Dietary shifts and diversities of individual life histories reveal cultural dynamics and interplay of millets and rice in the Chengdu Plain, China during the Late Neolithic (2500-2000 cal. BC).

OBJECTIVES: We undertook a more comprehensive analyses than our previous study (Yi et al., International Journal of Osteoarchaeology, 2018, 28, 636-644) at the Gaoshan site (~2500-2000 cal. BC) to expand our understanding of the different roles of rice and millets to human subsistence strategies, diachronic shift of human diets, diversity of human life histories and cultural influence (dental ablation) to human population. MATERIALS AND METHODS: Carbon and nitrogen isotopic analyses of human (ribs and long bones, n = 68) and animal (n = 15) bones as well as carbonized seeds from rice and millets (n = 8) were undertaken. Human bones were directly AMS-14 C dated. In addition, sequential sampling of 16 individuals with varied age and sex and cultural contexts for isotopic analysis was also conducted. RESULTS: The calibrated dating results (n = 27) indicate that there existed two periods of occupation at the site, ~2500-2200 BC and ~2200-1900 BC. Moderate high δ15 N values were found in the crops. Isotopic data from bone collagen suggest that the humans mainly relied on C3 -based animal protein and were supplemented by C4 -based foods. This isotopic pattern is also seen in pigs. Significant difference of human δ13 C values (Mann-Whitney U test, p < 0.05) between the two periods was observed. Compared to the bones, the isotopic data of human dentine serial sections show a much wider variability and higher δ13 C values. DISCUSSION: The crops (millets and rice) were probably manured. Human individuals subsisted on rice/millet agriculture and pigs in general. In combination with the radiocarbon dates, the increase of C3 (rice) consumption by the humans was found from the early (2500-2200 cal. BC) to late (2200-2000 cal. BC) periods, indicating the intensification of rice agriculture through time. However, four categories of human life histories during childhood are identified given different isotopic profiles of dentine sections, demonstrating that C3 (rice) and C4 (millets)-based foods played different roles in human lives. Even though, there were similar weaning practices among the human populations. It is surprising that human individuals with dental ablation, cultural characteristic in the Middle and Lower Yangtze River Valley, consumed more millets during childhood in the early period than those without dental ablation in the late period. Our study here provides novel insights into cultural dynamics and the interplay between rice and millets in rice-millet agricultural system during the Late Neolithic in Southwest China.

The upper limb skeleton and behavioral lateralization of modern humans from Zhaoguo Cave, southwestern China.

OBJECTIVES: Aims of the study are to initially describe and comparatively evaluate the morphology of the new Zhaoguo M1 upper limb remains, and contextualize upper limb functional adaptations among those of other worldwide Upper Paleolithic (UP) humans to make inferences about subsistence-related activity patterns in southwestern China at the Pleistocene-Holocene boundary. MATERIALS AND METHODS: The preserved Zhaoguo M1 skeletal remains include paired humeri, ulnae, and radii, among others. These specimens were scanned using micro-computed tomography to evaluate internal structural properties, while external osteometric dimensions of the Zhaoguo M1 upper limb elements also were acquired. Both sets of measurements were compared to published data on Neandertals, and Middle and Upper Paleolithic modern humans. RESULTS: The upper limb elements of Zhaoguo M1 display a suite of characteristics that generally resemble those of other contemporary Late UP (LUP) modern humans, while robusticity indices generally fall within the upper range of LUP variation. The Zhaoguo M1 upper limb elements display fewer traits resembling those of late archaic humans. The Zhaoguo M1 individual exhibits diaphyseal asymmetry in several upper limb elements suggesting left hand dominance. When evaluating the full range of magnitudes of humeral bilateral asymmetry in the comparative sample, Zhaoguo M1 falls at the lower end overall, but yet is relatively higher than contemporary LUP modern humans specifically from East Eurasia. DISCUSSION: The Zhaoguo M1 individual suggests typical LUP modern human upper limb morphology persisted in southwest China until the end of the last glacial period. Upper limb bone asymmetry of Zhaoguo M1 also indicates that behavioral activities attributed to a hunter-gatherer tradition apparently extended through the Pleistocene-Holocene transition in this region.