Biomechanical approach to the reconstruction of activity patterns in Neolithic Western Liguria, Italy

Abstract

This paper investigates the changes in upper and lower limb robusticity and activity patterns that accompanied the transition to a Neolithic subsistence in western Liguria (Italy). Diaphyseal robusticity measures were obtained from cross-sectional geometric properties of the humerus and femur in a sample of 16 individuals (eight males and eight females) dated to about 6,000-5,500 BP. Comparisons with European Late Upper Paleolithics (LUP) indicate increased humeral robusticity in Neolithic Ligurian (NEOL) males, but not in females, with a significant reduction in right-left differences in both sexes. Sexual dimorphism in robusticity increases in upper and lower limb bones. Regarding the femur, while all female indicators of bending strength decrease steadily through time, values for NEOL males approach those of LUP. This suggests high, and unexpected, levels of mechanical stress for NEOL males, probably reflecting the effects of the mountainous terrain on lower limb remodeling. Comparisons between NEOL males and a small sample of LUP hunter-gatherers from the same area support this interpretation. In conclusion, cross-sectional geometry data indicate that the transition to Neolithic economies in western Liguria did not reduce functional requirements in males, and suggest a marked sexual division of labor involving a more symmetrical use of the upper limb, and different male-female levels of locomotory stress. When articulated with archaeological, faunal, paleopathological, and ethnographic evidence, these results support the hypothesis of repetitive, bimanual use of axes tied to pastoral activities in males, and of more sedentary tasks linked to agriculture in females.

Insights on the paleoepidemiology of ancient tuberculosis from the structural analysis of postcranial remains from the Ligurian Neolithic (northwestern Italy)

“…As already noted in previous studies when compared to females, adult males show a significantly greater stature and body mass, also displaying significantly more robust humeri and tibiae (e.g. Marchi et al, 2006Marchi et al, , 2011Sparacello and Marchi, 2008). Moreover, males have significantly higher femoral and tibial shape indices, as well as a higher degree of humeral bilateral asymmetry.…”

“…Cross-sectional properties of most of the adult individuals in this study have been analyzed in previous studies (Marchi et al, 2006Marchi, 2008;Sparacello and Marchi, 2008;Sparacello et al, 2011Sparacello et al, , 2014; Table 1). Cross-sectional geometric properties for the recently excavated individual from Pian del Ciliegio (Pian del Ciliegio 1, Del Lucchese, 2014) were estimated using the SolidCSG method.…”

“…Humeral asymmetry in AQ1 is very low, a characteristic that is typical of Ligurian Neolithic females, and might be due to the use of querns for cereal processing using both arms (Marchi et al, 2006;Sparacello et al, 2011). The upper limbs of AQ1 are therefore compatible, both in terms of robusticity and lateralization, with the profile of a normally active Ligurian Neolithic female.…”

“…Ligurian Neolithic people show highly characteristic and sex-specific CSG indices: males have shown asymmetry in mechanically induced robusticity of the humeri, which suggests the frequent use of tools using one hand (maybe axes for woodworking), while females show symmetry, suggesting the use of both arms (possibly querns for cereal processing; Marchi et al, 2006;Sparacello and Marchi, 2008;Sparacello et al, 2011). Furthermore, lower limb CSG shape indices have also been associated with mobility levels (Carlson and Marchi, 2014); Ligurian Neolithic males show high 'mobility indices' in the lower limbs, probably due to the importance of pastoralism among these people (Rowley-Conwy, 1997;Marchi et al, 2006Marchi et al, , 2011. Given that participation in subsistence related activities in the Neolithic probably began as early as late childhood (especially herding, as happens cross-culturally; Dyson-Hudson and Dyson-Hudson, 1980;Hobbs et al, 1999), it is expected that some of those postcranial adaptations may be present in adolescents, including AC5.…”

“…Among adults, only individuals showing signs of advanced senescence are usually excluded from CSG studies Macintosh et al, 2014). As in previous research (Marchi et al, 2006), adults were included in a single age category, and adult status was determined based on the complete fusion of the long bone epiphyses and eruption of the permanent dentition.…”