A simple carbon isotope model for reconstructing prehistoric human diet

Early Colonial Diet in El Japón, Xochimilco, Mexico: Examining dietary continuity through stable isotope analysis of bone collagen and bioapatite

OBJECTIVES

Early colonial documents from central Mesoamerica detail raising and planting of European livestock and crops alongside native ones. The extent to which Indigenous people, especially of the rural commoner class, consumed newly introduced foods is less known. This gap in knowledge is addressed through stable isotope analysis and comparison to published archaeological botanical, human, and faunal data.

MATERIALS AND METHODS

Stable isotope analysis of bone collagen and bioapatite is applied to 74 skeletal samples of Indigenous human remains representing Colonial period individuals from El Japón-a farming hamlet in the Xochimilco area-to provide insight into long-term individual dietary practices in the context of a rapidly transforming Mesoamerican world.

RESULTS

Carbon isotope ratios in collagen (δ13Ccollagen) average -8.10/00 VPDB (SD 0.55), while δ15N averages 8.90/00 AIR (SD 0.50). δ13Cbioapatite averages -2.90/00 VPDB (SD 0.60). Modest increase in carbon isotopic diversity is observed among more recent males from El Japón when compared to earlier males and females.

DISCUSSION

Based on the isotopic results, it is estimated that the individuals of El Japón consumed maize or other C4 plants as a central source of carbohydrates. Dietary protein was largely supplied through domestic maize-fed fauna but potentially supplemented by wild terrestrial and aquatic fauna and fowl. Similarity in skeletal isotopic composition between precontact Mesoamericans from other sites and El Japón individuals of both earlier and later stratigraphy is interpreted as continuity in local diets and foodways despite potentially available European alternatives. Colonial taxation demands on preexisting agricultural regimes may have incentivized maize production, thus indirectly contributing to the maize-centered aspect of local foodways.

Local circulation of elites punctuated by transregional mobility enabled steppe political consolidation in the Xiongnu nomadic state

The Xiongnu polity (ca. 200 BC- 150 AD) emerged out of indigenous community-centered socio-political structures to forge a powerful state that commanded the Mongolian steppe and beyond. Underpinned by a highly mobile pastoralist population, accustomed to seasonally rhythmic moves and embedded in an equestrian culture that facilitated rapid transport over long-distances, it remains unclear precisely how the movement of commoners, local aristocrats and regional elites abetted the formation and organization of Xiongnu state structures. Here, we evaluate Xiongnu movement and dietary intake through multi-stable isotopic analyses of tooth enamel from directly dated Xiongnu intermediate elites recovered from the mortuary center of Baga Gazaryn Chuluu-a prominent granite outcrop set in the Gobi Desert. Carbon isotope (δ13C) analysis indicates millet was consumed by some individuals, but whether or not this C4 cultivar contributed to the diets of most elites remains ambiguous in this C3/C4 desert-steppe environment. The effectiveness of oxygen isotopes (δ18O) to establish mobility appears much reduced in steppe environments, where geospatially sensitive information appears disrupted by extraordinary seasonality in meteoric water oxygen isotopes, pronounced oxygen isotopic variation in potential drinking water sources, and culturally mediated drinking practices. Most revealing, strontium isotopes (87Sr/86Sr) indicate circulation of local elites around this central place and beyond, a mobility format that helped leaders cement their own position through political consolidation of spatially dispersed mobile pastoralist communities. The consistent presence at Baga Gazaryn Chuluu of extra-local intermediate elites also points toward the importance of transregional mobility in binding together the Xiongnu polity over the vast distances of the eastern steppe.

Shrouded in history: Unveiling the ways of life of an early Muslim population in Santarém, Portugal (8th- 10th century AD)

In around 716 AD, the city of Santarém, Portugal, was conquered by the Berber and Arab armies that swept the Iberian Peninsula and went on to rule the region until the 12th century. Archaeological excavations in 2007/08 discovered an Islamic necropolis (Avenida 5 de Outubro #2-8) that appears to contain the remains of an early Muslim population in Santarém (8th- 10th century). In this study, skeletal material from 58 adult individuals was analysed for stable carbon (δ13Ccol; δ13Cap), nitrogen (δ15N) and sulphur (δ34S) isotope ratios in bones, and stable oxygen (δ18O), carbon (δ13Cen) and radiogenic strontium (87Sr/86Sr) isotopes in tooth enamel. The results of this study revealed a dietary pattern of predominantly C3-plant and domestic C3-fed herbivore consumption during adulthood (δ13Ccol and δ15N, respectively) but a higher proportion of C4-plant input during childhood (δ13Cen) for some individuals-interpreted as possible childhood consumption of millet porridge, a common practice in North Africa-in those with unorthodox burial types (Groups 1 and 2) that was not practiced in the individuals with canonical burials (Group 3). In this first mobility study of a medieval Muslim population in Portugal, δ18ODW values revealed greater heterogeneity in Groups 1 and 2, consistent with diverse origins, some in more humid regions than Santarém when compared to regional precipitation δ18O data, contrasting the more homogenous Group 3, consistent with the local precipitation δ18O range. Ancient DNA analysis conducted on three individuals revealed maternal (mtDNA) and paternal (Y-chromosome) lineages compatible with a North African origin for (at least) some of the individuals. Additionally, mobility of females in this population was higher than males, potentially resulting from a patrilocal social system, practiced in Berber and Arab communities. These results serve to offer a more detailed insight into the ancestry and cultural practices of early Muslim populations in Iberia.

The role of farming and fishing in the rise of social complexity in the Central Andes: a stable isotope perspective

For many years, the rise of stratified societies along the Central Andean coast, known as the birthplace of Andean civilization, has been closely linked to a marine-oriented economy. This hypothesis has recently been challenged by increasing evidence of plant management and cultivation among Andean populations long before the emergence of complex societies and monumental architecture. The extent to which marine and plant-based economies were integrated and their contributions to early sedentism, population growth, and intra-community stratification, however, remain subjects of ongoing and contentious debate. Using Bayesian Mixing Models we reanalyze the previously published stable isotopes (δ15Ncollagen, δ13Ccollagen, δ13Capatite) values of 572 human individuals from 39 archaeological sites in the Central Andes dated between ca. 7000 BCE and 200 CE to reconstruct dietary regimes in probabilistic terms. Our results reveal that fish, terrestrial fauna, and cultivated plants variably contributed to the diet of prehistoric Andean populations; in coastal and middle valley settlements plant cultivation, not fishing, fueled the development of the earliest complex societies during the Formative Period (from 3000 BCE). Similarly, in the highlands the societies that built ceremonial centers show a plant-based economy. Our findings also show that maize only became a staple food (> 25% dietary contribution) in more recent phases of Andean prehistory, around 500 BCE.

A Bayesian multi-proxy contribution to the socioeconomic, political, and cultural history of late medieval Capitanata (southern Italy)

Medieval southern Italy is typically viewed as a region where political, religious, and cultural systems coexisted and clashed. Written sources often focus on elites and give an image of a hierarchical feudal society supported by a farming economy. We undertook an interdisciplinary study combining historical and archaeological evidence with Bayesian modelling of multi-isotope data from human (n = 134) and faunal (n = 21) skeletal remains to inform on the socioeconomic organisation, cultural practices, and demographics of medieval communities in Capitanata (southern Italy). Isotopic results show significant dietary differences within local populations supportive of marked socioeconomic hierarchies. Bayesian dietary modelling suggested that cereal production, followed by animal management practices, was the economic basis of the region. However, minor consumption of marine fish, potentially associated with Christian practices, revealed intra-regional trade. At the site of Tertiveri, isotope-based clustering and Bayesian spatial modelling identified migrant individuals likely from the Alpine region plus one Muslim individual from the Mediterranean coastline. Our results align with the prevailing image of Medieval southern Italy but they also showcase how Bayesian methods and multi-isotope data can be used to directly inform on the history of local communities and of the legacy that these left.

Paired stable carbon and oxygen isotope analyses of human enamel for forensic human geolocation: An exploratory study

Stable carbon isotope analysis has proven utility for reconstructing dietary information in humans in past populations. The usefulness of stable carbon for forensic geolocation has been little investigated, largely because of the globalization of the human diet seemingly rendering it inconsequential. This study queried this assumption at a country-wide level on a known sample group. Stable carbon isotope values were obtained from human enamel with known biographical and geographical information to determine whether stable carbon, when paired with stable oxygen isotope values, could differentiate Canadians from non-Canadians. Samples originating outside of Canada were separated into three regions, and a linear discriminant analysis was used to generate discriminant functions that best separate the regions according to the stable carbon and oxygen isotope values. The results revealed two functions, where the first function explained 92.1% and the second 7.9% of the variance. Although some overlap in stable carbon and oxygen values was observed for individuals from both the United States and Canada, differences were observed between those from Canada and other geographical regions. This study demonstrated that pairing the dietary isotope carbon with the geolocator stable oxygen isotope, produced an interesting separation geographically, one that might well be helpful when attempting a geolocation query on unknown human remains.

Ecological flexibility and adaptation to past climate change in the Middle Nile Valley: A multiproxy investigation of dietary shifts between the Neolithic and Kerma periods at Kadruka 1 and Kadruka 21

Human responses to climate change have long been at the heart of discussions of past economic, social, and political change in the Nile Valley of northeastern Africa. Following the arrival of Neolithic groups in the 6th millennium BCE, the Northern Dongola Reach of Upper Nubia witnessed a cultural florescence manifested through elaborate funerary traditions. However, despite the wealth of archaeological data available from funerary contexts, including evidence for domesticated animals and plants as grave goods, the paucity of stratified habitation contexts hinders interpretation of local subsistence trajectories. While it is recognised archaeologically that, against the backdrop of increasing environmental deterioration, the importance of agriculture based on Southwest Asian winter cereals increased throughout the Kerma period (2500-1450 BCE), the contribution of domesticated cereals to earlier Neolithic herding economies remains unclear. This paper presents direct dietary data from a total of 55 Middle Neolithic and Kerma period individuals from Kadruka 21 and Kadruka 1. Microbotanical data obtained from human dental calculus and grave sediments are integrated with human and faunal stable isotopes to explore changes in dietary breadth over time. The combined results demonstrate the consumption of wild plant species, including C4 wetland adapted grasses, by Middle Neolithic individuals at Kadruka 1. Despite existing evidence for domesticated barley in associated graves, the results obtained in this study provide no clear evidence for the routine consumption of domesticated cereals by Middle Neolithic individuals. Rather, direct microparticle evidence for the consumption of Triticeae cereals is only associated with a single Kerma period individual and corresponds with an isotopic shift indicating a greater contribution of C3-derived resources to diet. These results provide evidence for Neolithic dietary flexibility in Upper Nubia through the persistence of foraging activities and support existing evidence linking increased agricultural reliance to the development of the Kerma culture.

Provenancing antiquarian museum collections using multi-isotope analysis

Many of the most significant archaeological sites in Europe were excavated by antiquarians over one hundred years ago. Modern museum collections therefore frequently contain human remains that were recovered during the nineteenth and early twentieth centuries. Here we apply multi-isotope analysis (⁸⁷Sr/⁸⁶Sr, δ ¹⁸O, δ ¹³C, δ ¹⁵N) and ¹⁴C dating to evaluate the provenance of human remains within a collection that is thought to have been recovered from one of the most important archaeological sites in Britain. Excavated in 1910, the site of Coldrum in Kent is a megalithic burial monument that may be one of the earliest sites associated with the transition to farming in Britain. The interpretation of this site is therefore key to understanding how agriculture began. Using isotope analysis we show that although the human skeletal collections attributed to Coldrum do contain some of the earliest dated Neolithic human remains in Britain, they also contain the remains of individuals of fifth to seventh centuries AD date. We evaluate subsistence and mobility patterns of early Neolithic populations and provide new information about the origins of those individuals in the collection that date to the fifth to seventh centuries AD. We demonstrate the utility of employing isotope analysis to provide direct and independent information about the provenance of human remains in museum collections.

Galápagos tortoise stable isotope ecology and the 1850s Floreana Island Chelonoidis niger niger extinction

A consequence of over 400 years of human exploitation of Galápagos tortoises (Chelonoidis niger ssp.) is the extinction of several subspecies and the decimation of others. As humans captured, killed, and/or removed tortoises for food, oil, museums, and zoos, they also colonized the archipelago resulting in the introduction of invasive plants, animals, and manipulated landscapes for farming, ranching, and infrastructure. Given current conservation and revitalization efforts for tortoises and their habitats, here we investigate nineteenth and twentieth century Galápagos tortoise dietary ecology using museum and archaeological specimens coupled with analysis of carbon (δ¹³C_collagen and δ¹³C_apatite), nitrogen (δ¹⁵N), hydrogen (δD) and oxygen (δ¹⁸O_apatite) stable isotopes and radiocarbon dating. We identify that Galápagos tortoise diets vary between and within islands over time, and that long-term anthropogenic impacts influenced change in tortoise stable isotope ecology by using 57 individual tortoises from 10 different subspecies collected between 1833 and 1967-a 134-year period. On lower elevation islands, which are often hotter and drier, tortoises tend to consume more C₄ vegetation (cacti and grasses). Our research suggests human exploitation of tortoises and anthropogenic impacts on vegetation contributed to the extinction of the Floreana Island tortoise (C. n. niger) in the 1850s.

On the relationship between collagen- and carbonate-derived carbon isotopes with implications for the inference of carnivore dietary behavior

Studies of Rancho La Brea predators have yielded disparate dietary interpretations when analyzing bone collagen vs. enamel carbonate—requiring a better understanding of the relationship between stable carbon isotopes in these tissues. Stable carbon isotope spacing between collagen and carbonate (Δca-co) has also been used as a proxy for inferring the trophic level of mammals, with higher Δca-co values indicative of high carbohydrate consumption. To clarify the stable isotope ecology of carnivorans, past and present, we analyzed bone collagen (carbon and nitrogen) and enamel carbonate (carbon) of extinct and extant North American felids and canids, including dire wolves, sabertooth cats, coyotes, and pumas, supplementing these with data from African wild dogs and African lions. Our results reveal that Δca-co values are positively related to enamel carbonate values in secondary consumers and are less predictive of trophic level. Results indicate that the foraging habitat and diet of prey affects Δca-co in carnivores, like herbivores. Average Δca-co values in Pleistocene canids (8.7+/−1‰) and felids (7.0+/−0.7‰) overlap with previously documented extant herbivore Δca-co values suggesting that trophic level estimates may be relative to herbivore Δca-co values in each ecosystem and not directly comparable between disparate ecosystems. Physiological differences between felids and canids, ontogenetic dietary differences, and diagenesis at Rancho La Brea do not appear to be primary drivers of Δca-co offsets. Environmental influences affecting protein and fat consumption in prey and subsequently by predators, and nutrient routing to tissues may instead be driving Δca-co offsets in extant and extinct mammals.

Earliest evidence of primate captivity and translocation supports gift diplomacy between Teotihuacan and the Maya

A multimethod archaeometry study (zooarchaeological, isotopic, ancient DNA, paleobotanical, and radiocarbon dating) of a spider monkey sacrificed in the ceremonial center of Teotihuacan, Mexico (1 to 550 CE) is interpreted as a diplomatic gift exchange with neighboring Maya. Not only does this spider monkey provide the earliest known instance of primate translocation and captivity in Mesoamerica, it helps date incipient modes of interregional diplomacy between two major powers during Early Classic Mesoamerica: Teotihuacan and the Maya. Details of human-primate interaction include age at capture and transport (before ∼3 y of age), captive duration (over 2 y), anthropogenic diet (staple was maize, though secondary resources unique to anthropogenic diet including arrowroot and chili pepper were also found), context of sacrifice (tethered and associated with complete golden eagle and an array of other statecrafts), and general site context (including presence of Maya vessels and Maya-style murals). The timing of the spider monkey's sacrifice (250 to 300 CE) and its life history suggest a reconsideration of epigraphically attested militaristic involvement of Teotihuacan at certain Maya sites. We propose that a period of more multilateral and fluid ritual exchange with Maya dignitaries preceded the Teotihuacan state's eventual ascent to prominence.

Herd management and subsistence practices as inferred from isotopic analysis of animals and plants at Bronze Age Politiko-Troullia, Cyprus

The Bronze Age village of Politiko-Troullia, located in the foothills of the copper-bearing Troodos mountains of central Cyprus, was occupied ~2050-1850 cal BCE. Excavated evidence shows that community activities included copper metallurgy (ore processing, smelting and casting), crop cultivation, and rearing of livestock. Faunal analysis reveals day-to-day subsistence practices that included consumption of sheep, goat, cattle, and pig, as well as community-scale ritual feasting focused on fallow deer, Dama dama mesopotamica. In this paper, we present bone collagen stable isotope data from these taxa to infer how these animals were managed. We incorporate stable isotope baselines calculated from modern cereal grains and compare these to archaeological seeds from Politiko-Troullia. Mean values of δ13C and δ15N cluster for livestock consistent with a diet of C3 plants, with a wider range in goats that suggests free-browsing herds. Higher δ15N values in cattle may reflect supplemental feeding or grazing in manured fields. Plant isotope values suggest livestock diets were predominantly composed of cultivated taxa. In contrast, deer and pig bones produce more negative mean δ13C and δ15N values suggesting that the villagers of Politiko-Troullia complemented their management of domesticated animals with hunting of wild deer and feral pigs in the woodlands surrounding their village.

The diet at the onset of the Andean Civilization: New stable isotope data from Caral and Áspero, North-Central Coast of Peru

OBJECTIVES

The subsistence system of the first urban centers with monumental architecture from the North-Central Coast of Peru, the core area for the social complexity process of Central Andes, has been debated since the late 1960s. To shed light on this aspect, we report paleodietary data from the two most important sites of the Supe Valley: Caral (3000-200 BC), the major settlement of the middle valley, and Áspero (3000-1800 BC), a notable coastal settlement. Our main objective was to test the Maritime Foundations of Andean Civilization hypothesis.

MATERIALS AND METHODS

Stable isotope values (δ¹³ C_col , δ¹³ C_ap , and δ¹⁵ N) from 52 individuals (70 samples: 44 bones and 26 teeth) were analyzed using conventional methods and Bayesian Mixing Models to address the role of marine products and plants in people's diet at both sites over time.

RESULTS

Our results suggest high C₃ carbohydrate consumption (55%-68% total calories in Áspero and >70% in Caral). The consumption of marine resources was stable for Áspero between 3300 and 1800 BC, but it decreased for Caral between 2550 and 200 BC.

DISCUSSION

Marine protein was more important in Áspero than in Caral over time. C₃ plants, possibly tubers, formed the foundation of the diet in both sites during the Formative period (~3000-200 BC). Maize was a marginal food (<12% of calories) at least until 800 BC (29% of calories). The Maritime Foundations hypothesis does not completely account for these findings. Our results suggest the predominance of crop-focused agriculture during the evaluated period.

Tracking breastfeeding and weaning practices in ancient populations by combining carbon, nitrogen and oxygen stable isotopes from multiple non-adult tissues

This paper explores the potential of combining different isotope systems from different tissues to improve resolution when reconstructing breastfeeding and weaning practices (BWP) in archaeology. Additionally, we tested whether changes in diet can be detected in deciduous teeth. Rib collagen samples from 22 infants/children from the archaeological site of Bacuranao I (Mayabeque, Cuba) were processed for nitrogen (δ¹⁵N) and carbon (δ¹³C_co) stable isotopes and assessed using a Bayesian model (WARN). In addition, enamel of 48 teeth from 30 infants/children were analyzed for oxygen (δ¹⁸O_en) and carbon (δ¹³C_en) stable isotopes. Data revealed that the timing of weaning cannot be characterized precisely by analyzing either δ¹⁸O or δ¹⁵N. While a depletion in both δ¹⁵N and δ¹³C_co is only evident after one year, the WARN model suggested that the weaning process started at around 3 months and ended around 1.7 years. Most teeth were enriched in δ¹⁸O_en compared to deciduous incisors, suggesting a breastfeeding signal. However, a high variability in δ¹⁸O was found between similar teeth from the same individuals. Higher enrichment in δ¹⁸O_en, and variability, was observed in tissues formed during the first six months of life. A δ¹³C enrichment of 1.0‰ was observed among deciduous teeth and ribs. While most individuals enriched in δ¹⁵N showed enrichment in δ¹³C, the δ¹⁸O values were more variable. Our data suggests that stable isotopes of deciduous teeth, especially δ¹³C_en, can be used to detect changes in diet during the weaning process. It is also possible that the δ¹⁸O enrichment observed in M1 is influenced by the effects of cooking techniques on weaning foods. The combination of multiple isotope systems and tissues overcome some of the limitations posed by single tissue approaches.

Sidon on the breadth of the wild sea: Movement and diet on the Mediterranean coast in the Middle Bronze Age

OBJECTIVES

Excavations at Sidon (Lebanon) have revealed dual identities during the Middle Bronze Age (ca. 2000-1600 BCE): a maritime port and center for local distribution, as well as a settlement with a heavy subsistence dependence on the extensive inland hinterlands. We aim to investigate residential mobility at Sidon using isotopic analyses of 112 individuals from 83 burials (20 females, 26 males, and 37 subadults). Veneration and remembrance of the dead is evident from funerary offerings in and near the tombs. With marine fish a major component in funerary offerings, we predict major marine reliance in this coastal population.

MATERIALS AND METHODS

New isotopic evidence of paleomobility (⁸⁷ Sr/⁸⁶ Sr, δ¹⁸ O) and diet (δ¹³ C_carbonate ) is the focus of this research. Previous bulk bone collagen δ¹³ C and δ¹⁵ N analysis is strengthened by further sampling, along with δ³⁴ S where collagen yield was sufficient.

RESULTS

The five non-locals identified (8.9% of the 56 analyzed) come from constructed tombs with high-status grave goods except for one, which was heavily disturbed in antiquity. Dietary investigation of the population confirms reliance on terrestrial resources with no significant marine input. No significant differences in diet between the sexes or burial types are present.

CONCLUSIONS

Although Sidon was part of a growing Mediterranean network evidenced through artefactual finds, relatively low immigration is evident. While religious feasts venerating the dead may have involved significant piscine components, no appreciable marine input in diet is observed. Fish may have been reserved for the deceased or only consumed on feast days alongside the dead rather than a regular part of the Bronze Age menu.

A chimpanzee enamel-diet δ13C enrichment factor and a refined enamel sampling strategy: Implications for dietary reconstructions

Reconstructing diets from stable carbon isotopic signals in enamel bioapatite requires the application of a δ¹³C enamel-diet enrichment factor, or the isotopic offset between diet and enamel, which has not been empirically determined for any primate. In this study, an enamel-diet enrichment factor (ε∗_enamel-diet) of 11.8 ± 0.3‰ is calculated for chimpanzees (Pan troglodytes) at Ngogo in Kibale National Park, Uganda, based on a comprehensive isotopic assessment of previously analyzed dietary plant data and new isotopic analyses of enamel apatite. Different enamel sampling methods are evaluated to determine the potential influence of weaning on isotopic enamel values and dietary interpretations. The new chimpanzee enrichment factor and a sampling strategy that excludes teeth that formed before weaning completion are applied to all known chimpanzee δ¹³C_enamel data, either previously published or newly derived in this study, resulting in a dietary range of almost 6‰ across all chimpanzees sampled. This new chimpanzee enamel-diet enrichment factor is then used to reassess dietary reconstructions of 12 fossil hominin species whose isotopic enamel signatures have been determined. Results reveal hominin diets that are isotopically more positive than previously reconstructed, highlighting the widespread contribution of ¹³C-enriched C₄/crassulacean acid metabolism (CAM) resources in fossil hominin diets and emphasizing the broad use of these resources during human evolution. These findings stress the importance of ascertaining and employing an appropriate enrichment factor for dietary reconstructions of specific taxa as well as standardizing the sampling protocol for tooth enamel in isotopic paleodietary reconstructions.

Carbon and nitrogen stable isotopic offsets between diet and hair/feces in captive orangutans

Estimating stable isotopic offset values is crucial for dietary reconstructions. Although research into stable isotope ecology of wild nonhuman primates is increasing overall, only a minority of studies involve laboratory experiments. This study is the first to report the carbon and nitrogen stable isotopic offset values in hair and feces of orangutans. During an experiment lasting 1 week, the weight of each consumed food item was recorded for each of six captive Bornean orangutan (Pongo pygmaeus) individuals. The food, hair, and fecal samples were collected for a few days, and their stable carbon and nitrogen isotope ratios were measured using an elemental analyzer/isotope ratio mass spectrometer. Subsamples of feces were treated with ethanol during the preservation process. Monte Carlo analyses showed that the 95% confidence intervals (CIs) of the carbon and nitrogen offset values between hair and diet were +0.9‰ to +3.9‰ and +2.3‰ to +4.5‰, respectively. The 95% CIs of the carbon and nitrogen offset values between feces and diet were -3.7‰ to -0.9‰ and +0.3‰ to +2.7‰, respectively. The effect of ethanol treatment on the stable isotope ratios of feces was unclear and inconclusive. The computed offset values of hair in captive orangutans are similar to those reported in other nonhuman primates, although those of feces showed greater interspecies variations. The offset values estimated in this study contribute to isotopic studies into the feeding ecology of free-ranging orangutans who are critically endangered in most wild settings.

Breastfeeding and weaning in Late Holocene hunter-gatherers of the lower Paraná wetland, South America

OBJECTIVE

In this study, we analyze breastfeeding and weaning practices in pre-Columbian complex hunter-gatherers from the lower Paraná River basin (South America).

MATERIALS AND METHODS

We carried out bone isotope analyses concerning δ¹³ C in collagen and apatite, the spacing between both carbon sources and δ¹⁵ N in a sample of 23 subadult and adult individuals of both sexes recovered from Late Holocene archaeological sites, ranging from 1665 ± 45 to 680 ± 80 ¹⁴ C years BP.

RESULTS AND DISCUSSION

The results indicate that exclusive breastfeeding continued until the age of ~2 years, and weaning probably until 4 years of age. Supplementary foods included C₃ plants and probably animal fats and C₄ carbohydrates. A high fractionation of 4.9‰ in δ¹⁵ N values was recognized between breastfeeding infants and adult females, perhaps reflecting episodic hyper-protein diets in women linked to men's food provisioning during women's gestational/postpartum period. Additionally, male adults present a higher protein intake than females. Although this difference is not statistically significant with the current sample size, it could be a clue related to a sexual division in food procurement.

Multi-isotope evidence of population aggregation in the Natufian and scant migration during the early Neolithic of the Southern Levant

Human mobility and migration are thought to have played essential roles in the consolidation and expansion of sedentary villages, long-distance exchanges and transmission of ideas and practices during the Neolithic transition of the Near East. Few isotopic studies of human remains dating to this early complex transition offer direct evidence of mobility and migration. The aim of this study is to identify first-generation non-local individuals from Natufian to Pre-Pottery Neolithic C periods to explore the scope of human mobility and migration during the Neolithic transition in the Southern Levant, an area that is central to this historical process. The study adopted a multi-approach resorting to strontium (⁸⁷Sr/⁸⁶Sr), oxygen (δ18O_VSMOW) and carbon (δ¹³C) isotope ratio analyses of tooth enamel of 67 human individuals from five sites in Jordan, Syria, and Israel. The isotope ratios point both to a significant level of human migration and/or mobility in the Final Natufian which is compatible with early sedentarism and seasonal mobility and with population aggregation in early sedentary hamlets. The current findings, in turn, offer evidence that most individuals dating to the Pre-Pottery Neolithic were local to their respective settlements despite certain evidence of non-locals. Interestingly, isotopic data suggest that two possible non-local individuals benefitted from particular burial practices. The results underscore a decrease in human mobility and migration as farming became increasingly dominant among the subsistence strategies throughout the Neolithic transition of the Southern Levant.

Measuring the impact of corn on mammalian omnivores

In human-dominated landscapes throughout the world, wildlife seek out anthropogenic foods because they are high in nutritional value and are consistently available. To investigate this mode of foraging, some researchers use stable isotope analysis to detect these animals in populations and estimate their individual diets. In this study, we develop an integrative approach to measure the proportion of corn, a C4 plant, in the diets of free-ranging mammalian omnivores in C3-dominated ecosystems. We fed captive mice corn, C3 plants, and meat until carbon stable isotopes (δ 13C) from each diet equilibrated in their hair. We then used carbon discrimination factors (Δ 13C; offsets between stable isotope values of consumer tissues and their foods) for mice from these feeding trials and a simple carbon stable isotope mixing model to estimate the corn-based diets of free-ranging American black bears in Wisconsin and brown bears in Slovenia. We used Δ 13C factors for mice to estimate the diets of bears because mouse models are used commonly to study mammalian diet and health, including humans and bears, and body mass has no effect on carbon discrimination factors in monogastric mammalian omnivores. In this study, we found that mice grew fastest, largest, and δ 13C values equilibrated quickest in the hair of mice fed meat versus plant-based diets, suggesting protein quantity (quality was the same) has an effect on Δ 13C. Evidence also suggests that Δ 13C did not increase with animal growth rate as all mice grew throughout the 109-day feeding trials, but isotopic equilibration occurred early while mice still were subadults and was maintained throughout their adult lives. We also found that Δ 13C was highest and most variable in the hair, serum, and liver, of mice fed a mixed diet of C3 plants, supporting our mixed diet hypothesis that states that Δ 13C varies more among tissues of animals fed mixed diets than animals fed nonmixed diets because the former are composed of multiple foods, each with different macromolecular and isotopic compositions. Lastly, we found that corn may have been a more important component of bear diets in Wisconsin than previously thought (adults: x¯ = 29%; x¯ = 33%; subadults: x¯ = 22%; x¯ = 28%), and male brown bears may have fed on 50% more corn (x¯ = 47% versus 31%) in autumn during a year when beechnut availability was low. In a world that is rapidly changing, it is more important than ever to develop the appropriate quantitative tools to measure the impact people have on wildlife. Here, we provide such a tool for monogastric mammalian omnivores and encourage other researchers to do the same for other taxa of interest.

Re-evaluating Scythian lifeways: Isotopic analysis of diet and mobility in Iron Age Ukraine

The Scythians are frequently presented, in popular and academic thought alike, as highly mobile warrior nomads who posed a great economic risk to growing Mediterranean empires from the Iron Age into the Classical period. Archaeological studies provide evidence of first millennium BCE urbanism in the steppe while historical texts reference steppe agriculture, challenging traditional characterizations of Scythians as nomads. However, there have been few direct studies of the diet and mobility of populations living in the Pontic steppe and forest-steppe during the Scythian era. Here, we analyse strontium, oxygen, and carbon isotope data from human tooth enamel samples, as well as nitrogen and carbon isotope data of bone collagen, at several Iron Age sites across Ukraine commonly associated with ‘Scythian’ era communities. Our multi-isotopic approach demonstrates generally low levels of human mobility in the vicinity of urban locales, where populations engaged in agro-pastoralism focused primarily on millet agriculture. Some individuals show evidence for long-distance mobility, likely associated with significant inter-regional connections. We argue that this pattern supports economic diversity of urban locales and complex trading networks, rather than a homogeneous nomadic population.

Bronze Age innovations and impact on human diet: A multi-isotopic and multi-proxy study of western Switzerland

The archaeological Bronze Age record in Europe reveals unprecedented changes in subsistence strategies due to innovative farming techniques and new crop cultivation. Increasing cultural exchanges affected the economic system. The inhabitants of Switzerland played a pivotal role in this European context through relationships with the Mediterranean, the High and Middle Danube regions and the Alps thanks to the area’s central position. This research aims to reconstruct, for the first time in Switzerland, human socio-economic systems through the study of human diet, herding and farming practices and their changes throughout the Bronze Age (2200–800 BCE) by means of biochemical markers. The study includes 41 human, 22 terrestrial and aquatic animal specimens and 30 charred seeds and chaff samples from sites in western Switzerland. Stable isotope analyses were performed on cereal and legume seeds (δ¹³C, δ¹⁵N), animal bone collagen (δ¹³C_coll, δ¹⁵N, δ³⁴S), human bone and tooth dentine collagen (δ¹³C_coll, δ¹⁵N,) and human tooth enamel (δ¹³C_enamel). The isotopic data suggest a) an intensification of soil fertilization and no hydric stress throughout the Bronze Age, b) a human diet mainly composed of terrestrial resources despite the proximity of Lake Geneva and the Rhone river, c) a diet based on C₃ plants during the Early and Middle Bronze Age as opposed to the significant consumption of ¹³C-enriched resources (probably millet) by individuals from the Final Bronze Age, d) no important changes in dietary patterns throughout an individual’s lifespan but a more varied diet in childhood compared to adulthood, e) no differences in diet according to biological criteria (age, sex) or funerary behavior (burial architecture, grave goods).

Early specialized maritime and maize economies on the north coast of Peru

We assess diet and economies of middle Holocene (∼7,500 to 4,000 calibrated [cal] B.P.) humans at coexisting mound sites (Huaca Prieta and Paredones) in north coastal Peru and document regular consumption of maize by ∼6,500 to 6,000 cal B.P. and its earliest use as a staple food in this area of the Andes between 5,000 and 4,500 cal B.P. Stable isotope data from enamel carbonates and dentin collagen (childhood diet) and dental microwear texture analysis (adult diet) demonstrate dietary and economic specialization. Previous studies revealed maize and mixed-food refuse at both sites, but this study documents actual food consumption, showing that these communities situated a few hundred meters apart had significantly distinct diets in childhood and adulthood. Huaca Prieta focused on marine resources, although there are some contributions from terrestrial meat. Paredones individuals primarily consumed maize during childhood (up to 70% of the juvenile diet), as shown by δ¹³C values, apatite-collagen spacing, and discriminant analysis of δ¹³C_coll, δ¹³C_carb, and δ¹⁵N values. Maize was likely used as a weaning food (e.g., gruel and/or chicha-a maize beverage), hinting at the significant role of breastfeeding mothers, weanling infants, and children in the development of maize as a staple crop. Additionally, dental microwear data show Paredones adult diets are high in abrasives, potentially from maize processing. The distinct foodways at these neighboring sites result from and also reflect their social and political distinctions. These differences in food production, distribution, and consumption generated opportunities for exchange, an interaction that bound them together in mutual benefit.

Strontium (87 Sr/86 Sr) isotope analysis of the Namu skeletal assemblage: A study of past human migration on Taumako, a Polynesian Outlier in the eastern Solomon Islands

OBJECTIVES

This study aims to assess if inter-island mobility can be identified during the Namu period (ca. 1,510-1800 AD) using ⁸⁷ Sr/⁸⁶ Sr analysis of dental enamel for individuals from the Namu burial ground on Taumako Island in the eastern Solomon Island Chain. Historic evidence from this region suggests that females migrated between the Duff, Reef, and Santa Cruz islands for marriage purposes. We hypothesize that observable trends in migrational (⁸⁷ Sr/⁸⁶ Sr) and dietary (δ¹³ C and δ¹⁵ N) isotopes can reveal the relationship between demographic factors, social status, diet, and female mobility on Taumako.

METHODS

This research analyzes enamel ⁸⁷ Sr/⁸⁶ Sr for 58 individuals in the Namu skeletal sample. The ⁸⁷ Sr/⁸⁶ Sr results were compared with published dietary isotope data (bone collagen and dentin δ¹³ C and δ¹⁵ N values) and type/number of grave goods to assess whether trends within the data may be related to sex, age, or burial wealth.

RESULTS

The results show that females display significantly higher ⁸⁷ Sr/⁸⁶ Sr values compared to males. One young adult female displayed a ⁸⁷ Sr/⁸⁶ Sr value that was +2SD outside the mean for the sampled individuals. A linear mixed-effects model and principle components analysis of ⁸⁷ Sr/⁸⁶ Sr, δ¹³ C, and δ¹⁵ N values suggest that wealth, sex, and age-cohort membership have an observable influence on the isotopic variation for the Taumako population.

CONCLUSION

We suggest that during the Namu period, Taumako was patrilocal and that some females migrated there from the nearby Santa Cruz and Reef islands. One female immigrated to Taumako from a geologically distinct region outside of the Duff, Reef, and Santa Cruz Island groups.

The prehistoric roots of Chinese cuisines: Mapping staple food systems of China, 6000 BC-220 AD

We conducted a meta-analysis of published carbon and nitrogen isotope data from archaeological human skeletal remains (n = 2448) from 128 sites cross China in order to investigate broad spatial and temporal patterns in the formation of staple cuisines. Between 6000-5000 cal BC we found evidence for an already distinct north versus south divide in the use of main crop staples (namely millet vs. a broad spectrum of C3 plant based diet including rice) that became more pronounced between 5000-2000 cal BC. We infer that this pattern can be understood as a difference in the spectrum of subsistence activities employed in the Loess Plateau and the Yangtze-Huai regions, which can be partly explained by differences in environmental conditions. We argue that regional differentiation in dietary tradition are not driven by differences in the conventional "stages" of shifting modes of subsistence (hunting-foraging-pastoralism-farming), but rather by myriad subsistence choices that combined and discarded modes in a number of innovative ways over thousands of years. The introduction of wheat and barley from southwestern Asia after 2000 cal BC resulted in the development of an additional east to west gradient in the degree of incorporation of the different staple products into human diets. Wheat and barley were rapidly adopted as staple foods in the Continental Interior contra the very gradual pace of adoption of these western crops in the Loess Plateau. While environmental and social factors likely contributed to their slow adoption, we explored local cooking practice as a third explanation; wheat and barley may have been more readily folded into grinding-and-baking cooking traditions than into steaming-and-boiling traditions. Changes in these culinary practices may have begun in the female sector of society.

Isotopic and microbotanical insights into Iron Age agricultural reliance in the Central African rainforest

The emergence of agriculture in Central Africa has previously been associated with the migration of Bantu-speaking populations during an anthropogenic or climate-driven ‘opening’ of the rainforest. However, such models are based on assumptions of environmental requirements of key crops (e.g. Pennisetum glaucum) and direct insights into human dietary reliance remain absent. Here, we utilise stable isotope analysis (δ¹³C, δ¹⁵N, δ¹⁸O) of human and animal remains and charred food remains, as well as plant microparticles from dental calculus, to assess the importance of incoming crops in the Congo Basin. Our data, spanning the early Iron Age to recent history, reveals variation in the adoption of cereals, with a persistent focus on forest and freshwater resources in some areas. These data provide new dietary evidence and document the longevity of mosaic subsistence strategies in the region.

Bleasdale et al. examine the introduction of agricultural crops in the Congo Basin with stable isotope analysis of human and animal remains, charred food remains, and plant microparticles from dental calculus. Their findings reveal variation in the adoption of cereals from the early Iron Age, and provide long-term insights into changing human reliance on different resources.

Environmental drivers of megafauna and hominin extinction in Southeast Asia

Southeast Asia has emerged as an important region for understanding hominin and mammalian migrations and extinctions. High-profile discoveries have shown that Southeast Asia has been home to at least five members of the genus Homo^1-3. Considerable turnover in Pleistocene megafauna has previously been linked with these hominins or with climate change⁴, although the region is often left out of discussions of megafauna extinctions. In the traditional hominin evolutionary core of Africa, attempts to establish the environmental context of hominin evolution and its association with faunal changes have long been informed by stable isotope methodologies^5,6. However, such studies have largely been neglected in Southeast Asia. Here we present a large-scale dataset of stable isotope data for Southeast Asian mammals that spans the Quaternary period. Our results demonstrate that the forests of the Early Pleistocene had given way to savannahs by the Middle Pleistocene, which led to the spread of grazers and extinction of browsers-although geochronological limitations mean that not all samples can be resolved to glacial or interglacial periods. Savannahs retreated by the Late Pleistocene and had completely disappeared by the Holocene epoch, when they were replaced by highly stratified closed-canopy rainforest. This resulted in the ascendency of rainforest-adapted species as well as Homo sapiens-which has a unique adaptive plasticity among hominins-at the expense of savannah and woodland specialists, including Homo erectus. At present, megafauna are restricted to rainforests and are severely threatened by anthropogenic deforestation.

Comparative isotope ecology of western Amazonian rainforest mammals

Closed-canopy rainforests are important for climate and ecology, yet identifying this ecosystem in the fossil record is challenging. An existing paradigm for identification of closed-canopy rainforests using fossil mammal carbon isotope data is the presence of highly negative δ¹³C_diet values (<−31‰) in the herbivore community, as observed in modern equatorial African rainforest ecosystems. Our data from western Amazonian mammals, however, show that the absence of these values is not evidence for absence of closed-canopy rainforests. Our results also document that the proposed relationship between carbon isotope spacing variables and traditional dietary ecological classifications is not straightforward, and that better characterizations of the mixture of nutrients in animal diets are necessary to fully understand diet-tissue isotopic fractionation patterns.

Closed-canopy rainforests are important for climate (influencing atmospheric circulation, albedo, carbon storage, etc.) and ecology (harboring the highest biodiversity of continental regions). Of all rainforests, Amazonia is the world’s most diverse, including the highest mammalian species richness. However, little is known about niche structure, ecological roles, and food resource partitioning of Amazonian mammalian communities over time. Through analyses of δ¹³C_bioapatite, δ¹³C_hair, and δ¹⁵N_hair, we isotopically characterized aspects of feeding ecology in a modern western Amazonian mammalian community in Peru, serving as a baseline for understanding the evolution of Neotropical rainforest ecosystems. By comparing these results with data from equatorial Africa, we evaluated the potential influences of distinct phylogenetic and biogeographic histories on the isotopic niches occupied by mammals in analogous tropical ecosystems. Our results indicate that, despite their geographical and taxonomic differences, median δ¹³C_diet values from closed-canopy rainforests in Amazonia (−27.4‰) and equatorial Africa (−26.9‰) are not significantly different, and that the median δ¹³C_diet expected for mammalian herbivores in any closed-canopy rainforest is −27.2‰. Amazonian mammals seem to exploit a narrower spectrum of dietary resources than equatorial African mammals, however, as depicted by the absence of highly negative δ¹³C_diet values previously proposed as indicative of rainforests (<−31‰). Finally, results of keratin and bioapatite δ¹³C indicate that the predictive power of trophic relationships, and traditional dietary ecological classifications in bioapatite-protein isotopic offset expectations, must be reconsidered.

Linking isotope analysis and paleopathology: An andean perspective

This paper reviews the significant advances in isotopic investigations in Andean South America and directs scholars to explore new theoretical and analytical directions, specifically the applicability of isotope data to paleopathology. Excellent preservation and large skeletal collections of human remains make the Central Andes ideal for biogeochemical reconstructions and advancements in isotopic methods. Our aims are twofold: first, we present a meta-analysis of stable and radiogenic isotope research in the Central Andes since 1985, and highlight those that combine analyses of isotope ratios and pathological conditions. Second, we discuss useful directions for incorporating stable isotope analysis more explicitly in studies of paleopathology in the Andes more in the future. Principle research foci have described dietary variation and regional population mobility since the 1980s, where early methodological explorations identified significant trends in isotopic variation. For the years 1980-2017, we identified 96 scholarly publications through a meta-data analysis of major peer-reviewed journals, book chapters, and conference proceedings. These demonstrate specific trends in topical and methodological preferences across the Andean region and a shift from 10 publications pre-1997 to 67 in the last 10 years. However, combined isotope and paleopathology studies in this region remain sparse; given the ecological, geological, and cultural complexity of the Central Andes, analyses of pathological conditions in different regions would significantly benefit from the information on diet, mobility, and local ecology that isotope ratios provide. Isotope analysis requires destruction of archaeological tissues, and interpreting isotope data can be complex, but it can also provide unique insights into the pathogenesis of multifactorial conditions and assist differential diagnosis. Therefore, we also discuss research designs for pairing isotopic and paleopathological variables that will allow researchers to better capture disease ecologies in archaeological samples and their variation across different regions, within related sites, and within individual lifespans.

Early isotopic evidence for maize as a staple grain in the Americas

Maize is a cultigen of global economic importance, but when it first became a staple grain in the Americas, was unknown and contested. Here, we report direct isotopic dietary evidence from 52 radiocarbon-dated human skeletons from two remarkably well-preserved rock-shelter contexts in the Maya Mountains of Belize spanning the past 10,000 years. Individuals dating before ~4700 calendar years before present (cal B.P.) show no clear evidence for the consumption of maize. Evidence for substantial maize consumption (~30% of total diet) appears in some individuals between 4700 and 4000 cal B.P. Isotopic evidence after 4000 cal B.P. indicates that maize became a persistently used staple grain comparable in dietary significance to later maize agriculturalists in the region (>70% of total diet). These data provide the earliest definitive evidence for maize as a staple grain in the Americas.

Coalescing traditions-Coalescing people: Community formation in Pannonia after the decline of the Roman Empire

The decline of the Roman rule caused significant political instability and led to the emergence of various ‘Barbarian’ powers. While the names of the involved groups appeared in written sources, it is largely unknown how these changes affected the daily lives of the people during the 5^th century AD. Did late Roman traditions persist, did new customs emerge, and did both amalgamate into new cultural expressions? A prime area to investigate these population and settlement historical changes is the Carpathian Basin (Hungary). Particularly, we studied archaeological and anthropological evidence, as well as radiogenic and stable isotope ratios of strontium, carbon, and nitrogen of human remains from 96 graves at the cemetery of Mözs-Icsei dűlő. Integrated data analysis suggests that most members of the founder generation at the site exhibited burial practises of late Antique traditions, even though they were heterogeneous regarding their places of origin and dietary habits. Furthermore, the isotope data disclosed a nonlocal group of people with similar dietary habits. According to the archaeological evidence, they joined the community a few decades after the founder generation and followed mainly foreign traditions with artificial skull modification as their most prominent characteristic. Moreover, individuals with modified skulls and late Antique grave attributes attest to deliberate cultural amalgamation, whereas burials of largely different isotope ratios underline the recipient habitus of the community. The integration of archaeological and bioarchaeological information at the individual level discloses the complex coalescence of people and traditions during the 5^th century.

Reconstructing Bronze Age diets and farming strategies at the early Bronze Age sites of La Bastida and Gatas (southeast Iberia) using stable isotope analysis

The El Argar society of the Bronze Age in the southeast of the Iberian Peninsula (2200–1550 cal BCE) was among the first complex societies in Europe. Its economy was based on cereal cultivation and metallurgy, it was organized hierarchically, and successively expanded its territory. Most of the monumentally fortified settlements lay on steeply sloped mountains, separated by fertile plains, and allowed optimal control of the area. Here, we explore El Argar human diets, animal husbandry strategies, and food webs using stable carbon and nitrogen isotope analysis of charred cereal grains as well as human and animal bone collagen. The sample comprised 75 human individuals from the sites of La Bastida (n = 52) and Gatas (n = 23), 32 domesticated and wild animals as well as 76 barley and 29 wheat grains from two chronological phases of a total time span of ca. 650 years. The grains indicate extensive cereal cultivation under rain-fed conditions with little to moderate application of manure. Especially at La Bastida, crops and their by-products contributed significantly to the forage of the domesticated animals, which attests to a strong interrelation of cultivation and animal husbandry. Trophic level spacing and Bayesian modelling confirm that human diets were largely based on barley with some contribution of meat or dairy products. A cross-sectional analysis of bone collagen suggests that children were breastfed until about 1.5–2 years old, and infants from Gatas may have suffered from more metabolic stress than those at La Bastida. Adults of both sexes consumed similar diets that reflect social and chronological variation to some extent. Despite significantly higher δ¹³C and δ¹⁵N values at La Bastida than at Gatas, the isotopic data of the staple crops and domestic animals from both sites indicate that such differences do not necessarily correspond to different average human diets, but to agricultural strategies. These results urge for a reassessment of previous isotope studies in which only human remains have been taken into account. The study highlights that disentangling the complex influences on human isotope compositions requires a firm set of comparative data.

At the world's edge: Reconstructing diet and geographic origins in medieval Iceland using isotope and trace element analyses

Objectives

A multi‐isotope study was conducted on individuals buried at Skriðuklaustur monastery (AD 1493–1554) to investigate their geographic origins and dietary composition. Comparative material from individuals excavated from Skeljastaðir, an inland farm site was also analyzed.

Materials and methods

Bone collagen was extracted from 50 humans (Skriðuklaustur and Skeljastaðir) and 25 animals (Skriðuklaustur) and analyzed for δ¹³C, δ¹⁵N, and δ³⁴S. Dental enamel samples from 31 individuals (Skriðuklaustur) were also analyzed for ⁸⁷Sr/⁸⁶Sr, δ¹⁸O, δ¹³C, and trace elements (Pb, Sr, Zn, Ba).

Results

The mean value determined from individuals from Skriðuklaustur (n = 36) was δ¹³C = −18.7 ± 0.8‰, δ¹⁵N = 12.8 ± 1.1‰, and δ³⁴S = 9.0 ± 1.6‰, whereas at Skeljastaðir (n = 14), it was δ¹³C = −20.5 ± 0.8‰, δ¹⁵N = 7.8 ± 0.9‰, and δ³⁴S = 9.4 ± 1.6‰. At Skriðuklaustur, human dental enamel samples (n = 31) provided a ⁸⁷Sr/⁸⁶Sr range of 0.7060–0.7088, δ¹⁸O_phosphate from 13.9 to 16.1‰ and δ¹³C_carbonate from −16.6 to −12.9‰. Inferred drinking water (δ¹⁸O_dw) values range from −12.3 to −8.9‰. Sr concentrations range from 25.8 to 156.7 ppm, Ba from 0.11 to 0.81 ppm, Zn from 43.8 to 145.8 ppm, and Pb from 0.13 to 9.40 ppm.

Discussion

A combination of results indicates that the people from Skriðuklaustur were born in Iceland, but some lived inland during childhood while others lived closer to the coast. Since Skriðuklaustur was a hospital, these individuals may have sought medical treatment at the monastery. The δ¹³C and δ¹⁵N values determined from bone collagen indicate that the people residing at Skriðuklaustur consumed a diet high in marine protein, while those residing at Skeljastaðir exhibit values more consistent with terrestrial resources.

Carbon and nitrogen isotopic signatures of hair, nail, and breath from tropical African human populations

RATIONALE

Stable isotopic analyses are increasingly used to study the diets of past and present human populations. Yet, the carbon and nitrogen isotopic data of modern human diets collected so far are biased towards Europe and North America. Here, we address this gap by reporting on the dietary isotopic signatures of six tropical African communities: El Molo, Turkana (Kerio), Luhya (Webuye), Luhya (Port Victoria), and Luo (Port Victoria) from Kenya, and Baka from Cameroon; representing four subsistence strategies: fishing, pastoralism, agriculturalism, and hunter-gatherer.

METHODS

We used an elemental analyser coupled in continuous-flow mode to an isotope ratio mass spectrometer to measure the carbon and nitrogen isotopic ratios of hair (n = 134) and nail (n = 80) and the carbon isotopic ratios of breath (n = 184) from these communities, as well as the carbon and nitrogen isotopic ratios of some food samples from the Kenyan communities.

RESULTS

We expand on the known range of δ¹³ C values in human hair through the hunter-gatherer Baka, with a diet based on C₃ plants, and through the agriculturalist Luhya (Webuye), with a diet based on C₄ plants. In addition, we found that the consumption of fish from East African lakes is difficult to detect isotopically due to the combined effects of high nitrogen isotopic ratios of plants and the low nitrogen isotopic ratios of fish. Finally, we found that some of the communities studied are markedly changing their diets through increasing sedentism and urbanisation.

CONCLUSIONS

Our findings contribute substantially to the understanding of the environmental, demographic, and economic dynamics that affect the dietary landscape of different tropical populations of Africa. These results highlight the importance of studying a broader sample of human populations and their diet, with a focus on their precise context - from both isotopic and more general anthropological perspectives.

Does faecal matter reflect location? An initial assessment of isotopic variability between consumed prey remains and faecal matter for wild jaguars. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2019;55:478-498. [PMID: 31402710 DOI: 10.1080/10256016.2019.1648263]

Faecal isotopic analysis may complement other non-invasive wildlife survey tools for monitoring landscape use by carnivores, such as motion-detecting cameras and non-invasive genetic sampling. We analysed carbon, nitrogen, and strontium isotopes in faecal matter produced by jaguars (Panthera onca) as well as bones from consumed prey at the Mountain Pine Ridge Forest Reserve (MPR) in Belize, Central America. The MPR is ideally suited for a spatial isotope study as vegetation and geology both vary considerably. The isotopic composition of faecal matter should reflect the habitat and geology where consumed prey lived. We used bone from consumed prey recovered from jaguar scats as a proxy for diet. Faecal matter and bone showed comparable spatial isotopic trends, suggesting that the isotopic composition of jaguar faeces can be used to detect foraging in different habitats (pine forest versus broadleaf forest) or on different geologies (Mesozoic carbonates; Palaeozoic granite, contact metamorphics, and metasediments). This result is reassuring as bones are not always present in carnivore scats. Studying landscape use by cryptic and wide-ranging carnivore species like jaguars remains challenging. Isotopic analysis of faecal matter complements the existing array of non-invasive spatial monitoring tools.

Multidisciplinary investigations of the diets of two post-medieval populations from London using stable isotopes and microdebris analysis

This paper presents the first multi-tissue study of diet in post-medieval London using both the stable light isotope analysis of carbon and nitrogen and analysis of microdebris in dental calculus. Dietary intake was explored over short and long timescales. Bulk bone collagen was analysed from humans from the Queen's Chapel of the Savoy (QCS) (n = 66) and the St Barnabas/St Mary Abbots (SB) (n = 25). Incremental dentine analysis was performed on the second molar of individual QCS1123 to explore childhood dietary intake. Bulk hair samples (n = 4) were sampled from adults from QCS, and dental calculus was analysed from four other individuals using microscopy. In addition, bone collagen from a total of 46 animals from QCS (n = 11) and the additional site of Prescot Street (n = 35) was analysed, providing the first animal dietary baseline for post-medieval London. Overall, isotopic results suggest a largely C₃-based terrestrial diet for both populations, with the exception of QCS1123 who exhibited values consistent with the consumption of C₄ food sources throughout childhood and adulthood. The differences exhibited in δ¹⁵N_coll across both populations likely reflect variations in diet due to social class and occupation, with individuals from SB likely representing wealthier individuals consuming larger quantities of animal and marine fish protein. Microdebris analysis results were limited but indicate the consumption of domestic cereals. This paper demonstrates the utility of a multidisciplinary approach to investigate diet across long and short timescales to further our understanding of variations in social status and mobility.

Multiproxy isotopic analyses of human skeletal material from Rapa Nui: Evaluating the evidence from carbonates, bulk collagen, and amino acids

OBJECTIVES

Stable isotope ratio analysis of bulk bone collagen dominates research into past diet; however, bone carbonate and compound specific isotope analyses (CSIA) of amino acids provide alternative, yet complementary, lines of evidence toward that same research goal. Together they inform on different aspects of diet, allowing greater certainty in reconstructions. Here we present new data on carbonate isotopes for Rapa Nui and reevaluate prehistoric diet in the context of these new and previously published bulk collagen and CSIA data.

MATERIALS AND METHODS

We analyzed carbon isotopes in bone carbonate from 28 prehistoric human teeth from Rapa Nui. These represent a subset of material examined previously for carbon and nitrogen isotope ratios in bulk collagen. We then reevaluate prehistoric diet in light of these and other published data. In addition, we analyzed carbon and nitrogen isotope ratios in 28 modern plant specimens from Rapa Nui to better approximate the isotopic value of the terrestrial endmember.

RESULTS

Bulk data suggest a predominantly terrestrial diet, with the amount of marine sources incorporated varying though time. While previously argued to reveal greater amounts of marine consumption, reanalysis of recently published CSIA data suggests this result may relate to the proportion of carbon assimilated rather than consumed. Utilizing models incorporating concentration dependence for estimating dietary proportions results in much lower estimates of marine consumption, in line with findings of the bulk data.

DISCUSSION

While these data indicate a larger focus on terrestrial resources, limitations in all forms of analysis make it difficult to determine exact dietary contributions in this mixed system. Better understanding of the complex physiological processes governing isotopic routing and fractionation, and knowledge of appropriate isotopic endmember values are needed to advance this research.

Flows of people in villages and large centres in Bronze Age Italy through strontium and oxygen isotopes

This study investigates to what extent Bronze Age societies in Northern Italy were permeable accepting and integrating non-local individuals, as well as importing a wide range of raw materials, commodities, and ideas from networks spanning continental Europe and the Mediterranean. During the second millennium BC, the communities of Northern Italy engaged in a progressive stabilization of settlements, culminating in the large polities of the end of the Middle/beginning of the Late Bronze Age pivoted around large defended centres (the Terramare). Although a wide range of exotic archaeological materials indicates that the inhabitants of the Po plain increasingly took part in the networks of Continental European and the Eastern Mediterranean, we should not overlook the fact that the dynamics of interaction were also extremely active on local and regional levels. Mobility patterns have been explored for three key-sites, spanning the Early to Late Bronze Age (1900-1100 BC), namely Sant'Eurosia, Casinalbo and Fondo Paviani, through strontium and oxygen isotope analysis on a large sample size (more than 100 individuals). The results, integrated with osteological and archaeological data, document for the first time in this area that movements of people occurred mostly within a territorial radius of 50 km, but also that larger nodes in the settlement system (such as Fondo Paviani) included individuals from more distant areas. This suggests that, from a demographic perspective, the process towards a more complex socio-political system in Bronze Age Northern Italy was triggered by a largely, but not completely, internal process, stemming from the dynamics of intra-polity networks and local/regional power relationships.

Coastal complexity: Ancient human diets inferred from Bayesian stable isotope mixing models and a primate analogue

An extensive ecological literature applies stable isotope mixing models to derive quantitative dietary reconstructions from isotope ratios of consumer tissues. While this approach works well for some organisms, it is challenging for consumers with complex, varied diets, including humans; indeed, many archaeologists have avoided the use of mixing models because uncertainties in model outputs are sufficiently large that the findings are not helpful in understanding ancient lifeways. Here, we exploit an unparalleled opportunity to evaluate the feasibility of dietary quantification in a nutritionally and isotopically complex context on the Cape Peninsula, South Africa. Delta values (δ13C and δ15N) of 213 indigenous food samples enable us to characterise four food groups: terrestrial plants, terrestrial vertebrates, marine invertebrates and marine vertebrates. A recent study of baboons that consumed marine and terrestrial foods provides insight into the relationship between such foods and consumer tissue isotopes. We use this information to refine our interpretation of δ15N and especially δ13C in bone collagen from 35 archaeological hunter-gatherers, achieving better estimates of the relative importance of marine and terrestrial foods in the diet than has hitherto been possible. Based on Bayesian stable isotope mixing model (SIMM) outputs, we infer that the trophic enrichment factor (TEF) for δ13Cbone collagen in these coastal humans is closer to +3 than +5‰. In the most 13C- and 15N-rich individuals, 65-98% of bone collagen (95% credible intervals) derived from marine foods. Conversely, in 13C and 15N-poor individuals, 7-44% of bone collagen derived from marine foods. The uncertainties discussed here highlight the need for caution when implementing SIMMs in studies of consumers with complex diets. To our knowledge, this work constitutes the most detailed and most tightly constrained study of this problem to date.

Multi-tissue stable carbon and nitrogen isotope models for dietary reconstruction: Evaluation using a southern African farming population

OBJECTIVES

Multi-tissue stable isotope models to reconstruct past diets (Froehle, Kellner, & Schoeninger, 2012; Kellner & Schoeninger, 2007) have lacked data from a heavily C₄ -dependent population. Using new data from southern African agriculturalists, published models are evaluated for accuracy in dietary reconstruction and applicability to isotopically diverse diets. Additionally, isotopic variation between tooth enamel and bone apatite, which are often treated as isotopically equivalent, is investigated.

MATERIALS AND METHODS

δ¹³ C_{bone apatite} , δ¹³ C_{tooth enamel} , δ¹³ C_collagen , and δ¹⁵ N_collagen values for 51 adult southern African agriculturalists are presented. Bivariate (linear) and multivariate (cluster analysis, discriminant function analysis) models are recreated including these data, and the resulting dietary reconstructions evaluated against what we know of archaeological diets.

RESULTS

Δ¹³ C_{collagen-enamel} (5.67 ± 1.66‰) is significantly larger than Δ¹³ C_{collagen-bone apatite} (4.77 ± 1.42‰) and are significantly different from each other (Mann Whitney U-Test, p = 0.0). δ¹³ C_{bone apatite} and δ¹³ C_{tooth enamel} were uncorrelated (R² = 0.24). The agriculturalists consumed highly variable and heterogeneous diets, (mean δ¹³ C_{bone apatite} = -6.25 ± 2.49‰, δ¹³ C_{tooth enamel} = -2.88 ± 2.48‰, δ¹³ C_collagen = -8.65 ± 2.16‰, δ¹⁵ N_collagen = 10.05 ± 1.9‰). Multi- and bi-variate models under-estimate the probable contribution of C₃ energy sources, and recreation of cluster analysis results in a significant reduction in the parsimony of the dietary clusters derived in Froehle et al., 2012.

CONCLUSION

Bone apatite and tooth enamel are distinct biominerals, and their δ¹³ C values should not be treated as equivalent. Multiple tissue isotopes provide valuable insight into diet that cannot be achieved with single tissues, but current models are limited by the lack of isotopic diversity in the data on which they are based.

Dietary inferences through stable isotope analysis at the Neolithic and Bronze Age in the southern Caucasus (sixth to first millenium BC, Azerbaijan): From environmental adaptation to social impacts

OBJECTIVES

Subsistence strategies are of great interest for understanding how prehistoric societies adapted to their environment. This is particularly the case for the southern Caucasus where relationships have been shown with the northern Caucasus and Mesopotamia since the Neolithic and where societies are alternately described as sedentary and mobile. This article aims, for the first time, to characterize human diets and their evolution using biochemical markers, from the Neolithic to the Bronze Age (sixth-first millenium BC), at Mentesh Tepe, a site in the middle Kura valley in Azerbaijan.

MATERIALS AND METHODS

The data set belongs to 40 humans, 32 domestic and wild animals, and 42 charred seeds discovered in situ and perfectly dated. Stable isotope analyses were performed, including (a) δ¹³ C_co and δ¹⁵ N for animal and human bone collagens and for seeds, and (b) δ¹³ C_ap for human bone apatite.

RESULTS

Almost all the data (25/31) suggest an increased contribution of cereals, lentils, and freshwater fish during the Neolithic, whereas afterwards, until the Late Bronze Age, all individuals consumed more animal proteins from their livestock. None of the biological criteria (age at death and sex) and burial types (mass/single graves) were found to be related to a specific diet over time. Comparisons with other isotopic data from contemporary sites in Georgia argue in favor of a wide variety of dietary sources in the vicinity of the Kura valley and for highly mobile populations. Clear evidence of millet consumption has only been found for the Late Bronze Age.

Stable carbon and nitrogen isotopes in kukui (Aleurites moluccanus) endocarp along rainfall and elevation gradients: Archaeological implications

Stable carbon and nitrogen isotopes are often used to make inferences of past environments and social patterns. We analyze δ ¹³C and δ ¹⁵N values in contemporary kukui (Aleurites moluccanus) endocarp to examine the effects of site environment. Results from across environmental transects on Hawai‘i Island show strong patterns for both stable isotopes. For δ ¹³C a robust linear relationship with elevation is exhibited, strengthened by the inclusion of rainfall. This relationship breaks down at a minimum threshold of annual rainfall, possible relating to physiological responses to drought. For δ ¹⁵N, the only significant relationship observed pertains to substrate age. The endocarp from kukui is one of the most readily identified plant remains in the Pacific archaeological records and is often targeted for radiocarbon dating. We discuss the potential implications of our results regarding ancient climate, inferred diets, and habitat composition.

Jaguar and puma captivity and trade among the Maya: Stable isotope data from Copan, Honduras

From Moctezuma’s zoo to animals kept in captivity at Teotihuacan, there is increasing evidence that Mesoamericans managed wild animals for a myriad of purposes. The present study situates ritualized animal management of highly symbolic fauna in the broader context of Classic Mesoamerica by examining another core site, the Maya center of Copan, Honduras (A.D. 426–822). In this study, we identify two animal populations among the faunal remains from public and private rituals spanning the Copan dynasty. One population, with diets heavily composed of atypically sourced C₄ inputs indicative of artificial feeding, corresponds with the felids interred in Altar Q and Motmot caches. The second population is composed of felids and felid products bearing a predominance of C₃ signatures indicative of a more natural dietary regime. As with Copan deer, species-specific δ¹⁸O variations within these felid populations further substantiates the postulation that an expansive faunal trade network operated throughout the greater Copan Valley and beyond. Animals routed from sites of capture into the mesh of this network would have been processed into pelts, venison and other secondary goods or delivered alive to centers of state power for ritual usage and display. Our data reveal that at Copan, wild animals were routinely brought into intimate contact with human settlements to be managed and physically manipulated in a variety of ways in order to fulfill ritual and symbolic purposes.

Evidence of variability in carbohydrate consumption in prehistoric fisher-hunter-gatherers of Southeastern Brazil: Spatiotemporal trends of oral health markers

OBJECTIVES

In this study, we evaluate the role of plants in the diet of fisher-hunter gatherers adapted to highly productive coastal environments. Oral health markers were used to track spatiotemporal variations (regional and diachronic) in the composition of carbohydrate in the diets of prehistoric shell mound builders (sambaqui) from the Southeast of Brazil. Our main objective is to test the supposed stability in the dietary habits of sambaqui populations and identify modulating effects of chronological, cultural, and/or ecological factors.

METHODS

Eighteen oral health markers (divided into three categories: caries, periodontal disease, and dental wear) were applied in 233 individuals from 7 sambaquis (dated between 4800 and 1100 BP) from 5 geographic regions.

RESULTS

Our results reveal variable oral health patterns among sites. Despite that, we found a number of common features, such as dental wear and associated pulp lesions. Some oral health patterns are compatible with cariogenic diets and high carbohydrate consumption.

CONCLUSIONS

Our analyses suggest that plant resource management is plausible at some sites and support the emerging evidence that plant consumption among sambaqui populations was driven more by ecologic factors than chronological or cultural ones. A comprehensive record of oral health markers shows promise as a methodology to differentiate between otherwise extremely similar diets.

4000 years of human dietary evolution in central Germany, from the first farmers to the first elites

Investigation of human diet during the Neolithic has often been limited to a few archaeological cultures or single sites. In order to provide insight into the development of human food consumption and husbandry strategies, our study explores bone collagen carbon and nitrogen isotope data from 466 human and 105 faunal individuals from 26 sites in central Germany. It is the most extensive data set to date from an enclosed geographic microregion, covering 4,000 years of agricultural history from the Early Neolithic to the Early Bronze Age. The animal data show that a variety of pastures and dietary resources were explored, but that these changed remarkably little over time. In the human δ¹⁵N however we found a significant increase with time across the different archaeological cultures. This trend could be observed in all time periods and archaeological cultures (Bell Beaker phenomenon excluded), even on continuously populated sites. Since there was no such trend in faunal isotope values, we were able largely to exclude manuring as the cause of this effect. Based on the rich interdisciplinary data from this region and archaeological period we can argue that meat consumption increased with the increasing duration of farming subsistence.

In δ¹³C, we could not observe any clear increasing or decreasing trends during the archaeological time periods, either for humans or for animals, which would have suggested significant changes in the environment and landscape use. We discovered sex-related dietary differences, with males of all archaeological periods having higher δ¹⁵N values than females, and an age-related increasing consumption of animal protein. An initial decrease of δ¹⁵N-values at the age of 1–2 years reveals partial weaning, while complete weaning took place at the age of 3–4 years.

Urban and nomadic isotopic niches reveal dietary connectivities along Central Asia's Silk Roads

The ancient 'Silk Roads' formed a vast network of trade and exchange that facilitated the movement of commodities and agricultural products across medieval Central Asia via settled urban communities and mobile pastoralists. Considering food consumption patterns as an expression of socio-economic interaction, we analyse human remains for carbon and nitrogen isotopes in order to establish dietary intake, then model isotopic niches to characterize dietary diversity and infer connectivity among communities of urbanites and nomadic pastoralists. The combination of low isotopic variation visible within urban groups with isotopic distinction between urban communities irrespective of local environmental conditions strongly suggests localized food production systems provided primary subsistence rather than agricultural goods exchanged along trade routes. Nomadic communities, in contrast, experienced higher dietary diversity reflecting engagements with a wide assortment of foodstuffs typical for mobile communities. These data indicate tightly bound social connectivity in urban centres pointedly funnelled local food products and homogenized dietary intake within settled communities, whereas open and opportunistic systems of food production and circulation were possible through more mobile lifeways.

Land use and mobility during the Neolithic in Wales explored using isotope analysis of tooth enamel

Objectives

The nature of land use and mobility during the transition to agriculture has often been debated. Here, we use isotope analysis of tooth enamel from human populations buried in two different Neolithic burial monuments, Penywyrlod and Ty Isaf, in south‐east Wales, to examine patterns of land use and to evaluate where individuals obtained their childhood diet.

Materials and Methods

We employ strontium (⁸⁷Sr/⁸⁶Sr) and oxygen (δ¹⁸O) and carbon (δ¹³C) isotope analysis of enamel from adjacent molars. We compare strontium isotope values measured in enamel to locally bioavailable ⁸⁷Sr/⁸⁶Sr values. We combine discussion of these results with evaluation of new radiocarbon dates obtained from both sites.

Results

The majority of enamel samples from Penywyrlod have strontium isotope ratios above 0.7140. In contrast, the majority of those from Ty Isaf have ⁸⁷Sr/⁸⁶Sr values below 0.7140. At Penywyrlod oxygen isotope ratios range between 25.9 and 28.2 ‰ (mean 26.7 ± 0.6 ‰, 1σ, n = 15) and enamel δ¹³C_carbonate values range between −18.0 and −15.0 ‰ (mean −16.0 ± 0.8 ‰, 1σ, n = 15). At Ty Isaf oxygen isotope ratios exhibited by Neolithic individuals range between 25.4 and 27.7 ‰ (mean 26.7 ± 0.6 ‰, 1σ, n = 15) and enamel δ¹³C_carbonate values range between −16.9 and −14.9 ‰ (mean −16.0 ± 0.6 ‰, 1σ, n = 15).

Discussion

The strontium isotope results suggest that the majority of individuals buried at Penywyrlod did not source their childhood diet locally. One individual in this group has strontium isotope ratios that exceed all current known biosphere values within England and Wales. This individual is radiocarbon dated to the first few centuries of the 4^th millennium BC, consistent with the period in which agriculture was initiated in Wales: the results therefore provide evidence for migration during the transition to farming in Wales. In contrast, all individuals sampled from Ty Isaf post‐date the period in which agriculture is considered to have been initiated and could have sourced their childhood diet from the local region in which they were buried.