American Journal of Biological Anthropology最新文献

The “gold standard” for the assessment of trabecular bone structure is high-resolution micro-CT. In this technical note, we test the influence of initial scan resolution and post hoc downsampling on the quantitative and qualitative analysis of trabecular bone in a Gorilla tibia. We analyzed trabecular morphology in the right distal tibia of one Gorilla gorilla individual to investigate the impact of variation in voxel size on measured trabecular variables. For each version of the micro-CT volume, trabecular bone was segmented using the medical image analysis method. Holistic morphometric analysis was then used to analyze bone volume (BV/TV), anisotropy (DA), trabecular thickness (Tb.Th), spacing (Tb.Sp), and number (Tb.N). Increasing voxel size during initial scanning was found to have a strong impact on DA and Tb.Th measures, while BV/TV, Tb.Sp, and Tb.N were found to be less sensitive to variations in initial scan resolution. All tested parameters were not substantially influenced by downsampling up to 90 μm resolution. Color maps of BV/TV and DA also retained their distribution up to 90 μm. This study is the first to examine the effect of variation in micro-CT voxel size on the analysis of trabecular bone structure using whole epiphysis approaches. Our results indicate that microstructural variables may be measured for most trabecular parameters up to a voxel size of 90 μm for both scan and downsampled resolutions. Moreover, if only BV/TV, Tb.Sp or Tb.N is measured, even larger voxel sizes might be used without substantially affecting the results.

A central goal of biological anthropology is connecting environmental variation to differences in host physiology, biology, health, and evolution. The microbiome represents a valuable pathway for studying how variation in host environments impacts health outcomes. While there are many resources for learning about methods related to microbiome sample collection, laboratory analyses, and genetic sequencing, there are fewer dedicated to helping researchers navigate the dense portfolio of bioinformatics and statistical approaches for analyzing microbiome data. Those that do exist are rarely related to questions in biological anthropology and instead are often focused on human biomedicine. To address this gap, we expand on existing tutorials and provide a “road map” to aid biological anthropologists in understanding, selecting, and deploying the data analysis and visualization methods that are most appropriate for their specific research questions. Leveraging an existing dataset of fecal samples and survey data collected from wild geladas living in Simien Mountains National Park in Ethiopia (Baniel et al., 2021), this paper guides researchers toward answering three questions related to variation in the gut microbiome across host and environmental factors. By providing explanations, examples, and a reproducible workflow for different analytic methods, we move beyond the theoretical benefits of considering the microbiome within anthropological research and instead present researchers with a guide for applying microbiome science to their work. This paper makes microbiome science more accessible to biological anthropologists and paves the way for continued research into the microbiome's role in the ecology, evolution, and health of human and non-human primates.

Health inequality is not only a major problem today; it left its mark upon past societies too. For much of the past, health inequality has been poorly studied, mostly because bioarchaeologists have concentrated upon single sites rather than a broader social landscape. This article compares 476 adults in multiple locations of medieval Cambridge (UK). Samples include ordinary townspeople (All Saints), people living in a charitable institution (the Hospital of St. John), and members of a religious order (the Augustinian Friary). These groups shared many conditions of life, such as a similar range of diseases, risk of injury, and vertebral disk degeneration. However, people living on charity had more indicators of poor childhood health and diet, lower adult stature, and a younger age at death, reflecting the health effects of poverty. In contrast, the Augustinian friars were members of a prosperous, well-endowed religious house. Compared with other groups, they were taller (perhaps a result of a richer diet during their adolescent growth period); their adult carbon and nitrogen isotope values are higher, suggesting a diet higher in terrestrial and/or marine animal protein; and they had the highest prevalence of foot problems related to fashionable late medieval footwear. As this illustrates, health inequality will take particular forms depending upon the specificities of a social landscape; except in unusual circumstances where a site and its skeletal samples represent a real cross-section of society, inequality is best investigated by comparison across sites.

An ethical paradigm shift currently taking place within biological anthropology is pushing scholars to envisage and develop paths toward more ethical futures. Drawing from case studies in our own teaching, research, and fieldwork experience, we reflect on the complex, diverse, and dynamic nature of ethical considerations in our field. We discuss the acquisition and institutional narrative of a human osteological teaching collection at the University of Louisville as an embodiment of structural apathy turned structural violence, and the need for professional guidance in the potential retirement of deceased individuals from our classrooms. In documented collections (i.e., the Robert J. Terry Collection), we share our process and scholarly reemphasis of the humanity of a deceased individual through contextualized analysis (i.e., osteobiography and archival history) and postmortem agentive acts. Lastly, we present an archeological site in the U.S. Virgin Islands, which poses ethical concerns as biocultural bioarcheologists and archeologists attempt to negotiate the possible wishes of the deceased with the cultural value of reconstructing the community's otherwise undocumented past, all amidst the immediate threat of anthropogenic climate change. We offer these exercises and discussion in ethically engaged projects transparently and with an overarching admission that none are models for replication. Rather, at various stages in our careers and engagement with ethics, we acknowledge that progress is worthwhile, albeit challenging, and that proceeding forward collectively as biological anthropologists should be deliberate, reflexive, and compassionate for deceased individuals and their descendant communities, as well as among and between colleagues.