The proposed project is a follow-up and expansion of preious research using stable isotope analysis and paleo-DNA to discuss the population history from four locations, the Chaluka midden site, Shiprock, and Kagamil caves, in the Eastern Aleutians, using samples from human and non-human faunal remains. The original project addressed hypotheses concerning the biological difference between ?Paleo? and ?Neo-Aleuts,? originally defined using craniometrics and cranial morphology and concluded that the differences did not reflect wholesale population replacement as had previously been hypothesized. The results from Coltrain?s previous analysis suggested that the historic populations in different localities differentially used terrestrial and marine subsistence resources. This project would expand the suite of stable isotopes, specifically sulfur to separate food taxa, carbon isotopes from bone apatite, oxygen isotopes as a proxy for temperature levels, and compound-specific nitrogen to separate specific amino acids. Analysis of these various isotopes would allow the researcher to more closely identify the diets of the individuals represented in the historic populations and provide more specific evidence for a separation of diet between the same population, rather than the skeletal sample representing two separate populations as previously thought.