The positive identification of a decedent is paramount to a forensic investigation in which human remains have been recovered and must be identified. Due to increasing global mobility in the world's populations, it is not inconceivable that an individual might die far away from his or her home. Pinpointing an individual's geographic origin may contribute to definitive forensic identification of contemporary human skeletal remains in cases where dental records and other means of identification are either unavailable to law enforcement personnel or do not yield immediate results. Stable isotope analysis of biogenic tissues such as tooth enamel and bone mineral has become a well‐recognized and increasingly important method for determining the provenance of human remains, and it has been used successfully in bioarchaeological studies as well as forensic investigations. Both 18O and 2H stable isotope signatures are well established proxies as environmental indicators of climate (temperature) and source water and are therefore considered reliable indicators of geographic life trajectories of animals and humans. Similarly, 13C and 15N abundance data have distinguished dietary preferences in ancient human populations, and have been used to qualify 2H and 18O geolocational data that may be consistent with more than one location. Few if any studies have systematically investigated the multi-isotopic signatures in human tooth enamel and dentin from living individuals. Since 18O abundance values obtained from tooth enamel of late-erupting molars are a source of information on geographic origin of an individual during adolescence when crown formation takes place, it was hypothesized that: 1) the stable isotope abundance of 2H, 18O, and 13C in human tooth enamel and dentin is consistent with self-reported residential history and dietary preferences data, and 2) the isotopic variability evident between individuals with shared residential history and nutrient intake is quantifiable, and indicative of intra-individual variability. Two pilot studies were conducted to: 1) evaluate the feasibility of extracting and measuring the 2H composition of human tooth enamel and its suitability as a proxy for human geographic provenance, and 2) compare the isotopic abundance of isotopic abundance of 2H and 13C in human crown dentin collagen obtained from archaeological and modern teeth with the 18O and 13C isotopic composition of the corresponding tooth enamel carbonate. A protocol for preparing tooth enamel for 2H analysis was successfully devised and implemented; however, no correlation was observed between tooth enamel 2H abundance values as measured plotted against source water 2H abundance values. While unexpectedly low rates of hydrogen exchange within mineral hydroxyl groups were documented, and it was possible to analyze tooth enamel for its 2H isotopic composition, the seemingly fixed nature of 2H abundance in tooth enamel means that the 2H isotopic signature of tooth enamel cannot be used as an indicator of geographic provenance. Conversely, positive correlations between collagen 2H abundance values of primary dentin with 2H abundance values for source water and also with enamel 18O abundance values suggests that primary dentin collagen 2H values are linked to the isotopic composition of source water. Third molar tooth enamel was sampled from 10 living volunteers undergoing routine tooth extractions at University of Toronto affiliated dental clinics in Ontario, Canada. The mixed-sex group of patients was given questionnaires in which they provided detailed residential history and answered questions pertaining to dietary preferences (e.g., vegetarian) prior to donating all four third molars. Enamel was drilled from the crown of two third molars from each subject, chemically cleaned, and subjected to an acid digest before being analyzed for its 18O and 13C composition using Isotope Ratio Mass Spectrometry. Herewith, isotope abundance values are presented using the delta notation as delta values in per mil (‰). Mean d13CVPDB values for all samples ranged from -9.47 ‰ to -11.31 ‰ (pooled mean = -10.37 ‰), which suggested a persistent C4 plant dietary influence at the time the sampled tooth enamel was forming and is consistent with the typical North American diet. While inter-subject variation contributed the largest proportion of total d13C variability, differences were not significant. The pooled mean d18OVSMOW value for enamel samples was 24.39 ‰, while individual subject mean d18OVSMOW values ranged from 23.76 ‰ to 25.18 ‰. Marked offsets (0.01 ‰ - 0.51 ‰) in mean d18OVSMOW values for each pair of third molars were observed. While subject variation was significant (p=0.0034), neither diet nor sex significantly influenced the oxygen (or carbon) isotope data. Following conversion of d18OVSMOW values to d18OPhosphate values, drinking water values were calculated using the Daux et al. (2008) equation, and compared to their corresponding regional estimated annual average d18O values in precipitation retrieved from the Online Isotopes in Precipitation Calculator (OIPC) (Bowen 2014). Despite observed correlations between the drinking water d18OWater values and d18OOIPC values of four subjects, no statistically significant correlations were evident between the two limited data sets. However, when the isotopically similar d18O values of Toronto area residents were averaged and combined with the remaining Canadian data and the 18O data from 5 enamel samples analyzed in the 2H enamel pilot study, strong positive correlations were evident between d18OPhosphate valuesand d18OOIPC values (R2 = 0.87). Moreover, an equally strong linear relationship was observed between modeled annual precipitation 18O and calculated source water 18O (R2 = 0.87). Based on the d2H, d18O, and d13C values measured in tooth enamel and dentin, it is possible to infer and confirm geographic provenance and dietary intake. However, while enamel carbonate d13C values were consistent with self-reported dietary intake information and residential history, as could be expected vegetarians could not be distinguished from those who consumed meat without determining C/N isotopic ratios in dentin collagen. Further, the presence of strong linear relationships between the 18O composition of enamel carbonate and modeled source water 18O in the merged dataset illustrates the importance of considering site-specific isotopic complexities and using multi-isotope data obtained from multiple tissues when investigating the geographic origins of humans in an archaeological or forensic context. It is not possible to quantify intra-individual isotopic variability without sampling from larger, geographically diverse populations and controlling for as many variables as possible. The construction of regional databases containing 18O and 2H isotopic data obtained from a variety of environmental and human and faunal tissue samples, and the application of such data to individual cases in which geographic origins are desired, is recommended provided the following caveats are considered: 1) whenever possible, d18OPhosphate values should be used when comparing d18O values in tooth enamel with those in precipitation in order to avoid the unmitigated error associated with the application of carbonate conversion equations to enamel phosphate d18O data, 2) the continuous consumption of food sourced elsewhere is liable to affect the overall enamel carbonate d18O values, 3) d18O values in precipitation are not inclusive of the variety of postprecipitation and hydrological processes unique to a particular location, nor are they an accurate representation of the isotopically mixed nature of tap water sourced from distant reservoirs. Hence, extrapolations should be made with caution. Enamel sequential microsampling methods may be advisable for narrowing down a geographic timeline if the overlapping of isotopic signals at various points along the tooth’s longitudinal plane can be quantified and validated. While standardization of analytical methodology is critical to appropriate interpretations of the data, stable isotope profiling is not a standalone method and should be used in conjunction with other lines of evidence in determinations of human provenance.

京都大学 / 新制・課程博士 / 博士(地球環境学) / 甲第23351号 / 地環博第209号 / 新制||地環||40(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)教授 德地 直子, 教授 柴田 昌三, 准教授 西川 完途 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DGAM

Herbivorous coral reef fishes play an important role in helping to structure their environment directly by consuming algae and indirectly by promoting coral health and growth. These fishes are generally separated into three broad groups: browsers, grazers, and excavators/scrapers, with these groupings often thought to have a fixed general function and all fishes within a group thought to have similar ecological roles. This categorization assumes a high level of functional redundancy within herbivorous fishes. However, recent evidence questions the use of this broad classification scheme, and posits that there may actually be more resource partitioning within these functional groupings. Here, I use a compound-specific stable isotope approach (CSIA) to show there appears to be a greater diversity of functional roles than previously assumed within broad functional groups. The δ13C signatures from essential amino acids of reef end-members (coral, macroalgae, detritus, and phytoplankton) and fish muscle were analyzed to investigate differences in resource use between fishes. Most end-members displayed clear isotopic differences, and most fishes within functional groups were dissimilar in their isotopic signature, implying differences in the resources they target. No grazers closely resembled each other isotopically, implying a much lower level of functional redundancy within this group; scraping parrotfish were also distinct from excavating parrotfish and to a lesser degree distinct between scrapers. This study highlights the potential of CSIA to help distinguish fine-scale ecological differences within other groups of reef organisms as well. These results question the utility of lumping nominally herbivorous fishes into broad groups with assumed similar roles. Given the apparent functional differences between nominally herbivorous reef fishes, it is important for managers to incorporate the diversity of functional roles these fish play.

This project tests the hypothesis that the Langobard migration into the Roman/Byzantine Veneto (northeastern Italy) resulted in significant dietary changes from Late Antiquity (4-5th centuries AD) to the Early Medieval period (6-8th centuries AD). At the end of the Great Germanic Migrations in AD 568, Langobards from Pannonia entered and occupied two-thirds of the Italian peninsula. It is unclear how large these migrations were, as historical documents exaggerate mass movements; however, conservative estimates suggest they made up 8% of the areas they occupied. The degree to which the Langobards influenced economic change and subsistence in this area is poorly understood. Therefore, the goal of this research is to use stable isotope analyses on human remains in conjunction with historical and archaeological data to understand how the migration of the Langobards influenced the population structure and political economy (diet) in the Veneto. A total of 149 individual bone samples from seven sites spanning the 4-8th centuries AD from the Veneto underwent stable carbon and nitrogen isotope analysis. In addition, 60 premolars were sampled for stable carbon, nitrogen, and oxygen isotope analysis to assess migration and dietary changes. Previous paleodietary analyses suggest that the traditional Roman diet consisted of C3 terrestrial plants, such as wheat and barley, and domesticated animals with some contributions from fish. The Langobards consumed a mix of C3 and C4 (millet and sorghum) terrestrial plants and animals. C4 plants such as millet were often considered a low socioeconomic status food source during the Roman Empire. The results indicate that migrating Langobards are not present in the cemetery samples; however, migrating Roman/Byzantines are. This suggests a migration inland from the Byzantine occupied coast for better economic prospects. Byzantine occupied areas in Italy experienced heavy taxations, while the Langobards reduced this burden on the location populations. The dietary analyses show significant differences in diet between local and non-local individuals, with non-local individuals consuming more C3 energy sources (wheat) earlier in life. In terms of overall diet in the Veneto, there appears to be an increase in millet consumption from Late Antiquity to the Early Medieval period. There are no significant differences in socioeconomic status or sex, suggesting that millet became standardized in the Veneto, reflecting a sociocultural change in dietary practices. This research is significant because it fills a geographical and chronological gap in Italian history, during a period of significant migration and economic change.

A mass grave containing the remains of at least 3269 Napoleonic soldiers from 1812 was discovered in Vilnius, Lithuania in 2001. Stable carbon and nitrogen isotopic analyses were performed on collagen from 78 femoral samples to explore dietary variation within the sample. Starvation and nutritional distress were also evaluated through the examination of nitrogen enrichment in bone collagen. Clinical studies have demonstrated that enriched nitrogen isotope values can indicate periods of nutritional stress and starvation; however, this is the first study to examine its use as a diagnostic indicator of starvation in a historical population using bone tissue. According to the carbon isotope data, a vast majority of the soldiers in this sample consumed predominantly C3 plants with only five individuals consuming more than 50% of their plant dietary protein in the form of C4 plants, with δ13C ratios for this sample ranging from -19.22‰ to -11.76‰ and a mean of -17.18‰. This conforms to expectations given that a majority of human plant consumption in Europe is C3 pathway plants. Twenty-nine individuals exhibit enriched δ15N values, with δ15N values for this sample ranging from 7.14‰ to 13.63‰ and a mean of 10.49‰. The combination of historical and isotopic evidence suggests prolonged nutritional stress may be the cause of enrichment in this sample. The results of this study demonstrate the applicability of this method on archaeological samples as a line of evidence in the investigation of starvation and famine.

Forested streams are closely linked to terrestrial catchments which affects their biogeochemical cycling and carbon inputs. Catchment disturbances alter stream water quality and food webs, including changes in productivity. Such changes in stream conditions can potentially alter consumers’ reliance on autochthonous (in-stream) or allochthonous (terrestrial) sources and mercury bioaccumulation. A recent outbreak of the spruce budworm (SBW) that feeds on spruce and fir trees has provided the unique opportunity to examine stream food web responses across watersheds experiencing a range of defoliation in the Gaspé Peninsula, Québec. This project compares streams in twelve watersheds which were selectively sprayed to control SBW and create a gradient in defoliation. Food web samples (food sources, invertebrates, fish) were analyzed for stable isotopes of carbon and nitrogen in 2019 and 2020 to characterize food web structure, and algal productivity was measured in 2019. Hierarchical partitioning models were used throughout the study to compare the contributions of various local and landscape conditions to stream responses. Models indicated that watershed defoliation contributed to increasing autochthonous production, although some invertebrates were more allochthonous in heavily defoliated watersheds, and brook diets were unaffected by defoliation. Next, food web samples were analyzed for methylmercury (food sources, invertebrates) or total mercury (fish) and trophic magnification slopes were determined for each stream food web. Mercury levels in carnivorous invertebrates and brook trout were driven by dissolved organic carbon (DOC), but not consumer autochthony or watershed defoliation. Additionally, rates of trophic magnification were not related to defoliation severity or DOC. This study found that defoliation contributed to increasing autochthonous production and invertebrate consumer allochthony. However, this disturbance did not increase consumer mercury levels or biomagnification in stream food webs. These findings suggest that intervention to reduce defoliation would mitigate algal responses and dietary shifts, but not mercury cycling as it is influenced by DOC levels in the streams of this region. / Thesis / Master of Science (MSc) / A recent spruce budworm outbreak is causing widespread defoliation of spruce and fir trees, but the impacts to stream environments, including primary production, its consumption, and contaminant levels, are largely unknown. Streams are sensitive to conditions in the surrounding terrestrial environment, as such changes can affect the diets of stream invertebrates and fish and are also linked to increased contaminant levels in aquatic organisms. Specifically, mercury is a metal that is transferred through diet and can reach toxic levels in fish. This study found that defoliation is contributing to increased algal production in streams in the Gaspé Peninsula, Québec. However, some stream invertebrates consumed more terrestrial material in streams that had heavier defoliation. Furthermore, defoliation and algal diets did not increase levels of mercury in aquatic organisms, but this contaminant was affected by increasing concentrations of dissolved organic carbon in the streams. These findings suggest that forest defoliation can alter organisms’ diets but not mercury levels.

This thesis examines breastfeeding, weaning, and the post-weaning diets of 18 adults (18y+) and two subadults (aged 10y – 14y) from the rural Imperial Roman (1st – 4th c. CE) site of Vagnari, located in southern Italy. The investigation used a new method to sample dentine sections that accounts for the oblique nature of dentine development and allowed for the assignment of age categories to diagenetically altered teeth without visible dentine lines. The results indicate Vagnari children were weaned by ~3.5y, and that some males appear to have been breastfed longer than females. Despite the similar ages-at-weaning across the sample, the individuals in this study demonstrated a variety of weaning rates (i.e., speeds or paces), post-weaning dietary trends, and changes in diet across the life course. Some individuals (n = 6) appear to have been weaned rapidly, marked by significant removal of breastmilk prior to 2.5y, with small amounts of breast milk remaining in the diet until ~3.5y. Other children (n = 9) were weaned gradually, with slow, consistent removal of breastmilk until as late as 5.0y. Throughout and after the weaning period, children were fed a diet based on C3 plants and terrestrial proteins such as wheat, goat/sheep, and their by-products. A comparison of early life dentine and adult bone collagen signals for 14 individuals revealed changes in diet with increasing age, in which most people had increased access to higher terrestrial food sources such as pork and/or small amounts of marine food later in life. However, there was notable variation in dietary trends and practices across the sample, suggesting diverse dietary patterns among people from Vagnari. / Thesis / Master of Arts (MA) / In this thesis, I used samples from tooth dentine to analyze longitudinal stable isotope data for breastfeeding, weaning, and post-weaning dietary signals in a sample of 20 individuals from the Roman Imperial estate of Vagnari (1st – 4th c. CE) located in southern Italy. On average, children were weaned by ~3.5 years of age. Despite the similar age-at-weaning across the sample, individuals exhibited different weaning patterns and diversity in early life dietary practices at Vagnari. During and after weaning, the isotope data indicate that children were fed with C3 plants (e.g., wheat) and terrestrial proteins such as sheep/goat and pig. I analyzed childhood and adult diet by comparing dentine stable isotope data to bone collagen results from a sub-sample of 14 individuals. There was variability between the childhood dentine data and the adult bone collagen data, where individuals appeared to eat more pork and small amounts of fish later in life. This is the first study to explore breastfeeding and weaning practices of rural Roman children in southern Italy using stable isotope analysis of tooth dentine.

This thesis investigates breastfeeding and weaning patterns in an Iron Age (7th – 4th century BCE) sample of subadults (n=12) and adults (n=9) buried at the sites of Botromagno, Parco San Stefano and Padreterno in southern Italy. Stable isotope analysis of both human tooth dentine and bone collagen for each subadult, and tooth dentine for adults, was undertaken to create early-life feeding histories. The dentine serial sections were used to determine the onset and completion of weaning for each individual, as well as distinguish general trends in early feeding practices at these Iron Age sites. Results indicate that the average onset of weaning in subadults occurred at 8 ± 3.4 months and weaning was completed by 4 years of age at the latest for all individuals; however, the patterns of breastfeeding and weaning were variable in this sample. This study also explores variation in early childhood diet between survivors and non-survivors (i.e., < 4 years of age). Non-survivors were weaned more rapidly than survivors – possibly contributing to their earlier death – and some non-survivors demonstrated elevated δ15N values that may have been a result of physiological stress. It is, however, difficult to distinguish signals of breastfeeding versus stress in young children who were still likely consuming breast milk. Finally, differences in isotope data between dentine serial sampling and bulk-bone sampling of rib and femoral collagen from the same individuals were investigated. The results show that the combined use of dentine and bone data contribute to more nuanced interpretations of weaning. Further, rib samples represent diet closer to the time of death than femoral samples, as faster bone turnover rate in ribs allow for the incorporation of more recent dietary changes. / Thesis / Master of Arts (MA)

Yes / There are few reliable osteological indicators to detect parity or infer puberty in skeletal remains. Nitrogen (δ15N) and stable carbon (δ13C) isotope ratios in human tissues can be affected by metabolically unbalanced states engendered by pregnancy or rapid growth, offering potential biomarkers. This pilot study explores the potential of incremental dentine-collagen isotope ratio analysis to identify puberty and gestation. Methodology: Incremental dentine δ15N and δ13C profiles were produced by analysing third molars extracted as part of dental treatment of 10 individuals living in Sudan. Demographic and anthropometric data at the time of tooth extraction was available. Medical histories were unknown. Results: Isotopic signatures potentially related to pubertal growth, with an average δ15N reduction of 0.78±0.29‰, are indicated. Six isotopic signals suggestive of pregnancy, with an average δ15N decrease of 0.48±0.22‰, are also observed. The timing, speed and amplitude of post-partum δ15N patterns seemingly infer infant feeding practices and maternal nutritional status. Conclusion: This pilot study highlights the potential of incremental dentine isotope analysis for the reconstruction of early reproductive histories in skeletal remains. However, controlled studies with larger human cohort are needed to validate these findings, establish isotopic signals linked to puberty and lactation, and improve chronology accuracy.

No / The adventus Saxonum is a crucial event in English protohistory. Scholars from a range of disciplines dispute the scale and demographic profile of the purported colonizing population. The 5th-7th century burial ground at West Heslerton, North Yorkshire, is one of the few Anglian cemeteries where an associated settlement site has been identified and subjected to extensive multidisciplinary postexcavation study. Skeletal and grave good evidence has been used to indicate the presence of Scandinavian settlers. A small, preliminary study using lead and strontium isotope analysis of tooth enamel, mineralized in early childhood, from Neolithic/Early Bronze Age (n = 8), Iron Age (n = 2), and Early Anglo-Saxon (n = 32) skeletons, was carried out to directly investigate this hypothesis. Results suggest that lead provides dissimilar types of information in different time periods. In post-Roman England, it appears to reflect the level of exposure to circulated anthropogenic rather than natural geological lead, thus being a cultural rather than geographical marker. Consequently, only strontium provides mobility evidence among the Anglian population, whereas both isotope systems do so in pre-Roman periods. Strontium data imply the presence of two groups: one of local and one of nonlocal origin, but more work is required to define the limits of local variation and identify immigrants with confidence. Correlations with traditional archaeological evidence are inconclusive. While the majority of juveniles and prehistoric individuals fall within the local group, both groups contain juveniles, and adults of both sexes. There is thus no clear support for the exclusively male, military-elite invasion model at this site.