Human Skeletal Samples Research Articles

Familial hypodontia in bronze age Northwest China (1046–771BC)

ObjectiveThis research aimed to report hypodontia cases in a Middle Bronze Age high-tier cemetery in China and test the possible hereditary behind hypodontia by performing kinship tests on those individuals. DesignIn this study, dental anomalies were observed on a human skeletal sample (n = 45) uncovered from Yaoheyuan, China. Ancient DNA analysis was subsequently employed on a subsample of the Yaoheyuan individuals (n = 15), including individuals observed hypodontia and individuals randomly sampled from the cemetery for preliminary investigation on the cemetery demography. Kinship estimation tests (READ, TKGWV2, KIN, and F3 test) were subsequently employed. ResultsThe Yaoheyuan elite population had a prevalence (n = 7, 15 %) of tooth agenesis in either the maxilla or mandible, with one to two teeth missing. All missing teeth were incisors, except for one individual missing maxillary second molar. Preliminary ancient DNA results indicate that several kinship groups existed among interred individuals, including those with hypodontia, indicating the hereditary origin of these cases. ConclusionsThe prevalence of hypodontia observed on site is high compared to that in both modern East Asian populations and archaeological samples in the Chinese population. The preliminary kinship analysis suggests a case of familial hypodontia. Ancient DNA analysis should be thoroughly conducted in future studies to understand the genetic markers contributing to those hypodontia cases among the Yaoheyuan individuals.

3D Mitochondrial Structure in Aging Human Skeletal Muscle: Insights into MFN-2 Mediated Changes.

Age-related atrophy of skeletal muscle, is characterized by loss of mass, strength, endurance, and oxidative capacity during aging. Notably, bioenergetics and protein turnover studies have shown that mitochondria mediate this decline in function. Although exercise has been the only therapy to mitigate sarcopenia, the mechanisms that govern how exercise serves to promote healthy muscle aging are unclear. Mitochondrial aging is associated with decreased mitochondrial capacity, so we sought to investigate how aging affects mitochondrial structure and potential age-related regulators. Specifically, the three-dimensional (3D) mitochondrial structure associated with morphological changes in skeletal muscle during aging requires further elucidation. We hypothesized that aging causes structural remodeling of mitochondrial 3D architecture representative of dysfunction, and this effect is mitigated by exercise. We used serial block-face scanning electron microscopy to image human skeletal tissue samples, followed by manual contour tracing using Amira software for 3D reconstruction and subsequent analysis of mitochondria. We then applied a rigorous in vitro and in vivo exercise regimen during aging. Across 5 human cohorts, we correlate differences in magnetic resonance imaging, mitochondria 3D structure, exercise parameters, and plasma immune markers between young (under 50 years) and old (over 50 years) individuals. We found that mitochondria we less spherical and more complex, indicating age-related declines in contact site capacity. Additionally, aged samples showed a larger volume phenotype in both female and male humans, indicating potential mitochondrial swelling. Concomitantly, muscle area, exercise capacity, and mitochondrial dynamic proteins showed age-related losses. Exercise stimulation restored mitofusin 2 (MFN2), one such of these mitochondrial dynamic proteins, which we show is required for the integrity of mitochondrial structure. Furthermore, we show that this pathway is evolutionarily conserved as Marf, the MFN2 ortholog in Drosophila, knockdown alters mitochondrial morphology and leads to the downregulation of genes regulating mitochondrial processes. Our results define age-related structural changes in mitochondria and further suggest that exercise may mitigate age-related structural decline through modulation of mitofusin 2.

Examining evidence for violence at the end of the Assyrian trading colonies period at Kaman‐Kalehöyük

AbstractThe end of the Assyrian Trading Colonies Period (ATCP) in Anatolia represents a time of significant change in the region. Historical and archaeological evidence suggests that considerable conflict and turmoil were associated with the end of the ATCP, but thus far little evidence from human skeletal remains has been available to support this hypothesis. One of the largest human skeletal samples dating to the end of the ATCP has been excavated at Kaman‐Kalehöyük in central Anatolia. A minimum of 73 individuals have been found in and around areas of the site that have signs of destruction and burning. These individuals appear to be associated with a battle that occurred in the town in the mid‐18th century BCE. The results show that the victims of the battle included individuals of all age groups and both sexes. The degree of burning and fragmentation made the identification of perimortem trauma challenging; however, perimortem trauma was observed in at least two individuals. An additional five individuals had evidence of antemortem trauma that was likely the result of interpersonal violence prior to the attack on the town. The skeletal evidence for trauma further supports the idea that a battle occurred at the site. This battle may have also been a part of a regional pattern of violence corresponding with the end of the ATCP, as suggested by the textual and archaeological evidence.

Life and death in the Roman period Pula – A bioanthropological analysis of human skeletal remains from the Ozad Arene site

Human skeletal and dental remains are the primary focus of bioarchaeological research, as different diseases and pathological conditions can leave marks on the bones and teeth. Study of these remains provides insights into the lifestyle, health and quality of life of past populations. In this paper, the human skeletal remains from the Ozad Arene archaeological site in Pula (Istria, Croatia), originating from 25 graves and four bone assemblages dated between the 1st and the 4th centuries CE, were analysed. The aim of the paper is to reconstruct demographic and pathological characteristics of the Roman period population from Pula to gain insight into the living conditions and the quality of life in this community, and to determine whether the site differs from other archaeological sites from the same period in terms of general health and living conditions. The human skeletal sample in question comprises skeletal remains of a minimum 48 individuals; the high subadult mortality rate and high prevalence of dental enamel hypoplasia and the presence of cribra orbitalia, porotic hyperostosis, and periostitis indicate overall poor living conditions and widespread metabolic stress during childhood in Pula. Vertebral osteoarthritis and Schmorl′s nodes in the spines of younger individuals suggest continuous hard labour and strenuous physical activity. Based on the available data, it seems that living conditions in the Roman period Pula did not differ significantly from other Roman sites on the eastern Adriatic coast.

Sporadic inclusion body myositis-derived myotube culture revealed muscle cell-autonomous expression profiles.

Sporadic inclusion body myositis (sIBM) is a muscle disease in older people and is characterized by inflammatory cell invasion into intact muscle fibers and rimmed vacuoles. The pathomechanism of sIBM is not fully elucidated yet, and controversy exists as to whether sIBM is a primary autoimmune disease or a degenerative muscle disease with secondary inflammation. Previously, we established a method of collecting CD56-positive myoblasts from human skeletal muscle biopsy samples. We hypothesized that the myoblasts derived from these patients are useful to see the cell-autonomous pathomechanism of sIBM. With these resources, myoblasts were differentiated into myotubes, and the expression profiles of cell-autonomous pathology of sIBM were analyzed. Myoblasts from three sIBM cases and six controls were differentiated into myotubes. In the RNA-sequencing analysis of these "myotube" samples, 104 differentially expressed genes (DEGs) were found to be significantly upregulated by more than twofold in sIBM, and 13 DEGs were downregulated by less than twofold. For muscle biopsy samples, a comparative analysis was conducted to determine the extent to which "biopsy" and "myotube" samples differed. Fifty-three DEGs were extracted of which 32 (60%) had opposite directions of expression change (e.g., increased in biopsy vs decreased in myotube). Apolipoprotein E (apoE) and transmembrane protein 8C (TMEM8C or MYMK) were commonly upregulated in muscle biopsies and myotubes from sIBM. ApoE and myogenin protein levels were upregulated in sIBM. Given that enrichment analysis also captured changes in muscle contraction and development, the triggering of muscle atrophy signaling and abnormal muscle differentiation via MYMK or myogenin may be involved in the pathogenesis of sIBM. The presence of DEGs in sIBM suggests that the myotubes formed from sIBM-derived myoblasts revealed the existence of muscle cell-autonomous degeneration in sIBM. The catalog of DEGs will be an important resource for future studies on the pathogenesis of sIBM focusing on primary muscle degeneration.

Skeletal remains of human perinatal individuals from the fortified Iberian Period settlement of Ca n’Oliver (6th century to 50 years BCE)

Burial customs in the Iberian Period (Iron Age II) included cremation. Only perinatal and newborn infants were buried directly beneath floor settlement. These infants represent the very few unburned human remains recovered from Iberian sites. The interpretation of these infant burials is in debate, focusing on whether they are unnatural or natural deaths. Our aim is to infer mortality patterns and developmental conditions of these individuals, in order to respond if infanticide was present in these assemblages. A large perinatal human skeletal sample from the Ca n’Oliver site (sixth century to 50 years BCE) from the Iberian Period of the northeast of the Iberian Peninsula was analysed, combining osteological methods together with tooth histology and aDNA analysis. Combining osteological and odontological estimates indicated ages between 22 and 42 weeks of gestation for 47 out of a total of 48 individuals. The remaining individual died at about 6 months after birth. Tooth height and enamel histology indicated in 9 out of a subgroup of 13 individuals a low probability of live birth. The remaining 4 individuals possibly survived birth for less than 2 months. According to morphological and molecular results, the sex ratio of this sample is approximately 1:1 male to female. The mortality distribution is consistent with natural mortality. These perinatal deaths were probably spontaneous abortions and neonatal deaths, reflecting an endogenous mortality profile due to genetic and maternal influences. The present study will serve to broaden our knowledge on perinatal individuals of the Iberian Period.

Gains in relative cortical area during growth and their relationship to nutrition, body size, and physical activity.

In studies of growth in the past, low percentage of cortical area (%CA) is commonly attributed to poor general health, due to factors including poor nutrition, low socioeconomic status, or other physiological stressors. What constitutes low relative cortical dimensions has not been established across a diverse range of human skeletal samples. This study examines %CA in a large immature skeletal sample to establish typical variation in humans with consideration of both body mass and subsistence strategy. Percentage of cortical area was calculated at the midshaft of the humerus, femur, and tibia in seven skeletal samples. Age at death was estimated from dental development, and body mass from bone dimensions. Patterns of %CA with age and log-transformed body mass were examined in the pooled sample and compared among samples using LOESS regression, Welch's ANOVA, and Kruskal-Wallis tests. Across all samples, %CA displays a generally non-linear pattern, but variation in %CA with age was high, particularly in samples with lower levels of %CA. There was no relationship between %CA and age-adjusted body mass. The lack of a relationship between %CA and body mass suggests that %CA should not be used as an indicator of mechanical loading. The variation present across samples implies that appositional bone growth is affected by physiological stress in varying ways. Without a deeper understanding of what is "typical" for long bone development, it is impossible to draw conclusions about individual or population level health.

Tentative indicators of malaria in archaeological skeletal samples, a pilot study testing different methods

ObjectiveThis study attempts to integrate multiple methods to investigate the presence of malaria in human skeletal samples from an archaeological context. Materials33 well preserved human remains originating from a 17th-century archaeological site in southeastern Romania. MethodsThe human bone samples were analyzed using rapid diagnostic tests for malaria antigens and PCR amplification of Plasmodium falciparum apical membrane antigen 1. A preliminary test was performed to identify and briefly characterize the presence of hemozoin using a combination of TEM imaging and diffraction. ResultsThe rapid diagnostic tests indicated that more than half of the examined samples were positive for Plasmodium antigens, but no traces of the parasites’ genetic material were detected despite repeated attempts. The TEM images indicated that hemozoin might be a promising diagnostic marker of malaria in ancient bones. ConclusionsThe indisputable identification of malaria in the analyzed archaeological population was not possible as none of the applied methodological strategies turned out to be straightforward. SignificanceThis study reinforces the intricacy and limitations of unequivocally identifying malaria in past populations and sets the stage for future studies on such life-threatening infectious disease in a geographical space, which is currently underrepresented in the bioarchaeological literature. LimitationsThe low sample size and the lack of consistency across all assays hindered understanding the role of malaria in the studied population. Suggestions for further researchFurther thorough multidisciplinary approaches on malaria detection in ancient settlements would be appropriate to inform our knowledge of its origins, frequency, and pathogen changes over centuries.

1883-P: Metformin Increases Protein Phosphatase 2A Activity in Primary Skeletal Muscle Cells Derived from Lean Healthy Insulin-Sensitive Human Participants

Skeletal muscle insulin resistance is one of the primary contributors of type 2 diabetes (T2D). Metformin is the first-line drug for the treatment of T2D. Main known effects of metformin include inhibition of glucose production in liver and attenuation of insulin resistance in skeletal muscle. However, molecular mechanism of metformin’s action in skeletal muscle is not well understood. Protein phosphatase 2A (PP2A), a major serine/threonine phosphatase, plays a pivotal role in cellular processes (e.g., signal transduction, apoptosis), and acts through dephosphorylating key signaling molecules such as AKT, AMPK, etc. However, whether or not PP2A plays a role in metformin-induced insulin sensitivity improvement in human skeletal muscle cells remains to be elucidated. In the present study, hyperinsulinemic-euglycemic clamp was performed to assess insulin sensitivity in human subjects and skeletal muscle biopsy samples were obtained. Primary human skeletal muscle cells (shown to retain metabolic characteristics of donors) were cultured from these muscle biopsies from 8 lean insulin sensitive participants (4 Female and 4 male; age: 21.4±0.8 yrs; BMI: 22.1±0.7 kg/m2; 2-hour OGTT: 96.5± 6.3 mg/dl; HbA1c: 5.3±0.1 %; fasting plasma glucose: 87.5±1.4 mg/dl; M-value; 10.9±0.8 mg/kgBW/min). The cells were expanded, differentiated into myotubes, and treated with 50µM metformin (the physiologic concentration) for 24 hours before harvesting. PP2A activity was measured by a phosphatase activity assay (Millipore). The results indicated that metformin increased the activity of PP2A in the myotubes derived from all 8 participants, and the average fold increase is 1.59±0.13 (p<0.05). These results provided the first evidence to suggest that metformin promotes activation of PP2A in human skeletal muscle cells derived from lean insulin sensitive participants, and may help to understand metformin’s action in skeletal muscle in humans. Disclosure A.H. Mestareehi: None. B. Seyoum: None. Z. Msallaty: None. A.P. Mallisho: None. X. Zhang: None. A. Kowluru: None. Z. Yi: None. Funding American Diabetes Association (1-13-TS-27 to Z.Y.); National Institutes of Health (R01DK107666, R01DK081750 to Z.Y.), (T32HL120822 to A.H.M.); DOTS Scholars (to A.H.M., Z.Y.)

Pastoralist strategies and human mobility: oxygen (δ18Op) and strontium (87Sr/86Sr) isotopic analysis of early human remains from Egiin Gol and Baga Gazaryn Chuluu, Mongolia

The steppes of Central Asia have long been inhabited by communities practicing various forms of mobile pastoralism as their primary means of subsistence. This study explores the relationship between human mobility and organizational strategies at two distinct micro-regions situated within the modern-day borders of Mongolia. Our investigation was based on an analysis of oxygen (δ18Op) and strontium (87Sr/86Sr) isotopes in archeological human skeletal remains (n = 30) from Baga Gazaryn Chuluu, situated within the middle Gobi Desert and the Egiin Gol Valley in north-central Mongolia. The results indicate a marked degree of separation in local baseline values between the two regions, and corresponding variation was observed in the human skeletal samples. Intra-regional comparisons found that most individuals appear to have spent their childhood years within a “local” range for each particular region, with several notable exceptions that likely indicate a greater degree of lifetime mobility for certain individuals. Overall, the results support the probability that mobility patterns in the past were related to subsistence strategies developed within the discrete environmental zones that characterize the central regions of Mongolia.

Socio-economic Determinants of Bone Health from Past to Present

Increasing epidemiology evidence amounts for social determinants of bone health underlying musculo-skeletal conditions such as osteoporosis. Amongst different facets influencing skeletal health, socio-economic status (SES) has been identified as a critical factor determining one’s access to resources, health care, education, nutrition, and physical activity. Recent conceptual and epigenetic studies assessing SES links with DNA methylation offer further support for the adverse effects of social disadvantage in early life on bone quantity and quality in adulthood. However, this evidence for socially patterned risks in bone fragility is not restricted to the contemporary society. Data exist for ancient human skeletal samples deriving from SES stratified cemeteries that also reflect bone changes consistent with lifestyles specific to social standing. Similarly to modern data, the conclusion drawn from the ancient times has been for a negative effect of low SES on bone growth and maintenance. Some contradictory results, mirroring previously reported inconsistencies in epidemiological studies, have also been reported showing that high SES can equally result in poor bone health. It becomes clear that ancient perspectives can offer a further line of support into these ongoing epidemiological and epigenetic research efforts. Taken together, a holistic approach to clinical understanding and practice of bone health is recommended, building upon ancient and modern findings to target living groups who are most at risk of developing low bone mass and compromised bone micro-architecture.

Chemical relative dating of skeletons of the Iron Age cemetery of Tabriz on the basis of fluorine, uranium, and nitrogen content

Relative dating of archaeological bones by the measurement of fluorine, uranium, and/or nitrogen content is a well-established method, where the content of these elements in the bone structure must be determined. This research aims to study the human skeletal samples of Iron Age site of Blue Mosque in Tabriz, IRAN, on the basis of FUN relative dating method. In this way, the amount of fluorine in the selected samples was measured by UV–Vis spectrophotometry method, while the amount of uranium and nitrogen was determined by ICP-MS, and CHNS and Kjeldahl techniques, respectively. Totally, four bone samples of the skeleton from the cemetery were selected to be relatively dated. The results showed that sample no. 81.9 is the first one buried. Although the nitrogen content of this sample was the same as that of sample no. 80.6, but due to its higher concentration of fluorine and uranium compared to the other samples, it was likely the oldest sample studied at this work. While sample no. 80.6 had the lowest nitrogen content, but due to its lower levels of fluorine and uranium, it could be considered as the youngest,. Also, comparing the relative age of the two samples, no. 81.7 and no. 81.8, it can be concluded that sample no. 81.8 has spent more time under the soil. The results of this study clearly showed the necessity of applying all the three types of relative chemical dating methods (fluorine, uranium, and nitrogen dating) alongside, which is known as the FUN dating method.

Ancient mitochondrial DNA and population dynamics in postclassic Central Mexico: Tlatelolco (ad 1325–1520) and Cholula (ad 900–1350)

The past composition and genetic diversity of populations from Central Mexico during the Postclassic period (ad 900–1520) are still little understood. Two of the largest centres of ancient groups, Tlatelolco and Cholula, declined after European conquest and questions about their relationships with other Central Mexican cities and ritual activities have been debated. Tlatelolco was a Mexica group that practiced the Quetzalcoatl cult and human sacrifice, including the sacrifice of children, while Cholula was considered the main pilgrimage centre and multiethnic city during the Postclassic. This study analysed the mitochondrial DNA control region of 28 human skeletal samples to estimate the genetic affinities of individuals buried at Tlatelolco and Cholula. Amelogenin analysis and whole genome sequencing (WGS) were also applied to determine the sex of the 15 Tlatelolco subadults from sacrificial contexts. Networks, PCoA and Nei genetic distances were calculated to compare Tlatelolco and Cholula haplotypes with available ancient haplotype data from Mesoamerican groups and the two borderland areas, Paquime and Greater Nicoya. Mitochondrial haplogroups were characterized for 11 of the 15 samples from Tlatelolco (73%) and 12 samples out of 13 from Cholula (92%), revealing the presence of four distinct Amerindian mitochondrial lineages at Tlateloloco, A (n = 6; 55%), B (n = 2; 18%), C (n = 1; 9%) and D (n = 2; 10%); and three lineages in Cholula, A (n = 5; 42%), B (n = 5; 42%) and C (n = 2; 16%). Statistical analysis of the haplotypes, haplogroup frequencies and Nei genetic distances showed close affinity of Tlatelolco’s subadults with ancient Mexica (Aztecs) and closer affinities between Cholula and the Xaltocan of the Basin of Mexico. Sex determination of Tlatelolco subadult sacrifice victims revealed that 83% were females, in contrast to previous studies of subadult sacrificial patterns at the site. Together, these results demonstrate the multi-ethnic nature of religious and economic centres in Postclassic Central Mexico.

Who Were the Natufians? A Dental Assessment of their Biological Coherency

The Natufians were complex, semi-sedentary hunter-gatherers who intensively exploited wild plant resources in the southern Levant 12,800 to 10,200 BP. They represent the human culturo-behavioral transition from simple, mobile hunter-gatherers to fully sedentary agriculturalisits. The Natufians have been the subject of much archaeological and biological study because of their pivotal postion in human prehistory. Previous studies of Natufian population biology, which mployed osteometrics, craniometrics, and odontometrics, qualitatively supported the following archaeologically-defined hypothesis. Every human skeletal sample found at each Natufian site belonged to a biologically coherent populations. The present study tests the hypothesis of Natufian biological coherency by analyzing their dental morphology. The data were collected from nearly all available Natufian dental material, using the Arizona State University Dental Anthropology System. The results of the multivariate Mean Measure of Divergence statistical analysis support the biological coherency of the Natufian population.

Typicality and Predictive Distributions in Discriminant Function Analysis

While discriminant function analysis is an inherently Bayesian method, researchers attempting to estimate ancestry in human skeletal samples often follow discriminant function analysis with the calculation of frequentist-based typicalities for assigning group membership. Such an approach is problematic because it fails to account for admixture and for variation in why individuals may be classifijied as outliers or nonmembers of particular groups. This article presents an argument and methodology for employing a fully Bayesian approach in discriminant function analysis applied to cases of ancestry estimation. The approach requires adding the calculation, or estimation, of predictive distributions as the fijinal step in ancestry-focused discriminant analyses. The methods for a fully Bayesian multivariate discriminant analysis are illustrated using craniometrics from identifijied population samples within the Howells published data. The article also presents ways to visualize predictive distributions calculated in more than three dimensions, explains the limitations of typicality measures, and suggests an analytical route for future studies of ancestry and admixture based in discriminant function analysis.

Lumbosacral Defects in a 16th-18th-Century Joseon Dynasty Skeletal Series from Korea.

Paleopathological evidence for congenital and degenerative disorders of the lumbosacral vertebrae is informative about ancient individual lifeways and physical conditions. However, very few studies have focused on the paleopathology of the lumbosacral vertebrae in ancient skeletal series from East Asia. One reason for the lack of studies is that skeletal samples from East Asia are typically insufficient in size to represent populations for comparative studies within the continent. Here, we present the first comprehensive analysis of lumbosacral defects in an East Asian human skeletal sample, examining occurrences of spina bifida occulta (SBO), lumbosacral transitional vertebrae (LSTV), and spondylolysis in remains from Joseon tombs dating to the 16–18th centuries in Korea. In this study, we present an alternative methodology for understanding activities of daily life among ancient Koreans through paleopathological analysis.

Typicality and Predictive Distributions in Discriminant Function Analysis

While discriminant function analysis is an inherently Bayesian method, researchers attempting to estimate ancestry in human skeletal samples often follow discriminant function analysis with the calculation of frequentist-based typicalities for assigning group membership. Such an approach is problematic because it fails to account for admixture and for variation in why individuals may be classified as outliers or nonmembers of particular groups. This article presents an argument and methodology for employing a fully Bayesian approach in discriminant function analysis applied to cases of ancestry estimation. The approach requires adding the calculation, or estimation, of predictive distributions as the final step in ancestry-focused discriminant analyses. The methods for a fully Bayesian multivariate discriminant analysis are illustrated using craniometrics from identified population samples within the Howells published data. The article also presents ways to visualize predictive distributions calculated in more than three dimensions, explains the limitations of typicality measures, and suggests an analytical route for future studies of ancestry and admixture based in discriminant function analysis.

Chromatin Immunoprecipitation of Skeletal Muscle Tissue.

Chromatin immunoprecipitation (ChIP) is an invaluable method for studying interactions between histone proteins and genomic DNA regions and transcriptional regulation using antibodies to enrich genomic regions associated with these epitopes. Either to monitor the presence of histones with post-translational modifications at specific genomic locations or to measure transcription factor interactions with a candidate target gene, protein-DNA complexes are most commonly crosslinked using formaldehyde, which stabilizes these transient interactions. Chromatin is then fragmented to allow separation of genomic fragments bound by the histone or transcription factor of interest away from those that are unbound. Following immunoprecipitation, formaldehyde crosslinks are reversed and enriched DNA fragments are purified. While some investigators have successfully performed ChIP experiments from crosslinked skeletal muscle in cell culture, the process is relatively inefficient compared to whole tissue. This chapter provides protocols specifically designed for the crosslinking and immunoprecipitation of human skeletal muscle biopsy samples in preparation for chromatin immunoprecipitation-sequencing (ChIP-seq).

Trends in mortality and biological stress in a medieval polish urban population

Urbanization in pre-modern populations may have had a variety of consequences related to population crowding. However, research on the effects of urbanization have provided inconsistent results regarding the biological impact of this transition on human populations. The purpose of this study is to test the hypothesis that urbanization caused an increase in overall biological stress in a medieval (10th–13th centuries AD) Polish population. A human skeletal sample (n=164) was examined for the presence of porotic hyperostosis, cribra orbitalia, linear enamel hypoplasia, periosteal reaction, and specific infectious diseases. Prevalence rates were compared among three temporal samples: initial urbanization, early urbanization, and later urbanization. Results indicate no significant trends for any of the pathological conditions. Cox proportional hazards analyses, however, revealed a significant increase in the risk of death over time, which supports the hypothesis. These results reflect the necessity of using multiple analyses to address bioarchaeological questions. The lack of significant results from skeletal indicators may be due to an earlier urbanization trend in the population. This study illustrates that the association of urbanization with elevated biological stress is complicated and dependent on various factors, including culture and time period.

Spondylolysis in the past: A case study of hunter-gatherers from Southern Patagonia

Spondylolysis is a fracture of the pars interarticularis, the portion of the neural arch that lies between the superior articular facets and the inferior articular facets. Clinical evidence has suggested repetitive trauma to be the most probable cause, even though morphological weakness of the vertebra is probably also involved. Prevalence is between 3% and 8% in modern populations, while in archaeological samples it varies from 0% to 71.4%. Considering that very little data about this condition is available in past populations from the southern extreme of South America, the aim of this paper is to analyze the spondylolysis in a human skeletal sample from Southern Patagonia and, at the same time, to explore the prevalence of spondylolysis in archaeological contexts around the world to gain a better understanding of the results presented here. The Southern Patagonian skeletal series analyzed here showed a prevalence of 20%, with lower prevalence in the pre contact sample (11.1%) than in the contact period (23.1%). Skeletons from the Salesian Mission “Nuestra Señora de La Candelaria” showed a higher prevalence (25%) than the sample of skeletal remains recovered from outside the mission (20%), suggesting that changes in lifestyle of hunter-gatherers during contact could be implicated in the development of spondylolysis in this sample. A worldwide survey displays a wide range of prevalence figures in American and Asian samples and low diversity between African and European populations. Hunter-gatherers from Southern Patagonia showed similar values to those observed in other American samples.