The Pacopampa site, located in the northern highlands of Peru, is an archeological site belonging to the Formative Period (2500 BC–0 AD). The purposes of this study are to observe and describe the human skeletal remains from the Pacopampa site, to estimate the sex and age-at-death of each individual, and finally to diagnose morphological traits and skeletal disorders. The materials used here are 498 human skeleton parts. The sample comprises at least 18 individuals: eight subadult skeletons, eight adult skeletons, one skeleton aged 10–39 years, and one of unknown age. The age distribution (six of eight subadults were less than one year) suggests a high proportion of infants in the population. The sexual ratio of three adult males to four adult females indicates a skeletal population with hardly any sexual bias. A paleopathological examination revealed that the percentage of permanent teeth affected by dental caries was 9% (18/192). Two elderly females exhibit periodontal disease in both the maxillae and mandibles. This is the first study to examine the lives and deaths of a Formative Period population from the perspective of bioarcheology.
The Japan Islands, a small island chain on the western rim of the circum-Pacific region, have experienced several cultural contacts and human migrations from northern and eastern continental Asia. In this study, craniometric diversification of Asian peoples was assessed using the R-matrix method based on 21 metric traits in 25 representative male and female samples of prehistoric and modern northeastern and eastern Asians, including inhabitants of the Japan Islands. The prehistoric series show, in general, greater observed variance than expected. In the Japanese series, the greater than expected variation of the Jomon is strongly contrasted with the lower level of variability seen in the continental immigrant Yayoi, suggesting a founder effect stemming from the small population size of the initial immigrants represented by the Yayoi series. Scattergrams based on the morphological distances transformed from the R-matrix showed that the Jomon, Ainu, and prehistoric Okhotsk (northeastern immigrants to the Japan Islands) were isolated from the main eastern and northeastern Asian cluster, suggesting greater phenotypic diversity in the Japan Islanders. Despite less variability in the Yayoi series, the phenotypic contribution of the Yayoi to the main-island Japanese populations was considerable, probably because of the existence of successive immigrants after the Yayoi period and/or a higher growth rate of the Yayoi immigrant groups. An assessment of intra-regional variation of the five major Asian regional series by the R-matrix method confirmed that the Japanese series representing populations living on small islands have greater craniometric diversity than the Arctic and Coastal northeastern Asian samples.
The endometrium is important for luteal phase function, implantation, placentation, and gestation. Endometrial morphology has been shown to impact early pregnancy success in in vitro fertilization and egg donor cycles and has been implicated in conception success in spontaneous cycles. However, few studies have monitored endometrial morphology in normo-ovulatory women or examined possible population variation in its physiology or thickness. Further, the methodology of most studies of the endometrium is to take a single measurement close to ovulation, meaning the endometrium is not often measured during the window of implantation; the assumption has been that an individual’s endometrial thickness (ET) is consistent through the luteal phase. Therefore, we have tested the hypothesis that ET is independent of luteal phase day in a study of urban-dwelling US and rural Polish women. We found that ET is not independent of luteal phase day in this sample of rural Polish women: ET is negatively associated with cycle day (P = 0.03). Compared to the US sample, the Polish sample also had a significantly later age at menarche (P = 0.002), lower midluteal progesterone concentrations (P = 0.0006), lower C-peptide concentrations (P = 0.0003), and higher energy expenditure (P = 0.03), suggesting greater energetic constraint. The relationship between ET and luteal phase length highlights the need to measure the endometrium serially over the menstrual cycle in order to better document inter- and intra-population variation in reproductive function.
Although a considerable number of discussions on human evolution based upon the rich fossil remains in Indonesia have been conducted, studies on living humans in this region are rather scarce. The aim of this study is to determine the specific morphological characteristics of present-day adult Indonesians compared with present-day Japanese. The height, sitting height, and weight of 61 male and 77 female Javanese Indonesians, aged 20s–50s, were measured in 2005. Leg length, leg-length-to-height ratio, and body mass index (BMI) were calculated from these measurements for each subject. In comparison with present-day Japanese, the Javanese were shorter in height and sitting height in both sexes. The Javanese males were lighter than the Japanese males, but not so the Javanese females vis-à-vis the Japanese females; therefore, the BMI of the Javanese was lower in the males and higher in the females than in those of their Japanese counterparts. As leg length was not shorter, the Javanese showed a greater leg-length-to-height ratio. The same physical characteristics were observed about 60 years ago, except in height, between Javanese and Japanese, both measured in 1944–1945. Observing this result, relative leg-length to height can be considered a physical characteristic reflecting an ecological adaptation to climate in so-called Mongoloid populations. A secular change during the intervening 60 years of increased body size was exhibited in both the Javanese and Japanese groups. However, this change in the Javanese was smaller than in the Japanese except for BMI, the increase in which was the same in both groups. Considering the remarkable socioeconomic improvement, especially in nutrition, in Japan, these results agree with the general observation that BMI/weight is more sensitive than height to sociocultural factors.
In order to further understand the genetic status of the Okhotsk people, who were distributed in southern coastal regions of the Okhotsk Sea during the 5th–13th centuries, nucleotide variations in the hypervariable region (HVR) and the coding regions of mitochondrial DNA (mtDNA) were analyzed. Targeting the coding regions provides reliable genetic information even from ancient DNAs that may have suffered post-mortem damage. MtDNA haplogroups of 38 individuals were classified according to mtDNA lineages known in northeastern Asian people. Comparisons of mtDNA haplogroup frequencies between the Okhotsk people and other Asian populations revealed that the genetic structures of the Okhotsk people are very similar to those of populations currently living around lower regions of the Amur River and the Ainu of Hokkaido. The results support our previous study on molecular phylogeny of mtDNA HVR 1 sequences, and strongly suggest that the Okhotsk people originated around the lower regions of the Amur River and became an intermediate of gene flow from the continental Sakhalin people to the Ainu.