FOCUS: effect of diet and protein source on carbon stable isotope ratios in collagen: follow up to

We analyzed carbon stable isotope data from bone collagen of animals consuming varied experimental diets, including recently published data from Warinner and Tuross [Warinner, C., Tuross, N., 2009. Alkaline cooking and stable isotope tissue–diet spacing in swine: archaeological implications. Journal of Archaeological Science 36, 1690–1697; this journal]. Comparing regression lines for the relationship between collagen and diet δ¹³C, we show that protein source, and not physiology, explains the apparent taxonomic difference between swine and rodents reported in that paper. Our results reveal a complex relationship between whole diet and dietary protein in determining collagen δ¹³C values, such that in many cases, collagen alone may not provide reliable reconstructions of paleodiet. We advocate the simultaneous use of both collagen and apatite δ¹³C, whenever possible, to assess the diets of prehistoric peoples.     

Applying new approaches to modeling diet and status: isotopic evidence for commoner resiliency and elite variability in the Classic Maya lowlands

Classic Maya states were characterized by a high degree of socioeconomic stratification. This paper investigates the degree to which status, as defined by grave goods and tomb construction, influenced dietary patterns of elites and commoners throughout the Classic Period (200–900/1000 AD) of the southern lowlands. We compile a database (N = 102) of previously-published stable isotope ratios (δ¹³C collagen, δ¹³C apatite, and δ¹⁵N collagen) from Maya bone mineral and collagen, and interrogate these data through two new isotopic modeling techniques: a simple carbon isotope model ( Kellner and Schoeninger, 2007; Froehle et al., 2010) and a multivariate isotope model ( Froehle et al., 2012). We find that Maya elite diet varied significantly through time in terms of maize consumption and trophic level, while commoner diet remained remarkably stable. These findings provide new information relevant to studies of ancient Maya class structure and to studies of subsistence strategies of the pre-Columbian Americas.     

Dietary adaptation during the Longshan period in China: stable isotope analyses at Liangchengzhen (southeastern Shandong)

Rice and millet were staple crops at Liangchengzhen, a late Neolithic Longshan site in Shandong, China, but the degree of dietary variation is not known. This study uses stable isotope analysis of human and faunal skeletal remains to quantitatively address the importance of these crops as well as terrestrial domesticates and aquatic resources in the diet at Liangchengzhen. Although no collagen could be extracted from the poorly preserved human bones, the δ¹³C stable isotope results for 2 apatite sample and 16 tooth enamel samples averaged −9.8‰ suggesting that diet was based on foods averaging from −24‰ to −18‰, with millet and millet-fed animals comprising at most approximately 25–30% of the diet. Pig faunal δ¹³C isotope values suggested that during the earlier Longshan period pigs were fed mainly millet with more C₃ foods such as rice included by the later Longshan period. Solid ceramic residues from two guan jar sherds produced δ¹³C values averaging −18‰ and δ¹⁵N values averaging +16‰, suggesting both vessels contained fish. The results of the study indicate that by the Longshan period, people in southeastern Shandong no longer relied as heavily on millet and that the agricultural crop of rice had increased in importance at Liangchengzhen. Unfortunately, without human collagen samples to provide nitrogen isotope results, we cannot estimate the relative contribution of aquatic and terrestrial protein to the diet of people at Liangchengzhen. In general, however, the pattern of a diverse agricultural system on the basis of the macrobotanical remains from Liangchengzhen is supported by the isotopic results.     

Human–environment interactions in medieval Poland: a perspective from the analysis of faunal stable isotope ratios

Stable isotope analyses of faunal remains provide valuable information about human–environment interactions in the past, including insights into past animal husbandry and land management strategies. Here, we report stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope values of collagen and carbonate from archaeological fauna from Ka?dus, a medieval settlement in North-Central Poland, to better understand human–environment interactions during a period of increasing urbanism and marketization. Wild and domestic animals can be separated on the basis of their isotopic values. The mean δ¹⁵N value for 12 domesticated animals is 7.6 ± 1.2‰ and for 5 wild animals is 4.3 ± 0.5‰ (p = 0.002). The mean collagen δ¹³C value for domesticated animals is −20.6 ± 1.1‰ and for wild animals is −22.0 ± 0.5‰ (p = 0.004). The mean carbonate δ¹³C value for domesticated animals is −13.14 ± 1.3‰ and for wild animals is −14.14 ± 0.9‰ (p = 0.034). The “canopy effect” and anthropogenic effects that alter stable isotope ratios of plants (manuring, swidden agriculture and ploughing) are discussed in relation to these differences. Fish are isotopically variable, which suggests broad-spectrum fishing strategies and/or trade, and increases our awareness of the difficulties in interpreting human paleodiet when freshwater fish were on the menu.     

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.     

Stable isotope evidence of human diet at the Nukdo shell midden site,South Korea

Carbon and nitrogen stable isotope analysis was undertaken on bone collagen extracted from archaeological human (n = 48) and animal (n = 45) skeletons from the Nukdo site, Location I C, South Korea. This shell midden and grave site is dated from the late Mumun (550–300 BC) to early Iron Age (300 BC-1 AD) periods. The herbivorous mammals fell within the range of C₃ consumers, with average values of δ¹³C = −21.0 ± 0.5‰ and δ¹⁵N = 3.6 ± 0.5‰ for deer (n = 16) and δ¹³C = −20.6 ± 0.5‰ and δ¹⁵N = 4.5 ± 2.0‰ for wild boar (n = 17). Humans from this site averaged δ¹³C = −18.3 ± 0.4‰ and δ¹⁵N = 11.2 ± 0.7‰ for adults (n = 15) and δ¹³C = −18.7 ± 0.7‰ and δ¹⁵N = 12.5 ± 1.1‰ for juveniles (n = 33). These δ¹³C values indicate that there was no significant input of C₄ plants in the human diets and this may be associated with the spread of rice agriculture in the Mumun period. Human bone collagen δ¹³C and δ¹⁵N values indicate that there was some consumption of marine foods, although the main protein sources were from terrestrial foods. The isotope data demonstrate that the humans at Nukdo had mixed diets that included marine and terrestrial protein, including C₃ plants such as rice. Finally, the isotope results from the juveniles indicate that weaning occurred before the age of 1.5 years in this period.     

Stable Carbon and Oxygen Isotope Spacing Between Bone and Tooth Collagen and Hydroxyapatite in Human Archaeological Remains

Spacing between stable isotope values in bones and teeth is a valuable tool for examining dietary influences and diagenesis. This study examines carbon and oxygen isotope values from collagen and hydroxyapatite (structural carbonate and phosphate) in archaeological human bones and teeth to derive species‐specific correlation equations and isotope spacing values. The δ¹³C_collagen and δ¹³C_{structural carbonate} in bone and dentin collagen show a strong correlation (R = 0.87, 0.90, respectively) with an average Δ¹³C_carb‐coll spacing of 5.4‰. The consistency of this isotope spacing with other large mammals and in humans with both low and high protein intake (as indicated by enriched δ¹⁵N values) suggests a similar allocation of protein‐derived carbon and whole diet‐derived carbon to collagen and structural carbonates, respectively, as other terrestrial mammals regardless of absolute meat intake. The δ¹⁸O_{structural carbonate} and δ¹⁸O_phosphate show the strongest correlation in enamel (R = 0.65), weaker correlations in dentin (R = 0.59) and bone (R = 0.35), with an average Δ¹⁸O_carb‐phos of 7.8‰. This isotope spacing is slightly lower than previously reported for large mammals and limited available data for humans. The results potentially indicate species‐specific fractionations and differing access to body water and blood‐dissolved inorganic carbonates in the presence of collagen formation. The use of correlation between δ¹⁸O_{structural carbonate} and δ¹⁸O_phosphate to determine diagenetic state is not recommended. The strength of this correlation observed in bones and teeth is variable and alternate indicators of diagenetic state (i.e. C:N ratios of collagen) provide more robust and independent evidence of isotope preservation despite presence/absence of a strong isotope correlation. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.     

The stable and radio-isotope chemistry of southeastern Utah Basketmaker II burials: dietary analysis using the linear mixing model SISUS,age and sex patterning,geolocation and temporal patterning

The Bayesian linear mixing model SISUS is used to reconstruct reliance on maize and intake of animal protein from the stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope values of 149 directly dated Basketmaker II burials. Maize is the primary dietary staple. δ¹³C values are also enriched by intake of yucca and wild C₄ plant foods but these resources are of minor importance in sampled diets. Animal protein intake is low and cottontail rabbits make the greatest contribution to female diets. Adolescent diets are indistinguishable from the diets of adult females and both groups are less reliant on artiodactyls than males. The δ¹³C and δ¹⁸O values of bone hydroxyapatite distinguish nursing infants and oxygen isotope values identify outsider adults relative to those local to the region where their deaths occurred. Most Utah Basketmaker II burials are contemporary with Black Mesa Lolomai phase occupations, postdating the Marsh Pass, AZ, White Dog phase. All burials in both studies were recovered from sheltered rather than open sites and reliance on maize does not increase over the temporal span of the Utah study, covering the two sigma range 415 BC–AD 322.     

Sensitivity of bulk sedimentary stable carbon isotopes to prehistoric forest clearance and maize agriculture

The stable carbon isotope compositions (δ¹³C) of tropical lake sediments and soils have been used to reconstruct the occurrence of prehistoric maize cultivation and its relative importance through time. This study assesses some of the possible variables affecting the response of lake sediment bulk organic carbon isotope (δ¹³C_TOC) values to variations in the scale of prehistoric maize cultivation and the potential of this proxy to yield quantitative estimates of the scale of prehistoric maize agriculture in small tropical watersheds. High resolution analyses of δ¹³C_TOC values, maize pollen concentrations, and mineral influx were conducted on sediments deposited during a ∼220 year period of prehistoric maize agriculture in the watershed of Laguna Castilla, a small lake in the mid-elevations of the Cordillera Central, Dominican Republic. Close correspondence between δ¹³C_TOC values and maize pollen concentrations in the Laguna Castilla sediment record indicates a close relationship between the isotopic values and the scale of prehistoric maize cultivation. Correlations between the δ¹³C_TOC signature and mineral influx indicate that the isotope record is also sensitive to variations in allochthonous carbon delivery. This study establishes that sedimentary δ¹³C_TOC values can provide a highly sensitive proxy of the spatial scale of prehistoric maize agriculture in small tropical watersheds, but emphasizes the need for a better understanding of sediment dynamics and carbon cycling in anthropogenically modified landscapes before this proxy can be widely employed in diverse archaeological settings.     

A palaeodietary investigation of carbon (C/C) and nitrogen (N/N) in human and faunal bones from the Copper Age cemeteries of Varna I and Durankulak,Bulgaria

Stable isotope analyses have been applied to human and faunal bone collagen from the Varna I and Durankulak cemeteries to explore palaeodietary adaptations in the Neolithic and Eneolithic (Copper Age). The results suggest both populations primarily utilised terrestrial, C₃-based diets, despite their proximity to the Black Sea. The wider δ¹⁵N range of the Durankulak humans likely indicates the differential utilisation of terrestrial meat sources, which is probably related to the degree to which primary and/or secondary ovicaprid products were consumed, particularly since ovicaprid δ¹⁵N values differ from other herbivores. The isotopic distribution of Varna I reflects a linear relationship between δ¹⁵N and δ¹³C, suggesting that a minority of individuals enriched in both isotopic parameters supplemented their diets with marine resources. These burials include the well known ‘chieftain’ (burial 43) and show notable material wealth by way of grave goods. At the population level, however, there is no significant correlation between stable isotope values and material wealth at Varna I, a fact with implications for theories regarding emergent social/economic hierarchies in Balkan prehistory. Five burials at Durankulak were found to have relatively enriched δ¹³C and δ¹⁵N values with respect to the rest of the population. These burials reflect a prominently marine-based or mixed terrestrial C₃-based diet that included C₄ inputs, possibly from millet, for which the limitations of stable isotope analysis on bulk collagen are not able to differentiate. AMS dating has shown that these burials belong to a much later period.     

Paleodiet in northern Chile through the Holocene: extremely heavy δN values in dental calculus suggest a guano-derived signature?

Dental calculus extracted from the teeth of 28 prehistoric human skeletons from coastal and valley archaeological sites in northern Chile that date from the Archaic period (∼2300 BC) to the Late Intermediate period (AD 1476) was analyzed for stable isotope (δ¹⁵N, δ¹³C) compositions. δ¹⁵N compositions were extremely heavy (+17.8 to +33.1‰), but comparable to some studies using conventional human biomaterials (hair, nail, muscle) at other prehistoric sites in northern Chile. There was a negative correlation between δ¹⁵N and δ¹³C for coastal sites, but a positive correlation for valley sites. Results for the valley sites point to a diet that was influenced by marine resources throughout all time periods. The unusually heavy δ¹⁵N values for the coastal sites require a dietary component with a δ¹⁵N composition significantly heavier than that of marine resources. The hyper-aridity at the study area (mean annual rainfall of 0.5–0.6 mm/year) is a likely contributing factor to the production of heavy δ¹⁵N values, but is unlikely to account for the heaviest δ¹⁵N values (>+30‰). One possible explanation for the heaviest δ¹⁵N values is that dietary components were impacted by isotopically-heavy guano, which is abundant in the region. Guano may have been used as a fertilizer during crop cultivation at the onset of the Formative period, continuing through the Historic period after Spanish contact. The indirect impact of guano from abundant bird habitats in the region may have influenced wild foodstuffs harvested throughout the pre-agricultural period. Results provide support for the utility of dental calculus as a proxy for obtaining stable carbon and nitrogen isotope signatures for use in paleodietary studies.     

Ascetic or affluent? Byzantine diet at the monastic community of St. Stephen’s,Jerusalem from stable carbon and nitrogen isotopes

Stable carbon and nitrogen isotope ratios from bone collagen in skeletons from the Byzantine (5th–7th century AD) monastery of St. Stephen’s in Jerusalem were examined in conjunction with a review of historical sources detailing dietary practices during this period in the Levant. Relatively low δ¹³C ratios (−19.0 ± 0.5‰, 1σ) indicate a diet consisting primarily of C₃ sources and display continuity with textual records describing monastic daily life. Conversely, human δ¹⁵N values (9.6 ± 1.2‰, 1σ) are enriched in ¹⁵N relative to local fauna (7.3 ± 1.1‰, 1σ) and point to the contribution of animal protein to the diet, an unexpected result based on both the rarity and expense of these luxury food items as well as dietary prohibitions associated with an ascetic monastic lifestyle. No sex-based differences in diet were detected for either δ¹³C or δ¹⁵N values, suggesting that men and women consumed isotopically similar foods. As the vast majority of monastic communities in the ancient Near East were located in the desert, the urban setting of St. Stephen’s monastery allows for a unique glimpse into a rarely-explored facet of Byzantine life.     

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.     

Assessing natural variation and the effects of charring,burial and pre-treatment on the stable carbon and nitrogen isotope values of archaeobotanical cereals and pulses

The aim of this study is to assess the potential of charred archaeobotanical cereal grain and pulse seed δ¹³C and δ¹⁵N values to provide evidence of crop growing conditions and as a potential component of palaeodietary studies. In order to reliably interpret archaeobotanical δ¹³C and δ¹⁵N values it is necessary to take into account the impact of charring, burial and laboratory pre-treatment procedures. We examine the effects of charring and burial on bulk δ¹³C, δ¹⁵N, %C, %N and C:N ratios in modern cereal and pulse material, and of cleaning by acid–base–acid (ABA) pre-treatment on modern and archaeobotanical charred material. Our study utilised bulk grain and seed samples to help account for within-ear/pod and between-plant variability in δ¹³C and δ¹⁵N values. Heating at relatively low temperatures and for prolonged times (230 °C for up to 24 h) is conducive to the formation of well preserved, undistorted charred cereal grain and pulse seed. Heating for 24 h has a systematic and predictable effect on δ¹⁵N values, with increases of around 1‰ on average in cereal grains and pulse seeds, and no consistent impact on δ¹³C values. Increases in δ¹⁵N are likely due to the loss of lighter ¹⁴N via N-containing volatiles. Burial (for up to 2 years) and ABA pre-treatment have no significant effects on δ¹³C or δ¹⁵N values. After pre-treatment, however, the %C and %N contents of the archaeobotanical material more closely resembles that of the modern charred grains and seeds, suggesting that archaeobotanical remains accumulate non-structural material during burial but retain their original carbon and nitrogen content. Therefore %C, %N contents and C:N ratios can provide useful criteria for assessing archaeobotanical preservation.     

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.     

Stable Isotopes and Oral Tori in Greenlandic Norse and Inuit

Palatine (PT) and mandibular torus (MT) have long been of interest to dental researchers and anthropologists, but their aetiology remains unresolved. Some combination of genetic and environmental factors influences their expression, but the relative role of each remains contentious. Previous research has shown that the Greenlandic Norse exhibit exceptionally high frequencies and pronounced expressions of PT and MT. In this regard, they are significantly different from genetically related medieval Scandinavian populations, so environmental factors have to be considered. An earlier study that estimated stable carbon and nitrogen isotope compositions for a Greenlandic Norse sample makes it possible to compare directly PT and MT expression with the relative degree of marine protein intake. For comparative purposes, parallel observations were made on a Greenlandic Inuit sample. Some researchers suggest the intake of marine resources could impact bone development, including torus expression, but our analysis found no significant correlation between PT or MT expression and δ¹³C and δ¹⁵N values in the Norse. In the Inuit, PT expression also showed no relationship to stable isotope compositions. MT size in the Inuit did, however, show a significant inverse relationship with δ¹³C and δ¹⁵N values. As MT size goes up, stable isotope compositions go down. Compared with contemporary European populations, the Greenlandic Norse show very positive isotope compositions, but the Inuit, with their high protein‐high fat diet, show significantly higher δ¹³C and δ¹⁵N values than the Norse. It is unclear how this relates to the contrasting findings for MT size and stable isotope values. Copyright © 2016 John Wiley & Sons, Ltd.     

The effects of PVAc treatment and organic solvent removal on δ13C, δ15N,and δ18O values of collagen and hydroxyapatite in a modern bone

The stable isotopic analysis of archaeological and paleontological bones has become a common method to examine questions of ecology, climate, and physiology. As researchers addressing such questions incorporate museum collections in their studies, it is necessary to understand the isotopic effects of common preservation techniques utilized in such collections to ensure the preservation of original isotopic values. This study examines the effects of PVAc glue (polyvinyl acetate) applied in acetone solution and the subsequent removal of PVAc using various organic solvents on the δ¹³C and δ¹⁵N values of extracted bone collagen, the δ¹³C and δ¹⁸O values of carbonate in bone hydroxyapatite, and the δ¹⁸O values of phosphate in hydroxyapatite. The data demonstrate that isotopic values in the collagen and phosphate are unaffected by any combination of PVAc treatment and solvent application. The carbonates show little variation in δ¹³C values, but exhibit variable δ¹⁸O values upon exposure to the PVAc solution. It is here suggested that δ¹⁸O values from carbonates in PVAc-treated bones do not retain an original isotopic value and should not be included in future studies.     

Crop Fertility Conditions in North-Eastern Gaul During the La Tène and Roman Periods: A Combined Stable Isotope Analysis of Archaeobotanical and Archaeozoological Remains

ABSTRACT

Considerable archaeobotanical datasets describe cereal cultivation in north-eastern France, from the Iron Age to the Roman period. This study aims to complement these by using stable isotope analysis on charred cereal grains. Soil fertility was investigated through δ¹⁵N and δ¹³C analyses of 1480 charred cereal grains, dated from the Late La Tène to the Late Antiquity periods. In the Île-de-France, charred grain Δ¹³C values suggested good hydric conditions, with drier episodes in the 1st and 3rd century AD; while in Champagne, the lower Δ¹³C values for spelt reflect the lower water holding capacity of the chalky soils. A wide range of cereal δ¹⁵N values (0.8–8.7‰) implies a wide range of soil fertility conditions. Jouars-Pontchartrain and Palaiseau (Île-de-France) yielded the highest cereal δ¹⁵N values, whereas Acy-Romance (Champagne) delivered among the lowest. From these three sites, the δ¹⁵N values of red deer bone collagen were used to estimate the reference δ¹⁵N values for unmanured plants. Unlike in Acy-Romance, there were significant differences in Palaiseau and Jouars-Pontchartrain, indicating that the cultivated cereals inherited their high δ¹⁵N values from manured soil. At Jouars-Pontchartrain, the δ¹⁵N value (almost 9‰) suggested a high trophic level manuring source, possibly from pig and/or human faeces.     

Early Neolithic diets at Baijia,Wei River valley,China: stable carbon and nitrogen isotope analysis of human and faunal remains

Stable carbon and nitrogen isotope values are presented for faunal and human bone collagen from Baijia, in the Wei River valley region of Shaanxi Province, China. The remains have a calibrated age range of ca. 5709–5389 BC, and correspond with the early Neolithic Laoguantai Period. Stable isotopic results indicate that human diets included millet and probably aquatic foods such as fish and shellfish. Bovid samples are tentatively identified as water buffalo, and have a mean δ¹³C value of −14.6‰, which reflects some millet consumption. Whether bovids were grazing on wild millet, or had diets directly influenced by humans, is not known. The single Sus sample from Baijia had a diet dominated by C3 plants and is thus unlikely to have been a domesticated animal. Overall, the stable isotope results presented here conform to the current concept that the people of the Laoguantai culture were millet farmers, who had subsistence strategies that included hunted wild foods.     

Stable isotope analysis of dog,fox, and human diets at a Late Holocene Chumash village (CA-SRI-2) on Santa Rosa Island,California

Stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope analyses of dog (Canis familiaris), island fox (Urocyon littoralis), and human bone collagen from CA-SRI-2 (AD 130–1830) on Santa Rosa Island, California provide a proxy of diet and the relationships between humans and these animals. Carbon isotopic signatures indicate that Native Americans and their dogs at CA-SRI-2 subsisted almost exclusively on marine resources, while the island fox ate primarily terrestrial foods. Nitrogen isotopes and archaeofaunal remains indicate that humans and dogs also ate higher trophic level foods, including finfishes, marine mammals, and seabirds with smaller amounts of shellfish. The CA-SRI-2 island foxes appear to have eaten higher amounts of terrestrial foods, similar to the diets observed in modern fox populations. These data generally confirm the commensal relationship assumed to exist between domesticated dogs and people, but the carbon isotopic composition of dogs is enriched ∼2‰ compared to humans. We hypothesize that the difference in carbon isotopes between dogs and humans may have resulted from a higher consumption of C3 plants with lower δ¹³C values by humans, or less likely from the ingestion by dogs of significant amounts of bone collagen, which is enriched by ∼4‰ over associated muscle.