Paleodemography of a medieval population in Japan: analysis of human skeletal remains from the Yuigahama-minami site

The purpose of this study is to obtain demographic data regarding the medieval population buried at the Yuigahama-minami site in Kamakura, Japan, and to detect a secular trend in the life expectancy of Japanese population over the last several thousand years. The Yuigahama-minami skeletal sample consists of 260 individuals, including 98 subadults (under 20 years old) and 162 adults. A Yuigahama-minami abridged life-table analysis yielded a life expectancy at birth (e0) of 24.0 years for both sexes, a life expectancy at age 15 years (e15) of 15.8 years for males, and an e15 of 18.0 years for females. The reliability of the estimated e0 was confirmed by analysis of the juvenility index. Demographic profiles comparing the Yuigahama-minami series with other skeletal series indicated that both the survivorship curve and life expectancy of the Yuigahama-minami sample are similar to those of the Mesolithic-Neolithic Jomon population, but are far lower than those of the early modern Edo population. These comparisons strongly suggest that life expectancy changed little over the thousands of years between the Mesolithic-Neolithic Jomon and medieval periods, but then improved remarkably during the few hundred years between the medieval period and early modern Edo period. The short-lived tendency of the Yuigahama-minami sample does not contradict the archaeological hypothesis of unsanitary living conditions in medieval Kamakura. This is the first investigation to address the demographic features of a medieval population in Japan, and will help refine our understanding of long-term trends in the demographic profiles of inhabitants of Japan.     

Attitudes towards abortion in the Danish population

This article reports the results of a survey, by mailed questionnaire, of the attitudes among a sample of the Danish population towards abortion for social and genetic reasons. Of 1080 questionnaires sent to a random sample of persons between 18 and 45 years, 731 (68%) were completed and returned.
A great majority of the respondents were liberal towards early abortion both for social reasons and in case of minor disease. In contrast, there was controversy about late abortions for social reasons and in the case of Down syndrome. Further there was strong reluctance to accept late abortion in case of minor disease.
An analysis of the response patterns showed that most of the respondents had gradualist views on abortion, i.e. they would allow all early abortions, but only abortions for some reasons later in pregnancy. It was also found that the number who would find an early abortion acceptable in general was much higher than the number who would accept it in their own case. These findings suggest that a great part of the resistance towards abortion does not rest on a concern for the rights and interests for the fetus. Instead it may be explained on a view according to which fetal life is ascribed intrinsic moral value.     

Wormian bone formation in the skeletal population from Lachish

Pathological, mechanical and genetic factors have been proposed as the primary causal mechanism in the occurrence of Wormian bones. Very high frequencies of Wormian Bones in some populations and their absence in others, geographically nearby or subject to similar environmental stress, suggest a genetic mechanism. If this is the case, the gene or genes causing the formation of Wormian bones must either confer a substantial selective advantage or occur as dominants; or the population must be subject to a high degree of inbreeding and/or genetic drift.The Lachish skeletal population is examined in order to establish the independence of Wormian bone formation from those genes or gene complexes responsible for the formation of the cranial vault. This is demonstrated through the use of t-tests carried out on means of osteometric variables, including the length of the basi-occiput. The probable influence of stabilizing selection, inbreeding and drift, promoting Wormian Bone formation in the Lachish population, is demonstrated by the absence of significant skewness and the presence of high positive kurtosis for the osteometric variables of the cranial vault. This interpretation is reinforced independently by the cultural behavior of the Lachish population.     

Rib remodeling dynamics in a skeletal population from Kulubnarti, Nubia

Bone remodeling variables in the rib were analyzed for a skeletal population of medieval antiquity (ca. A.D. 550-1450) from Kulubnarti, in Sudanese Nubia. The skeletal remains are naturally mummified and in an excellent state of preservation. The study sample consists of thin sections from the ribs of 80 individuals, ranging in age from 15-50+ years. Ribs were examined using a standard microscope and image analysis software. Numbers of intact osteons, fragmentary osteons, forming osteons, and resorption spaces were counted, osteon and Haversian canal areas were measured, and several variables were calculated to assess morphometric and remodeling status in the rib. Variables calculated included mean annual activation frequency, mean bone formation rate, and net osteonal remodeling. Results indicate that age changes are consistent with those observed for other archaeological and modern samples. High numbers of resorption spaces in young males may reflect slower skeletal development in boys compared to girls. Comparisons of rib data with results of a previous study on patterns of femoral bone remodeling in the same population indicate that ribs have more osteons and higher bone formation rates compared to the femur. Also, sexual differences in osteon size observed in the femur were not observed in the rib. Activation frequency and bone formation rate are low in the Kulubnarti population compared to previously published data for a modern sample, a finding consistent with reported results from other archaeological samples. Genetic factors influencing the minimum effective strain setpoint and duration of skeletal maturation, in addition to repetitive high strains at Kulubnarti, may contribute to observed differences.     

Phenotype frequency of LKE in the Danish population

A panel of 897 randomly chosen Danish donors of blood groups O and A was tested for the LKE antigen using a human anti-LKE. In this sample, 78.7% were LKE positive, 20.6% were weakly positive, whereas 0.7% were LKE negative. These phenotype frequencies are similar to those obtained by the first discovered human alloserum and by the monoclonal anti-SSEA-4 in previous studies. The previously reported lower LKE antigen strength in group A versus group O donors, and the association of LKE to the P system was confirmed.     

Ageing and dental attrition in a medieval rural Danish population

The rate of attrition on the permanent molars may depend on culturally and economically determined conditions of living. In order to analyse the relation the probability of having entered the stages of attrition is analysed by means of logistic regression on age at death. It is shown that not all teeth continue to be worn at the same rate throughout life and that there is an association between advanced attrition and risk of dying. The rate of dental attrition does not differ much by sex but there are some indications that male teeth are worn quicker than female teeth. This greater rate of attrition might be due to greater consumption of food in males than in females. The stages of dental attrition give some information on the age at death but they are poor age indicators on their own.     

The population variability of Yersinia pestis in soil samples from the natural focus of plague

Three Y. pestis strains were found to exist in the experimental soil ecosystem at a temperature of 4 degrees - 8 degrees C for a longer period (10 months, the term of observation) than at room temperature (3.5 months). Y. pestis population structure was characterized by relative stability in strains of the subspecies altaica and heterogeneity in the strain of the main subspecies, manifested by the loss of the pgm locus by vegetative cells and the preservation of pgm+ variants in the latent (uncultivable) form (LF). In the populations of all strains uniformity in calcium dependence, the tendency towards a decrease in the synthesis of factor 1, nutritional requirements in amino acids was observed. An important factor of the preservation of Y. pestis in the soil was LF formation. At room temperature this process quickly resulted in the death of the population. At 4 degrees - 8 degrees C A. pestis altaica avirulent strain could be inoculated onto solid nutrient media for a two-fold longer period (for 4 month) than the strain with selective virulence and for 5.5 months longer than Y. pestis pestis highly virulent strain.     

Temporomandibular joint osteoarthritis in a British skeletal population

The potential role of dental function in TMJ osteoarthritis is examined in an ancient British population. Human skeletal remains from five archaeological sites in England (n = 369) were studied to assess the associations between the presence of osteoarthritis and dental function variables, in particular antemortem tooth loss and dental attrition. Individuals aged over 17 years with at least a portion of either the left or right TMJ were included in the study. Each individual was scored for the occurrence of arthritic lesions on the mandibular condyle and glenoid fossa, the level of dental attrition, and antemortem tooth loss. A loglinear analysis was performed with osteoarthritis as the dependent variable and tooth loss, attrition, sex, and age as the independent variables. Tooth loss and sex are not significantly associated with TMJ osteoarthritis when attrition and age are included in the analysis. Attrition is significantly associated with osteoarthritis even when the analysis corrects for age. The significant association of attrition with osteoarthritis suggests that dental functions may have an influence, separate from ageing, on the development of TMJ osteoarthritis.     

Characterization of gout in a skeletal population sample: Presumptive diagnosis in a micronesian population

Characterization of the nature and skeletal distribution of gout was accomplished in a Chamoru (Chamorros) population with predilection to the disease. Uniform excavation by the gouty diathesis produces a punched-out appearance to these predominantly monarticular lesions. The lesion is distinct from that seen in rheumatoid arthritis, spondyloarthropathy, or infection. Reactive new bone formation in some gouty lesions also has an apparently unique, ivory-like discoloration (contrasted with the adjacent bone), which facilitates diagnosis. © 1995 Wiley-Liss, Inc.     

Dental morphology of a Griqua skeletal population

The dental crown morphology of 27 Griqua skulls is described and these are compared for microevolutionary consideration. The early Griqua dentitions show a high Khoikhoi/San component and little evidence of Caucasoid or Negroid admixture.     

Septal aperture of the humerus in a mediaeval human skeletal population

Humeral septal aperture is studied in a large Mediaeval skeletal series from England. The aims are to investigate associations between septal aperture and sex, age, side and humeral robusticity; and to evaluate any associations with relative projection of ulna coronoid and olecranon processes. In this way, it is hoped to shed light on age at occurrence and the causation of the trait. Results showed a paucity of cases in juveniles. In adults, the trait was more common in left bones and in females. No association was found with humeral robusticity or humero-ulnar conformation. Detailed morphological study of humeral septa of individuals with and without apertures suggested that septal aperture forms via resorption from the anterior surface of the septum. In this group, apertures appear generally to form in early adult life. It is suggested that in the study group septal aperture generally arises from impingement on the humeral septum by the coronoid and olecranon processes, chiefly the former. It is tentatively suggested that frequency of septal aperture may be an index of joint hypermobility in earlier populations.     

Local differentiation and gene dispersal distances in a Danish population of Armaria maritima

In a continuously distributed population of the self-incompatible species Armeria maritima , nine artificially delimited subpopulations were sampled in a transect with a length of 1300 m. Genetic variation was quantified with enzyme electrophoresis, which revealed five polymorphic loci. The genotypic distribution within subpopulations accorded to Hardy-Weinberg proportions, but revealed a Wahlund effect at one of the loci when the total population was considered. The Wahlund effect was supported by significant differences in allele frequencies among the nine subpopulations. The differentiation was low with a F_ST value of 0.028, which is much smaller than the previously reported value of 0.18 for 17 geographically separated Danish populations of this species. The low differentiation of the subpopulations was also revealed by an assignment test. In this test, the multilocus genotype of an individual is used to assign it to the subpopulation it has the highest likelihood to appear in. With this test, a lower percentage of individuals were assigned to the subpopulation of origin (24) than was seen with assignment of individuals to populations in Denmark (34). No abrupt changes in allele frequencies were observed. A spatial autocorrelation analysis suggested a breeding patch size of 500–700 m in diameter along the transect.     

Genetics of resistance against defences of the host plant Barbarea vulgaris in a Danish flea beetle population

One essential aspect of the study of the evolution of host-plant use by insects is (variation in) its genetic basis. The genetic basis of the ability of a flea beetle (Phyllotreta nemorum) to use the crucifer Barbarea vulgaris ssp. arcuata (G type) as a host plant was studied in a Danish population (Kvaerkeby) occurring naturally on this atypical host plant. Evidence was found that this ability was determined by a single, major, autosomal gene, although the presence of genes at additional loci at lower frequencies could not be excluded. No evidence was found for sex-linked inheritance, which was common in a second population in Denmark (Ejby) using Barbarea as a host plant. All beetles in the Kvaerkeby sample were homozygous 'resistant' to Barbarea defence. After crossing resistant F1 offspring from pairs consisting of a field-collected beetle and a susceptible one amongst each other, genotyping the F2 (reared on radish) showed a 1:2:1 ratio of homozygous resistant, heterozygous and susceptible beetles. No evidence was found for a reduction in the viability of beetles that were homozygous resistant at the autosomal locus, in contrast to what had been found earlier for two backcrossed lines founded by beetles from Ejby. The results show that there is variation in the genetic basis of host-plant use across local populations and imply that population structure should form part of the study of the interaction between P. nemorum and its host plants.