We investigated mitochondrial DNA haplogroups of four Jomon individuals from the Sanganji shell mound in Fukushima, Tohoku district, Japan. Partial nucleotide sequences of the coding and control region of mitochondrial DNA were determined. The success rate of sequencing increased when we analyzed short DNA sequences. We identified haplogroups from all four samples that were analyzed; haplogroup frequencies were 50% (n = 2) for N9b and 50% (n = 2) for M7a2. Haplogroup N9b has been previously observed in high frequencies in the other Tohoku Jomon, Hokkaido Jomon, Okhotsk, and Ainu peoples, whereas its frequency was reported to be low in the Kanto Jomon and the modern mainland Japanese. Sub-haplogroup M7a2 has previously been reported in the Hokkaido Jomon, Okhotsk, and modern Udegey (southern Siberia) peoples, but not in the Kanto Jomon, Ainu, or Ryukyuan peoples. Principal component analysis and phylogenetic network analysis revealed that, based on haplogroup frequencies, the Tohoku Jomon was genetically closer to the Hokkaido Jomon and Udegey people, than to the Kanto Jomon or mainland modern Japanese. The available evidence suggests genetic differences between the Tohoku and Kanto regions in the Jomon period, and greater genetic similarity between the Tohoku Jomon and the other investigated ancient (Hokkaido Jomon, Okhotsk) and modern (Siberian, Udegey in particular) populations. At the same time, the Tohoku and Hokkaido Jomon seem to differ in sub-haplotype representations, suggesting complexity in Jomon population structure and history.
Biological anthropologists have repeatedly demonstrated a sex difference of caries prevalence in past societies and have often ascribed this difference to cultural factors related to the sexual division of labor, as well as to biological factors stemming from the female reproductive function. Even though archaeological and historical evidence can hint at the prevailing living conditions, they are not detailed enough to confirm the cultural factors influencing oral disease. For this, skeletal remains in which the prevailing subsistence patterns have been documented by cultural anthropologists must be studied. This study demonstrates sex-specific oral disease prevalence (caries, antemortem tooth loss, periapical abscess, alveolar resorption, and calculus accretion) as well as degree of dental attrition, using the recent Bunun skeletal assemblage, one of the Taiwanese aboriginals. During Japanese rule, cultural anthropologists recorded that the staple product of the Bunun tribe was foxtail millet. Males were responsible for cultivation and hunting, while females were responsible for gathering and preparing foods. The results of this study showed the relatively high morbidity of oral disease, except periapical abscess, regardless of sex. The frequency of females suffering caries and alveolar resorption was significantly greater compared to that of males, and the inverse was true for calculus. Taking into account the fact that the Bunun tribe depend greatly on vegetable foods and smoke heavily, their high morbidity of oral disease is understandable. The combination of their higher morbidity in alveolar resorption and calculus is comparable to the Southeast Asian groups chewing betel nuts documented in previous studies. The sex-specific caries prevalence is believed to be related to the Bunun’s typical and strict sexual division of labor. The inconsistency of the sex difference patterns between alveolar resorption and calculus might be related to the multifactorial origin of the alveolar resorption.
Fossil crania are often fractured and fragmented due to compaction and diagenesis. To restore the antemortem appearance of a fossil cranium, it is necessary to correctly assemble the fragments into their original anatomical positions. In this study, we propose a concept for computerized reconstruction that employs surface extrapolation to aid the assembly of fossil neurocranial fragments. Specifically, we approximate the surface of each neurocranial fragment using a bicubic Bézier surface to extrapolate the surface and mathematically predict the shape of adjacent fragments. The positions and orientations of adjacent fragments were calculated by minimizing the fitting errors. To evaluate the usefulness of this concept, we virtually divided modern human and chimpanzee neurocrania into pieces and used the proposed method to reassemble the generated virtual fragments. The neurocranial fragments were smoothly and correctly assembled. Comparison of the results obtained using the proposed method and conventional manual assembly revealed that the proposed method delivered similar performance in terms of differences between the original and reassembled shapes. However, the accuracy of the reassembly was found to be worse in the chimpanzee case because the fragments were more curved than those for the human cranium. Although there are some methodological limitations, the proposed concept may be useful for development of digital reassembly of fossil neurocranial fragments.
Hyperostotic non-metric traits of the human cranium are characterized by excessive ossification over the non-anomalous condition. Although hyperostotic traits are considered age-progressive, the appearance of two hyperostotic traits, hypoglossal canal bridging and jugular foramen bridging, has been reported in fetal crania. In the present study, we show the detection of a pterygospinous foramen and two caroticoclinoid foramina in Japanese fetal crania. These findings suggest that these two types of foramen can appear at an early stage of craniofacial development. Analysis of the Spitalfields skeletal collection (London) has shown that the frequencies of both foramina in adults older than 20 years of age were slightly higher than those of children aged 0–6 years. However, statistical analyses did not show significant differences between children and adults. This suggests that these non-metric cranial traits may also be useful for anthropological population studies of juveniles.
Various studies have tried to elucidate the genomics underlying the ethnic diversity of Indian populations. The 48-basepair variable number tandem repeat (VNTR) of the DRD4 gene, besides its clinical importance, has been a subject of interest for understanding human evolutionary history worldwide. In spite of its highly polymorphic nature it has not been much explored by anthropologists, especially in the Indian context. In the present study, an attempt was made to infer the allelic variation of the repeat allele among 24 Indian ethnic groups belonging to different ethnic and linguistic groups along with different geographic affiliations. Only the 2R, 3R, 4R, 5R, 6R, and 7R repeat alleles were found in the studied populations, with 4R being the most frequent followed by 2R. All the other repeat alleles (3R, 5R, 6R, and 7R) occurred at very low frequency. Based on the 4R and 5R frequencies, the study reveals a common genetic substratum of the Indian population as already proposed by earlier studies. Further, the study also highlights the inflow of genes from the north.
Obtaining genetic information about early humans is indispensable to our understanding of the demographic history of mankind. In the present study, we performed a detailed mitochondrial DNA (mtDNA) analysis of a skeleton of the initial Jomon era unearthed from the Yugura cave site in Nagano, Japan, which was dated to 7920–7795 calBP by direct 14C dating. mtDNA of the Yugura skeleton was designated to haplogroup D4b2, which is widely observed in present-day East Asians, including the Japanese, but is absent in Hokkaido Jomon people. This finding indicates that the basal population of Japan was heterogeneous with respect to their mtDNA lineage. This is the first report on the genotype of the people from the initial phase of the Jomon period.