Collagen isotope ratios

DeNiro, M.J. 1985 Postmortem preservation and alteration of in vivo bone collagen isotope ratios in relation to palaeodietary reconstruction. Nature 317 806-809. 

Ambrose, S.H. and Norr, L. 1993 Experimental evidence for the relationship of the carbon isotope ratios ofwhole diet and dietary protein to those ofbone collagen and carbonate. In Lambert, J.B. and Grupe, G., eds.. Prehistoric Human Bone Archaeology at the Molecular Level. Berlin, Springer-Verlag 1-37. 

The 8 C values of the Preclassic humans at Cuello (Table 2.1) average -12.9 0.9%o (n = 28) in collagen, -9.8 1.0 in bone apatite (n = 16), and -8.7 2.3%o in tooth enamel apatite (n = 33) the S N values in collagen average 8.9 1.0%o (n = 23). The discrepancy in the number of specimens is due to the fact that more teeth were available than post-cranial material, while some of the specimens contained insufficient collagen to measure the nitrogen isotope ratios. Additional bone apatite analyses are in progress. 

Keegan, W.F. and DeNiro, M.J. 1988 Stable carbon- and nitrogen- isotope ratios of bone collagen used to study coral-reef and terrestrial components of prehistoric Bahamian diet. American Antiquity 53 320-336. 

Lee-Thorp, J.A., Sealy, J.C. and van der Merwe, N.J. 1989 Stable carbon isotope ratio differences between bone collagen and bone apatite, and their relationship to diet. Journal of Archaeological Science 16 585-599. 

Figure 3.3. Average carbon isotopic ratios for human bone collagen samples, corrected for climatic trends. Only countries with more than 10 samples are included. For a description of the climate correction procedure see text.

Schoeninger, M.J., DeNiro, M.J. and Tauber, H. 1983 Stable nitrogen isotope ratios of bone collagen reflect marine and terrestrial components of prehistoric human diet. Science 220 1381-1383. 

Walker, PL. and DeNiro, M.J. 1986 Stable nitrogen and carbon isotope ratios in bone collagen as indices of prebistoric dietary dependence on marine and terrestrial resources in Soutbem California. American Journal of Physical Anthropology 71 51-61. 

Variations in bone collagen nitrogen isotope ratios in C3 foodwebs are illustrated in Figure 4.2. 

Since it is possible to differentiate well-preserved from badly preserved collagen through amino acid analysis and gel electrophoresis, it is also possible to determine which bone samples are likely to give erroneous isotopic ratios. At least for 8 C, it should be possible to estimate the in vivo isotopic signature by correcting the changed amino acid concentrations of the collagen extract. This way, a reasonable approach to the reconstruction of pale-odiet should be possible. 

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). 

This paper will address three subjects a) carbon isotopic composition of bone carbonate b) the possible role of hpid metabolism in determining frae-tionation between bone carbonate and collagen and its apparent trophic signature and c) concepts of routing of carbon isotopes in the body, especially from protein foods to collagen. The discussion will be limited to carbon isotope ratios C C/ C), although we appreciate that N/ N ratios, which are also very useful in determining trophic levels and somces of protein, present similar biochemical problems. 

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