Stable carbon isotope analysis of human tooth enamel from the Bronze Age cemetery of Ya'amoun in Northern Jordan

Seventy-five teeth from the Bronze Age cemetery of Ya'amoun were sampled for carbon isotope analysis. The sampled teeth represented the transitional period of the Middle/Late Bronze Age. The results showed that the components of the diet that are reflected in the carbon isotope data remained the same during this period with an average δ¹³C of about −11.87‰. This value reflects more C₃ plant consumption.     

Paleodiet reconstruction of Bronze Age Siberians from the mortuary site of Khuzhir-Nuge XIV,Lake Baikal

Paleodiet reconstruction using stable isotopes of carbon and nitrogen was carried out on individuals from the Bronze Age cemetery, Khuzhir-Nuge XIV on the western shore of Lake Baikal, Russian Federation. The cemetery contained 79 graves with 89 individuals and was in use between approximately 2700 and 2000 cal. B.C. with the exception of one burial, dated to around 4000 B.C. Archaeological and ethnographic evidence indicates that hunting and fishing were the main subsistence activities while gathering was less important. δ¹³C from collagen and carbonate apatite was analysed, along with δ¹⁵N from collagen. Bone mineral preservation was evaluated using Fourier transform infrared spectroscopy. δ¹³C and δ¹⁵N of collagen are positively correlated and reflect varying reliance on terrestrial mammals, fish, and seals from Lake Baikal. Lake Baikal biota exhibit considerable variation in δ¹³C at the base of the food web thus; there is variation in human δ¹³C (−20.1‰ to −16.2‰) despite the fact that there are no C₄ plants in the region. δ¹⁵N results (range 10.3‰–16.5‰) indicate that fish, and possibly seals, made up some of the diet for everyone, but in varying amounts relative to terrestrial herbivores. δ¹³C from carbonate is not correlated with δ¹³C from collagen, a situation that has been found in remains from other coastal sites. A mixed diet from both terrestrial and freshwater ecosystems is the most likely explanation. Analysis of mortuary variables within the cemetery reveals three distinct clusters of graves with variations in burial treatment among the clusters. δ¹⁵N values are significantly different among these clusters, suggesting an association between diet and mortuary customs.     

Dietary patterns during the early prehispanic settlement in La Gomera (Canary Islands)

The dietary pattern of 10 adults interred in the Acceso al Pescante de Vallehermoso cave (La Gomera, Canary Islands), dated from 1600 to 1800 years BP, has been investigated using carbon and nitrogen stable isotope signatures, bone barium and strontium levels, and dental and oral pathologies. In addition, trabecular bone mass – as a parameter useful to evaluate overall nutrition – was also determined.     

Alkaline cooking and stable isotope tissue-diet spacing in swine: archaeological implications

In this study we examine the effects of alkaline cooking on carbon and oxygen stable isotopic ratios of mineralized tissues from nine pigs raised on monotonous mixed C3/C4 vegetarian diets. Two sources of collagen (humerus and mandible) and two sources of apatite (humerus and enamel) were analyzed. Within each diet group, humerus and mandible collagens were found to record equivalent δ¹³C and δ¹⁸O ratios; however, enamel apatite was found to be enriched over bone apatite by 2.3‰ in carbon and 1.7‰ in oxygen. Alkaline cooking was found to slightly, but significantly increase the Δ¹³C_{collagen-diet} and Δ¹⁸O_{collagen-diet} of bone collagen. A similar trend towards enrichment was observed in bone and enamel Δ¹³C_apatite-diet and Δ¹⁸O _apatite-diet, but the differences were not significant. Observed isotopic shifts were consistent with increased nutrient utilization of the alkaline-cooked maize as compared to raw maize. In addition, a reexamination of the relationship between diet and tissue carbon isotopic values suggests that species and alimentary type should be considered when interpreting ancient diets.     

An experimental study of nitrogen flux in llamas: is N preferentially excreted?

Nitrogen isotope analysis is now commonly used to investigate the diets, and to a lesser extent, the environments of ancient populations. These studies assume that mammals are predictably enriched in ¹⁵N over their food, and concomitantly, that ¹⁵N becomes increasingly concentrated as one moves up the food chain. The literature commonly states that this ¹⁵N-enrichment of mammalian tissues is due to preferential excretion of light nitrogen (¹⁴N), but there are few data to support this assertion. To address the gap, we conducted two nitrogen flux trials in which four llamas (Lama glama) were fed high- and low-protein diets. The ratios of fecal nitrogen loss to urinary nitrogen loss were 0.30 and 0.88 on the high- and low-protein diets respectively. Feces were enriched in ¹⁵N by approximately +3‰ on both diets, whereas urinary nitrogen was depleted in ¹⁵N (−2.1‰) on the low-protein diet, but not significantly different from intake δ¹⁵N on the high-protein diet. Most importantly, there was no statistically significant difference between dietary and total excreta δ¹⁵N on either diet. Given these data and theoretical considerations, we argue that the nitrogen influx and efflux of adult mammals at steady state should be isotopically commensurate. However, during growth, diet change, thermal or nutritional stress, animals may not be at steady state and fractionation between intake and excreta δ¹⁵N may occur.     

Bone collagen preservation in the tropics: a case study from ancient Puerto Rico

Bone collagen is a well-characterized and generally robust protein that plays a key role in both radiometric dating and stable isotopic reconstruction of paleodiet. To be useful for such purposes, however, analyzed collagen must be relatively taphonomically unaltered. To date, little research has been conducted to document the taphonomic fate of bone collagen from archaeological sites in the tropics. In the present work, a large (n = 298) dataset of archaeological bone samples from sites on the island of Puerto Rico is examined by means of radiometric, chemical, and elemental analyses. The ultimate conclusion of this work is that while collagen loss may be accelerated in the tropics versus that seen in samples from higher latitudes, what collagen remains is typically sufficiently well-preserved and taphonomically unaltered as to make radiocarbon dating and/or stable isotopic analysis worthwhile.     

Efficient but destructive: a test of the dental wash technique using secondary electron microscopy

The Boyadjian et al dental wash technique provides, in certain contexts, the only chance to analyze and quantify the use of plants by past populations and is therefore an important milestone for the reconstruction of paleodiet. With this paper we present recent investigations and results upon the influence of this method on teeth. A series of six teeth from a three thousand years old Brazilian shellmound (Jabuticabeira II) was examined before and after dental wash. The main focus was documenting the alteration of the surfaces and microstructures. The status of all teeth were documented using macrophotography, optical light microscopy, and atmospheric Secondary Electron Microscopy (aSEM) prior and after applying the dental wash technique. The comparison of pictures taken before and after dental wash showed the different degrees of variation and damage done to the teeth but, also, provided additional information about microstructures, which have not been visible before. Consequently we suggest that dental wash should only be carried out, if absolutely necessary, after dental pathology, dental morphology and microwear studies have been accomplished.     

Stable isotopic evidence of diet in a Greek colonial population from the Black Sea

Archaeological and literary sources indicate that the ancient Greeks relied heavily on terrestrial resources and that their access to certain types of foods varied by sex and status. Human and faunal remains from the Greek colonial site of Apollonia (5th to 2nd century BC) on the Black Sea coast of Bulgaria were analyzed for stable carbon and nitrogen isotopes in order to reconstruct the diet of this population, investigate the relative importance of marine vs. terrestrial resources, and explore variations in diet with respect to age, sex, and burial type. The results of this study indicate that the colonists of Apollonia relied on a mixed diet of terrestrial and marine foods, and that there was little or no variation in diet by age, sex, or burial type. The relationship between δ¹³C and δ¹⁵N data for these samples suggests that while marine foods were an important source of nitrogen, much of the carbon used to construct amino acids came from terrestrial foods.     

Stable carbon and nitrogen isotopes of human dental calculus: a potentially new non-destructive proxy for paleodietary analysis

Fifty-eight dental calculus samples from medieval and post-medieval skeletons from Vitoria, Spain, and a single sample from an Alaskan Inuit were tested for stable carbon and nitrogen isotope compositions. There was sufficient carbon and nitrogen concentrations to obtain δ¹³C and δ¹⁵N values, and the samples from Spain produced results that were replicable and comparable to European isotope values based on bone collagen collected from literature sources. The Alaskan Inuit calculus sample yielded a δ¹⁵N value of +17.5‰, well beyond the range of the Spanish samples, but consistent with literature data for modern Greenlandic Inuit consuming a diet rich in marine food. There are several potential sources for carbon and nitrogen in calculus. The results of this study yield stable isotope values consistent with those obtained from other biomaterials used as isotope proxies for paleodietary research, including bone collagen, hair, and fingernails, although further work is necessary to verify the fidelity of calculus as an isotope proxy. Many studies in bioarchaeology are precluded by curatorial concerns regarding the destructive analysis of primary biomaterials. However, calculus is an “add-on”, or secondary biomaterial, that is not an integral part of the dental or skeletal system. Hence, its consumption during analysis is technically not destructive. Therefore, isotope analysis of dental calculus may provide a potential new avenue for paleodietary analysis where the use of other primary biomaterials is precluded.     

Paleodietary analysis of a San Francisco Bay Area shellmound: stable carbon and nitrogen isotope analysis of late Holocene humans from the Ellis Landing site (CA-CCO-295)

The late Holocene archaeofaunal record of the San Francisco Bay Area demonstrates temporal declines in the abundance of low-cost, high-ranked marine and terrestrial resources. During later periods of occupation, faunal assemblages are often dominated by lower-ranked, higher-cost resources, suggesting an increase in diet breadth through time. Archaeological resource intensification models argue that this marks a late Holocene decline in foraging efficiency in the Bay Area, driven by human-induced harvest pressure. This study examines dietary change in the region using stable carbon and nitrogen isotope data from 65 human burials, spanning two temporal components (cal AD 55–890 and cal AD 762–1550) at the Ellis Landing site (CA-CCO-295). The strong linear relationship between collagen carbon and nitrogen isotope values reflects both marine and terrestrial food consumption, with individuals showing a high level of dietary variability at the site. No temporal trend or meaningful sex differences were found in isotope values. The widening of diet breadth predicted by the archaeofaunal record occurred prior to the occupation of the Ellis Landing shellmound site. The trend in exploiting a greater amount of terrestrial resources during the Middle and Late Period in central California was supported by isotopic evidence.