Occlusal molar microwear and the diets of the Ipiutak and Tigara populations (Point Hope) with comparisons to the Aleut and Arikara

Archaeological excavations at Point Hope, Alaska uncovered skeletal remains of two populations: the Ipiutak (100 B.C.–500 A.D.) and Tigara (1200–1700 A.D.). Archaeological evidence indicates that, although both groups relied on animal (largely marine) resources for their subsistence, the Ipiutak were mainly caribou hunters, whereas the Tigara were primarily whale hunters. To date, no study has attempted to ascertain whether the inferred dietary differences of these two groups could be substantiated using a more direct technique, e.g. microwear or stable isotope analysis. In this study, the occlusal molar microwear fabrics of the Ipiutak and Tigara were analyzed. Comparative data for two other modern human groups, the Aleut and Arikara, were also examined. Significant differences in microwear signatures were detected among the groups considered. The results of this study show that the Tigara have significantly more microwear features, more pits and narrower scratches compared to the Ipiutak. These results are concordant with interpretations that the two Point Hope populations had significantly different dietary habits. Differences in microwear signatures between the Aleut and the two Point Hope populations were also detected. Compared to the two Point Hope populations, the Aleut has significantly fewer features and wider scratches. The Aleut microwear signature further differs from that of the Tigara in having significantly lower pitting incidence. The microwear pattern of the Arikara, who had a mixed diet, differed from that of the mainly meat-eating Aleut and Point Hope peoples in that the Arikara has significantly fewer features, lower pitting incidence and narrower scratches.