A bioarchaeological approach to the reconstruction of changes in military organization among Iron Age Samnites (Vestini) From Abruzzo, Central Italy

Biomechanical Evaluation on the Bilateral Asymmetry of Complete Humeral Diaphysis in Chinese Archaeological Populations

Diaphyseal cross-sectional geometry (CSG) is an effective indicator of humeral bilateral asymmetry. However, previous studies primarily focused on CSG properties from limited locations to represent the overall bilateral biomechanical performance of humeral diaphysis. In this study, the complete humeral diaphyses of 40 pairs of humeri from three Chinese archaeological populations were scanned using high-resolution micro-CT, and their biomechanical asymmetries were quantified by morphometric mapping. Patterns of humeral asymmetry were compared between sub-groups defined by sex and population, and the representativeness of torsional rigidity asymmetry at the 35% and 50% cross-sections (J35 and J50 asymmetry) was testified. Inter-group differences were observed on the mean morphometric maps, but were not statistically significant. Analogous distribution patterns of highly asymmetrical regions, which correspond to major muscle attachments, were observed across nearly all the sexes and populations. The diaphyseal regions with high variability of bilateral asymmetry tended to present a low asymmetrical level. The J35 and J50 asymmetry were related to the overall humeral asymmetry, but the correlation was moderate and they could not reflect localized asymmetrical features across the diaphysis. This study suggests that the overall asymmetry pattern of humeral diaphysis is more complicated than previously revealed by individual sections.

Adapting in the Arctic: Habitual activity and landscape interaction in Late Holocene hunter-gatherers from Alaska

OBJECTIVES

This study compares lower limb diaphyseal robusticity between Native Alaskan hunter-gatherers to reconstruct patterns of mobility and engagement with terrain.

MATERIALS AND METHODS

Ancestral remains included in this study date between 600 and 1800 C.E. and were divided into three regions: Coastal Bay, Far North Coastal, and Inland/Riverine. Cross-sectional properties were determined at femoral and tibial midshafts and standardized by powers of body mass and bone length.

RESULTS

Consistently elaevated areas and second moments of area were found in ancestral remains from the Far North Coastal, while the Coastal Bay remains had reduced diaphyseal robusticity. Individuals from the Inland/Riverine region were intermediate in robusticity for male femora, but similar to the Coastal Bay group for females. Sexual dimorphism was greatest in the Inland/Riverine ancestral remains and comparable between Coastal Bay and Far North Coastal regions.

CONCLUSIONS

Ancestral remains from the Far North Coastal region have the greatest diaphyseal robusticity in response to intensive hunting and travel over rugged terrain. Reduced sexual dimorphism in the Far North Coastal region suggest female participation in hunting activities. Intermediate diaphyseal robusticity among Inland/Riverine males and increased sexual dimorphism reflects diverse patterns of mobility in relation to the hunting cycle between males and females. Reduced diaphyseal robusticity and sexual dimorphism among the Coastal Bay group is associated with sedentary villages established around net fishing in regions with low relief. Such findings argue against technocentric views of sedentism in hunter-gatherer lifeways and generally reflect diverse adaptive strategies and interaction with local terrain among Indigenous Late Holocene hunter-gatherers of Alaska.

The upper limb skeleton and behavioral lateralization of modern humans from Zhaoguo Cave, southwestern China

OBJECTIVES

Aims of the study are to initially describe and comparatively evaluate the morphology of the new Zhaoguo M1 upper limb remains, and contextualize upper limb functional adaptations among those of other worldwide Upper Paleolithic (UP) humans to make inferences about subsistence-related activity patterns in southwestern China at the Pleistocene-Holocene boundary.

MATERIALS AND METHODS

The preserved Zhaoguo M1 skeletal remains include paired humeri, ulnae, and radii, among others. These specimens were scanned using micro-computed tomography to evaluate internal structural properties, while external osteometric dimensions of the Zhaoguo M1 upper limb elements also were acquired. Both sets of measurements were compared to published data on Neandertals, and Middle and Upper Paleolithic modern humans.

RESULTS

The upper limb elements of Zhaoguo M1 display a suite of characteristics that generally resemble those of other contemporary Late UP (LUP) modern humans, while robusticity indices generally fall within the upper range of LUP variation. The Zhaoguo M1 upper limb elements display fewer traits resembling those of late archaic humans. The Zhaoguo M1 individual exhibits diaphyseal asymmetry in several upper limb elements suggesting left hand dominance. When evaluating the full range of magnitudes of humeral bilateral asymmetry in the comparative sample, Zhaoguo M1 falls at the lower end overall, but yet is relatively higher than contemporary LUP modern humans specifically from East Eurasia.

DISCUSSION

The Zhaoguo M1 individual suggests typical LUP modern human upper limb morphology persisted in southwest China until the end of the last glacial period. Upper limb bone asymmetry of Zhaoguo M1 also indicates that behavioral activities attributed to a hunter-gatherer tradition apparently extended through the Pleistocene-Holocene transition in this region.

New Insights into Activity-Related Functional Bone Adaptations and Alterations in Neolithic Liguria (Northwestern Italy)

This study offers a combined analysis of longbone mechanical properties (cross-sectional geometry, CSG), upper-limb enthesopathies (entheseal changes, ECs), and external auditory exostoses (EAEs) among Neolithic people from Liguria (Italy). Previous CSG studies have suggested a high degree of mobility in mountainous terrain and sexual dimorphism in the upper limbs, with males being more oriented toward unimanual activities and females performing strenuous bimanual tasks. The aims of the study were to: 1) increase the sample size of the CSG analysis via the acquisition of surface 3D models, 2) provide a solid chronological framework through direct dating in order to allow for subsampling of individuals dated to the Impresso-Cardial Complex (ICC, c. 5800–5000 BCE) and the Square-Mouthed Pottery culture (c. 5000–4300 BCE), 3) integrate the results of CSG analysis with information on ECs of the humeral epicondyles, and 4) assess possible marine activities through analysis of EAEs. Results from the CSG analysis confirmed those of previous studies, with no significant diachronic change. ECs in the humeral medial epicondyle parallelled CSG adaptations: males tended to display more changes, especially unilaterally. Only one individual from the ICC period showed bilateral EAE, suggesting that marine activities were not prevalent. This study adds to our knowledge on activity patterns in the Neolithic in Liguria, and shows that integrating structural adaptations with information from specific entheseal alterations and exostoses can improve reconstructions of past habitual activities.

Social reorganization and biological change: An examination of stature variation among Iron Age Samnites from Abruzzo, central Italy

Stature is a sensitive indicator of overall environmental quality experienced during growth and development, and can provide insights on a population's 'well-being'. This study investigated changes in estimated adult stature in a large (N=568) sample of Samnite Iron Age (800-27 BCE) people from central Italy, during a period of increasing sociopolitical complexity. Stature was analyzed diachronically, between sexes, and across social strata inferred using the 'Status Index' based on funerary treatment. It was expected: 1) a decrease in stature from the Orientalizing-Archaic period (O-A) to the fifth century BC (V SEC) and the following Hellenistic period (ELL), due to population increase and urbanization; 2) social status to positively influence the attainment of the full stature potential; 3) sexual dimorphism to be higher in more stratified groups. Results revealed no significant diachronic changes in stature (females: O-A: 154.2cm,V SEC: 154.2cm, and ELL: 153.6cm; males: O-A: 165.0cm,V SEC: 165.2cm, and ELL: 165.0cm) or sexual dimorphism. High-status males were taller than low-status (p=0.021), possibly due to a better diet, but only in the Orientalizing-Archaic period. Nonsignificant changes in females suggest either differential access to resources in women, or a better buffering from environmental optima or crises. The results of this study highlight the complex interrelation between social factors and human growth, and stress the importance of understanding the specific mechanisms leading to variation in adult stature.

The impact of subsistence changes on humeral bilateral asymmetry in Terminal Pleistocene and Holocene Europe

Analyses of upper limb bone bilateral asymmetry can shed light on manipulative behavior, sexual division of labor, and the effects of economic transitions on skeletal morphology. We compared the maximum (absolute) and directional asymmetry in humeral length, articular breadth, and cross-sectional diaphyseal geometry (CSG) in a large (n > 1200) European sample distributed among 11 archaeological periods from the Early Upper Paleolithic through the 20(th) century. Asymmetry in length and articular breadth is right-biased, but relatively small and fairly constant between temporal periods. Females show more asymmetry in length than males. This suggests a low impact of behavioral changes on asymmetry in length and breadth, but strong genetic control with probable sex linkage of asymmetry in length. Asymmetry in CSG properties is much more marked than in length and articular breadth, with sex-specific variation. In males, a major decline in asymmetry occurs between the Upper Paleolithic and Mesolithic. There is no further decline in asymmetry between the Mesolithic and Neolithic in males and only limited variation during the Holocene. In females, a major decline occurs between the Mesolithic and Neolithic, with resulting average directional asymmetry close to zero. Asymmetry among females continues to be very low in the subsequent Copper and Bronze Ages, but increases again in the Iron Age. Changes in female asymmetry result in an increase of sexual dimorphism during the early agricultural periods, followed by a decrease in the Iron Age. Sexual dimorphism again slightly declines after the Late Medieval. Our results indicate that changes in manipulative behavior were sex-specific with a probable higher impact of changes in hunting behavior on male asymmetry (e.g., shift from unimanual throwing to use of the bow-and-arrow) and food grain processing in females, specifically, use of two-handed saddle querns in the early agricultural periods and one-handed rotary querns in later agricultural periods.