Southeast Asia has a rich heritage of postpartum customs, many of which are gradually being forgotten and replaced by modern allopathic practices. This is particularly true in Brunei Darussalam where documentation of postpartum customs is lacking. This study explores the postpartum traditions and practices of three indigenous groups in Brunei—Kedayans, Brunei Malays, and Lun Bawangs. A qualitative study was conducted in the form of interviews at market areas and homes of the respondents, primarily targeting the Kedayan, Brunei Malay and Lun Bawang indigenous groups. Data were collected from 57 respondents, including traditional medical practitioners, elderly villagers knowledgeable in traditional medicine, postnatal caregivers, and parents of young children. The respondents were interviewed with predesigned questions about their knowledge of, and experience with, traditional postpartum practices and herbal plant preparations. Our study revealed similarities between the plants and practices adopted by the indigenous groups, especially between the Malays and Kedayans. The postpartum practices of the three groups can be generally categorized into the following: confinement period, ‘mother roasting,’ baths, massages, stomach binding (berbarut), topical applications, dietary prescriptions and restrictions (pantang), herbal drinks, breast care, healing of the delivery wounds, and removal of stitches. Behavioural taboos during the postnatal period and trends among younger generations were also discussed. The traditional postpartum practices of the Bruneian indigenous groups are unique and represent a significant part of Bruneian custom and culture. It is imperative to document and promote beneficial customary postpartum practices to preserve the indigenous traditions of Brunei.

The Jomon culture that spread across the Japanese archipelago began about 16000 years ago and lasted for over 10000 years. The population history of the Jomon people, prehistoric hunter-gatherers bearing the Jomon culture, is of great interest in understanding prehistoric East Eurasians. Traditionally, population size and its fluctuations, i.e. Jomon demography, have been estimated in the archaeological context, but over the past 20 years, statistical methods using genome sequence data have been sufficiently developed. To investigate their demography, we determined the complete whole-mitochondrial genome (mitogenome) sequences from 13 Jomon individuals and conducted population genetic analysis on 40 Jomon mitogenomes, including previously published data. By simulation, we showed that east–west frequency differences between two haplogroups typical of the Jomon people, N9b and M7a, could be caused by a genetic drift under conditions of a small initial effective population size, an extreme population split, and limited migration between the eastern and western populations, suggesting that the regionally unbalanced haplogroup distribution does not necessarily contradict the monophyletic origin scenario of the Jomon people implied by recent nuclear genome analyses. We found an effective population size (N_e) increase during the Incipient–Initial phase of the Jomon period, which had not been observed in analyses of mitogenome sequences from present-day Japanese populations. This endemic demographic pattern is pronounced in the eastern part of the archipelago, under the assumption of no gene flow between the Eastern and Western Jomon. This study sheds light on the demography of the Jomon people and shows an alternative scenario of the Jomon peopling history estimated based on whole-mitogenome data.

Third molar (M3) agenesis has become prevalent since the terminal Pleistocene in humans. Population-level studies suggest that M3 agenesis is related to genetic factors and to environmental stresses such as malnutrition and infectious diseases. In addition, the fact that there are populations, such as the Jomon people, that have a high frequency of enamel hypoplasia (EH), an indicator of stress, but a low M3 agenesis rate, suggests that there are population differences in how the effects of environmental stress on M3 agenesis are manifested. In this study, I used EH to investigate the effects of environmental stress on M3 agenesis in three populations with different genetic bases: recent Japanese (1868–1926), Jomon people, and Islamic Mesopotamians. The results showed the effects of environmental stress on M3 agenesis in recent Japanese and Islamic Mesopotamians, but not in Jomon people. Furthermore, it was shown that M3 agenesis of recent Japanese and Islamic Mesopotamians are similarly susceptible to environmental stress. Thus, the results showed that the extent to which environmental stress affects M3 formation varies among populations. Since M3 agenesis was observed even in Jomon people, whose M3s are not thought to have been affected by environmental stress, it is reasonable to assume that M3 agenesis can be congenital or caused by environmental stress, and each cause of agenesis occurred independently in human populations.

Bioarchaeological studies of people in Mesopotamia are scarce compared with other regions. This study investigated the prevalences of cribra orbitalia, enamel hypoplasia, and porotic hyperostosis on human skeletal remains excavated from the Hamrin Basin in the middle Tigris River, spanning from ~4000 BC to the Islamic period. The prevalence of cribra orbitalia and enamel hypoplasia was high and remained around 70–80% until the first century. The prevalence of stress indicators decreased in the Islamic period. The hypothesis that the rapid cooling and aridification in West Asia around 2000 BC increased stress levels was not statistically supported in this study. It seems that Mesopotamians were exposed to generally higher stresses than the Egyptians in contemporary periods.