The effectiveness of using carbonate isotope measurements of body tissues to infer diet in human evolution: Evidence from wild western chimpanzees (Pan troglodytes verus)

摘要

Changes in diet throughout hominin evolution have been linked with important evolutionary changes. Stable carbon isotope analysis of inorganic apatite carbonate is the main isotopic method used to reconstruct fossil hominin diets; to test its effectiveness as a paleodietary indicator we present bone and enamel carbonate carbon isotope data from a well-studied population of modern wild western chimpanzees (Pan troglodytes verus) of known sex and age from Tai, Cote d'Ivoire. We found a significant effect of age class on bone carbonate values, with adult chimpanzees being more C-13- and O-18-depleted compared to juveniles. Further, to investigate habitat effects, we compared our data to existing apatite data on eastern chimpanzees (P. troglodytes schweinfurthii) and found that the Tai chimpanzees are significantly more depleted in enamel delta C-13(ap) and delta O-18(ap) compared to their eastern counterparts. Our data are the first to present a range of tissue-specific isotope data from,the same group of wild western chimpanzees and, as such, add new data to the growing number of modern non-human primate comparative isotope datasets providing valuable information for the interpretation of diet throughout hominin evolution. By comparing our data to published isotope data on fossil hominins we found that our modern chimpanzee bone and enamel data support hypotheses that the trend towards increased consumption of C-4 foods after 4 Ma (millions of years ago) is unique to hominins. (C) 2015 Elsevier Ltd. All rights reserved.