Does obstetric protection apply to small-bodied females?: A comparison between small-bodied Jomon foragers and large-bodied Yayoi agriculturalists in the prehistoric Japanese archipelago.

OBJECTIVES: This study examined the relationship between maternal pelvic and body size in the transition from the Middle-Final Jomon period (c. 5000-3000 BC) to the Middle Yayoi period (c. 400~200 BC to around AD 1) in Japan. METHODS: Eight measurements, including the left hip bone, articulated pelvis, and femur, were taken from Jomon (females: 37, males: 26) and Yayoi skeletal remains (females: 32, males: 29). RESULTS: A statistically significant decrease in the anterior diameter of the true pelvic inlet was demonstrated in females from the Jomon to the Yayoi period, but not in males. While significant increases in stature from the Jomon to the Yayoi period were found in both males and females, no significant changes in body mass were seen. The correlation coefficients between true and false pelvic measurements (maximum pelvic height and maximum pelvic breadth) and body size (stature and body mass) suggested few significant relationships between true and false pelvic measurements or body size among the samples, but no significant correlations in small-bodied Jomon females. Results of principal component analysis using the log-size and log-shape variables suggested that the true pelvic size in Jomon and Yayoi females was not correlated with their general pelvic or body size, and there were correlations between sexually dimorphic aspects of true pelvis shape and either the false pelvis or body size in males but not females. CONCLUSIONS: These results suggest that the obstetrical dimensions in small-bodied Jomon females were maintained for obstetric needs.

A paleopathological approach to early human adaptation for wet-rice agriculture: The first case of Neolithic spinal tuberculosis at the Yangtze River Delta of China.

The earliest evidence of human tuberculosis can be traced to at least the early dynastic periods, when full-scaled wet-rice agriculture began or entered its early developmental stages, in circum-China countries (Japan, Korea, and Thailand). Early studies indicated that the initial spread of tuberculosis coincided with the development of wet-rice agriculture. It has been proposed that the adaptation to agriculture changed human social/living environments, coincidentally favoring survival and spread of pathogenic Mycobacterial strains that cause tuberculosis. Here we present a possible case of spinal tuberculosis evident in the remains of a young female (M191) found among 184 skeletal individuals who were Neolithic wet-rice agriculturalists from the Yangtze River Delta of China, associated with Songze culture (3900-3200 B.C.). This early evidence of tuberculosis in East Asia serves as an example of early human morbidity following the adoption of the wet-rice agriculture.

An assessment of postcranial indices, ratios, and body mass versus eco-geographical variables of prehistoric Jomon, Yayoi agriculturalists, and Kumejima Islanders of Japan.

OBJECTIVES: We explore variations in body and limb proportions of the Jomon hunter-gatherers (14,000-2500 BP), the Yayoi agriculturalists (2500-1700 BP) of Japan, and the Kumejima Islanders of the Ryukyus (1600-1800 AD) with 11 geographically diverse skeletal postcranial samples from Africa, Europe, Asia, Australia, and North America using brachial-crural indices, femur head-breadth-to-femur length ratio, femur head-breadth-to-lower-limb-length ratio, and body mass as indicators of phenotypic climatic adaptation. Specifically, we test the hypothesis that variation in limb proportions seen in Jomon, Yayoi, and Kumejima is a complex interaction of genetic adaptation; development and allometric constraints; selection, gene flow and genetic drift with changing cultural factors (i.e., nutrition) and climate. METHODS: The skeletal data (1127 individuals) were subjected to principle components analysis, Manly's permutation multiple regression tests, and Relethford-Blangero analysis. RESULTS: The results of Manly's tests indicate that body proportions and body mass are significantly correlated with latitude, and minimum and maximum temperatures while limb proportions were not significantly correlated with these climatic variables. Principal components plots separated "climatic zones:" tropical, temperate, and arctic populations. The indigenous Jomon showed cold-adapted body proportions and warm-adapted limb proportions. Kumejima showed cold-adapted body proportions and limbs. The Yayoi adhered to the Allen-Bergmann expectation of cold-adapted body and limb proportions. Relethford-Blangero analysis showed that Kumejima experienced gene flow indicated by high observed variances while Jomon experienced genetic drift indicated by low observed variances. CONCLUSIONS: The complex interaction of evolutionary forces and development/nutritional constraints are implicated in the mismatch of limb and body proportions.