We report in this paper two unusual cases of M1 agenesis recently discovered in Japanese macaques (Macaca fuscata). Molar agenesis is the congenital absence of molars. In general, molar agenesis occurs from the posterior molars. In most cases, missing teeth are third molars. Second molars may occasionally be absent in addition to the third molars. However, the congenital absence of first molars is hardly observed in humans, and to our knowledge, no case has been reported in other primates. In addition to the rareness of first molar agenesis, the present cases in M. fuscata are also quite unusual, because the posterior molars (M2 and M3) were completely preserved in contrast to the ordinary pattern of molar reduction. Interestingly, the two cases of the present study were observed in a single maternal lineage (a mother and her son), suggesting that M1 agenesis in these Japanese macaques is genetically inherited.
In this study, Chinese immigrant population history and structure was assessed using craniometric diversity in two historic cemeteries located in North America. Analyses addressed questions of population history, migration, and geographic origin for Chinese immigrants to the United States in the late 1800s. Craniometric diversity was assessed by the use of the R-matrix method on 19 metric traits in 62 male Chinese immigrant individuals. Using a population genetic model (Relethford–Blangero), our results indicate a low level of genetic diversity for these Chinese immigrants. Principal coordinate plots and neighbor-joining trees based on the morphological distances transformed from the R-matrix showed that the Chinese immigrant sample clusters closest to known East Asian populations. Further, we substantiate the biological origin for the Chinese immigrants as coming from South China. A historical reading suggests that the majority of Chinese emigrating to the United States departed and were born in southern China. Biological distances for the Chinese immigrants are more similar to samples from Guangdong Province and surrounding areas than to regions in North China. Identification bricks (grave markers) recovered during excavation in Nevada revealed two individuals born in Tai’shan, a city located along the Pearl River Delta and west of Hong Kong, a port used by Westerners during the late 19th century and used as a point of departure for many emigrating from mainland China. This evidence supports the historical and archaeological record and confirms the use of craniofacial variability to answer questions of population history and structure. This study is the first to assess Chinese immigrant population history using biological data.
In this study, we compare the craniofacial morphology of four Sumidouro skulls and one Lund skull of paleo South Americans from Lagoa Santa, Brazil, with worldwide prehistoric and recent human craniofacial metric data, and suggest an alternative view of the migration history of early South America. Affiliations of samples and individuals were examined by the principal coordinate plot generated by Relethford and Blangero’s R-matrix method, the neighbor-joining method based on genetic distance generated from the same R-matrix, and Mahalanobis distances and typicality probabilities. For these analyses, we examined certain variables claimed to have been influenced by the environment, such as maximum cranial length and maximum cranial breadth. Although the number of craniometric variables seems to influence the results of the analysis, it appeared to not obscure the ancestral and descendant relationships and regional kin relationships greatly in the instance of this study. Using Howells’ worldwide comparative dataset but without the Jomon sample, previous research had suggested that Brazilian Paleoamericans, the Lagoa Santa, were probably closely related to Australian Aborigines and Africans as opposed to Native Americans and Northeast Asians. On the other hand, using multivariate statistics, our results show that Lagoa Santa individuals exhibit stronger morphological affinities with the prehistoric Jomon of Japan, archaic Americans of Indian Knoll Kentucky, Windover Florida, and Tennessee, and recent Tierra del Fuegans of South America, than with the Melanesians and Australians. Moreover, Jomon, Lagoa Santa, and archaic North Americans all display close relationships and ties to each other. This suggests that the early inhabitants of South America were probably not related to Australo-Melanesians, but rather to the Late Pleistocene descendants of Northeast Asians such as the Jomon. Also, they are related to the archaic North American populations and recent Central and South Americans.
This paper reports the study of the osseous remains of an adult male (30–35 years) from a Spanish urban necropolis dating from the pre-industrial age (17th–18th centuries). We have diagnosed the presence of a severe unreduced forearm fracture, which has been classified as a Type I Monteggia fracture in the left arm. Injury occurred by a complete and poorly resolved ulnar fracture in its upper third. As result of this ulna fracture a radial head dislocation also occurred, creating a new articular surface on the humerus. The ulna also underwent two different types of angulation. The purpose of this study is to evaluate the anatomical changes of the elbow joint bones after a Monteggia fracture, assessing the completeness of functionality on the arm of this man. After the fracture, this individual lived the rest of his life with a permanent dislocation of his radius; therefore, loss of the forearm rotation, cubitus valgus, elbow instability and pain were all present. Movement was limited to an intermediate position or semipronative. A detailed description of the pathology is also accompanied by a discussion of the historical-cultural context in which this man lived and the common diseases of the population to which he belonged.
Significant differences in facial form between the Jomon and the post-Jomon series of the Yayoi, Medieval, and Early Modern period have been interpreted in terms of the gene flow from the Asian continent or the reduction of masticatory stress through the Jomon to the Early Modern period. However, the developmental process that produced these differences in facial form between the two groups has remains unknown. In this study we examined the factors contributing to differences in facial form by studying the developmental patterns of facial form using data from 311 subadult individuals from the middle-late Jomon (c. 5000–2500 BP) to the Early Modern period (1900–1950 AD). We found statistically significant differences in facial form among the temporally defined groups at early stages of development. Differences in upper facial height between the Jomon and the post-Jomon series were significant during both childhood (3–6 years, P < 0.05) and adolescence (12–20 years, P < 0.01). Differences in simotic index and bigonial breadth between the Jomon and the post-Jomon series were significant, beginning in childhood (P < 0.05), and differences in symphyseal height between the series were significant during both infancy (0–3 years, P < 0.05) and adolescence (P < 0.01). Based on previous ethnographical data, studies on the wear of the deciduous dentition in the Jomon and post-Jomon populations, and stable isotope analyses for reconstructing weaning diets in Jomon and Medieval children, it seems to be the first-stage juvenile stage (6–9 years) when the differences in masticatory load among the chronological groups become conspicuous enough to act on the functional adaptation of facial bones. Therefore, the patterns of group differences which begin in infancy or childhood and become remarkable in adolescence do not contradict the former explanation that the gene flow from the Asian continent largely contributed to the change of facial form during the transition between the Jomon and Yayoi periods.
This article presents the results of an assessment of the morphological affinities of the skeletal remains from a large mortuary assemblage, dated to Iron Age, in Phum Snay, a village in Banteay Meanchey Province, northwest Cambodia. The purpose of the research is to address the origin of these pre-Angkorian people. Multivariate comparisons using cranial and dental metrics, as well as dental nonmetric traits, demonstrate that the characteristic affinities intermediate between the early Holocene Hoabinhian groups akin to Australo-Melanesians and the present-day people in the mainland Southeast Asia. This finding suggests that the ancient people of Phum Snay preserved genetic traits of early indigenous populations, whereas modern mainland Southeast Asians, including Cambodians, were more affected by gene flow from later migrants from East Asia into this region.
In order to investigate further the allele frequencies of the adenosine triphosphate-binding cassette sub-family C11 (ABCC11) gene, which determines earwax phenotypes, among ancient populations in Hokkaido, Japan, the single-nucleotide polymorphism and the 27 bp deletion in the ABCC11 gene were analyzed in ancient DNA extracted from 38 Epi-Jomon, 24 Jomon, and one Satsumon specimens excavated from various archaeological sites in Hokkaido. Of the specimens analyzed, 10 Epi-Jomon and three Jomon specimens were successfully genotyped. One homozygote for the 27 bp deletion was found first in one Epi-Jomon specimen. Including previously reported data on the Okhotsk people and modern Ainu, exact tests of population differentiation showed that allele frequencies of the ABCC11 gene between the Jomon people and Ainu were statistically significantly different, whereas those between the Jomon and Epi-Jomon people and those between the Epi-Jomon people and Ainu were not significantly different. This result indicates that the Ainu, direct descendants of the Jomon people, were genetically affected by populations who possessed high frequencies of allele A (recessive dry allele) of the ABCC11 locus after the Jomon period.
Fractures are ubiquitous in the archaeological record but the majority of these are the consequence of a traumatic incident and do not reflect any loss of strength inherent to the bone. So-called fragility fractures, particularly hip fractures, are considered uncommon occurrences in skeletal populations from the past. Nevertheless, evidence of this type of fracture in the archaeological record is increasing. A methodical search for possible hip fractures in the excavation reports, theses and monographs housed in the Department of Anthropology of the University of Coimbra presented an occasion to describe six hip fractures, previously unpublished, from different Portuguese archaeological sites and to challenge the widespread assumption that hip fractures were nearly non-existent in the past.