Abstract
We investigated the stable nitrogen isotopic compositions of individual amino acids from human and faunal remains from a variety of archaeological sites in Japan in order to reconstruct the prehistoric human diets. In this study characteristic isotopic compositions were observed among the human populations in different regions and different periods, which were most clearly reflected in the nitrogen isotopic values of glutamic acid (+23 to +320/00 for the coastal regions and +10 to +120/00 for the inland regions) and phenylalanine (0 to +70/00 for the coastal regions and +6 to +70/00 for the inland regions) in bones. It should be noted that the nitrogen isotopic composition of these amino acids could be useful to quantitatively evaluate dietary contribution to the human diets from marine, freshwater and terrestrial ecosystems. For example, by applying the new method to above samples, we estimated that the coastal Jomon populations would obtain >70% of their dietary protein from marine resources. In contrast, it seems that inland Jomon and the Paleolithic populations exploited little protein from marine and freshwater resources.
