Historical overview and challenges in the development of bioarchaeology in Japan

Archaeological human skeletons provide direct evidence of the physical features, lifestyle, diseases, mortality, and health of our ancestors. Bioarchaeology explores population-based trends that vary according to subsistence, social stratification, urbanization, and industrial development. The first systematic bioarchaeological studies in Japan were those on medieval human skeletons in Kamakura City, Japan, in 2003. However, most anthropological studies have focused on the origin and population history of the Japanese since the end of 19th century. Moreover, the number of bioarchaeological studies in Japan is far lower than that in North America, Europe, and Latin America. This paper reviews the history of bioarchaeological research in Japan and discusses the problems associated with its development

Degenerative changes in the appendicular joints of ancient human populations from the Japan Islands

Degenerative changes in six major limb joints were investigated to compare their prevalence among five ancient skeletal populations from the Japan Islands. The populations assessed in this study consisted of the farmers in the northern Kyushu/Yamaguchi area and the foragers from the northwestern Kyushu area from the Yayoi period (5th century BC to 3rd century AD); the Okhotsk (5th to 12th centuries AD) foragers from Hokkaido and Sakhalin; the common people from medieval Kamakura (12th to 14th centuries AD) in Kanto, central Japan; and the early-modern farmers (17th to 19th centuries AD) from Kumejima, in the southernmost island chain (Ryukyu Islands). Crude prevalence comparisons showed that the shoulder and hip joints were principally affected in early-modern Kumejima and medieval Kamakura, which contrasted with the high prevalence of elbow and knee joint changes in the Okhotsk people. The heavy dependence on marine mammals and fish for dietary protein intake probably required flexion and extension movements of the most severely degenerated joints in the Okhotsk people. The northern Kyushu/Yamaguchi and northwestern Kyushu Yayoi peoples were more affected by degeneration in the wrist joints than others, possibly due to their use of innovative tools such as stone or shell knives and harpoons. A multivariate logistic regression analysis, adjusted for age, region, and sex as the predictor variables for degenerative changes in joints, was applied to only the two samples from Kumejima and Kamakura (including previously reported spine data) because of their better preservation. This revealed differences in the prevalence of changes in some joints; for example, age-related changes were recognized. The Kumejima people were more commonly affected by hip and knee joint changes, whereas the Kamakura people were more commonly affected by changes to apophyseal joints. Because a stable isotope analysis indicated that the trophic levels of the two populations were almost the same, the pattern of degenerative changes would have reflected differences in their specific workloads, such as wet rice cultivation using a peculiar hoe by the Kumejima people. This study, combining multivariate logistic regression analysis of degenerative joint changes and stable isotope analyses, uses large skeletal populations to add clarity to the actual rigors of ancient life. © 2015 Elsevier Ltd and INQUA

Table1_Historical overview and challenges in the development of bioarchaeology in Japan.XLSX

Archaeological human skeletons provide direct evidence of the physical features, lifestyle, diseases, mortality, and health of our ancestors. Bioarchaeology explores population-based trends that vary according to subsistence, social stratification, urbanization, and industrial development. The first systematic bioarchaeological studies in Japan were those on medieval human skeletons in Kamakura City, Japan, in 2003. However, most anthropological studies have focused on the origin and population history of the Japanese since the end of 19th century. Moreover, the number of bioarchaeological studies in Japan is far lower than that in North America, Europe, and Latin America. This paper reviews the history of bioarchaeological research in Japan and discusses the problems associated with its development.</p

Patterns of morphological variation in enamel-dentin junction and outer enamel surface of human molars.

Tooth crown patterning is governed by the growth and folding of the inner enamel epithelium (IEE) and the following enamel deposition forms outer enamel surface (OES). We hypothesized that overall dental crown shape and covariation structure are determined by processes that configurate shape at the enamel-dentine junction (EDJ), the developmental vestige of IEE. This this hypothesis was tested by comparing patterns of morphological variation between EDJ and OES in human permanent maxillary first molar (UM1) and deciduous second molar (um2). Using geometric morphometric methods, we described morphological variation and covariation between EDJ and OES, and evaluated the strength of two components of phenotypic variability, canalization and morphological integration, in addition to the relevant evolutionary flexibility, i.e. the ability to respond to selective pressure. The strength of covariation between EDJ and OES was greater in um2 than in UM1, and the way that multiple traits covary between EDJ and OES was different between these teeth. The variability analyses showed that EDJ had less shape variation and a higher level of morphological integration than OES, which indicated that canalization and morphological integration acted as developmental constraints. These tendencies were greater in UM1 than in um2. On the other hand, EDJ and OES had a comparable level of evolvability in these teeth. Amelogenesis could play a significant role in tooth shape and covariation structure, and its influence was not constant among teeth, which may be responsible for the differences in the rate and/or period of enamel formation

Pacopampa: Early evidence of violence at a ceremonial site in the northern Peruvian highlands

<div><p>Objectives</p><p>Pacopampa, a ceremonial complex in Peru’s northern highlands, reveals early evidence of trauma in the Middle to Late Formative Period coinciding with the emergence of social stratification in the area. We examine the prevalence of trauma in human remains found at the site and present evidence of the circumstances surrounding the deaths of individuals who lived during the early stages of Andean civilization.</p><p>Materials and methods</p><p>The materials are the remains of 104 individuals (38 non-adult and 66 adult) from the Middle to Late Formative Periods. We explored trauma macroscopically and recorded patterns based on skeletons’ locations, age at death, sex, social class, and chronology.</p><p>Results</p><p>We detected trauma in remains over the Middle to Late Formative Periods. While the prevalence of trauma was minimal in the Middle Formative Period, skeletons from the subsequent era exhibit more severe disturbances. However, all the skeletons show signs of healing and affected individuals experienced a low degree of trauma.</p><p>Discussion</p><p>Given the archaeological context (the remains were recovered from sites of ceremonial practices), as well as the equal distribution of trauma among both sexes and a lack of defensive architecture, it is plausible that rituals, rather than organized warfare or raids, caused most of the exhibited trauma. Pacopampa was home to a complex society founded on ritual activity in a ceremonial center: this is indicated by the presence of ritual violence in a society that built impressively large, ceremonial architecture and developed social stratification without any political control of surplus agricultural goods.</p></div