Results of paleoethnobotanical analysis from features at Soro Mik’aya Patjxa.

Ubiquity is measured as the proportion of archaeological features containing each taxon. Values based on 15 features, 300L of flotation, and 688 paleoethnobotanical artifacts (see Table 5).</p

Carbon and nitrogen plots for control samples and 25 human bone samples from Soro Mik’aya Patjxa and Wilamaya Patjxa, indicating a plant-dominant diet.

a) δ13Cdiet values are consistent with those of C3 plants with slight enrichment from some other resource types. b) δ15Ndiet values are most consistent with those of plants. c) Biplot of δ13C and δ15N values are consistent with a mixed diet principally based on C3 plants with low levels of enrichment from some other resource. Dietary values assume δ13C TEF = 5.0‰, δ15N TEF = 6.0‰ based on mixing model results (see Table 4). Dots = individual samples, ellipses = 95% variance ranges for each category, and crosshairs = mean values by category (see Tables 1 and 2).</p

Bayesian mixing model comparison considering different trophic enrichment factors.

Bayesian mixing model comparison considering different trophic enrichment factors.</p

Human bone collagen isotopic results for Soro Mik’aya Patjxa and Wilamaya Patjxa individuals.

Human bone collagen isotopic results for Soro Mik’aya Patjxa and Wilamaya Patjxa individuals.</p

Bayesian mixing model code in R language.

Current models of early human subsistence economies suggest a focus on large mammal hunting. To evaluate this hypothesis, we examine human bone stable isotope chemistry of 24 individuals from the early Holocene sites of Wilamaya Patjxa (9.0–8.7 cal. ka) and Soro Mik’aya Patjxa (8.0–6.5 cal. ka) located at 3800 meters above sea level on the Andean Altiplano, Peru. Contrary to expectation, Bayesian mixing models based on the isotope chemistry reveal that plants dominated the diet, comprising 70–95% of the average diet. Paleoethnobotanical data further show that tubers may have been the most prominent subsistence resource. These findings update our understanding of earliest forager economies and the pathway to agricultural economies in the Andean highlands. The findings furthermore suggest that the initial subsistence economies of early human populations adapting to new landscapes may have been more plant oriented than current models suggest.</div

Isotopic data for Soro Mik’aya Patjxa and Wilamaya Patjxa individuals.

Isotopic data for Soro Mik’aya Patjxa and Wilamaya Patjxa individuals.</p

Inter-laboratory comparison of isotopic results showing consistent results and acceptable atomic C/N ratios.

Inter-laboratory comparison of isotopic results showing consistent results and acceptable atomic C/N ratios.</p

Bayesian mixing model results for the six best-fit models showing that C₃ plants comprised the majority of the diet and mammals played a secondary role in the subsistence economies of Soro Mik’aya Patjxa and Wilamaya Patjxa.

a. model 14, b. model 9, c. model 13, d. model 15, e. model 16, f. model 10 (see Table 4).</p

Carbonized macrobotanical materials from Soro Mik’aya Patjxa flotation samples.

Carbonized macrobotanical materials from Soro Mik’aya Patjxa flotation samples.</p

Summary statistics for stable isotopic control data for high-altitude Andean food resources and archaeological samples from Soro Mik’aya Patjxa (SMP) and Wilamaya Patjxa (WMP).

Summary statistics for stable isotopic control data for high-altitude Andean food resources and archaeological samples from Soro Mik’aya Patjxa (SMP) and Wilamaya Patjxa (WMP).</p