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 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.     

Probing dietary change of the Kwädąy Dän Ts'ìnchį individual,an ancient glacier body from British Columbia: II. Deconvoluting whole skin and bone collagen δC values via carbon isotope analysis of individual amino acids

The remains of the Kwäd?y Dän Ts'ìnch? individual, a frozen male human, were recovered from a retreating glacier within the Tatshenshini-Alsek Park in British Columbia in August 1999. In order to provide information on both the geographical origin of this individual and low long he spent in the remote interior region prior to his death, molecular analysis and compound-specific carbon isotope analyses were performed on individual amino acids purified from his skin and bone. Gas chromatographic quantification of constituent amino acids of both tissues revealed a molecular distribution characteristic of collagen, dominated by glycine and to a lesser extent proline, hydroxyproline and alanine. Chiral gas chromatography indicated that protein preservation in both tissues was exceptional. Carbon isotope analysis of a faunal assemblage from an earlier prehistoric site from southern British Columbia provided reference dietary amino acid δ¹³C values for terrestrial (deer and domestic dog) and marine species (salmon and sealion), showing clear separation in all amino acids, particularly glycine which was extremely ¹³C-enriched in the marine animals. The distinction between terrestrial and marine organisms was increased by exploring Δ¹³C_{Glycine-Phenylalanine} values (6.6 ± 0.6‰ and 15.0 ± 2.1‰, respectively), which were higher in the latter by approximately 8‰, mirroring the increased δ¹⁵N_{Bulk collagen} values observed for the marine animals (R² = 0.78; p < 0.001). The Kwäd?y Dän Ts'ìnch? individual's bone had a similarly elevated Δ¹³C_{Glycine-Phenylalanine} value of 15.6 ± 1.0‰, indicating his extreme reliance on marine dietary resources throughout early life. The skin amino acid δ¹³C values were consistently lower than those observed for bone, with a concurrently lower Δ¹³C_{Glycine-Phenylalanine} value of 12.7 ± 0.9‰. The shift between the carbon isotope composition of bone (long-term diet) and skin amino acids (short-term diet) confirmed a sudden divergence away from marine food sources in the last months of life, consistent with his discovery 80 km inland.     

Probing dietary change of the Kwädąy Dän Ts'ìnchį individual,an ancient glacier body from British Columbia: I. Complementary use of marine lipid biomarker and carbon isotope signatures as novel indicators of a marine diet

The remains of the preserved ice body from the Kwäd?y Dän Ts'ìnch? discovery were recovered from a retreating glacier in the Tatshenshini-Alsek Park, British Columbia in August 1999. Despite the remote location 80 km inland, bone collagen stable isotope analysis indicated that the individual spent much of his life in a region rich in marine foods (δ¹³C −13.7‰ and δ¹⁵N +17.9‰). Since finds of such bodies are exceptionally rare we undertook detailed lipid analyses in order to assess their preservation and determine whether they might provide new insights into the individual’s dietary life history. Molecular fingerprinting and compound-specific carbon isotope analysis were performed on individual lipids extracted from his bone (turnover approximately ≥1 year) and skin (turnover approximately several weeks). A considerable abundance was observed of C_12:0, C_14:0, C_16:0, C_16:1, C_18:0 and C_18:1 fatty acids (FAs), cholesterol and hydroxy FAs (the latter being decay products). Most unusual was the presence of long-chain hydroxy FAs (LCHFAs), 10- and 12-hydroxyeicosanoic acid and 10- and 12-hydroxydocosanoic acid, in the bone. The latter components are most likely the products of microbially mediated hydration of the double-bonds of C_20:1 and C_22:1 FAs, the latter almost certainly originating from the consumption of a largely marine-based diet. A suite of three isoprenoidal lipids, phytanic acid, pristanic acid and 4,8,12-trimethyltetradecanoic (TMTD) acid, was also detected supporting the notion of a significant marine component of the diet for a substantial part of his life. In contrast, the skin lipid composition was dominated by C_{16:0 FA}, with lower abundances being observed of the marine LCHFAs and isoprenoidal compounds, suggesting reduced reliance on coastal marine foods in the last period of life. This interpretation is supported by the enhanced marine dietary signal observed in the bone than skin FA δ¹³C values.     

Species specific marine radiocarbon reservoir effect: a comparison of ΔR values between Patella vulgata (limpet) shell carbonate and Gadus morhua (Atlantic cod) bone collagen

A number of recent studies of the UK coastal environment have assessed the ¹⁴C marine radiocarbon reservoir effect (MRE) via quantification of ΔR values for several periods throughout the Holocene using marine mollusc shells. However, none have employed fish bone as the marine sample, and the importance of being able to use this material as a reliable dating tool is evident when considering the boom in the British fish trade during the first millennium AD, the so-called ‘fish event horizon’, and the corresponding volume of fish remains that appear in the archaeological record from this time. This study compares ΔR values derived using the multiple paired sample approach employing burnt cereal grain (Hordeum sp.) as the terrestrial sample and either fish bone [North Sea cod (Gadus morhua)] or marine shell [limpet (Patella vulgata)] as the marine sample. The results show a general trend of increasing ΔR for the fish bone compared to shell, however, the differences are not statistically significant when the standard error for predicted values is used as the measure of variability in the ΔR values.     

A bioarchaeological approach to the Iron Age in Switzerland: stable isotope analyses (δ<Superscript>13</Superscript>C, δ<Superscript>15</Superscript>N, δ<Superscript>34</Superscript>S) of human remains

In Switzerland, a large number of Iron Age burial sites were found in the last century. Changes in living conditions and socio-cultural behavior may have occurred over time and space and could be reflected in the dietary habits, social stratigraphy within populations and migration patterns. This study attempts to shed light on these aspects with the application of stable isotope analyses. Human remains from 11 different burial sites (n?=?164) in the area of today’s Swiss Plateau and Swiss Alpine regions were investigated. Temporal and geographical variations as well as sex and age-related dietary differences were analyzed through isotopic studies (δ¹³C, δ¹⁵N, and δ³⁴S). In total, the data of 129 individuals could be evaluated. Highly significant differences between the burial sites were found, with higher δ¹³C and δ¹⁵N values in the Alpine regions. Cultural and/or climatic changes as well as the different geological conditions might have led to distinct patterns of crop cultivation and animal husbandry and consequently to significantly different dietary habits in the Plateau and the Alpine regions. The data indicate a higher intake of millet and animal protein including early dairy production in the southern regions, probably influenced by the Mediterranean world. Cultural exchange between geographical regions might have been facilitated by migration during the Iron Age as suggested by the δ³⁴S.