Postcranial morphological variation between hunter‐gatherers and horticulturalists from the lower Paraná River Delta, Argentina

A comparative study of robusticity indices of long bones among hunter-gatherers and early agro-pastoral groups of India

OBJECTIVES

Diaphyseal robusticity and cross-sectional shapes of the bone tissues are influenced by mechanical loading history. It changes according to work demand on the body. It is the objective of this study to identify the shifts in the modes of subsistence, activities and mobility patterns through the comparison of the shape and strength of bone diaphyses among the Mesolithic, Chalcolithic and Harappan populations of India.

MATERIALS AND METHODS

For the analysis, 7 sites including 2 from Mesolithic (8000-4000 bc), 2 from Chalcolithic (2000-700 bc) and 3 from Harappan (3500-1800 bc) contexts are considered. The ratio obtained from the maximum length of the bones to their girth (at 50% or 35% from the distal end) and that from anterior-posterior and medio-lateral diameters were calculated (following Martin and Saller codes, 1957) to understand certain functional adaptations and stress markers on preserved long bones. Independent-sample T-tests and ANOVA were applied to detect mean differences of statistical significance within and between cultures.

RESULTS

The robusticity indices obtained from the humeri increase from the hunting-gathering phase (M/F; 19.39/18.45) to the Chalcolithic phase (M/F; 21.99/19.39) showing a slight drop in the Harappan phase (M/F; 18.58/18.37). The right humeri of Mesolithic females show a directional asymmetry of length (4.08%-5.13%) while that in males reach up to 26.09% indicating right-dominant lateralization. In the Harappan phase, females show a greater value for the right ranging from 0.31% to 3.07%. The femoral robusticity of females increases from 11.42 in hunting-gathering societies to 13.28 in Harappan times while mid-shaft of the Mesolithic population clearly shows greater loading along the anterior-posterior (A-P) plane as the index in most cases exceeds 100. There are significant differences among males and females within each group in terms of the indices but significant differences could be discerned between the Mesolithic, Chalcolithic and Harappan populations in case of tibiae, radii and ulnae only.

CONCLUSION

The occupation patterns certainly changed as humans became a food-producer from a hunter-gatherer. Occupations involving the extensive flexion and extension of upper limbs in the Chalcolithic period increase particularly in the Harappan phase. Sedentism gave rise to roundness of the femur and reduced the magnitude of lateralization. While equal level of mobility can be traced in case of both the sexes before the advent of agriculture, this distinction increases between the males and females in the agro-pastoral phases.

Sex differences in diet and life conditions in a rural Medieval Islamic population from Spain (La Torrecilla, Granada): An isotopic and osteological approach to gender differentiation in al-Andalus

OBJECTIVES

Gender differentiation can influence the diet, physical activity, and health of human populations. Multifaceted approaches are therefore necessary when exploring the biological consequences of gender-related social norms in the past. Here, we explore the links between diet, physiological stress, physical activity, and gender differentiation in the Medieval Islamic population of La Torrecilla (Granada, Spain, 13th-15th century AD), by analyzing stable isotope patterns, stature, and long bone diaphyseal measurements.

MATERIALS AND METHODS

The sample includes 96 individuals (48 females, 48 males) classified as young and middle adults (20-34 and 35-50 years of age respectively). Diet was reconstructed through the analysis of δ¹³ C and δ¹⁵ N. Stature, humeral and femoral diaphyseal shape and product of diaphyseal diameters served as proxies of physiological stress and physical activity.

RESULTS

Isotopic ratios suggest a substantial dietary contribution of C₄ plants (e.g., sorghum, millet), a variable access to animal proteins, and no differences between the sexes. Sexual dimorphism in stature derives from a markedly low female stature. Long bone diaphyseal properties suggest that men performed various physically stressful activities, whereas women were involved in less physically demanding activities (possibly related to household work).

DISCUSSION

Gender differentiation in La Torrecilla was expressed by a possibly differential parental investment in male versus female offspring and by culturally sanctioned gender differences in the performance of physical tasks. Diet was qualitatively homogenous between the sexes, although we cannot rule out quantitative differences. Our results shed new light on the effects of gender-related social norms on human development and lifestyle.

Gendered division of labor in a Celtic community? A comparison of sex differences in entheseal changes and long bone shape and robusticity in the pre-Roman population of Verona (Italy, third-first century BC)

OBJECTIVES

The presence of a gendered subdivision of labor has been bioarchaeologically investigated in various prehistoric and historical contexts. Little is known, however, about the type of differences in daily activities characterizing men and women among the Celtic communities of Italy. The focus of the present study is the analysis of differences in patterns of entheseal changes (ECs) and long bone shape and robusticity between sexes among the Cenomani Gauls of Seminario Vescovile (SV-Verona, Italy, third-first century BC).

MATERIALS AND METHODS

The sample includes 56 adult individuals (22 females and 34 males). Presence of ECs on nine bilateral postcranial attachment sites, and values of humeral and femoral shape and robusticity indices based on external measurements were compared between sexes by means of generalized linear models and Mann-Whitney tests.

RESULTS

Results show a lack of difference between sexes in long bone shape and robusticity, and a higher incidence of upper and, especially, lower limb ECs in males.

DISCUSSION

These results suggest the presence of sex-specific activities at SV mostly related to farming and differently influencing the considered variables. Also, this study suggests the relevance of a series of nonbiomechanical factors (developmental, hormonal, genetic, and methodological) when attempting biocultural reconstructions from osteoarchaeological samples.