Human Bone Collagen Research Articles

Reconstructing diet after the fall of the Wari Empire in the central Andean Highlands: A study of human dental calculus

Stable isotopes from bones and teeth have been used to reconstruct human lifeways in bioarchaeological research for over 30 years. Recently, there have been efforts to use less invasive methods of analysis that meet ethical standards and do not compromise the integrity of human skeletal remains. To that end, this study examines dental calculus from human teeth as a proxy for paleodietary reconstruction. This current work builds on a handful of studies that have tested the use of dental calculus for reconstructing diet, which have shown mixed results. This study contributes to those ongoing efforts to improve methods and capacities in paleodiet research. The sample is comprised of dental calculus from individuals from the Wari (600–1000 CE) and post-Wari periods (1000–1400 CE). Individuals from both time periods with stable carbon and nitrogen isotope data from the calculus are directly compared to the stable isotope results from human bone collagen, dental carbonates, and bone carbonates. Results from dental calculus show δ13C that range from -20.5 ‰ to −12.3 ‰, consistent with the use of C4 plants (maize) as a major component of the diet. The δ13C from calculus are isotopically lighter and more varied than those obtained from collagen, and this is likely explained by the distinct composition of calculus compared to that of bone collagen and apatite. The δ15N from calculus range from +8.9 ‰ to +18.8 ‰, which is heavier than expected for highland maize-based diets in the Peruvian Andes. This may be explained by 15N enrichment from aridity or crop fertilization (e.g., camelid dung), especially during the post Wari period, a time of social upheaval and severe drought. The differences in stable isotope values may also be partially explained by the diet-sourced isotopes in bone collagen (e.g., averaging the last 5–10 years of life) versus that of dental calculus (e.g., averaging the last few years of life). Documenting these differences in stable isotope ratios from distinct components may aid in richer understandings of past diets and provide additional ways to compare diet through time and space. Indeed, as more researchers begin analyzing the stable isotope ratios from dental calculus, we can minimize destructive techniques and make direct comparisons between studies that use dental calculus. We suggest that this is an important expansion of our analytical toolkit.

An improved linear systems model of hydrothermal isometric tension testing to aid in assessing bone collagen quality: Effects of ribation and type-2 diabetes.

This study sought to further develop and validate a previously proposed physics-based model that maps denaturation kinetics from differential scanning calorimetry (DSC) to the isometric tension generated during hydrothermal isometric tension (HIT) testing of collagenous tissues. The primary objectives of this study were to verify and validate two physics-based model parameters: α, which indicates the amount of instantaneous isometric tension developed per unit of collagen denaturation, and β, which captures the proportionality between temperature and the generated isometric tension post denaturation initiation. These parameters were used as measures of bone collagen quality, employing data from HIT and DSC testing of human bone collagen from two previous studies. Additionally, given the physical basis of the model, the study aimed to further validate Max.Slope, the rate of change in isometric tensile stress with change in temperature, as an independent measure of collagen network connectivity. Max.Slope has previously been positively correlated with measures of cortical bone fracture resistance. Towards this verification and validation, the hypotheses were a) that α would correlate strongly with HIT denaturation temperature, Td, and the enthalpy of melting (ΔH) from DSC, and b) that β would correlate positively and strongly with Max.Slope.The model was employed in the analysis of HIT-DSC data from the testing of demineralized bone collagen isolated from cadaveric human femurs in two prior studies. In one study, data were collected from HIT-DSC testing of cortical bone collagen from 74 donors. Among them, 38 had a history of type 2 diabetes +/− chronic kidney disease, while the remaining 36 had no history of T2D again with or without CKD. Cortical bone specimens were extracted from the lateral mid-shaft. The second study involved 15 donor femora, with four cortical bone specimens extracted from each. Of these four, two specimens underwent a 4-week incubation in 0.1 M ribose at 37 °C to induce non-enzymatic ribation and advanced glycation endproducts, while the other two served as non-ribated controls.The examination involved investigating correlations between the model parameters α and β and various measures, such as Max.Slope, Td, ΔH, age, and duration of type 2 diabetes. The results revealed positive correlations between the model parameter β and Max.Slope (r = 0.55–0.58). The parameter α was found to be associated with Td, but also sensitive to the shape of the HIT curve around Td resulting in difficulties with variability and interpretation. As a result, while both hypotheses are confirmed, Max.Slope and β are better indicators of bone collagen quality because they are measures of the connectivity or, more generally, the integrity of the bone collagen network.

Life histories in Fiji as reconstructed from first millennium CE Sigatoka Sand Dune burials using isotopes

This paper aims to re-examine the dietary practices of individuals buried at Sigatoka Sand Dunes site (Fiji) in Burial Ground 1 excavated by Simon Best in 1987 and 1988 using two approaches and a reassessment of their archaeological, bioarchaeological and chronological frame. First, stable carbon and nitrogen isotope analysis was applied to document dietary changes between childhood and adulthood using an intra–individual approach on paired bone–tooth. Second, the potential adaptation of the individuals to their environment was evaluated through regional and temporal comparisons using inter–individual bone analysis. Ten AMS radiocarbon dates were measured directly on human bone collagen samples, placing the series in a range of approximately 600 years covering the middle of the first millennium CE (1,888 to 1,272 cal BP). δ13C and δ15N ratios were measured on bone and tooth collagen samples from 38 adult individuals. The results show that δ15N values from tooth are higher than those s from bone while bone and tooth δ13C values are similar, except for females. Fifteen individuals were included in an intra–individual analysis based on paired bone and tooth samples, which revealed six dietary patterns distinguished by a differential dietary intake of marine resources and resources at different trophic levels. These highlight sex–specific differences not related to mortuary practices but to daily life activities, supporting the hypothesis of a sexual division of labour. Compared to other Southwest Pacific series, Sigatoka diets show a specific trend towards marine food consumption that supports the hypothesis of a relative food self–sufficiency requiring no interactions with other groups.

Neolithisation through bone: Stable isotope analysis of human and faunal remains from Syltholm II, Lolland, Denmark

Despite an increasing number of studies, the application of stable sulfur (δ34S) isotope analysis to prehistoric bone collagen remains in its infancy. Conventionally, stable sulfur isotope compositions reflect coastal proximity and the interaction between humans and animals. Here, we undertook stable carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) isotope analysis of human and faunal bone collagen. To understand the local environmental conditions as well as the husbandry regime employed by the first farmers, and investigate where the animals were raised or hunted in non-specific terms, we sampled 50 faunal, including wild and domestic taxa, and human remains from the Late Mesolithic to Early-Middle Neolithic (c. 4860–2310 cal BC) site of Syltholm II on the island of Lolland, Denmark. We show that the wild animals were obtained from multiple locations surrounding the prehistoric Syltholm Fjord, including forested and open landscapes, areas impacted by sea spray and saltmarshes. In contrast, the domestic taxa, especially cattle, were tightly managed for the majority of their lives based on their δ13C and δ15N isotope compositions, though were likely raised in multiple locations, including sea spray-affected areas, saltmarshes and wetlands, based on their δ34S values. The domestic dogs had a broad range of δ13C, δ15N and δ34S values, reflecting the consumption of varying degrees of marine foodstuffs, including animals that were sulfide-derived. Overall, our results contribute to a growing body of evidence for possible cultural and animal husbandry duality during the earliest Neolithic in southern Scandinavia.

Staple food and possible famine food in Han Dynasty Guanzhong: Archeobotanical and stable isotopic perspectives

AbstractAgricultural yield fluctuations caused by environmental and social factors in ancient China have been well recorded in extensive ancient documents; however, comparatively little is known archaeologically. This study revealed the consumption and utilization of staple cereal and possible famine food by Han Dynasty inhabitants in the Guanzhong area based on archeobotanical evidence, including plant macro‐remains and phytoliths uncovered from pottery granaries and isotopic evidence from human bone collagen from Miaojiazhai cemetery. This preliminary multidisciplinary research with clear archaeological contexts provides archaeological evidence to reveal the food diversification and indicate that the possible occurrence and coping strategies to mitigate fluctuations in agricultural yields in Han Dynasty Guanzhong and broaden the understanding of the Han Dynasty agricultural economies and society.

Millet agriculture and social complexity in the Central Plains of the Neolithic (9000-5000 BP): Isotopic reconstruction of human diet from the Shanggangyang site in China

The core area of the Central Plains is one of the crucial regions for the origin of Chinese civilization, and the settlement site cluster in the mid-late Yangshao period (6000-5000 BP) provides a unique opportunity to investigate the human dietary pattern in the Central Plains for the origin of Chinese civilization. However, previous studies have not yet been able to adequately explain why the Central Plains has developed into an area in which the process of social complexity has accelerated significantly and the emergence of early Chinese civilization based on the development of millet agriculture in the core area of the Central Plains in the mid-late Yangshao period. In this case study, stable isotope analysis of the human bone collagen from the Shanggangyang site was conducted. The isotopic data showed that the majority of the Shanggangyang inhabitants (−8.0 ± 0.7‰, 9.0 ± 0.8‰, n = 24) were on a C4 millet-based diet, while the M13 individuals (−15.9 ± 0.1‰, 6.5 ± 0.1‰, n = 2) was on a C3 and C4 mixed diet. Furthermore, temporal investigations of the development of millet agriculture from isotopic perspective during the middle to late Neolithic period (9000-5000 BP) in the Central Plains comprehensively and explicitly revealed that millet agriculture developed and matured, and became the predominant subsistence economy in the mid-late Yangshao period (6000-5000 BP). This prosperous subsistence economy based on millet farming of the mid-late Yangshao period not only played an important role in generally accelerating the process of social complexity in the Central Plains, but also provided a substantial economic foundation for the emergence of early Chinese civilization in the core area of the Central Plains.

Effects of lipid extraction on human bone collagen: Comparing stable carbon and nitrogen isotope values with and without lipid extraction

This study analyzes 24 human bone fragments to assess how lipid extraction affects stable carbon and nitrogen isotope ratios. Eighteen samples were archaeological bone and six were modern bone. Each bone was split into two pieces, producing 48 bone samples, and half underwent lipid extraction and half did not. This was done to assess whether the two techniques yielded statistically significant differences in δ13C and δ15N. The results are an important contribution for establishing standard stable isotope preparation protocols, which affect time and cost of laboratory procedures. Further, given that many dietary stable isotope studies compare original results to published material, this study addresses whether those comparisons are suitable if some samples undergo lipid extraction while others do not.We also examine 144 articles that report stable carbon and nitrogen isotope results to evaluate the proportion of studies that conduct lipid extraction versusthose that do not. We explore those outcomes by archaeological geographic region and by stable isotope laboratories. Findings show that 15% of the published studies do lipid extraction, and they tend to be grouped by researchers and laboratories who conduct research in specific global regions. The meta-analysis of the published articles and the findings that some laboratories conduct lipid extraction, while others do not, prompted the experimental portion of this study.Results of the experimental study show no significant differences in δ13C between samples prepared with and without lipid extraction and no significant differences in δ15N between samples prepared with and without lipid extraction. These results suggest that stable carbon and nitrogen isotope analysis of human bone collagen may not require lipid extraction for certain dietary reconstruction studies, specifically for non-coastal contexts (i.e., non-marine based diets). The isotope data was analyzed overall and among subgroups (e.g., archaeological bone, modern bone, mid-valley Peruvian ecological zones, and highland Peruvian ecological zones). In all cases, stable isotope ratios from samples prepared with and without lipid extraction were not significantly different.

COMPARING BIOAPATITE AND COLLAGEN RADIOCARBON DATES FROM A 16TH CENTURY CEMETERY CONTEXT—EL JAPÓN, XOCHIMILCO, MEXICO CITY

ABSTRACT El Japón is a 16th century hamlet site in the marshlands of the southern Basin of Mexico in central Mesoamerica. Radiocarbon (14C) dating and OxCal modeling of human bone collagen (n = 11) identifies a range of burials at El Japón cemetery from 1550–1650 cal. CE. The refined chronology identifies use of this rural settlement well after the onset of colonial government-sponsored relocation of Indigenous people to larger settlements (congregaciones). Historically documented information in this work supports chronological modeling beyond stand-alone calibration. Stable isotopic study of bone samples demonstrates similar sources of dietary protein and carbohydrates. The similarity of carbon sources for bone apatite (bioapatite) and collagen offers security that both bone fractions are viable 14C dating opportunities. Recent extension of this work examines bioapatite 14C dates (n = 5) from the same bone samples when quality parameters are met—atomic carbon-nitrogen ratios of 3.2–3.3 and collagen yield of 10–20%. No significant difference is found between collagen and bioapatite dates of the same individuals (p = 0.17, Mann-Whitney U test). 14C dates from human bone samples in this primarily terrestrial dietary context can be successfully acquired from either collagen or bioapatite fractions.

Human and camelid paleodiets in El Bolsón valley (NW Argentina): A stable isotope approach

AbstractThis exploratory study aims at reconstructing human paleodiets and that of camelids—their staple animal resource—in El Bolsón, an Andean valley in Catamarca Province, NW Argentina, as a way of exploring variations in the strategies and patterns of food procurement, production, preparation, and consumption by local agricultural‐pastoralist societies over the last 1500 years. We present the first systematically obtained data on carbon (13C/12C) and nitrogen (15N/14N) isotopic relationships as measured on camelid and human bone collagen. They come from five camelid individuals from Los Viscos archaeological site, dating to the last 1200 years, and from six human individuals from archaeological rescues and isolated finds bracketed between at least ca. 1300 cal CE and ca. 500 cal CE, as no other human samples are available in the study area. The results suggest that camelids consumed predominantly locally available C3 pastures, while the human paleodiet was primarily based on C4 plants, with camelid protein not being central to it. Here, we discuss how local productive strategies would have played a part in the selective diet of the human inhabitants and interpret this picture in the context of the larger area comprising the Andean valleys of NW Argentina.

Human and dog Bayesian dietary mixing models using bone collagen stable isotope ratios from ancestral Iroquoian sites in southern Ontario

Under the archaeological canine surrogacy approach (CSA) it is assumed that because dogs were reliant on humans for food, they had similar diets to the people with whom they lived. As a result, the stable isotope ratios of their tissues (bone collagen and apatite, tooth enamel and dentine collagen) will be close to those of the humans with whom they cohabited. Therefore, in the absence of human tissue, dog tissue isotopes can be used to help reconstruct past human diets. Here δ13C and δ15N ratios on previously published dog and human bone collagen from fourteenth-seventeenth century AD ancestral Iroquoian village archaeological sites and ossuaries in southern Ontario are used with MixSIAR, a Bayesian dietary mixing model, to determine if the dog stable isotope ratios are good proxies for human isotope ratios in dietary modeling for this context. The modeling results indicate that human dietary protein came primarily from maize and high trophic level fish and dogs from maize, terrestrial animals, low trophic level fish, and human feces. While isotopes from dog tissues can be used as general analogs for human tissue isotopes under CSA, greater insights into dog diets can be achieved with Bayesian dietary mixing models.

REFINING CERAMIC CHRONOLOGY AND EPICLASSIC REOCCUPATION AT LA VENTILLA, TEOTIHUACAN USING TRAPEZOIDAL BAYESIAN MODELING

ABSTRACTAccelerator mass spectrometry radiocarbon (AMS 14C) dates (n = 78) from human bone collagen were analyzed in the largest high-resolution chronology study to date at the ancient city of Teotihuacan in central Mexico (ca. AD 1–550). Samples originate from the residential neighborhood of La Ventilla, located in the heart of this major urban center. Here, a trapezoidal model using Bayesian statistics is built from 14C dates combined with data derived from the stylistic analysis of ceramics from burial contexts. Based on this model, we suggest possible refinements to Teotihuacan’s ceramic chronology, at least within the La Ventilla neighborhood. We also explore the abandonment and reoccupation of La Ventilla after the political collapse of Teotihuacan in the Metepec and Coyotlatelco phases. Findings suggest that these ceramic phases began earlier than is currently projected and that the well-documented abandonment period of La Ventilla may have occurred more abruptly than originally estimated.

Diverse subsistence strategies related to the spatial heterogeneity of local environments in the Hengduan Mountain Region during the Bronze Age

Human subsistence strategies in East Asia changed significantly during the Bronze Age. The notable spatial variability in these strategies has been mainly attributed to the asynchronous introduction and adoption of new crops and livestock, as well as climate changes. However, the impact of differential local environments on spatial patterns of subsistence strategies in diverse geomorphic areas, such as the Hengduan Mountain Region (HMR), is poorly understood. In this study, we present new carbon and nitrogen isotopic data of human bone collagen from the Adong and Gaozhai tombs in the HMR. Adong is located in a mountain area, and Gaozhai is located on a river terrace. Both sites were dated to the early third Millennium BP (before the present). Our results suggest that human diets at Gaozhai were dominated by C3 foods. Human diets at Adong, alternatively, displayed more differentiation, with greater consumption of C4 foods. Further evidence is needed to discuss the significant differences in δ15N values of human bone collagen between the Gaozhai and Adong tombs. By comparing published isotopic, archaeobotanical, and zooarchaeological data, as well as the altitude and precipitation at the archaeological sites, we propose that precipitation may have affected the diversity of human dietary strategies in the Bronze Age HMR. We conclude that at higher altitudes, humans adopted diverse subsistence strategies and obtained meat resources by hunting. Some of this preferential behavior is likely explained by the survival pressure in the highlands of the HMR during the Bronze Age.

The subsistence strategies of Qin humans in the Guanzhong Plain before the establishment of Qin Empire: A combined stable isotope and archaeobotanical approach

The turbulent stage before the unification of China under the first Empire, the Qin Dynasty (221–207 BC), witnessed remarkable changes in economic livelihood and social conditions. This study aims to investigate the subsistence strategies of humans living in the Guanzhong Plain during the Late Qin State (350–221 BC) by using carbon and nitrogen isotope analysis on animal and human bone collagen, as well as starch grain analysis of human dental calculus, from Podi cemetery, Shannxi Province, China. We argue that Podi humans likely relied on a mixed subsistence strategy based on animal husbandry practices and diverse crop agricultural pattern which consist of millet, soybean, wheat, and probably supplemented by hunting and gathering (Job's tears, nuts and tubers) economy. Combined with bioarcheological studies on Qin humans, we infer that previously traditional animal husbandry economy was still being practiced in the Qin period along with the inclusion of a newly introduced agricultural economy.

The Origins of the Civilisation of Angkor, Volume Seven: The Excavation of Non Ban Jak ed. by C.F.W. Higham and A. Kijngam

Reviewed by: The Origins of the Civilisation of Angkor, Volume Seven: The Excavation of Non Ban Jak ed. by C.F.W. Higham and A. Kijngam Carmen Sarjeant The Origins of the Civilisation of Angkor, Volume Seven: The Excavation of Non Ban Jak. Edited by C.F.W. Higham and A. Kijngam. Authors: H. R. Buckley, N. Chang, K. Domett, S. E. Halcrow, H. R. Heath, C.F.W. Higham, T.F.G. Higham, N. Ling, B.F.J. Manly, D.J.W. O’Reilly, L. Pederson, F. Petchey, L. Shewan, R. Thosarat, and S. Ward. Bangkok: The Fine Arts Department, 2020. xx + 524 pp., 583 figures, 42 tables, 2 appendices, bibliography, index. Hardback US $31, ISBN 978-616-283-497-4. The seventh volume in the Origins of the Civilisation of Angkor series comprehensively describes the findings from excavations at Non Ban Jak (NBJ) over several field seasons in the upper Mun Valley, northeast Thailand. Two mounds were excavated, human burials [End Page 126] recovered, and the material culture from domestic and industrial contexts and faunal remains are presented. The volume includes further analysis of the ceramic industry and health and disease. The volume summary includes comparisons with nearby Noen U-Loke (NUL) and Ban Non Wat (BNW) and offers important insights on social change in response to climate in mainland Southeast Asia between a.d. 200 and 800. Dating to the Late Iron Age, NBJ retains intact evidence of domestic structures from a prehistoric context that is rare in mainland Southeast Asia at this scale. Furthermore, significant evidence of local ceramic production from kilns and iron smithing was recovered. NBJ has much to offer in future research and the volume is an essential contribution to understanding the origins of early agrarian states in Southeast Asia. The first chapter (by Higham, Higham, and Petchey) provides an introduction and chronology for NBJ, a large, moated site in the upper Mun Valley of northeast Thailand. As with other studies in the Origins of the Civilisation of Angkor series, the chronology is meticulously outlined with over 70 dates reported from charcoal, bivalve shell, carbonized rice grains, human bone collagen, and a bird’s egg. A small portion of the site contains Neolithic period evidence, but not in situ. The reliable sequence from a.d. 220–380 to a.d. 700–820 covers four centuries of rapid house building. Chapters 2 through 5 (by Higham) cover the east mound excavations, documented layer by layer with photos and a summary of the recovered materials, features, and burials. These chapters contain detailed information of the findings, easily referred to when considering the interpretations in the subsequent chapters. The eastern mound burials are outlined in chapter 6 (by Higham, Buckley, Halcrow, and Domett) with images and mortuary goods catalogued. This chapter leads into the east mound material culture discussed in chapter 7 (by Higham). The pottery includes the contents of the kilns, historic period pits, and occupational contexts (specifically from residential settings). The frequent presence of two bowls placed lip to lip was identified in various contexts, potentially related to buildings and burials and found in occupation layers with no clear feature association. Other ceramic items include spindle whorls, anvils, bow pellets, skin rubbers, structural clay daub associated with houses and kilns, and other clay building materials for house walls and floors. Notably, no ceramic casting bronze moulds were found at NBJ. Iron artifacts from non-mortuary contexts included ploughshares, points, sickles, and knives, indicative of the agricultural activities at the site. Glass beads and bronze ornaments (especially bangles) were found. Stone adzes and burnishing stones were rare. The morphology of ceramics are described in greater detail. However, the descriptions summarizing each vessel form are not consistently cited to images of the forms in plan and profile views where needed in the text. The provided images of the ceramics found within specific contexts such as pits and kilns are crucial for understanding local production. Later in chapter 7, the citing of images in the text is more consistent in the M and N squares section. Chapter 8 (by Higham) is on the cultural sequence of the western mound. This portion of the site had a small...

Synchronous change in the intensified millet cultivation and ecological environment from the early to middle Holocene on the Inner Mongolia Plateau, northern China

The mechanisms of the origin and dispersal of millet agriculture in northern China are poorly understood. We used plant macroremains, stable isotope compositions of human bone collagen, and pollen records from the Sitai site to reconstruct changes in subsistence strategies and their relationship with the ecological environment from the early to middle Holocene on the Inner Mongolian Plateau in northern China. Charred weed-like seeds, the bones of small mammals, eggshell fragments, together with microliths, indicate the practice of hunter-gatherer subsistence strategies during 10,500–10,200 cal yr BP. Deciduous broadleaved forest-steppe vegetation was present around the Sitai site during the early middle Holocene (8000–7000 cal yr BP). Additionally, isotopic compositions of human bones and plant remains reveal that millet agriculture and hunting-gathering appeared in the early middle Holocene. The spread of millet agriculture on the Inner Mongolian Plateau was likely favored by an increase in precipitation between 8000 and 7000 cal yr BP. The development of millet agriculture on the Inner Mongolia Plateau and the Loess Plateau was the prelude to its subsequent spread to the Tibet Plateau.

Past maize consumption correlates with population change in Central Western Argentina

This paper explores the relationships between population change and human diet after the adoption of domesticated resources in northwest Mendoza, a subregion of central western Argentina (CWA). To estimate population, we used summed probability distributions of radiocarbon ages (RC-SPD). We used carbon and nitrogen stable isotope values (ẟ13Cco, ẟ13Cca, and ẟ15N) obtained on human bone (collagen and carbonate) to reconstruct human diet. The population trend of late Pleistocene-Holocene hunter-gatherers changed its trajectory ca. 2300 cal years BP coincident with the adoption of domesticates. After this date, a significant increase in human population occurred. We observe population increases (“booms”) followed by notable drops (“busts”). Stable isotopes (ẟ13C) on human bone follow a similar trend, indicating an increased consumption of maize during the “boom” periods and a decreased consumption during the “bust” periods. Based on the association between estimated changes in human population and changes in human bone isotope values over the last 2300 cal years BP, we propose that levels of maize consumption emerge from human predator–prey and plant-herbivore interactions. The use of maize, thus, is not part of a social evolutionary stage, but, rather, an outcome of continuous social-ecological process in which maize use may increase or decrease over time.

A RADIOCARBON CHRONOLOGY FOR ESTADIO DE QUILLOTA IN THE ACONCAGUA VALLEY, CENTRAL CHILE, WITH REFERENCE TO THE ADOPTION OF INTENSIVE MAIZE AGRICULTURE AND REVISITING THE TIMING OF INKA INFLUENCE ON THE SOUTHERN FRONTIER

ABSTRACTEstadio de Quillota (EDQ) is the largest known pre-Columbian cemetery site within the Aconcagua Valley of Central Chile. Despite its importance, existing chronological data for EDQ are limited and questions remain regarding the prehistory of the Valley, particularly around the adoption and intensification of maize agriculture, as well as the timing of Inka influence reaching the region. Seventeen new AMS radiocarbon dates presented here indicate two distinct phases of use at EDQ: An earlier phase (339–196 cal BC to cal AD 128–339), and a later phase (cal AD 1280–1387 to cal AD 1413–1458). Accompanying stable isotope (δ13C and δ15N) analyses of human bone collagen (n=22) demonstrate diachronic dietary changes corresponding to these phases, with a reliance on terrestrial C3 resources during the earlier period, followed by a heavy dependence on C4-based (maize) resources during the later use. Bayesian modeling of the dates from Late Period contexts suggests Inka influence arrived in Central Chile by ca. cal AD 1400, decades before the date cited in traditional chronologies, AD 1471. Inka expansion likely occurred here with an initial phase of interaction and exchange preceding a later phase of integration. This finding supports growing evidence that the traditional chronology of the Inka Empire requires reconsideration.

Tracing Maize History in Northern Iroquoia Through Radiocarbon Date Summed Probability Distributions

Abstract The evolution of maize as an organism, its spread as an agricultural crop, and the evolution of Native American maize-based agricultural systems are topics of research throughout the Western Hemisphere. Maize was adopted in Northern Iroquoia, comprising portions of present-day New York, Ontario, and Québec by 300 BC. By the fourteenth-century AD, maize accounted for >50 to >70% of ancestral Iroquoian diets. Was this major commitment to maize agriculture a gradual incremental evolution, or was there a rapid increase in commitment to maize-based agriculture around AD 1000 as traditional archaeological narratives suggest? Summed probability distributions of direct radiocarbon dates on maize macrobotanical remains and cooking residues containing maize phytoliths combined with maize macrobotanical maize densities at sites and previously published stable isotope values on human bone collagen used with Bayesian dietary mixing models and cooking residues show an initial increase in maize use at AD 1200–1250 and a subsequent increase at AD 1400–1450. These results indicate maize history in Northern Iroquoia followed an exponential growth curve, consistent with Rindos’ (1984) model of agricultural evolution.

Raman microscopic spectroscopy as a diagnostic tool to detect Staphylococcus epidermidis in bone grafts

IntroductionRaman microscopic spectroscopyis a new approach for further characterization and detection of molecular features in many pathological processes. This technique has been successfully applied to scrutinize the spatial distribution of small molecules and proteins within biological systems by in situ analysis. This study uses Raman microscopic spectroscopyto identify any in-depth benefits and drawbacks in diagnosing Staphylococcus epidermidis in human bone grafts. Material and Methods40 non-infected human bone samples and 10 human bone samples infected with Staphylococcus epidermidis were analyzed using Raman microscopic spectroscopy. Reflectance data were collected between 200 cm−1 and 3600 cm−1 with a spectral resolution of 4 cm−1 using a Senterra II microscope (Bruker, Ettlingen, Germany). The acquired spectral information was used for spectral and unsupervised classification, such as principal component analysis. ResultsRaman measurements produced distinct diagnostic spectra that were used to distinguish between non-infected human bone samples and Staphylococcus epidermidis infected human bone samples by spectral and principal component analyses. A substantial loss in bone quality and protein conformation was detected by human bone samples co-cultured with Staphylococcus epidermidis. The mineral-to-matrix ratio using the phosphate/Amide I ratio (p = 0.030) and carbonate/phosphate ratio (p = 0.001) indicates that the loss of relative mineral content in bones upon bacterial infection is higher than in non-infected human bones. Also, an increase of alterations in the collagen network (p = 0.048) and a decrease in the structural organization and relative collagen in infected human bone could be detected. Subsequent principal component analyses identified Staphylococcus epidermidis in different spectral regions, respectively, originating mainly from CH2 deformation (wagging) of protein (at 1450 cm−1) and bending and stretching modes of C-H groups (∼2800-3000 cm−1). ConclusionRaman microscopic spectroscopyis presented as a promising diagnostic tool to detect Staphylococcus epidermidis in human bone grafts. Further studies in human tissues are warranted.

HUMAN DIET DURING THE STONE AGE AND EARLY METAL PERIOD (7000–1 CAL BC) IN LITHUANIA: AN UPDATE

ABSTRACTIn this study we present new carbon (δ13C) and nitrogen (δ15N) stable isotope data of human (n=13) and animal (n=40) bone and/or dentine collagen samples, alongside accelerator mass spectrometry radiocarbon (AMS 14C) dates of human remains (n=16). The studied material was sampled from Lithuanian sites dating from the Late Mesolithic to the pre-Roman Iron Age. For the first time, we present δ13C and δ15N data from Lithuanian freshwater fish as well as AMS 14C, δ13C, and δ15N measurements of human remains from six disturbed graves at the Donkalnis cemetery and from two pre-Roman Iron Age graves. According to the new results, human diet derived protein from the Late Mesolithic to Subneolithic (ca. 7000–2900 cal BC) was primarily based on freshwater fish. While previous macrobotanical and stable isotope studies has suggested that C4 plants, i.e., millet, became more widely used from the Late Bronze Age (1100–500 cal BC), our data suggests that millet consumption may have decreased during the pre-Roman Iron Age (500–1 cal BC) in the southeastern Baltic.