Origin of ethnic groups, linguistic families, and civilizations in China viewed from the Y chromosome.

East Asia, geographically extending to the Pamir Plateau in the west, to the Himalayan Mountains in the southwest, to Lake Baikal in the north and to the South China Sea in the south, harbors a variety of people, cultures, and languages. To reconstruct the natural history of East Asians is a mission of multiple disciplines, including genetics, archaeology, linguistics, and ethnology. Geneticists confirm the recent African origin of modern East Asians. Anatomically modern humans arose in Africa and immigrated into East Asia via a southern route approximately 50,000 years ago. Following the end of the Last Glacial Maximum approximately 12,000 years ago, rice and millet were domesticated in the south and north of East Asia, respectively, which allowed human populations to expand and linguistic families and ethnic groups to develop. These Neolithic populations produced a strong relation between the present genetic structures and linguistic families. The expansion of the Hongshan people from northeastern China relocated most of the ethnic populations on a large scale approximately 5300 years ago. Most of the ethnic groups migrated to remote regions, producing genetic structure differences between the edge and center of East Asia. In central China, pronounced population admixture occurred and accelerated over time, which subsequently formed the Han Chinese population and eventually the Chinese civilization. Population migration between the north and the south throughout history has left a smooth gradient in north-south changes in genetic structure. Observation of the process of shaping the genetic structure of East Asians may help in understanding the global natural history of modern humans.

Excavating new facts from ancient Hepatitis B virus sequences.

Recently, two independent studies discovered 15 ancient Hepatitis B virus (aHBV) sequences, of which 7 dated back to the Neolithic age (NA) and the Bronze Age (BA). In the present research, all the available aHBV sequences were collectively re-analysed with reference to extant HBV diversity to understand the role of these aHBV genotypes in evolution of extant HBV genetic diversity. Several intergenotype recombination events were documented, which corroborated well with population admixture and ancient human migration. Present analyses suggested replacement of HBV genotype associated with early Neolithic European farming cultures by the migrating steppe people, during Bronze Age Steppe migration. Additionally, detailed analyses of recombinations revealed evolution of a number of extant genotypes and suggested their possible site of origin. Through this manuscript, novel and important findings of the analyses are communicated.

Intentional cranial modification from the Houtaomuga Site in Jilin, China: Earliest evidence and longest in situ practice during the Neolithic Age.

OBJECTIVES: Intentional cranial modification (ICM) was a long-established tradition used to reshape the head. Unfortunately, motivation of the act is unclear. It has been found in recent and contemporary human populations throughout the Old and New Worlds, yet the drawback of the quest into the origin, diffusion, and meanings of ICM is the lack of early materials for scientific examination. This study reports the discovery of ICM from the Neolithic Houtaomuga Site in Northeast China and the importance in deepening our knowledge of this intriguing tradition. MATERIALS AND METHODS: Twenty-five skeletons unearthed from the Neolithic cultural Phases 1-4 in the Houtaomuga Site were visually screened for ICM features. Cranial measurements were conducted to quantify the degree of variation in the modified skulls and typical ones were computer tomography (CT) scanned to obtain a diploë structure and 3D model. RESULTS: Eleven skulls carrying signs of ICM from both sexes varying in age from juveniles to full adults were identified ranging from 12,000 BP to 5,000 BP. Three types of modification patterns were observed and most of them were of typical fronto-occipital modification pattern. In particular, there were remarkable variations in the curvature of the crania along the sagittal direction. DISCUSSION: Overall, the antiquity as well as the cultural and genetic continuity of the population in Houtaomuga Site demonstrated the earliest confirmed ICM cases from the easternmost Old World, and the longest in situ duration of ICM practice at one single Neolithic site. This circumstance largely contributes to our understanding of the origins and distribution of ICM in Eurasia and the American continent.

Dental occlusion analysis in the Mesolithic-Neolithic Age, Bronze Age, and Roman to Medieval times in Serbia: Tooth size comparison in skeletal samples.

OBJECTIVE: Anthropological studies have reported that tooth size decreases in the context of diet changes. Some investigations have found a reverse trend in tooth size from the prehistoric to the modern times. The aims of this study were to analyze tooth size in skeletal samples from Mesolithic-Neolithic Age, Bronze Age, and Roman to Medieval times to determine sex differences and establish a temporal trend in tooth size in the aforementioned periods. DESIGN: Well-preserved permanent teeth were included in the investigation. The mesiodistal (MD) diameter of all teeth and buccolingual (BL) diameter of the molars were measured. Effects of sex and site were tested by one-way ANOVA, and the combined effect of these factors was analyzed by UNIANOVA. RESULTS: Sexual dimorphism was present in the BL diameters of all molars and MD diameters of the upper first and the lower third molar. The lower canine was the most dimorphic tooth in the anterior region. The MD diameter of most teeth showed no significant difference between the groups, (sample from: Mesolithic-Neolithic Age-group 1; Bronze Age-group 2; Roman times-group 3; Medieval times-group 4), whereas the BL diameters of the upper second and the lower first molar were the largest in the first group. Multiple comparisons revealed a decrease in the BL diameter of the upper second and the lower first molar from the first to the later groups. Lower canine MD diameter exhibited an increase in the fourth group compared to the second group. CONCLUSION: On the basis of the MD diameter, a temporal trend could not be observed for most of the teeth. The lower canine exhibited an increase in the MD diameter from the prehistoric to the Medieval times. Changes of BL diameter were more homogeneous, suggesting that the temporal trend of molar size decreased from the Mesolithic-Neolithic to Medieval times in Serbia.