Bone morphologies and histories: Life course approaches in bioarchaeology

Analyzing Patterns of Skeletal Indicators of Developmental Stress Through the Double Lens of Ontogeny and the Life Course Approach in a Contemporary Reference Sample

OBJECTIVES

Skeletal indicators of developmental stress are commonly used to assess health, disease, and patterns of morbidity and mortality in past populations. Incorporating information about individual life history, such as adverse life events, allows for a more thorough understanding of their etiology. This paper adopts the double lens of ontogeny and the life course to analyze indicators of developmental stress in relation to known individual pathologies and developmental patterns of the cranium, vertebrae, and long bones.

MATERIAL AND METHODS

Six skeletal indicators were collected on CT scans or virtual skeletal reconstructions of 1033 contemporary deceased male and female individuals aged between 0 and 20 years from New Mexico: cribra orbitalia, porotic hyperostosis, Harris lines, stunting, vertebral neural canal diameters, and bone mineral density. Autopsy reports provided information on age, sex, disease type, and duration. Polychoric and polyserial correlations, boxplots, balloon plots, factor analyses of mixed data, and cluster analyses were used to explore patterns among indicators, ontogeny, sex, and disease.

RESULTS

The presence and prevalence of indicators varied depending on age and disease: Harris lines, stunted growth, and cribra orbitalia were common in younger age groups and in cases of long-term or respiratory illnesses, while porotic hyperostosis was more prevalent in adolescent and young adult males.

DISCUSSION

Skeletal indicators of developmental stress are most likely associated with the timing of adverse life events in relation to the corresponding ontogenetic patterns, developmental sensitivity to stressors, and developmental plasticity/canalization of the different skeletal elements that bear them.

Rickets, resorption and revolution: An investigation into the relationship between vitamin D deficiency in childhood and osteoporosis in adulthood in an 18th-19th century population

OBJECTIVE

This study employs a Developmental Origins of Health and Disease (DOHaD) approach to assess the effect of vitamin D deficiency (VDD) in childhood on the risk of osteoporosis in adulthood in an archaeological sample of skeletons dating from the 18th to 19th centuries.

MATERIALS

Femora and lumbar vertebrae of 65 adults aged 18+ years (26 diagnosed with residual rickets and 39 without) from an 18th-19th century Quaker burial ground at Coach Lane, North Shields, England.

METHODS

Bone mineral density (BMD) was measured for the femoral neck and first four lumbar vertebrae of each individual using a dual energy X-ray absorptiometry (DXA) scanner as a proxy for assessing osteoporotic fracture risk.

RESULTS

3-way ANOVA revealed no statistically significant differences in BMD between individuals with and without residual rickets across age and sex.

CONCLUSIONS

A combination of lifestyle and environmental factors likely influenced the BMD of people buried at Coach Lane across the life course. The impact of childhood VDD on BMD later in life can be mitigated through other factors such as physical activity and diet.

SIGNIFICANCE

This is one of the first bioarchaeological studies to take a DOHaD approach to understand osteoporosis risk in 18th-19th century England. It highlights the complexity of aetiological factors for osteoporosis and that VDD in early life does not necessarily predispose a person to osteoporosis in adulthood.

LIMITATIONS

BMD is not the only indicator of osteoporosis. Microscopic methods for the assessment of childhood vitamin D deficiency, such as inter-globular dentine analysis, were not applied.

Hidden in plain text: Uncovering hidden heterogeneity and social stratification in Ireland AD 1150-1800

OBJECTIVES

Between the Irish late medieval (AD 1150-c.1550) (LMP) and post-medieval (AD c.1550-1800) (PMP) periods, colonial practices changed land ownership. Contextualizing these periods within a biocultural political economy framework supports increasing social inequality in the PMP, which we expect to be reflected in different skeletal markers of longevity and stress. Therefore, we hypothesized that widespread exposure to stressors and resource deprivation contributed to lower longevity in the PMP compared to the LMP, and that there would be greater variation between sites in the frequency of linear enamel hypoplasias (LEH) in the PMP.

MATERIALS AND METHODS

We estimated age and counted matched pairs of LEH on 526 adult skeletons from the Irish counties of Dublin, Kildare, Louth, and Meath. Age-at-death was compared through Kaplan-Meier survival functions and non-parametric tests. Linear enamel hypoplasias prevalences were analyzed with Mann-Whitney U tests and Generalized Linear Models.

RESULTS

Age-at-death distribution changed between the LMP and PMP for males, with males experiencing an increase in median-age-at-death. The same was untrue for females, who show no changes in median age-at-death. Analysis of LEH frequency per individual showed that variation between sites was significant in the post-medieval period but not in the late medieval period.

CONCLUSION

These results suggest that social organization contributed to embodied health experiences that varied across time periods. Specifically, populations from the PMP appear to have embodied greater social inequality in their more varied susceptibility to stress. Our work demonstrates the strength of pairing historical texts with the analysis of skeletal remains to evaluate the impact of social structures on biological frailty.

High prevalence of adult and nonadult scurvy in an early agricultural transition site from Mainland Southeast Asia was associated with decreased survivorship

OBJECTIVES

The osteological paradox recognizes that the presence of lesions is not always directly related with increased mortality. When combined with the clinical, historical, and epidemiological literature on scurvy, survivorship analysis, a form of statistical analysis to assess the relationship between the presence of diseases in the archeological record and survival, helps determine the overall burden of the disease both in terms of morbidity and mortality. This article explores the relationship between scurvy and survivorship in 26 adults from Man Bac, a Neolithic site from northern Vietnam together with prepublished evidence of scurvy in the nonadult population (n = 44).

METHODS

Diagnosis of scurvy included differential diagnosis combined with the Snoddy, A. M. E., Buckley, H. R., Elliott, G. E., Standen, V. G., Arriaza, B. T., & Halcrow, S. E. (2018). Macroscopic features of scurvy in human skeletal remains: A literature synthesis and diagnostic guide. American Journal of Physical Anthropology, 167(4), 876-895. https://doi.org/10.1002/ajpa.23699 threshold criteria and the Brickley, M. B., & Morgan, B. (2023). Assessing diagnostic certainty for scurvy and rickets in human skeletal remains. American Journal of Biological Anthropology, 181, 637-645 diagnostic certainty approaches. Kaplan-Meier survival curves were produced to assess the relationship between the presence of probable scurvy and age-at-death.

RESULTS

The prevalence of probable scurvy in adults (35%) was considerably lower than reported for the nonadults (80%). Almost all lesions observed in the adults were in a mixed stage of healing. Kaplan-Meier analysis demonstrated no difference in survivorship between infants and children (<15 years) with or without probable scurvy, whereas a meaningful difference was observed for the adults and adolescents (15+ years).

CONCLUSIONS

The findings demonstrate that scurvy considerably decreased survivorship to older age categories. The degree of lesion remodeling, however, indicates that scurvy was not necessarily the direct cause of death but contributed to an overall disease burden that was ultimately fatal.

No relationship found between dental fluctuating asymmetry, birthweight, and birth term in two modern North American samples

OBJECTIVE

Deciduous dental crowns primarily develop during gestation and early infancy and embody early life stress exposures. Composite measures of dental fluctuating asymmetry (DFA) generated from the deciduous teeth may therefore indicate cumulative gestational stress in developmental origins of health and disease (DOHaD) studies. This study examines whether higher composite measures of deciduous DFA are associated with low birthweight and prematurity, two aspects of birth phenotype consistently associated with increased morbidity and mortality risks in adulthood.

SUBJECTS AND METHODS

We evaluated associations between composite deciduous DFA, birthweight, and birth term in two contemporary North American samples: an autopsy sample from New Mexico (n = 94), and sample from a growth cohort study in Burlington, Ontario (n = 304). Dental metric data for each sample was collected from postmortem CT scans and dental casts, respectively. Composite DFA was estimated using buccolingual (BL) and mesiodistal (MD) crown diameters from paired deciduous teeth.

RESULTS

Contrary to expectations, the results of linear regression indicated no significant relationship between birthweight and DFA, or birth term and DFA, in either sample.

CONCLUSIONS

Deciduous DFA does not predict aspects of birth phenotype associated with gestational stress. Birthweight and birth term are plastic relative to the more developmentally stable deciduous dentition, which may only subtly embody early life stress. We suggest that deciduous DFA should be utilized with caution in DOHaD studies until its relationship with gestational stress is clarified.

Investigating femoral growth disruption in subadults from the 10th-13th century St. Étienne cemetery of Toulouse, France

OBJECTIVES

The skeleton embodies an individual's environment and lived experiences. Studying childhood growth disruption can, therefore, aid in understanding the experiences of children in the past. This study evaluates growth disruption in a medieval Toulousian subadult sample to explore factors that may have influenced childhood growth and mortality at this site and to assess the utility of Harris line (HL) interpretations in bioarchaeology.

MATERIALS AND METHODS

Femoral growth disruption was assessed in n = 71 subadults (0.125-12.42 years) from the 10th-13th century St. Étienne cemetery of Toulouse, France, using femoral length, total area, cortical area, and relative cortical area. Femoral radiographs were assessed for HLs. To determine the prevalence of growth disruption, z-scores were calculated using data from the Denver growth study.

RESULTS

The majority of subadults in this sample suffered from femoral growth disruption. Young children (1.0-3.99 years) were the most affected, with >65% experiencing reduced appositional growth and linear growth stunting at time-of-death. Additionally, while many individuals presented with observable HLs, linear and appositional growth did not significantly differ between individuals with and without HLs.

DISCUSSION

Maternal malnutrition and inadequate complementary feeding practices likely contributed to the high prevalence of growth disruption among the youngest individuals in the study. The older children and adolescents buried at St. Étienne experienced an amelioration in growth deficits, indicating an improvement in nutrition and/or disease load. The results of this study suggest that more consideration is required when interpreting the presence/absence of HLs, and that studies assessing HLs may benefit from using a more individualistic approach.

Reading children's teeth to reconstruct life history and the evolution of human cooperation and cognition: The role of dental enamel microstructure and chemistry

Studying infants in the past is crucial for understanding the evolution of human life history and the evolution of cooperation, cognition, and communication. An infant's growth, health, and mortality can provide information about the dynamics and structure of a population, their cultural practices, and the adaptive capacity of a community. Skeletal remains provide one way of accessing this information for humans recovered prior to the historical periods. Teeth in particular, are retrospective archives of information that can be accessed through morphological, micromorphological, and biogeochemical methods. This review discusses how the microanatomy and formation of teeth, and particularly enamel, serve as archives of somatic growth, stress, and the environment. Examining their role in the broader context of human evolution, we discuss dental biogeochemistry and emphasize how the incremental growth of tooth microstructure facilitates the reconstruction of temporal data related to health, diet, mobility, and stress in past societies. The review concludes by considering tooth microstructure as a biomarker and the potential clinical applications.

Technical note: Capturing shape-Linear measurements and geometric morphometrics of the immature femora

OBJECTIVES

Growth and developmental studies have been a prominent theme in bioarchaeology. These works traditionally focus on metric measurements of long bone length and age-at-death or cross-sectional geometric studies with the use of computed tomography scans for questions on growth and mobility. However, teasing apart aspects of size and shape have been difficult due to the cylindrical nature of immature long bones. This research investigates the methodological use of surface geometries from linear measurements and geometric morphometric methods (GMM) to answer questions on mobility and allometry during childhood.

MATERIALS AND METHODS

Left femora were selected from 42 individuals ranging from fetal to 12 years of age from medieval St Gregory's Priory, Canterbury, UK. Femora were digitized with structured-light-scanning for auto3dgm analysis and measurements were obtained from physical caliper measurements. Individuals were put into age groups based on biomechanical milestones during this age range.

RESULTS

Ratio and GMM confirm hypotheses of allometry and biomechanical milestones. Geometric morphometrics, however, detects more subtle differences in mobility at each age group.

DISCUSSION

The findings of this preliminary study support the potential use of GMM of immature femora, while indicating that the extent in range of mobility that can occur varies at different biological milestones.

Ageing and disease risk factors: A new paleoepidemiological methodology for understanding disease in the past

OBJECTIVES

To outline a methodology that enables the reconstruction of age-related disease risk in past societies.

MATERIALS

Modern epidemiological evidence considering risk factors for age-related disease is combined with contextual information about an archaeological society of interest.

METHODS

Data gathered is used to create a qualitative population-specific risk model for the disease of interest. To provide a case study, a risk model is constructed for Chronic Obstructive Pulmonary Disease (COPD) in the Eastern English Bronze Age.

RESULTS

This enables the first rigorous approach to reconstructing age-related disease risk in the past. A risk model shows a high degree of COPD risk in the Eastern English Bronze Age, with a major contribution from indoor airborne pollution and agricultural practices.

SIGNIFICANCE

This represents a significant new approach in human paleopathology, facilitating understanding of the occurrence of a wide variety of diseases in the past, without the need for well-preserved skeletons of identified elderly individuals.

LIMITATIONS

The risk models generated are, of necessity, qualitative rather than quantitative, since we are unable to calculate the size of risk factors in the past with certainty.

SUGGESTIONS FOR FURTHER RESEARCH

The methodology could be applied to a wide variety of diseases and for many past societies.

The various meanings and uses of bone "remodeling" in biological anthropology: A review

OBJECTIVES

In modern bone biology, the term "remodeling" generally refers to internal bone turnover that creates secondary osteons. However, it is also widely used by skeletal biologists, including biological anthropologists as a catch-all term to refer to different skeletal changes. In this review, we investigated how "remodeling" is used across topics on skeletal biology in biological anthropology to demonstrate potential problems with such pervasive use of a generalized term.

METHODS

Using PubMed and Google Scholar, we selected and reviewed 205 articles that use the term remodeling to describe skeletal processes and have anthropological implications. Nine edited volumes were also reviewed as examples of collaborative work by different experts to demonstrate the diverse and extensive use of the term remodeling.

RESULTS

Four general meanings of bone "remodeling" were identified, namely, internal turnover, functional adaptation, fracture repair, and growth remodeling. Additionally, remodeling is also used to refer to a broad array of pathological skeletal changes.

DISCUSSION

Although we initially identified four general meanings of bone remodeling, they are not mutually exclusive and often occur in combination. The term "remodeling" has become an extensively used catch-all term to refer to different processes and outcomes of skeletal changes, which inevitably lead to misunderstanding and a loss of information. Such ambiguity and confusion are potentially problematic as the field of biological anthropology becomes increasingly multidisciplinary. Therefore, we advocate for precise, context-specific definitions and explanations of bone remodeling as it continues to be used across disciplines within and beyond biological anthropology.

Comparison of frame index reference percentiles in Argentine and European boys and girls

INTRODUCTION

The frame index (FI), based on measurements of elbow breadth and height, is the body frame size parameter most frequently used in child and adolescent populations to assess skeletal robustness. In 2018, the first FI reference percentiles were elaborated with data of boys and girls aged 0-18 years from different European populations. In Argentina, the FI reference values were published in 2022.

OBJECTIVE

The present study aims to compare the Argentine (AR) and European (EU) FI reference percentiles to evaluate possible variation in bone robustness between populations.

METHODS

The values of the 3rd, 50th and 97th percentiles of the AR and EU FI references for boys and girls aged 4-14 years were compared using the Wilcoxon test (p < .05). Percentage differences between means (PDM) were calculated to analyze the magnitude of the differences between both references. The R 3.2.0 program was used to plot the percentile curves.

RESULTS

The FI reference values were lower in AR than in EU in both the 3rd and the 50th percentiles, regardless of sex and age. Conversely, the AR reference values of the 97th percentile were higher than the EU values at most ages.

CONCLUSIONS

The comparison of the AR and EU FI references showed similar age and sex growth patterns. However, differences in percentile values between populations were observed, highlighting the importance of having local references for the evaluation of skeletal robustness.

Operationalizing the structural vulnerability profile within the medical examiner context

The medicolegal death investigation process in the United States, historically focused on personal identification and determination of cause and manner of death, has evolved in recent decades to include space for advocacy centered around public health. Particularly, in the domain of forensic anthropology, practitioners have begun to incorporate a structural vulnerability perspective on human anatomical variation, with the goals of articulating the social determinants of ill health and early death and ultimately influencing public policy. This perspective has explanatory power far beyond the anthropological sphere. In this piece, we argue that biological and contextual indicators of structural vulnerability can be incorporated into medicolegal reporting with potentially powerful impacts on policy. We apply theoretical frameworks from medical anthropology, public health, and social epidemiology to the context of medical examiner casework, highlighting the recently proposed Structural Vulnerability Profile developed and explored in other articles in this special issue. We argue that: 1. Medicolegal case reporting provides a valuable opportunity to record a faithful accounting of structural inequities in the annals of death investigation, and 2. Existing reporting infrastructure could, with limited modifications, provide a powerful opportunity to inform State and Federal policy with medicolegal data, presented within a structural vulnerability framework.

Beyond dirty teeth: Integrating dental calculus studies with osteoarchaeological parameters

The study of ancient human dental calculus (mineralized dental plaque, also known as tartar) is becoming increasingly important in osteoarchaeology, human palaeoecology and environmental archaeology. Microremains of different origin (e.g. starch granules, pollen, phytoliths, feather barbules) as well as biomolecules and chemical compounds retrieved from its mineral matrix may represent an important link between past humans and their physical, biological and social environment, but they are rarely fully linked to the evidence from skeletal remains. This paper critically reviews the lines of evidence retrieved from dental calculus in relation to osteoarchaeological parameters, employing macroscopic, microscopic and biomolecular approaches, assessing synergy potential and limitations. The scope of this paper is also to contribute to the building of a much needed theoretical framework in this emerging subfield.

Contextualizing bilateral asymmetry and gender: A multivariate approach to femoral cross-sectional geometry at rural Medieval Pieve di Pava, Italy

OBJECTIVES

Our objective was to identify the relationship between biocultural factors of sex-gender and age and patterns of femoral cross-sectional geometry with historical evidence about labor and activity from an archeological skeletal sample excavated from the rural Medieval site Pieve di Pava.

MATERIALS AND METHODS

The study site, Pieve di Pava, was a rural parish cemetery in Tuscany with osteoarcheological remains from the 7th to 12th centuries. Cross-sectional geometric analysis of femora from 110 individuals dated to the 10th-12th centuries were used to examine trends in bone quantity, shape, and bending strength between age and sex groups, as well as in clusters identified through Hierarchical Cluster Analysis (HCA).

RESULTS

Overall, our study sample showed remarkable heterogeneity and our cluster analysis revealed a complex underlying structure, indicating that divisions of labor did not follow a strict gender binary in our sample. We found high levels of bilateral asymmetry in our sample in multiple cross-sectional areas for a significant proportion of the population. We found minimal differences between age groups or sex.

DISCUSSION

Our results suggest that males and females had varied experiences of labor and work during their lives that did not reflect the strict binary gender roles sometimes documented for medieval Europe. One important axis of difference is the direction and magnitude of bilateral asymmetry observed in our femur sample, which is associated with divergent trends in section moduli and bone area measures.

Compounding vulnerabilities: Syndemics and the social determinants of disease in the past

OBJECTIVE

This article explores the theory and utility of a syndemic approach for the study of disease in the past. Syndemic principles are examined alongside other theoretical developments within bioarchaeology. Two case studies are provided to illustrate the efficacy of this approach: Tuberculosis and vitamin D deficiency in 18th and 19th century England, and malaria and helminth infections in Early Medieval England.

MATERIALS

Public health studies of present syndemics, in addition to published bioarchaeological, clinical and social information relating to the chosen case studies.

METHODS

The data from these two historical examples are revisited within a syndemic framework to draw deeper conclusions about disease clustering and heterogeneity in the past.

RESULTS

A syndemic framework can be applied to past contexts using clinical studies of diseases in a modern context and relevant paleopathological, archaeological, and historical data.

CONCLUSIONS

This approach provides a means for providing a deeper, contextualised understanding ancient diseases, and integrates well with extant theoretical tools in bioarchaeology SIGNIFICANCE: Syndemics provides scholars a deep-time perspective on diseases that still impact modern populations.

LIMITATIONS

Many of the variables essential for a truly syndemic approach cannot be obtained from current archaeological, bioarchaeological, or historical methods.

SUGGESTIONS FOR FURTHER RESEARCH

More detailed and in-depth analysis of specific disease clusters within the past and the present, which draws on a comprehensive analysis of the social determinants of health.

Exploring adolescence as a key life history stage in bioarchaeology

Adolescence is a unique period in the life history of an individual. It is characterized by a myriad of changes that bioarchaeologists are only just coming to appreciate, related to sexual maturation, linear growth, immunological transformation, and emotional and cognitive development. New methods allow us to measure this age of transition through the stages of the adolescent growth, as a proxy for the physical development associated with sexual maturation (puberty). This review outlines ways bioarchaeologists may draw on research developments from the fields of human biology, evolutionary theory and neurobiology to advance a more holistic approach to the study of adolescence in the past. It considers current theoretical and analytical approaches to highlight the research potential of this critical stage of life history. This synthesis integrates the most recent research in the medical sciences concerned with body and brain development, and outlines the biological processes involved with sexual and physical maturation of the adolescent. The goal of this review is to help inform potentially rewarding areas of research that bioarchaeologists can contribute to and draw from, as well as the challenges and limitations, theoretical and methodological questions, and ways in which we can develop the study of adolescence in the discipline going forward.

Female bone physiology resilience in a past Polynesian Outlier community

Remodelling is a fundamental biological process involved in the maintenance of bone physiology and function. We know that a range of health and lifestyle factors can impact this process in living and past societies, but there is a notable gap in bone remodelling data for populations from the Pacific Islands. We conducted the first examination of femoral cortical histology in 69 individuals from ca. 440-150 BP Taumako in Solomon Islands, a remote 'Polynesian Outlier' island in Melanesia. We tested whether bone remodelling indicators differed between age groups, and biological sex validated using ancient DNA. Bone vascular canal and osteon size, vascular porosity, and localised osteon densities, corrected by femoral robusticity indices were examined. Females had statistically significantly higher vascular porosities when compared to males, but osteon densities and ratios of canal-osteon (~ 8%) did not differ between the sexes. Our results indicate that, compared to males, localised femoral bone tissue of the Taumako females did not drastically decline with age, contrary to what is often observed in modern populations. However, our results match findings in other archaeological samples-a testament to past female bone physiology resilience, also now observed in the Pacific region.

Missing data in bioarchaeology II: A test of ordinal and continuous data imputation

OBJECTIVES

Previous research has shown that while missing data are common in bioarchaeological studies, they are seldom handled using statistically rigorous methods. The primary objective of this article is to evaluate the ability of imputation to manage missing data and encourage the use of advanced statistical methods in bioarchaeology and paleopathology. An overview of missing data management in biological anthropology is provided, followed by a test of imputation and deletion methods for handling missing data.

MATERIALS AND METHODS

Missing data were simulated on complete datasets of ordinal (n = 287) and continuous (n = 369) bioarchaeological data. Missing values were imputed using five imputation methods (mean, predictive mean matching, random forest, expectation maximization, and stochastic regression) and the success of each at obtaining the parameters of the original dataset compared with pairwise and listwise deletion.

RESULTS

In all instances, listwise deletion was least successful at approximating the original parameters. Imputation of continuous data was more effective than ordinal data. Overall, no one method performed best and the amount of missing data proved a stronger predictor of imputation success.

DISCUSSION

These findings support the use of imputation methods over deletion for handling missing bioarchaeological and paleopathology data, especially when the data are continuous. Whereas deletion methods reduce sample size, imputation maintains sample size, improving statistical power and preventing bias from being introduced into the dataset.

Twenty-first century bioarchaeology: Taking stock and moving forward

This article presents outcomes from a Workshop entitled "Bioarchaeology: Taking Stock and Moving Forward," which was held at Arizona State University (ASU) on March 6-8, 2020. Funded by the National Science Foundation (NSF), the School of Human Evolution and Social Change (ASU), and the Center for Bioarchaeological Research (CBR, ASU), the Workshop's overall goal was to explore reasons why research proposals submitted by bioarchaeologists, both graduate students and established scholars, fared disproportionately poorly within recent NSF Anthropology Program competitions and to offer advice for increasing success. Therefore, this Workshop comprised 43 international scholars and four advanced graduate students with a history of successful grant acquisition, primarily from the United States. Ultimately, we focused on two related aims: (1) best practices for improving research designs and training and (2) evaluating topics of contemporary significance that reverberate through history and beyond as promising trajectories for bioarchaeological research. Among the former were contextual grounding, research question/hypothesis generation, statistical procedures appropriate for small samples and mixed qualitative/quantitative data, the salience of Bayesian methods, and training program content. Topical foci included ethics, social inequality, identity (including intersectionality), climate change, migration, violence, epidemic disease, adaptability/plasticity, the osteological paradox, and the developmental origins of health and disease. Given the profound changes required globally to address decolonization in the 21st century, this concern also entered many formal and informal discussions.

Exploring physical activity in Central Chile during the Early Ceramic Period and Late Intermediate Period (200-1450 CE)

OBJECTIVES

We explore physical activity in early farming societies of Central Chile during the Early Ceramic and Late Intermediate Periods (200-1450 CE), a time of technological changes and intensification of food production. The existence of differences in entheseal changes (EC) between females and males is evaluated in two periods with different subsistence strategies.

MATERIAL AND METHODS

EC were recorded with method in the upper and lower limbs of 56 male and female adult individuals from the Early Ceramic Period (ECP) and Late Intermediate Period (LIP). Hierarchical multiple factor analysis and hierarchical clustering on principal components were performed using an exploratory approach.

RESULTS

In all the analyzed limbs, the EC scores are higher in males than females, which may be explained by sexual dimorphism. A constant overlap in the variability of the EC among males and females is observed. However, the EC scores show a different pattern of variability when comparing ECP females with LIP females. The results show that the scores increase in the latter. In contrast, when comparing ECP males with LIP males scores decrease in the later period.

DISCUSSION

Physical activity in the societies of Central Chile with incipient agriculture did not vary by sex or during the timeframe studied. Nevertheless, the interaction between sex-period and the variability pattern of the EC from one period to another suggests different ways of doing similar physical activities or different emphases for similar biomechanical actions.

Sex-Based Differences in Age-Related Changes of the Vertebral Column from a Bronze Age Urban Population in Ancient China

The health disparities between males and females in bioarchaeological settings are important indicators of gender-based differences in socioeconomic roles. In this study, sex-based differences of the vertebral column in spine pathology were investigated in human skeletons excavated from a Bronze Age cemetery of the Western Zhou Dynasty at the Dahekou site in Shanxi, China. Results demonstrated that females had a higher prevalence of vertebral compressive fractures, with the majority found in those between twenty-five and thirty years old, suggesting that the fractures were a consequence of osteoporosis and its early onset in females. In contrast, males expressed overall more severe ageing in all vertebral divisions compared to females. Males also had a higher prevalence of vertebral facet joint osteoarthritis in cervical and thoracic divisions than females. Likewise, the incidence of facet joint osteoarthritis was more asymmetric between the left and right joints in males than in females. These findings reflect disparities of vertebral health between the two sexes in an urban setting, in which ageing and injuries of the vertebral column might be driven by different mechanisms. Age-related changes in female vertebral columns may have been more influenced by conditions of hormone deficiency such as menopause, while male vertebral columns might have been more prone to age-related changes due to heavy labor-induced physical stressors. Further studies on the differentiation of ageing mechanisms between the two sexes based on physiology, socioeconomic roles, and living conditions are warranted. The studies are necessary in understanding how multiple sociocultural and physiological factors contribute to health disparities in historic and contemporary environments.

Interpreting error in the estimation of skeletal growth profiles from past populations: An example demonstrating skeletal growth in historic African American communities

OBJECTIVES

The study of growth in the past is a critical component of bioarcheological analyses. However, our understanding of growth in the past is subject to a number of methodological challenges. This study aims to model the skeletal growth of past populations by considering the challenges associated with the data collection process and the challenges associated with the age estimation procedures.

MATERIALS AND METHODS

We use skeletal remains from two historic African American cemeteries in the American South to model femoral diaphyseal length-for-age. We estimate the age of each individual using dental development techniques and present growth curves as both a product of the maximum likelihood (MLE) age estimate and the estimated posterior age distribution. Growth was compared against a reference sample from the University of Colorado Child Research Council Study.

RESULTS

The results of our analyses showed that femoral diaphyseal length in two historic African American communities is small-for-estimated age as compared to a modern reference sample. However, the magnitude and characterization of this difference is variable when taking into account the broader posterior age distribution.

DISCUSSION

Both samples may be small-for-age due to physiological stress associated with racism, inequality, and the compounding effects of early urbanization. However, the interpretation of growth in the past is muddled when considering the relationship between the study sample and the reference sample, when accounting for uncertainty in the age estimation procedure, and the error-inducing steps taken during the data collection process. Future interpretation of skeletal growth in the past must include a full account of the possible sources of error in order to present an accurate representation of growth.

Height and health in Roman and Post-Roman Gaul, a life course approach

OBJECTIVE

The present study explores growth and health in Roman (1st-3rd centuries CE) and Post-Roman (4th-7th centuries CE) Gaul, incorporating a life-course approach, to better understand the influence of Roman practices and lifestyles on health, and the impact of cultural change from the Roman to the Post-Roman period.

MATERIALS AND METHODS

The skeletal remains of 844 individuals were analyzed for non-specific signs of physiological stress, including growth disruption (diaphyseal and adult maximum femur length), dental enamel hypoplastic defects (DEH), cribra orbitalia (CO), and periosteal reaction of the tibiae (Tibia PR).

RESULTS

The Gallo-Roman sample demonstrated shorter femoral lengths, and higher rates of DEH and Tibia PR. Post-Roman groups demonstrated longer femoral lengths and higher rates of CO.

CONCLUSIONS

Gallo-Roman individuals may have been more regularly exposed to infectious pathogens throughout childhood, inhibiting opportunities for catch-up growth, resulting in high rates of DEH and shorter femoral lengths ('intermittent stress of low lethality'). This could be the result of overcrowding and insalubrious urban environments. Higher rates of CO in the Post-Roman samples may have been influenced by dietary changes between the periods.

SIGNIFICANCE

The intertwined and often synergistic relationships between early life environment, nutrition and settlement structure is highlighted, helping to further understandings of life experiences during the Roman and Post-Roman periods.

LIMITATIONS

It was not possible to obtain sufficient data from northern regions during the Gallo-Roman period, limiting this analysis.

SUGGESTIONS FOR FURTHER RESEARCH

Further application of life course approaches can reveal subtle patterns in stress indicators.

What is normal bone health? A bioarchaeological perspective on meaningful measures and interpretations of bone strength, loss, and aging

Bioarchaeological (the study of archeological human remains together with contextual and documentary evidence) offers a unique vantage point to examine variation in skeletal morphology related to influences such as activity, disease, and nutrition. The human skeleton is composed of a dynamic tissue that is forged by biocultural factors over the entire life course, providing a record of individual, and community history. Various aspects of adult bone health, particularly bone maintenance and loss and the associated skeletal disease osteoporosis, have been examined in numerous past populations. The anthropological study of bone loss has traditionally focused on the signature of postmenopausal aging, costs of reproduction, and fragility in females. The a priori expectation of normative sex-related bone loss/fragility in bioanthropological studies illustrates the wider gender-ideological bias that continues in research design and data analysis in the field. Contextualized data on bone maintenance and aging in the archeological record show that patterns of bone loss do not constitute predictable consequences of aging or biological sex. Instead, the critical examination of bioarchaeological data highlights the complex and changing processes that craft the human body over the life course, and calls for us to question the ideal or "normal" range of bone quantity and quality in the human skeleton, and to critically reflect on what measures are actually biologically and/or socially meaningful.

Examining developmental plasticity in the skeletal system through a sensitive developmental windows framework

Developmental plasticity facilitates energetically costly but potentially fitness-enhancing adjustments to phenotypic trajectories in response to environmental stressors, and thus may significantly impact patterns of growth, morbidity, and mortality over the life course. Ongoing research into epigenetics and developmental biology indicate that the timing of stress exposures is a key factor when assessing their impact on developmental processes. Specifically, stress experienced within sensitive developmental windows (SDWs), discrete developmental periods characterized by heightened energy requirements and rapid growth, may alter the pace and tempo of growth in ways that significantly influence phenotypic development over both the short and long term. In human skeletal biology, efforts to assess how developmental environments shape health outcomes over the life course could be enhanced by incorporating the SDW concept into existing methodological approaches. The goal of this article is to outline an interpretive framework for identifying and interpreting evidence of developmental stress in the skeletal system using the SDW concept. This framework provides guidance for the identification of elements most likely to capture evidence of stress most relevant to a study's core research questions, the interpretation of developmental stress exhibited by those elements, and the relationship of skeletal indicators of stress to the demographic patterning of morbidity and mortality. Use of the SDW concept in skeletal biology has the potential to enrich traditional approaches to addressing developmental origins of health and disease hypotheses, by targeting periods in which individuals are most susceptible to stress and thus most likely to exhibit plasticity in response.

Using a multimethod life history approach to navigate the osteological paradox: A case study from Prehispanic Nasca, Peru

OBJECTIVES

We leverage recent bioarchaeological approaches and life history theory to address the implications of the osteological paradox in a study population. The goal of this article is to evaluate morbidity and mortality patterns as well as variability in the risk of disease and death during the Late Intermediate period (LIP; 950-1450 C.E.) in the Nasca highlands of Peru. We demonstrate how the concurrent use of multiple analytical techniques and life history theory can engage the osteological paradox and provide salient insights into the study of stress, frailty, and resilience in past populations.

MATERIALS AND METHODS

Crania from LIP burial contexts in the Nasca highlands were examined for cribra orbitalia (n = 325) and porotic hyperostosis (n = 270). All age groups and both sexes are represented in the sample. Survivor/nonsurvivor analysis assessed demographic differences in lesion frequency and severity. Hazard models were generated to assess differences in survivorship. The relationship between dietary diversity and heterogeneity in morbidity was assessed using stable δ¹⁵ N and δ¹³ C isotope values for bone collagen and carbonate. One hundred and twenty-four crania were directly AMS radiocarbon dated, allowing for a diachronic analysis of morbidity and mortality.

RESULTS

The frequency and expression of both orbital and vault lesions increases significantly during the LIP. Survivor/nonsurvivor analysis indicates cranial lesions co-vary with frailty rather than robusticity or longevity. Hazard models show (1) decreasing survivorship with the transition into the LIP, (2) significantly lower adult life expectancy for females compared to males, and (3) individuals with cranial lesions have lower survivorship across the life course. Stable isotope results show very little dietary diversity. Mortality risk and frequency of pathological skeletal lesions were highest during Phase III (1300-1450 C.E.) of the LIP.

CONCLUSION

Results provide compelling evidence of increasing physiological stress and mortality in the Nasca highlands during the LIP, but also reveal substantial heterogeneity in frailty and the risk of death. Certain members of society experienced a heavier disease burden and higher mortality compared to their contemporaries. Elevated levels of disease and lethal trauma among females account for some of the sex differences in survivorship but cannot explain the large degree of female-biased mortality. We hypothesize that parental investment in males or increased female fertility rates may explain these differences.

Quantifying cortical bone in fragmentary archeological second metacarpals

OBJECTIVES

Skeletal variation in cortical bone thickness is an indicator of bone quality and health in archeological populations. Second metacarpal radiogrammetry, which measures cortical thickness at the shaft midpoint, is traditionally used to evaluate bone loss in bioarcheological and some clinical contexts. However fragmentary elements are regularly omitted because the midpoint cannot be determined. This methodological limitation reduces sample sizes and biases them against individuals prone to fracture, such as older individuals with low bone mass. This study introduces a new technique for measuring cortical bone in second metacarpals, the "Region of Interest" (ROI) method, which quantifies bone in archeological remains with less-than-ideal preservation while accounting for cortical heterogeneity.

MATERIALS AND METHODS

The ROI method was adapted from digital X-ray radiogrammetry (DXR), a clinical method used to estimate bone mineral density, and tested using second metacarpals from Middenbeemster, Netherlands, a 19th century known age and sex skeletal collection. The ROI method quantifies cortical bone area within a 1.9 cm-long, mid-diaphyseal region, standardized for body size differences using total area (CAI_ROI ). CAI_ROI values were compared to traditional radiogrammetric cortical indices (CI) to assess the method's ability to identify age-related bone loss.

RESULTS

CAI_ROI values have high intra- and interobserver replicability and are strongly and significantly correlated with CI values for both males (r[n = 39] = 0.906, p = 0.000) and females (r[n = 58] = 0.925, p = 0.000).

CONCLUSION

The ROI method complements traditional radiogrammetry analyses and provides a reliable way to quantify cortical bone in incomplete second metacarpals, thereby maximizing sample sizes, allowing patterns in bone acquisition and loss to be more comprehensively depicted in archeological assemblages.

Intersectionality and trauma analysis in bioarchaeology

Intersectionality, the theory named by Kimberlé Crenshaw, outlines how multiple elements of an individual's social identity overlap to create and preserve societal inequalities and discrimination. Recently bioarchaeology's engagement with intersectionality has become increasingly explicit, as the field recognizes the lived experience of multiple axes of an individual's identity. Evidence of trauma can remain observable in an individual's skeleton for years, making it an ideal subject of study for intersectional analyses in bioarchaeology. Using contrasting case studies of two individuals who died in hospitals and were unclaimed after death, we explore the theoretical and methodological application of intersectionality to investigations of accidental and interpersonal trauma. Differences in identities and structural inequalities affect bone quality and health outcomes. As we demonstrate, a broken bone is the intersecting result of biological, histomorphological, sociocultural, and behavioral factors. This approach allows for a better acknowledgement of the inherent complexity of past lives, elevating and amplifying previously silenced voices. In this way, intersectionality in bioarchaeology demands social justice.

The elusive parasite: comparing macroscopic, immunological, and genomic approaches to identifying malaria in human skeletal remains from Sayala, Egypt (third to sixth centuries AD)

Although malaria is one of the oldest and most widely distributed diseases affecting humans, identifying and characterizing its presence in ancient human remains continue to challenge researchers. We attempted to establish a reliable approach to detecting malaria in human skeletons using multiple avenues of analysis: macroscopic observations, rapid diagnostic tests, and shotgun-capture sequencing techniques, to identify pathological changes, Plasmodium antigens, and Plasmodium DNA, respectively. Bone and tooth samples from ten individuals who displayed skeletal lesions associated with anaemia, from a site in southern Egypt (third to sixth centuries AD), were selected. Plasmodium antigens were detected in five of the ten bone samples, and traces of Plasmodium aDNA were detected in six of the twenty bone and tooth samples. There was relatively good synchronicity between the biomolecular findings, despite not being able to authenticate the results. This study highlights the complexity and limitations in the conclusive identification of the Plasmodium parasite in ancient human skeletons. Limitations regarding antigen and aDNA preservation and the importance of sample selection are at the forefront of the search for malaria in the past. We confirm that, currently, palaeopathological changes such as cribra orbitalia are not enough to be certain of the presence of malaria. While biomolecular methods are likely the best chance for conclusive identification, we were unable to obtain results which correspond to the current authentication criteria of biomolecules. This study represents an important contribution in the refinement of biomolecular techniques used; also, it raises new insight regarding the consistency of combining several approaches in the identification of malaria in past populations.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12520-021-01350-z.

Paleodemographic analysis of age at death for a population of Black Sea Scythians: An exploration by using Bayesian methods

OBJECTIVES

Studies of the demography of past populations involving deterministic life tables can be criticized for ignoring the errors of estimation. Bayesian methods offer an alternative, by focusing on the uncertainty of the estimates, although their results are often sensitive to the choice of prior distributions. The aim of this study is to explore a range of Bayesian methods for estimating age at death for a population of nomadic warriors-Scythians from the Black Sea region.

MATERIALS AND METHODS

In total, skeletons of 312 individuals (93 children and 219 adults) from Glinoe (Moldova), dated to the 5th-2nd century BCE, were examined. We unified the age categories corresponding to different aging methods, allowing an application of a probabilistic assessment of the age categorization. A hierarchical Bayesian multinomial-Dirichlet-Dirichlet model was applied, with a hypothetical, subjective reference population, a real reference population, and no reference.

RESULTS

Stationary-population life expectancy was estimated as 27.7 years (95% CI: 25.1-30.3) for a newborn (e₀ ), and 16.4 years (14.0-19.0) for 20-year-olds (e₂₀ ), although with high uncertainty, and sensitive to the model specification. Slight differences in longevity between different social strata and between the Classical and Late chronological periods were found, although with high estimation errors. A more robust finding, confirming earlier studies, was a high probability of death in young adulthood, which could depend on Scythian lifestyle (conflicts, wars).

DISCUSSION

Our study shows a way to overcome some limitations of broad age categorization by using the Bayesian approach with alternative model specifications, allowing to assess the impact of reference populations.

Influence of climatic stress on nonmetric sexually dimorphic features of the skull and pelvis

OBJECTIVES

Human sexual dimorphism is frequently assessed through skull and pelvic size and shape. Researchers suggest that climatic variation and the associated stress may be significant factors in sexual dimorphism's etiology. However, little research has specifically investigated climatic effects on nonmetric skeletal indicators of sex. To further appreciate the plasticity of human biology, a comparative study of standard skull and pelvic nonmetric sex indicators is presented.

METHODS

A Native Alaskan archeological sample (n = 104) and a component of the Terry collection (n = 99) represent populations originating from different climatic environments in recent history. These sex-balanced groups are compared through Tukey-Kramer's method and Greene's t-test to determine any variation in degree of sexual dimorphism within and between samples.

RESULTS

The results reinforce the complex and multifaceted relationship between climate and sexual dimorphism. The Terry sample demonstrated a greater degree of sexual dimorphism with statistically significant differences in robusticity of the mastoid process and nuchal crest compared with the Native Alaskans. A more "male" morphotype and reduced dimorphism are appreciated in the pelves of Native Alaskans than the Terry sample.

CONCLUSIONS

This research highlights a reduction in sexual dimorphism in populations under greater climatic stress and contributes to the production of more accurate skeletal assessments in future investigations. Discussion of confounding factors suggest more research is necessary to untangle climate and human morphology's complex relationship. This study contributes to a greater appreciation of human biological plasticity, ecogeographic variation, and the evolution of modern human diversity.

Biocultural pathways linking periodontal disease expression to food insecurity, immune dysregulation, and nutrition

OBJECTIVES

In this article, we test theoretical pathways leading to and resulting from periodontal disease to better understand how periodontal disease, which is measurable in both past and present populations, integrates biocultural context and affects whole-body physiology.

METHODS

We use data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and logistic and linear regressions to test pathways linking psychosocial stress to periodontal disease, and periodontal disease to serum vitamin C levels. We then use causal mediation analysis to test the role of mediating variables in these pathways (n = 1853 individuals).

RESULTS

Food insecurity was positively associated with periodontal disease and negatively associated with serum counts of C-reactive protein (CRP) and neutrophils. Neither CRP nor neutrophils significantly mediated the relationship between food insecurity and periodontal disease. Periodontal disease was negatively associated with serum vitamin C levels and positively associated with neutrophil counts. Neutrophils may mediate the relationship between periodontal disease and vitamin C.

CONCLUSIONS

We identify two main findings: (a) periodontal disease contributes to and may result from immune dysregulation, particularly of neutrophils, and (b) an immune response to chronic infection such as periodontal disease is metabolically expensive for the body to maintain and likely depletes serum micronutrient levels. Both micronutrient status and serum neutrophil counts affect multiple skeletal and physiological phenotypes and thus position periodontal disease in whole-body context.

A comparison of subadult skeletal and dental development based on living and deceased samples

OBJECTIVES

A fundamental assumption in biological anthropology is that living individuals will present with different growth than non-survivors of the same population. The aim is to address the question of whether growth and development data of non-survivors are reflective of the biological consequences of selective mortality and/or stress.

MATERIALS AND METHODS

The study compares dental development and skeletal growth collected from radiographic images of contemporary samples of living and deceased individuals from the United States (birth to 20 years) and South Africa (birth to 12 years). Further evaluation of deceased individuals is used to explore differential patterns among manners of death (MOD).

RESULTS

Results do not show any significant differences in skeletal growth or dental development between living and deceased individuals. However, in the South African deceased sample the youngest individuals exhibited substantially smaller diaphyseal lengths than the living sample, but by 2 years of age the differences were negligible. In the US sample, neither significant nor substantial differences were found in dental development or diaphyseal length according to MOD and age (>2 years of age), though some long bones in individuals <2 years of age did show significant differences. No significant differences were noted in diaphyseal length according to MOD and age in the SA sample.

DISCUSSION

The current findings refute the idea that contemporary deceased and living individuals would present with differential growth and development patterns through all of ontogeny as well as the assumptions linking short stature, poor environments, and MOD.

An integrative approach to studying plasticity in growth disruption and outcomes: A bioarchaeological case study of Napoleonic soldiers

OBJECTIVES

The aim of this study was to investigate how much variation in adult stature and body mass can be explained by growth disruption among soldiers who served in Napoleon's Grand Army during the Russian Campaign of 1812.

METHODS

Linear enamel hypoplasia (LEH) were recorded as representations of early life growth disruption, while the impact on future growth was assessed using maximum femur length (n = 73) as a proxy for stature and maximum femoral head diameter (n = 25) as a proxy for body mass. LEH frequency, severity, age at first formation, and age at last formation served as explanatory variables in a multiple regression analysis to test the effect of these variables on maximum femur length and maximum femoral head diameter.

RESULTS

The multiple regression model produced statistically significant results for maximum femur length (F-statistic = 3.05, df = 5 and 67, P = .02), with some variation in stature (adjusted r² = 0.13) attributable to variation in growth disruption. The multiple regression model for maximum femoral head diameter was not statistically significant (F-statistic = 1.87, df = 5 and 19, P = .15).

CONCLUSIONS

We hypothesized stress events during early life growth and development would have significant, negative, and cumulative effects on growth outcomes in adulthood. The results did not support our hypothesis. Instead, some variables and interactions had negative effects on stature, whereas others had positive effects. This is likely due to catch-up growth, the relationship between acute and chronic stress and growth, resilience, and plasticity in human growth over the life course.

"The dead shall be raised": Multidisciplinary analysis of human skeletons reveals complexity in 19th century immigrant socioeconomic history and identity in New Haven, Connecticut

In July 2011, renovations to Yale-New Haven Hospital inadvertently exposed the cemetery of Christ Church, New Haven, Connecticut's first Catholic cemetery. While this cemetery was active between 1833 and 1851, both the church and its cemetery disappeared from public records, making the discovery serendipitous. Four relatively well-preserved adult skeletons were recovered with few artifacts. All four individuals show indicators of manual labor, health and disease stressors, and dental health issues. Two show indicators of trauma, with the possibility of judicial hanging in one individual. Musculoskeletal markings are consistent with physical stress, and two individuals have arthritic indicators of repetitive movement/specialized activities. Radiographic analyses show osteopenia, healed trauma, and other pathologies in several individuals. Dental calculus analysis did not identify any tuberculosis indicators, despite osteological markers. Isotopic analyses of teeth indicate that all four were likely recent immigrants to the Northeastern United States. Nuclear and mitochondrial DNA were recovered from three individuals, and these analyses identified ancestry, hair/eye color, and relatedness. Genetic and isotopic results upended our initial ancestry assessment based on burial context alone. These individuals provide biocultural evidence of New Haven's Industrial Revolution and the plasticity of ethnic and religious identity in the immigrant experience. Their recovery and the multifaceted analyses described here illuminate a previously undescribed part of the city's rich history. The collective expertise of biological, geochemical, archaeological, and historical researchers interprets socioeconomic and cultural identity better than any one could alone. Our combined efforts changed our initial assumptions of a poor urban Catholic cemetery's membership, and provide a template for future discoveries and analyses.

Beyond Individual Lives: Using Comparative Osteobiography to Trace Social Patterns in Classical Italy

Osteobiographical studies have usually focused upon investigating an individual's life experience. However, we can also understand variation in the shape of the life course itself as an object of study: Are there common patterns for how lives unfold within a society? Are there events or experiences that channel life courses? This approach to the life course can be adopted for ancient as well as for modern lives. A key element here is developing new methodologies for characterizing and comparing how lives develop through time, for instance, by ordering biological data in sequence, looking for time-structured patterns in them both by eye and through multivariate statistics. This article presents an initial exploration of this problem, using skeletal and archaeological data on 47 adults from the fifth to third centuries B.C. at Pontecagnano, an urban site in Campania, Italy. The results show both the importance of gender in the life course and the effects of different kinds of physical stress, probably due to specialization in labor. The result is not discrete categories of people but fuzzy envelopes of life possibilities.

Osteobiography: A Platform for Bioarchaeological Research

Osteobiography provides a rich basis for understanding the past, but its conceptual framework has not been outlined systematically. It stands in conceptual opposition to a traditional statistical approach to bioarchaeology modeled upon clinical studies in biomedicine, but is interdependent with it. As such, its position mirrors those of clinical case histories as opposed to statistical studies, participant-observation ethnography as opposed to quantitative sociology, and microhistory and biography as opposed to quantitative history. Such disciplinary comparisons provide a framework for exploring the strengths and weaknesses of osteobiography. It is not merely a tool for engagingly illustrating the "typical" life history as established statistically. Rather, it allows us to understand issues that population studies cannot explore. These include both analytical directions (exploring the complexity of deeply layered data, understanding the role of contingency in human lives, integrating osteological and cultural evidence) and philosophical directions (the interaction of material and conceptual factors in the creation of human bodies, embodiment, the experience of time).

Foot binding in a Ming dynasty cemetery near Xi'an, China

This paper describes the morphology of the feet of a population of elite women from the Ming dynasty (1368-1644 CE) in Shaanxi province. This is a social stratum, time, and place in which foot binding was practiced. Among a group of 31 skeletons exhumed from the cemetery, eight were women with well-preserved foot bones. Macroscopic examination revealed that half these women (4/8) had clearly altered foot bones: the metatarsal bones, and the few observable phalanges, were gracile and small, while the tarsal bones exhibited a slight reduction in size but no dramatic change in morphology. The other half of the women (4/8) had apparently unmodified metatarsal bones. T-tests comparing linear measurements of the foot bones between the two groups revealed that metatarsal bones were the most affected by binding, and among the tarsal bones, the talar trochlea and calcaneal dimensions were most impacted. This small group of skeletons reveals that some elite women in Shaanxi apparently still did not practice foot binding in the late Ming dynasty, or practiced a much milder form of foot binding, and that there was considerable variation even among those who did practice it.

Vitamin D's role in health and disease: How does the present inform our understanding of the past?

While the role of vitamin D in supporting bone homeostasis during growth and maintenance is well substantiated, emerging evidence from ecological and observational studies suggests that a deficiency of vitamin D is associated with some cancers, immune disorders, cardiovascular disease, abnormal glucose metabolism, and neurodegenerative diseases. Biological plausibility for extraskeletal functions originated with the discovery of the vitamin D receptor in many body tissues and knowledge that the conversion of 25-hydroxyvitamin D (25(OH)D) to its active metabolite 1,25(OH)₂D occurs in many cell types in addition to the kidney. The association of vitamin D status in humans as an etiological factor in developmental programming of bone, in some chronic diseases, and in all-cause mortality, in addition to skeletal morbidity, is supported by some but not all observational studies and randomized controlled trials. These clinical observations have implications for paleopathology, both in terms of specific comorbidities and the potential role of vitamin D in individuals who display no evidence for skeletal disease. This paper outlines recent clinical research on vitamin D metabolism and its novel biological roles, and explores the possible relevance to paleopathological research designs, theoretical models, and interpretations of disease experience.

Developmental stability and environmental stress: A geometric morphometrics analysis of asymmetry in the human femur

OBJECTIVES

The evaluation of developmental stability (DS) by measuring fluctuating asymmetry (FA), a bioindicator of general cumulative stress, is an approach that has often been used to characterize health status in past populations. New techniques of geometric morphometrics now enable a better appreciation of FA than before, with a more refined quantification of variation. The aim of our study is to determine the effectiveness of geometric morphometrics analyses of asymmetry in the human femur for the study of individual DS and inferring health status of human populations.

MATERIALS AND METHODS

We conducted a comparative analysis between two diachronic populations of distinct and known health status. Two samples of 70 pairs of adult femurs from individuals of comparable age range and sex were selected and CT-scanned. For each 3D reconstruction, two sets of 27 landmarks were digitized to quantify and minimize the effect of measurement error on the evaluation of FA.

RESULTS

While the measurement of FA in femoral centroid size seemed comparable between the samples, the amount of FA in femoral shape differed. Individuals who experienced high levels of environmental stress presented higher intra-individual variation. In parallel, results did not reveal any significant differences in DS between sexes or age groups.

DISCUSSION

The geometric morphometrics analysis of femoral asymmetry was effective for distinguishing two populations. After considering various factors of influence, genetics and biomechanics seem to have a limited impact on the results. Expressing FA appears to be normal but dependent on the disturbances of DS produced by environmental stress.

Can early-life growth disruptions predict longevity? Testing the association between vertebral neural canal (VNC) size and age-at-death

This study tests the association of vertebral neural canal (VNC) size and age-at-death in a Portuguese skeletal collection from the 19^th-20th century. If the plasticity and constraint model best explains this association, VNC size would be negatively related to mortality risk. If the predictive adaptive response (PAR) model is a better fit, no association can be inferred between VNC size and age-at-death. Ninety individuals were used in this study. The anteroposterior and transverse diameters of all vertebrae were measured. A Cox regression analysis was performed by sex to assess the effect of VNC size on age-at-death, after adjusting for the effects of year of birth and cause of death. Several measurements of VNC diameters have a statistically significant effect on age-at-death, but when the covariates were considered, this association became non-significant. The PAR model seems the best fit to explain the relation between VNC and age-at-death. Individuals who went through stressful events early in life were prepared to face a stressful environment later in life, allowing them to cope with adversity without affecting longevity. However, developmental plasticity may be buffered by maternal capital accumulated over several generations, and health hazards encountered throughout life can contribute to health outcomes and longevity.

The role of infant life histories in the construction of identities in death: An incremental isotope study of dietary and physiological status among children afforded differential burial

OBJECTIVES

Isotope ratio analyses of dentine collagen were used to characterize short-term changes in physiological status (both dietary status and biological stress) across the life course of children afforded special funerary treatment.

MATERIALS AND METHODS

Temporal sequences of δ¹⁵ N and δ¹³ C isotope profiles for incrementally forming dentine collagen were obtained from deciduous teeth of 86 children from four early-medieval English cemeteries. Thirty-one were interred in child-specific burial clusters, and the remainder alongside adults in other areas of the cemetery. Isotope profiles were categorized into four distinct patterns of dietary and health status between the final prenatal months and death.

RESULTS

Isotope profiles from individuals from the burial clusters were significantly less likely to reflect weaning curves, suggesting distinctive breastfeeding and weaning experiences. This relationship was not simply a factor of differential age at death between cohorts. There was no association of burial location neither with stage of weaning at death, nor with isotopic evidence of physiological stress at the end of life.

DISCUSSION

This study is the first to identify a relationship between the extent of breastfeeding and the provision of child-specific funerary rites. Limited breastfeeding may indicate the mother had died during or soon after birth, or that either mother or child was unable to feed due to illness. Children who were not breastfed will have experienced a significantly higher risk of malnutrition, undernutrition and infection. These sickly and perhaps motherless children received care to nourish them during early life, and were similarly provided with special treatment in death.

An association between adult lifespan and stature in preindustrial Lithuanian populations: Analysis of skeletons

The aim of this study was to test the null hypothesis that no relationship between maximal living stature and adult lifespan had existed in prehistoric and historic Lithuanian populations. The sample analyzed consisted of 1713 skeletons of adult individuals who died between the 2nd century CE and the beginning of the 19th century CE, collected from 118 archaeological sites located in the current territory of Lithuania. A cumulative logit model was applied to model ordinal age-related changes in the auricular surface and the pubic symphysis (measures of lifespan) as a function of maximal length of femur (an indicator of maximal living stature), sex, burial site and its chronology as a proxy for the place of residence and period. The lack of strong association between adult lifespan and femur length was observed for males and females, various periods and places of residence. However, the results failed to reject convincingly the hypothesis that no relationship between these two variables had existed in preindustrial Lithuanian populations. In addition to concerns regarding sampling and measurement errors, heterogeneous frailty in early life and resulting selective mortality may partly explain the results obtained.