Revisiting osteoarthritis in the Cis-Baikal: Understanding behavioral variability and adaptation among middle Holocene foragers

Abstract

This examination of osteoarthritis (OA) focuses on better understanding behavioral variability among the middle Holocene foragers of the Cis-Baikal, Siberia, particularly as it pertains to a unique period of diachronic cultural change in the region. The three cemetery populations considered lie on either side of an 800–1000 year biocultural ‘hiatus’—characterized by a cessation in the use of formal cemeteries—and are located in two of the Cis-Baikal's four main micro-regions. Two of the cemetery samples, Lokomotiv and Shamanka II, represent the pre-hiatus early Neolithic (EN) Kitoi culture (8000–7000/6800 cal. BP), while the third, Ust'-Ida I, represents the post-hiatus late Neolithic–early Bronze Age (LN–EBA) Isakovo–Serovo–Glazkovo (or ISG) cultural complex (6000/5800–4000 cal. BP). Results reveal a dynamic pattern of variability across both time and space. Of particular interest is an apparent dichotomy between the two pre-hiatus EN sites, namely considerably higher OA severity at Lokomotiv compared to Shamanka II. This disparity suggests fundamental behavioral differences between the populations despite their contemporaneity and cultural continuity, possibly reflecting distinct residential mobility patterns and population densities in their respective micro-regions. In addition, intra-site analyses reveal that activity may have differed considerably between the sexes, whether in type, intensity, and/or duration. Male-dominated logistical foraging on both sides of the hiatus may explain, at least in part, these discrepancies. Finally, results of intra-joint component analyses of the elbow and knee were similar across age, sex, and cemetery groups, and largely consistent with those of epidemiological studies. Taken together, these results add to our growing understanding of pre- and post-hiatus adaptive strategies in the Cis-Baikal by providing a more detailed picture of the complex and highly variable behavioral and activity patterns employed by the region's middle Holocene foragers.