Investigating Dietary Patterns with Stable Isotope Ratios of Collagen and Starch Grain Analysis of Dental Calculus at the Iron Age Cemetery Site of Heigouliang,Xinjiang, China

Here, we present δ¹³C and δ¹⁵N results for the dietary reconstruction of nomadic pastoralists from the Iron Age (ca. 1000 bc –8 ad ) site of Heigouliang. The human (n = 27) δ¹³C values range from −19.6‰ to −17.0‰ with a mean value of −18.5 ± 0.5‰, and the δ¹⁵N results range from 11.5‰ to 13.8‰ with a mean value of 12.4 ± 0.6‰. The results indicated that animals, like sheep, were part of the predominately C₃ terrestrial diet, but two individuals have values greater than −18‰ that is indicative of some input of C₄ foods in their diets. Because of a lack of faunal samples and to supply complementary information concerning plant consumption, teeth from four individuals were analysed for dental calculus microfossils. Starch grains were found to correspond to Triticeae and Poaceae, possibly including wheat (Triticum aestivum), barley (Hordeum vulgare), highland barley (H. vulgare L var. nudum), foxtail millet (Setaria italica) and/or common millet (Panicum miliaceum). At the population level, no dietary differences were detected between burial owners and sacrificial victims, but variations were found when specific tombs were analysed. In particular, individuals with bone trauma associated with armed conflict also had distinct isotopic signatures possibly suggesting that some of the sacrificial victims could have been captured warriors that were sacrificed for the burial owners. While limited, the results are some of the first from an Iron Age population from Xinjiang and contribute to our understanding of the dietary patterns of this region. Copyright © 2015 John Wiley & Sons, Ltd.     

Reconstructing Diet of the Early Qin (ca. 700–400 BC) at Xishan,Gansu Province,China

Here we report the bone collagen carbon and nitrogen isotopic results of humans (n = 33) and animals (n = 58) to reconstruct the dietary practices of an early Qin population dating to the Zhou Dynasty (Late Western–Early Eastern period ca. 700–400 BC ) at the Xishan site in Gansu Province, China. The humans have a very large range of δ¹³C (−23.3‰ to −7.1‰) and δ¹⁵N (4.3‰ to 10.9‰) values which reflects extraordinarily diverse diets and included individuals with predominately C₃ as well as those with exclusive C₄ diets. This wide span of isotopic results produced a subtle linear trend (R² = 0.62) in the human data, which paralleled the animals across the C₃ and C₄ environmental gradient. However, the majority of the individuals had a predominately C₄ diet based on millet with δ¹⁵N results only slightly elevated above the animals, except for the pigs and cattle. This is evidence that many of the animals were likely used for their secondary products, labour or as sacrificial offerings and that pork and beef were the main sources of animal protein for the population. High status individuals had elevated δ¹⁵N values (10.2 ± 0.6‰) compared to medium (8.9 ± 0.3‰) and lower status (8.8 ± 0.8‰) individuals, possibly related to increased animal protein in the diet. Differences related to gender were also found with females having elevated δ¹³C (−11.2 ± 1.9‰) and δ¹⁵N (9.4 ± 0.8‰) values compared to the males (δ¹³C = −14.1 ± 4.2‰; δ¹⁵N = 7.9 ± 1.9‰), but these results necessitate caution given the large number of individuals that could not be sexed. The results of this study support the view that the early Qin people were a more sedentary society focused on millet agriculture and animal husbandry, and that they were influenced by the pre‐existing populations of the central Gansu region. Copyright © 2015 John Wiley & Sons, Ltd.     

Horticulturists and oxygen ecozones in the tropical and subtropical forests of Southeast South America

We analyse the isotopic values (δ¹³C, δ¹⁵N) of the diet of pre-Columbian horticulturalist populations from tropical and subtropical areas of southeastern South America, belonging to the Guarani and Taquara archaeological units. The data indicate different trends in each one (T?=?4.21; P?=?0.0004), showing a mixed diet with maize consumption in the Guarani samples (δ¹³C_co?=??15.5?±?1.8‰; δ¹³C_ap ?10.4?±?0.8‰) and a depleted one in the Taquara ones (δ¹³C_co ?18.2?±?1.7‰; δ¹³C_ap ?11.9?±?0.9‰), with a significant internal dispersion in both populations. The first population has higher nitrogen values (δ¹⁵N 11.1?±?0.6‰) compared to the Taquara samples (δ¹⁵N 9.3?±?1‰), suggesting a more carnivorous diet. The recognition of these pre-Columbian mixed diets involves the identification of maize cultivation on the Atlantic side of the southernmost area of South America (Parana Delta, 34° SL). Through the analysis of δ¹⁸O we have identified two isotopic ecozones, the first along the Paraná River Valley, with an average value of δ¹⁸O ?3.7?±?0.5‰ (CV?=?13.5%; CI?=??3.83 / ?3.16), and the second one, located in the Planalto of southern Brazil (Araucaria Forest), with a mean value of δ¹⁸O ?1.5?±?0.3‰ (CV?=?16.5%; CI?=??1.69 / ?1.29). The isotopic data (δ¹³C, δ¹⁵N and δ¹⁸O) suggest human movements between these two ecozones.     

Isotopic Evidence for Diet Among Historic Bedouin of Khirbat al‐Mudayna,Jordan

Interpreting the behaviours of nomadic groups from the archaeological record is particularly challenging owing to the ephemeral remains produced by their lifestyle. As such, human burials – even from isolated contexts – provide a wealth of information about these transient groups. Stable carbon and nitrogen isotope analysis of a series of human skeletal remains (n = 22) from isolated burials were utilized to reconstruct the diet of historic (ca. 13^th–19^th century CE) Bedouin from the Khirbat al‐Mudayna vicinity in modern‐day Jordan. Carbon isotope values ranging from −17.7 to −12.5‰ point to variable dietary contributions from both C₃‐ and C₄‐based foods, while corresponding faunal δ¹³C ratios ( = −19.0 ± 1.7‰, 1σ) exhibit depletion in ¹³C characteristic of a predominantly C₃ diet. While mean human δ¹⁵N values ( = 12.7 ± 1.9‰, 1σ) may suggest that the majority of protein consumed by these nomads came from animal and not plant sources, elevated δ¹⁵N ratios in some fauna may be indicative of ¹⁵N‐enriched soils as reported in some arid desert environments. Considerable variability in both δ¹³C and δ¹⁵N values also points to differences in individual life histories and subsistence economies over time. Despite a lack of temporal cohesion, these data illustrate the information that can be gleaned from the isolated interments of nomadic or semi‐nomadic individuals. Copyright © 2015 John Wiley & Sons, Ltd.     

Distinguishing sheep and goats using dental morphology and stable carbon isotopes in C4 grassland environments

Distinguishing between sheep and goats in C₄ grass environments using new dental morphology criteria and enamel bioapatite stable carbon isotope ratios (δ¹³C) was tested on 35 modern individuals from the Central Rift Valley of Kenya. Two morphological criteria on the second and third lower molars, one of which had been previously partially described by Halstead et al. [Journal of Archaeological Science 29 (2002) 545], were found to be highly reliable in this population. Identification of species using carbon isotope ratios is made possible in some circumstances by differences in the feeding behavior of sheep, which are mainly grazers, and goats, which are mainly browsers. In environments where C₄ grasses predominate, sheep include a higher proportion of C₄ plants in their diet, and thus have higher δ¹³C values than goats. In the present study, the annual range and seasonal variation of carbon isotope ratio of diet of sheep and goats was measured from intra-tooth sequential analysis. Although the ranges of goat and sheep δ¹³C values overlap, those higher than −3.4‰ all belong to sheep; values lower than −5.2‰ all belong to goats. There is no overlap of the mean δ¹³C values by tooth, which range from −11.8‰ to −4.2‰ for goats, and from −3.1‰ to −1.3‰ for sheep. These results suggest that carbon isotope analysis of bone collagen and/or apatite will also distinguish sheep from goats in tropical C₄ grasslands. Application of the δ¹³C criteria to archaeological material must be restricted to C₄-dominated environments, and where potential access to C₃ plants (mobility, foddering) can be assessed. The utility of these morphological and isotopic criteria for differentiating sheep and goat breeds in other regions remains to be evaluated.     

Raising Practices of Neolithic Livestock Evidenced by Stable Isotope Analysis in the Wei River Valley,North China

Although a patchwork of projects shows a process of agriculture intensification in North China during the Neolithic, the impact of cereal farming on animal husbandry and their mutual interaction remain cloudy. This study reports bone collagen δ¹³C and δ¹⁵N of humans and animals from Wayaogou (ca 6.5–6.0 kyrs bp ) and Dongying (ca 5.9–5.6 kyrs bp , 4.6–4.0 kyrs bp ) to explore temporal trend of livestock raising and particularly the importance of millet fodder to stock raising practices in the Wei River valley, North China. The isotopic evidence overall shows that millet products increased in human and domestic animal diets during the mentioned chronological span. δ¹³C values of pigs and dogs at Dongying are higher than those at Wayaogou, implying that the importance of millet nutrients increased to animal husbandry diachronically. Interestingly, δ¹³C results of domestic cattle of Dongying late phase (−14.1 ± 1.1‰, N = 5) are more enriched than Wayaogou wild Bos (−17.8 ± 0.3‰, N = 3), indicating that millet fodder had taken a significant place in early cattle husbandry. Besides, differences between Bos species of the two periods also imply that δ¹³C values of bone collagen constitute a potential indicator for tracing the origin of cattle husbandry in North China. In addition, domestic sheep at Dongying produced similar isotope data to wild ovicaprid at Wayaogou, suggesting that they possibly had grazed for the most in grassland and therefore experienced a different lifestyle from cattle. Copyright © 2014 John Wiley & Sons, Ltd.     

Carbon Isotope Variability in the Bone Collagen of Red Kangaroos (Macropus rufus) is Age Dependent: Implications for Palaeodietary Studies

Isotopic assessment of bone collagen is often used as an environmental tracer in both contemporary and palaeoenvironmental studies. However, variability in the isotopic composition of this tissue remains poorly understood for naturally occurring and wild populations of animals. In this study the stable carbon isotope composition of both diet and bone collagen was assessed for a population of red kangaroos (Macropus rufus). Animals sampled ranged in age from approximately 10 months to 15 years. The diet of this population, estimated from faeces collected in the field, varied from predominantly C₄grasses in late summer (δ¹³C⋍−16·5‰) to mostly C₃herbage in late winter (δ¹³C⋍−22·5‰), with a long-term average δ¹³C of between −19 and −20‰. Bone collagen was enriched in¹³C by 3 to 4‰ in older animals relative to pouch young. Isotopic analysis of hair, used to assess more recent diet in individuals, indicated that diet selection was similar in all animals that had been weaned. We suggest that the most likely explanation for the age-dependent relationship in the δ¹³C of bone collagen occurs because milk (the only source of nutrition in suckling kangaroos) is not fractionated in the same manner as plant-derived carbon during its assimilation into skeletal tissue. If this is the case, then such a relationship should be most predominant in mammals that have low birth weights (relative to the adult mother) and gain significant weight from milk. Whatever the precise mechanism(s) for the observed fractionation, bone collagen of kangaroos seems to retain an isotopic memory of the carbon laid down prior to weaning, which takes several years to be diluted and replaced with carbon derived from an “adult” herbaceous diet. These results have implications for palaeoecological research where fossil skeletal tissue is used as dietary or environmental tracers particularly if the relative age of the animals sampled is unknown.     

The Seasonal Mobility Model for Prehistoric Herders in the South-western Cape of South Africa Assessed by Isotopic Analysis of Sheep Tooth Enamel

A pattern of seasonal mobility between the coast and the hinterland by Khoekhoe pastoralists in the south-western Cape of South Africa was documented at the time of European contact. Because the region is characterized by a mosaic of geological substrates of various ages and vegetation types with different proportions of C₃ and C₄ plants, this mobility model for prehistoric herders can be tested by analysis of carbon, oxygen and strontium isotope ratios in domestic bovid tooth enamel. Isotopic analysis was performed on archaeological sheep, cattle, eland and steenbok teeth from the Late Stone Age site of Kasteelberg on the Vredenburg Peninsula. Sequential sampling of enamel provided a chronological record of the isotopic composition of diet during tooth formation. Results from carbon and oxygen isotope analysis of archaeological and modern steenbok teeth show seasonal variation in the δ¹³C of local pastures in the vicinity of the site (up to 2·9‰ in a single individual), which could be due to seasonal change in proportions of C₃ and C₄ plants and/or seasonal variation in the δ¹³C of C₃ plants. A pattern of seasonal change of 0·9–3·5‰ in the δ¹³C of tooth enamel is also observed in the sheep teeth. This amplitude of variation could be due to local seasonal changes, thus it is not possible, from the δ¹³C values, to infer whether the sheep were moving seasonally. Results from ⁸⁷Sr/⁸⁶Sr analysis of two sheep suggest that one individual stayed all year round on the coast, whereas the other had grazed in the interior for part of its life. Both δ¹³C and ⁸⁷Sr/⁸⁶Sr values measured in a cow tooth suggest that this animal spent part of its life in the interior, even though it died at Kasteelberg. Results on this cow also suggest longer residence within habitats rather than seasonal mobility. A clear pattern of seasonal mobility between the coast and the interior has not been shown for prehistoric pastoralists. However, the pattern of mobility attested in historical times might have developed only later in prehistory, when cattle pastoralism developed in the region.     

Stable carbon and nitrogen isotope ratios of bone collagen: Variations within individuals,between sexes,and within populations raised on monotonous diets

The stable carbon and nitrogen isotope ratios of collagen of seven bones from each of three rabbits raised on a monotonous diet, and of two bones from each of eight female and seven male mink raised on another monotonous diet, were determined. The ranges of δ¹³C values and δ¹⁵N values were 0·5‰ and 0·6‰ for the rabbit bones and 1·0‰ and 1·4‰ for the mink bones. Uncertainties in the δ¹³C and δ¹⁵N values for prehistoric human diets estimated from the isotopic composition of collagen from the small numbers of bones which are typically available for analysis, and thus likely to be of the order of ±1‰.     

STABLE CARBON ISOTOPE MEASUREMENTS OF THE CARBOXYL CARBONS IN BONE COLLAGEN*

In order to explore the possibility that intramolecular differences in the δ¹³C value of bone collagen can provide useful infomation for isotopic dietary analysis, a method for reliably measuring the δ¹³C value of the peptide-bonded carboxyl carbons in collagen was developed and applied to a wide range of modem and ancient species, including humans. Carboxyl carbons were selectively removed as CO₂ by decarboxylation of collagen hydrolysates with ninhydrin (2,2-dihydroxy-l,3-indanedione). Carboxyl carbons were usually isotopically heavier than the total carbon in the collagen, with differences ranging from -0.9 to 4.0%c. Animals at higher trophic levels and with more positive δ¹⁵N values usually had smaller differences than the lower animals while humans had the largest range, reflecting their larger range of diets.     

Fisherfolk and farmers: Carbon and nitrogen isotope evidence from Middle Horizon Ancón,Peru

This study investigates human dietary patterns and economic trends at the coastal site of Ancón, Peru during the Andean Middle Horizon (550AD –1000AD ) using stable isotopic data from 32 individuals buried at the site. δ¹³C and δ¹⁵N results from human bone collagen and δ¹³C from human tooth enamel and bone carbonate indicate that inhabitants consumed a mixed diet composed primarily of marine protein and C₄ resources, with only marginal reliance on C₃ foods. Over time, Ancóneros appear to have relied more heavily on C₄ resources, particularly maize, despite the fact that the crop could not have been grown locally. These results are notable given that C₃ rather than C₄ or marine foods dominate the site's archaeological record. These data suggest that Ancón's inhabitants either had access to more fertile land up‐valley where maize could be cultivated successfully or that they engaged in trade relationships with their valley neighbours. A third possibility is that increased maize consumption at Ancón during the Middle Horizon resulted from Wari imperial influence and interregional exchange. Comparisons of δ¹³C values in enamel and bone carbonate from Ancón individuals indicate that δ¹³C_{carb_enamel} values are significantly more positive than δ¹³C_{carb_bone} values. This suggests that the diets of young children were systematically enriched in ¹³C compared to that of adults, perhaps as a result of nursing activity and/or differential dietary practices among various age groups at the site. Copyright © 2009 John Wiley & Sons, Ltd.     

Chicken and Egg: Testing the Carbon Isotopic Effects of Carnivory and Herbivory

In bone, the spacing between δ¹³C in collagen and bioapatite carbonate is greater in herbivores than carnivores, with implications for understanding animal dietary ecology from surviving hard tissues. Two explanations have been proposed: varying diet composition or differences in physiology between herbivores and carnivores. We measured the isotopic effects of carnivorous and herbivorous diets on a single species, to test the effect of diet composition alone. Protein δ¹³C and δ¹⁵N and carbonate δ¹³C were measured on egg and bone from hens on different diets. Herbivorous hens had a +14.3‰ spacing between egg albumen and shell δ¹³C, compared to +12.4‰ for omnivorous hens, and +11.5‰ for carnivorous hens. The bioapatite–collagen Δ¹³C spacing was measured as +6.2‰ for herbivorous hens, and calculated as +4.3‰ for omnivorous hens, and +3.4‰ for carnivorous hens—similar to observed mammalian herbivore and carnivore bioapatite–collagen Δ¹³C differences. We conclude that a shift in diet composition from herbivory to carnivory in a single species does alter the bioapatite–collagen carbon isotopic spacing. Our data strongly suggest that this results from differences in the Δ¹³C_{bioapatite–diet} spacing, and not that of Δ¹³C_{collagen–diet}.     

Early Neolithic diet and animal husbandry: stable isotope evidence from three Linearbandkeramik (LBK) sites in Central Germany

The first appearance of the Neolithic Linearbandkeramik (LBK) in Central Germany occurred during the 6th millennium BC. However, though LBK sites are abundant in the German loess areas, there are only a few studies that reconstruct the diet of these first farmers using biochemical methods. Here we present the largest study undertaken to date on LBK material using stable isotope analysis of carbon and nitrogen to reconstruct human diet and animal husbandry strategies. We analyzed the bone collagen of 97 human individuals and 45 associated animals from the sites of Derenburg, Halberstadt and Karsdorf in the Middle Elbe–Saale region of Central Germany. Mean adult human values are ?19.9 ± 0.4‰ for δ¹³C and 8.7 ± 0.8‰ for δ¹⁵N. The δ¹³C values are typical for terrestrial, temperate European regions, whereas the δ¹⁵N values fall within an expected range for farming societies with a mixed diet consisting of products from domestic animals and plants. The consumption of unfermented dairy products is unlikely as there is direct palaeogenetic evidence of lactose intolerance available for one of the sites. There are no clear indications for dietary differences in sex. Young children under three years of age are enriched in δ¹⁵N due to breastfeeding indicating that weaning likely occurred around the age of three years. The fauna exhibit mean δ¹³C values of ?20.9 ± 0.8‰ and mean δ¹⁵N values of 7.0 ± 0.9‰ respectively. Variation in the δ¹³C and δ¹⁵N in the domestic animals is probably caused by different livestock managements.     

IN VITRO DECOMPOSITION OF BONE COLLAGEN BY SOIL BACTERIA: THE IMPLICATIONS FOR STABLE ISOTOPE ANALYSIS IN ARCHAEOMETRY*

To understand biogenic collagen type I decomposition and to establish how diagenesis may bias archaeometric data, modern mammalian bone was inoculated with a selection of ubiquitous soil bacteria. The presence of exogenous microbial biomass in the inoculated specimens was then checked microscopically prior to collagen extraction. The experimentally degraded bone collagen showed altered amino acid compositions, attributable to the selective breakdown of certain amino acids by the bacteria. While both the bulk collagen extract and the single amino acids exhibited shifts to more negative δ¹³ C-values, enrichment was recorded for general δ¹³ N, and a depletion trend relative to unaltered collagen was observed for individual amino acid δ¹³ N. One explanation for the enrichment of the global δ¹⁵N-values is cleavage of peptide bonds, which leaves ¹⁵ N within the substrate, while the change of ¹³C is mostly due to the altered amino acid composition. On the other hand, possible repolymerization of cleavage products under experimental conditions may also be responsible for the depletion trend of individual amino acid δ¹³C- and δ¹⁵ N-values. This paper discusses the results as a basis for the development of a method for the reconstruction of the isotopic abundance of the original collagen, using the amino acid composition of the degraded product, the contribution of individual amino acids to its global δ-values and of isotope discriminations implied in the microbial decomposition.     

BIOARCHAEOLOGICAL ANALYSIS OF SUBSISTENCE AND HEALTH AT THE LAKE GEORGE SITE,MISSISSIPPI (22YZ557)

Abstract

Bioarchaeological investigations of subsistence and health were conducted on a skeletal population from the Lake George site (22YZ557), a large prehistoric settlement in the lower Yazoo basin of west-central Mississippi. Subsistence is inferred from oral health indicators (including dental caries, calculus, periodontal disease, abscesses, antemortem tooth loss, and macrowear) and stable carbon and nitrogen isotope ratios from bone collagen and apatite. Health is inferred from nonspecific indicators (including cranial porous lesions, enamel hypoplasias, and Harris lines). The sample includes 25 adults and 25 subadults, all of which date to the Coles Creek period (A.D. 700–1200). Frequencies of all pathological conditions are reported for the entire sample and divided by sex and age for adults. Results indicate a heavy pathology load at Lake George, but one that is not dissimilar to other Coles Creek populations. Isotope values indicate a diet that included primarily C3 plants (δ¹³C_Col = ?21.03‰, δ¹³C_Ap-Diet = ?22.06) and terrestrial protein (δ¹⁵N = 9.72‰). The sources of nonspecific pathologies are attributed to stressors associated with increasing population density and cultural complexity that occurred during the Coles Creek period.     

A comprehensive review of hydrocarbons and genetic model of the sandstone‐hosted Dongsheng uranium deposit,Ordos Basin,China

The Dongsheng uranium deposit, the largest in situ leach uranium mine in the Ordos Basin, geometrically forms a roll‐front type deposit that is hosted in the Middle Jurassic Zhiluo Formation. The genesis of the mineralization, however, has long been a topic of great debate. Regional faults, epigenetic alterations in surface outcrops, natural oil seeps, and experimental findings support a reducing microenvironment during ore genesis. The bulk of the mineralization is coffinite. Based on thin‐section petrography, some of the coffinite is intimately intergrown with authigenic pyrite (ore‐stage pyrite) and is commonly juxtaposed with some late diagenetic sparry calcite (ore‐stage calcite) in primary pores, suggesting simultaneous precipitation. Measured homogenization temperatures of greater than 100°C from fluid inclusions indicate circulation of low‐temperature hydrothermal fluids in the ore zone. The carbon isotopic compositions of late calcite cement (δ¹³C_VPDB = ?31.0 to ?1.4‰) suggest that they were partly derived from sedimentary organic carbon, possibly from deep‐seated petroleum fluids emanating from nearby faults. Hydrogen and oxygen isotope data from kaolinite cement (δD = ?133 to ?116‰ and δ¹⁸O_SMOW = 12.6–13.8‰) indicate that the mineralizing fluids differed from magmatic and metamorphic fluids and were more depleted in D (²H) than modern regional meteoric waters. Such a strongly negative hydrogen isotopic signature suggests that there has been selective modification of δD by CH₄±H₂S±H₂ fluids. Ore‐stage pyrite lies within a very wide range of δ³⁴S (?39.2 to 26.9‰), suggesting that the pyrite has a complex origin and that bacterially mediated sulfate reduction cannot be precluded. Hydrocarbon migration and its role in uranium reduction and precipitation have here been unequivocally defined. Thus, a unifying model for uranium mineralization can be established: Early coupled bacterial uranium mineralization and hydrocarbon oxidation were followed by later recrystallization of ore phases in association with low‐temperature hydrothermal solutions under hydrocarbon‐induced reducing conditions.     

The variation in δ13C values in bone collagen for two wild herbivore populations: Implications for palaeodiet studies

The δ¹³C values for un-defatted bone gelatin of individual members of wild populations of mule deer (Odocoileus hemionus hemionus) and field vole (Microtus townsendii) have been measured to determine the variability within each population. Means and standard deviations for the mule deer sample (N=55) and vole sample (N=22) are −20·6±0·5‰ and −23·2±0·6‰, respectively. The distributions of δ¹³C values for each of these populations are normal and we observed no correlation in δ¹³C values with age or sex.     

The Middle Byzantine menu: palaeodietary information from isotopic analysis of humans and fauna from Kastella,Crete

We report here on the measurements of carbon and nitrogen stable isotopes of bone collagen from the Middle Byzantine site of Kastella, in the city of Heraklion, on the island of Crete, Greece. The data derived from the analysis suggest a diet based primarily on terrestrial, C₃ protein, probably from animal sources, with the inclusion of some marine protein. The adult diet at this site is relatively uniform, with no detectable differences between average isotopic values for males and females. We also found that bone collagen δ¹⁵N values for a small number of juveniles decreased to adult levels after the age of two years, indicating that weaning occurred at or before this age. Copyright © 2006 John Wiley & Sons, Ltd.     

Stable isotopic analysis of human bones from Jiahu site,Henan, China: implications for the transition to agriculture

We have investigated change in subsistence during the transition to agriculture in the site of Jiahu, Henan Province, China, using stable isotopic analysis of collagen and apatite in human bones. Millet agriculture is well documented at drier high latitudes of the Yellow River Valley, while rice agriculture predominated at wetter lower latitudes of the Yangtze Valley region. The early Neolithic site of Jiahu lies near the boundary between the drier north and wetter south. Archaeobotanical evidence shows that rice was a significant component of diet at Jiahu, but its δ¹³C value is similar to that of other foods, and therefore cannot be conclusively identified by carbon isotope analysis. Foxtail and broomcorn millets are the only C₄ crops known for the Chinese Neolithic. Because of their high δ¹³C values, their consumption can be evaluated by stable carbon isotope analysis of human bone. Collagen reflects mainly the δ¹³C value of dietary protein, and apatite accurately records that of the whole diet. Isotopic analysis of 15 well-preserved samples from three periods shows that collagen δ¹³C values were very low for almost all individuals, suggesting C₃-based foods dominated their diets. However, apatite carbonate δ¹³C values and δ¹³C spacing between collagen and apatite (Δ¹³C_ap-co) indicate that millet may have been a minor component of the diet in this region. Individuals, who consumed the smallest amounts of animal protein, as indicated by low δ¹⁵N, generally had the highest apatite δ¹³C values. Archaeobotanical evidence for millet at Jiahu is needed to support this interpretation.     

C4‐Plant Foraging in Northern Italy: Stable Isotopes,Sr/Ca and Ba/Ca Data of Human Osteological Samples from Roccapelago (16th–18th Centuries AD)

Human osteological samples (n = 23) taken from different anatomical parts of 11 individuals from the early modern (16th–18th century AD) site of Roccapelago (Modena, Italy) were systematically analysed for δ¹³C, δ¹⁵N and trace elements to investigate their diet. δ¹³C and δ¹⁵N correlate and show a high variability between individuals, attesting to the dietary contribution of C₄ plants. This is supported by pollen analysis of the burial site samples, which revealed the presence of maize. δ¹⁵N correlates with Sr/Ca, suggesting that the main protein source could have been milk and dairy. We therefore interpret the strong correlation between δ¹³C and δ¹⁵N as evidence for C₄‐plant foraging practice and the exploitation of livestock for meat and milk, combined with possible direct intake of C₄ plants. The Roccapelago site represents an important case study to track the evolution of the post‐medieval diet and the introduction of maize cultivation in southern Europe, as also attested by historical sources.