American Journal of Biological Anthropology最新文献

Objectives: This study tests the accuracy of dental histology for perinatal age estimation using deciduous teeth from modern human infants of known age. We evaluate whether enamel and dentin incremental structures, particularly the Neonatal Line (NNL), can be used to provide a reliable estimate of chronological age.

Samples and methods: Seventeen unerupted deciduous teeth from 14 full-term infants (0-164 days old) were analyzed from the Granada identified skeletal collection in Spain. Thin sections were examined under transmitted light and confocal microscopy to identify the NNL, cross-striations, and von Ebner's lines. Daily secretion rates (DSR) were measured across crown and root to calculate crown formation time (CFT) and root formation time (RFT), which were compared with the documented ages at death.

Results: Mean enamel DSR was 3.38 μm/day, and mean root dentin DSR was 3.24 μm/day. Enamel DSRs varied between tooth types and crown regions. The NNL was identified in all individuals who survived birth and was absent in one stillbirth, confirming its reliability as an indicator of live birth. Prenatal CFTs fell within ranges reported for full-term gestation, supporting the interpretation that all individuals were born at term. Histologically derived ages differed from recorded ages by an underestimation of 8 to an overestimation of 1 day, with a mean difference of 1 day.

Conclusions: Deciduous dental histology provides an accurate estimate of chronological age for human juveniles in the year after birth. These findings suggest that perinatal age estimates derived from dental histology can be applied in bioarchaeological and forensic contexts.

Objectives: Variation in the material properties of bone has been linked to functional activity in mammals, including primates. This coheres to the paradigm that skeletal morphology, in general, provides insight into species-specific physical activity patterns. The role of phylogenetic history in conditioning bone material properties, however, is largely unexplored, despite consensus that patterns of morphological variation should be sensitive to degrees of relatedness among sampled taxa.

Materials and methods: We collected microindentation hardness data (a measure of bone material stiffness) from the mandibles of five sympatric primate species from Taï Forest, Côte d'Ivoire to test the hypothesis that degree of relatedness, rather than species differences in diet and feeding behavior, is more strongly associated with bone material variation. This hypothesis is tested using a generalized linear mixed model with Bayesian inference.

Results: Phylogenetic distance has a significant association with bone stiffness, with colobines exhibiting more compliant bone than cercopithecines. The alternative hypothesis, that differences in dietary mechanical demands are reflected in bone stiffness variation, is not supported.

Discussion: While these findings suggest a role for phylogeny in constraining skeletal adaptation, a functional explanation is not necessarily precluded. Ingestive behavioral differences between subfamily members may provide a biomechanical framework for explaining what is, at present, a nebulous invocation of phylogenetic "baggage."

Objectives: The transition from the latter part of the Early (Umm an-Nar: 2700-2000 bce) to Middle (Wadi Suq: 2000-1600 bce) Bronze Age in southeastern Arabia was once interpreted as a time of sociopolitical and economic collapse in the face of climate change. However, recent archaeological and bioarchaeological studies have demonstrated gradual and more nuanced adaptation in response to environmental challenges. The site of Shimal in the Emirate of Ras Al Khaimah, UAE is uniquely suited to expanding our understanding of this transition because-unlike most Umm an-Nar sites, which were abandoned by ca. 2000 bce-Shimal was continuously occupied throughout the third and second millennia.

Materials and methods: Strontium, oxygen, and carbon isotopes in human teeth (n = 57 teeth from 50 individuals) from two Umm an-Nar and four Wadi Suq tombs were analyzed to investigate shifting forms of social organization.

Results: Strontium isotope ratios differed statistically over time, although only a slight increase was evident in the Wadi Suq. Stable oxygen isotope values varied significantly between the earlier Umm an-Nar tomb Unar 1 and all later tombs. Stable carbon isotope values remained consistent throughout both periods.

Discussion: Continuity in the region is evident, reflective of the unique geographic location of Shimal as an oasis whose water resources enabled the community to better withstand the effects of aridification and to maintain subsistence strategies. At the same time, however, temporal shifts in strontium and oxygen isotopes may point to the presence of people who migrated north in search of environmental stability.

Retraction: P. Anagnostou, V. Dominici, C. Battaggia, N. Boukhchim, J. Ben Nasr, R. Boussoffara, E. Cancellieri, M. Marnaoui, M. Marzouki, H. Bel Haj Brahim, M. Bou Rass, S. di Lernia, G. Destro Bisol, "Berbers And Arabs: Tracing The Genetic Diversity And History of Southern Tunisia Through Genome Wide Analysis," American Journal of Biological Anthropology 173, no. 4 (2020): 697-708, https://doi.org/10.1002/ajpa.24139. The above article, published online on 16 September 2020 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors; the journal's Editors-in-Chief, Trudy Turner and Connie Mulligan; the American Association of Biological Anthropologists; and Wiley Periodicals LLC. Concerns were raised by a third party regarding the study's collection of genetic information from participants, and the timing of ethical approval in relation to data collection. The institution provided a copy of the ethical approval certificate; however, the University and the co-authors were unable to locate additional documentation that could help address the concerns raised about the consent procedure. Wiley investigators also learned that the first and corresponding author, Paolo Anagnostou, had passed away since the publication of the study. As a result, the senior author and population geneticist Giovanni Destro Bisol, in agreement with the authors, has proactively requested the retraction of their article.

Ethically responsible and culturally acceptable management, study, and stewardship of legacy skeletal and other human remains currently held and managed in scientific institutions is a longstanding concern that, over the length of these collections' existence, has been exiguously addressed. Most recently, the ethical treatment of legacy collections of individuals from the African American community in the United States has been especially highlighted. The American Association of Biological Anthropologists (AABA) created a Presidential Task Force to address these concerns about legacy collections in 2022 by drafting practices and recommendations for policies to be adopted by the AABA and sibling organizations. We report on the first ever convergent analysis of research priorities and perspectives on these topics from the communities of biological anthropologists and a national cross-section of African Americans. Based on the surveys and discussions with these communities, all groups expressed a desire to enter a mutual, formal partnership where descendant communities are empowered to make decisions about the study and disposition of legacy collections. Our recommendations focus on promoting dialogue between parties involved through partnerships where desired. To make this possible, institutions should inventory and determine provenance of remains in legacy collections, ascertain the identity of descendant communities, and contact those communities using guidelines we provide. We argue that a default position taken by researchers is that no research need occur without the explicit consent of relevant descendant communities or communities of care. Examples of successful community partnerships are provided, along with new practices in ethical engagement with descendant communities.

Objectives: This study assesses sex differences in subsistence strategies through bilateral asymmetry in the upper and lower limbs of Late Holocene hunter-gatherers from the lower Paraná River wetlands (Argentina).

Materials and methods: The sample comprises 55 adult individuals of both sexes. Entheseal changes, linear external measurements, and diaphyseal shape were analyzed to quantify absolute and directional asymmetries. Bivariate and bootstrap analyses were applied to identify sex differences, and Spearman correlations were used to explore relationships between asymmetries across skeletal elements. Comparative data from global hunter-gatherer populations were also considered to contextualize the findings.

Results: Bilateral asymmetry ranged from 0% to nearly 30%, especially in upper limb midshafts. Males showed significantly greater asymmetry than females, particularly in the upper limbs. Right-side dominance was common in both sexes, though left-side dominance also appeared, especially in males. Positive correlations between asymmetries of different bones were more frequent in females, whereas males also displayed negative correlations.

Discussion: High percentages of bilateral asymmetry are consistent with uni- and bimanual hunting techniques and food processing, possibly beginning in adolescence. Sex differences suggest a division of labor, with males likely performing high-intensity, unilateral tasks and rowing, while females engage in more balanced, bimanual activities. Comparisons with global hunter-gatherers reveal similar asymmetry patterns, though local deviations may reflect adaptations to specific environmental and economic contexts.