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Degenerative changes of the spine in people of the Okhotsk culture were investigated in adult human skeletal remains from 38 males and 34 females. These findings were then compared with those in materials obtained from the medieval Kamakura period and early-modern peasants on Kumejima, Ryukyu Islands. The three samples clearly showed different patterns. In the Okhotsk series, the cervical spine of each sex had most osteophytes on the vertebral body, while the Kumejima samples had the highest frequency on the lumbar vertebrae. In the Kamakura series, males were most affected on the lower thoracic vertebrae. Moreover, severe osteophytes on the body of the lumbar vertebrae were more frequently seen in the Okhotsk males. Degenerative changes of the articular process of the Okhotsk series were most frequently seen in the lumbar vertebrae and least frequently seen in the cervical vertebrae. This is well contrasted with a high frequency of degenerative changes of cervical apophyseal joint in early-modern Kumejima peasants. The Kamakura series of each sex had generally low frequencies. Severe degenerative changes of apophyseal joint dominantly affected the Okhotsk series. It is inferred that different dynamic loads caused a high frequency of degenerative changes in the corresponding articular parts. For example, because the Okhotsk culture developed a considerable maritime infrastructure, the lifestyle required for sea-mammal hunting and fishing seems to have particularly affected the incidence of severe degenerative changes of the lumbar vertebrae.

The demographic structure of prehistoric hunter-gatherer societies has contributed to our understanding of the life history patterns of past human populations. The purposes of this study are to examine the human skeletal remains associated with the Okhotsk culture, to estimate age-at-death distribution using the Buckberry-Chamberlain system of auricular surface aging and the Bayesian approach, and to discuss whether paleodemographic estimates can yield an appropriate mortality profile of prehistoric hunter-gatherers in Japan. The application of the Bayesian theorem to the age-at-death estimation was based on the modern Japanese and Spitalfields known-age collections, assuming uniform, reference, and model prior probabilities. The age distributions of the Okhotsk had low proportions of young adults and high proportions of elderly adults. The results indicated that 24.4-51.3% of individuals were above the age of 55 years. The newly employed technique of the Bayesian estimation yielded the age distributions with significant numbers of elderly individuals, which are contrary to usual paleodemographic estimates. The results of this study suggest direct and plausible evidence of demographic traits in the Okhotsk people and allow us to reveal the mortality schedules of the prehistoric hunter-gatherers that otherwise could not be reconstructed from historical or ethnological records.

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Degenerative changes in the appendicular joints of ancient human populations from the Japan Islands http://researchonline.ljmu.ac.uk/id/eprint/8316/ Article LJMU has developed LJMU Research Online for users to access the research output of the University more effectively.Abstract: 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 earlymodern 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 to 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. AbstractDegenerative 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 c...