Lipids as carriers of anthropogenic signals from prehistory

Studies performed during the last two decades have shown that lipids are preserved in association with a wide range of artefacts and ecofacts recovered from archaeological sites, e.g. pottery vessels and skeletal remains. The majority of work in this area has focused on the use of molecular structures ('biomarkers') and distributions ('fingerprints') to assess the nature and origin of commodities associated with past cultural, economic and agricultural practices. However, since lipids, like all other classes of biomolecule, are affected by degradation (both pre- and post-burial), emphasis is now being placed on the complementary use of diagenetically robust, compound-specific stable isotope measurements to enhance the scope and reliability of archaeological interpretations. A feature of the delta(13)C values of individual lipids, rather than bulk measurements of biochemically more heterogeneous materials, lies in their capacity to reflect differences in both the isotopic composition of the carbon sources used in their biosynthesis and the routing of dietary lipids and their metabolites in consumer organisms. This isotopic information, accessible by gas chromatography-combustion-isotope ratio mass spectrometry, has opened up new avenues of investigation concerning human activity in prehistory.