating to reveal aspects of past lifeways not visible in material culture alone.