Isotopic analyses bone collagen

Archaeological studies have used the stable isotope analysis of collagen extracted from fossil bones to reconsfruct the diet of prehistoric human populations (e.g. Schwarcz et al. 1985). 

The diet of the 19 century residents of Upper Canada was determined from historical sources and was reproduced in order to carry out chemical analysis. Stable carbon isotope analysis of food and human bone demonstrates that the spacing between the food eaten and the bone collagen is around 5.6%o. The value may vary slightly from this estimate since the latter is based on a reconstructed diet and a large number of bone samples, which exhibit a small amount of variation. Nevertheless, this empirically derived result agrees well with estimates from field (Vogel 1978), and laboratory studies (reviewed in Ambrose 1993). 

Tykot, R.H., van der Merwe, N.J. and Hammond, N. 1996 Stable isotope analysis of bone collagen, bone apatite, and tooth enamel in the reconstruction of human diet. A case study from Cuello, Belize. In Orna, M.V., ed., Archaeological Chemistry Organic, Inorganic, and Biochemical Analysis. ACS Symposium Series 625, Washington, DC, American Chemical Society 355-365. 

Van Klinken, GJ. 1991 Dating and Dietary Reconstruction by Isotopic Analysis of Amino Acids in Fossil Bone Collagen—with Special Reference to the Caribbean. Ph.D. dissertation. University of Groningen, The Netherlands. 

Ambrose, S.H. 1990 Preparation and characterization of bone and tooth collagen for isotopic analysis. Journal of Archaeological Science 17 431 51. 

Liden, K., Takahasi, C. and Nelson, D.E. 1995 The effects of lipids in stable carbon isotope analysis and the effects of NaOH treatment on the composition of extracted bone collagen. Journal ofArchaeological Science 22 321-326. 

NOTE ADDED IN PROOF This manuscript had been submitted shortly after the presentation of the paper at the Fourth Advanced Seminar on Pale-odiet, 1994. Ongoing research, especially stable isotope analysis of single amino acids from inoculated and non-inoculated marten bones (same specimens as in this paper) further and strongly support our conclusion that bacterial modifica-tion causes substantial shifts in collagen stable isotope ratios (Balzer et fl/. 1997). 

Paleodiet studies have focused on the analysis of collagen, due to its ability to survive in ancient bone. Like all proteins, collagen is composed of amino acid (AA) units present in relatively constant proportions characteristic of the specific protein. The isotopic composition of a sample of collagen is the weighted average of the 5 C values of each of the constituent amino acids. 

Balzer, A., Gleixner, G., Grupe, G., Schmidt, H.-L., Schramm, S., Turban-Just, S. (1997). In vitro decomposition of bone collagen by soil bacteria the implications for stable isotope analysis in archaeometry. Archaeometry 39 (2), 415-429. 

Jim, S., Jones, V., Ambrose, S. H. and Evershed, R. P. (2006) Quantifying dietary macronutrient sources of carbon for bone collagen using natural abundance stable carbon isotope analysis. British Journal of Nutrition 95, 1055 1062. 

McCullagh, J. S. O., Juchelka, D. and Hedges, R. E. M. (2006) Analysis of amino acid 13C abundance from human and faunal bone collagen using liquid chromatography/isotope ratio mass spectrometry. Rapid Communications in Mass Spectrometry 20, 2761 2768. 

Styring, A. K., Sealy, J. C. and Evershed, R. P. (in press) Resolving the bulk 81SN values of ancient human and animal bone collagen via compound specific nitrogen isotope analysis of constituent amino acids. Geochimica et Cosmochimica Acta. 

Ambrose, S.H. (1990). Preparation and characterization of bone and tooth collagen for isotopic analysis. Journal of Archaeological Science 17 431 451. Ambrose, S.H. (1993). Isotopic analysis of paleodiets methodological and interpretative considerations. In Investigations of Ancient Human Tissue Chemical Analysis in Anthropology, ed. Sandford, M.K., Gordon and Breach, Langhorne, pp. 59-130. 

In order to reconstruct human diet from bone tissue, direct isotopic analysis of animal and plant remains from the same archaeological context is the most reliable way to detect isotopic shifts involving the whole ecosystem due to environmental variation. Since this is often impossible for the lack of these control samples, we have explored the use of 8I80 to assess the environmentally induced variation in 8I3C and 8ISN values from collagen and apatite, and assess the dietary information they represent. This can be done assuming a scarce nutritional role of marine resources and the absence of C4 crops, as seems to be the case in the western Mediterranean and specifically in the Sardinian Neolithic and Bronze Age. 

Tripp, J.A., McCuUagh, J.S.O., and Hedges, R.E.M. Preparative separation of underiva-tized amino acids for compound-specific stable isotope analysis and radiocarbon dating of hydrolyzed bone collagen. J. Sep. Sci. 2006, 29, 41-48. 

The major sources of carbon for possible isotopic analysis in bone are collagen, which contains about 45% carbon and hydroxyapatite which contains a few percent of carbon present as carbonate ion substituted in the apatite crystals These two carbon sources are derived from different pathways and different parts of the diet Turnover of bone tissues is the slowest of all tissues in the body that have been studied the mean residence time of carbon in collagen being at least 30 years (14) ... 

The ratio of carbon to nitrogen in a sample is used as a measure of the quality of preservation in bone and a means to determine if samples are reliable for the analysis of collagen for radiocarbon dating and dietary analysis using light isotopes. The ratio of C N in living bone is 3.2 a ratio between 2.8 and 3.5 has been suggested as indicative of fossil bone sufficiently well preserved for analysis. 

For example, people who eat com have higher ratios of carbon isotopes in their bones. Changes in this isotope ratio in prehistoric bone can indicate when com becomes an important component of the diet. Such studies have been done both in Mexico to ascertain when com was first domesticated and in North America to record when this important staple first arrived. Analysis of carbon isotopes from human bone collagen in Mexico indicates that a heavy dependence on com began around 4500 bc. 

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