Tomohito Nagaoka

Stable isotopic reconstructions of adult diets and infant feeding practices during urbanization of the city of Edo in 17th century Japan

The urbanization of the city of Edo, the capital of premodern Japan, has been assumed to be not as a result of natural increase but that of in-migration although this assumption has never been verified. To obtain information on natural fertility in Edo, we analyzed stable carbon and nitrogen isotopes in 46 adult and 84 subadult human skeletons excavated from the Hitotsubashi site (1657-1683 AD: the early Edo period), Tokyo, Japan and reconstructed their breastfeeding period, one of the most important determinants of fertility. Adult females are significantly more depleted in (15) N by 0.7‰ than adult males, suggesting a dietary differentiation between sexes and/or the effect of pregnancy. The changes in the nitrogen isotope ratios of subadults suggest that supplementary foods were introduced around the age of 0.2 years and weaning ended around 3.1 years, which agrees with descriptions in various historical documents of the period. The duration of breastfeeding in the Hitotsubashi population was relatively longer than those in modern industrial and traditional societies and four previously reported populations in medieval and in the industrial England. As later weaning closely associates with longer inter-birth interval for mothers, our data suggest a lower natural fertility for the Hitotsubashi population. Assuming that the proportion of married people was also lower in the major cities of the earlier Edo period, our results support the assumption that Edo developed and increased its population by attracting immigrants during urbanization.

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.

Reliability of metric determination of sex based on long-bone circumferences: perspectives from Yuigahama-minami, Japan

The purpose of this study is to develop new standards to determine the sex of fragmentary human skeletal remains from archaeological sites in Japan. In order to accomplish this, we measured the long-bone circumferences of Japanese skeletons from the medieval period and provided metric diagnosis of sex using discriminant function analysis. We discuss whether the osteometric approach provides the criterion for sex assessment of human skeletal remains. The materials comprised human skeletal remains from the Yuigahama-minami site, Kamakura, Japan. The sample size used in this study was 68 males and 62 females excavated from individual burial graves. The accuracy of sex classification is more than 80% for discriminant functions with only one variable and reaches 90% for those with a combination of multiple variables. The multivariate functions provide better results than the univariate functions. Another improvement in sex diagnosis which this study contributes to is that new standards enabling reliable diagnosis with small numbers of variables are developed from well-preserved parts of the skeletons. This paper provides new standards, focusing on the diaphysial circumferences of limb bones from a medieval population, and will contribute to the advancement of medieval studies of skeletal remains from archaeological sites in Japan.

Weapon-related traumas of human skeletons from Yuigahama Chusei Shudan Bochi, Japan

The Yuigahama Chusei Shudan Bochi site (ad twelveth to thirteenth centuries), located along the seashore of the southern end of Kamakura City in Japan, and has yielded a mass grave containing hundreds of human crania. The purpose of this study is to document cut marks on crania made by an edged weapon, paying specific attention to individuals who may exhibit scratch marks, and to understand the variability of weapon-related traumas in the medieval period in Japan. The observation leads to tentative findings regarding the identification and interpretation of weapon-related traumas of human skeletal remains. From macroscopic observation, the marks display the sharpness of cut surfaces which are characteristic of unhealed cut marks. Scanning electron microscopic observation of the marks also shows that they are V-shaped in cross-section, a morphological feature that is characteristic of cut marks. This study first demonstrates that the scratches on the crania have morphological features consistent with human-induced cut marks, and that the macroscopic and microscopic approaches provide important information for identifying anthropogenic cut marks on the human skeletal remains from an archaeological site in Japan.

Proteomic profiling of archaeological human bone

Ancient protein analysis provides clues to human life and diseases from ancient times. Here, we performed shotgun proteomics of human archeological bones for the first time, using rib bones from the Hitotsubashi site (AD 1657–1683) in Tokyo, called Edo in ancient times. The output data obtained were analysed using Gene Ontology and label-free quantification. We detected leucocyte-derived proteins, possibly originating from the bone marrow of the rib. Particularly prevalent and relatively high expression of eosinophil peroxidase suggests the influence of infectious diseases. This scenario is plausible, considering the overcrowding and unhygienic living conditions of the Edo city described in the historical literature. We also observed age-dependent differences in proteome profiles, particularly for proteins involved in developmental processes. Among them, alpha-2-HS-glycoprotein demonstrated a strong negative correlation with age. These results suggest that analysis of ancient proteins could provide a useful indicator of stress, disease, starvation, obesity and other kinds of physiological and pathological information.

Size and Shape Variability in Human Molars during Odontogenesis

Under the patterning cascade model (PCM) of cusp development inspired by developmental genetic studies, it is predicted that the location and the size of later-forming cusps are more variable than those of earlier-forming ones. Here we assessed whether differences in the variability among cusps in total and each particular crown component (enamel-dentin junction [EDJ], outer enamel surface [OES], and cement-enamel junction [CEJ]) could be explained by the PCM, using human maxillary permanent first molars (UM1) and second deciduous molars (um2). Specimens were µCT-scanned, and 3D models of EDJ and OES were reconstructed. Based on these models, landmark-based 3D geometric morphometric analyses were conducted. Size variability in both tooth types was generally consistent with the above prediction, and the differences in size variation among cusps were smaller for the crown components completed in later stages of odontogenesis. With a few exceptions, however, the prediction was unsupported regarding shape variability, and UM1 and um2 showed different patterns. Our findings suggested that the pattern of size variability would be caused by temporal factors such as the order of cusp initiation and the duration from the beginning of mineralization to the completion of crown formation, whereas shape variability may be affected by both topographic and temporal factors.

Infant feeding practice in medieval Japan: Stable carbon and nitrogen isotope analysis of human skeletons from Yuigahama-minami

A longer breastfeeding duration provides various positive effects in subadult health because of abundant immunological factors and nutrients in human breast milk, and decreases the natural fertility of a population through lactational amenorrhea. In this study, we measured stable carbon and nitrogen isotope ratios in the bone collagen of three adults and 45 subadults from the Yuigahama-minami site (from 12th to 14th century) in Kamakura, the early medieval capital of Japan. Marine foods, C3 -based terrestrial foods, and freshwater fish are the primarily protein sources for adults. The changes in the nitrogen isotope ratios of subadults suggest that the relative dietary protein contribution from breast milk started to decrease from 1.1 years of age and ended at 3.8 years. The age at the end of weaning in the Yuigahama-minami population was greater than that in the typical non-industrial populations, a premodern population in the Edo period Japan, and medieval populations in the UK. Skeletons of townspeople from medieval Kamakura indicate severe nutritional stress (e.g., enamel hypoplasia and cribra orbitalia), yet this longer duration of breastfeeding did not compensate adverse effects for nutritional deficiency. The longer breastfeeding period may have been a consequence of complementary food shortage and bad health of subadults. Kamakura experienced urbanization and population increase in the early medieval period. The younger age-at-death distribution and high nutritional stresses in the Yuigahama-minami population and later weaning, which is closely associated with longer inter-birth interval for mothers, suggests that Kamakura developed and increased its population by immigration during urbanization.

Facial reconstruction of Egyptian mummy "Senu"

mummy “Senu”, believed to be more than 3700 years old. This mummy was excavated from the undisturbed tomb at the Dahshur north archeological site by a team from Waseda University in January 2005. Digital technology was first used by Hospital for Sick Children, Toronto in 1977 to CT scan the Egyptian mummy.[2] Attardi et al. [1] in 1999 made a facial reconstruction from CT data using 3D computer graphics, and the team of National Geographic[5] reconstructed the face of Tutankhamun in 2005. Kahler et al.[3] proposed a facial reconstruction method that is based on anatomy to incorporate skin and muscle. Our project is the collaboration between anatomists, Egyptologists and digital artists to produce photo-realistic 3D digital facial reconstruction based on anatomy and Egyptology.

Prevalence of cribra orbitalia in Pacopampa during the formative period in Peru

Cribra orbitalia is characterized by an aggregation of small apertures in the orbital roof in response to marrow hypertrophy. This pathological change is indicative of biological stress during youth. We examined the prevalence of this lesion in Pacopampa, a ceremonial center of the formative period, located in the northern highlands of Peru. Using this evaluation of cribra orbitalia, we reconstructed aspects of the population’s health and nutritional status during the formation of Andean civilization. We examined 41 orbits of 27 adult individuals (13 males, 14 females) and recorded the macroscopic presence or absence of cribra orbitalia. The presence or absence of cribra orbitalia was the same bilaterally for all 14 individuals having both orbits preserved. The pathology was present in two of the 13 males (15.4%), one of the 14 (7.1%) females, and three of 27 individuals (11.1%) for both sexes combined. There was no difference in the frequency between sexes. The prevalence of cribra orbitalia was found to be lower in Pacopampa than in the comparative data of coastal populations. It is reasonable to assume that the increase in social complexity in Pacopampa was probably unrelated to the decline in overall health of the people.

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

Objectives 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. Materials and methods 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. Results 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. Discussion 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.