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Dental enamel defects have been used extensively in past human populations to elucidate patterns of health and physiological disruption (often simply referred to as stress). These defects are most commonly assessed through visual examination and used to infer such information as the frequency and age at occurrence of stress events. However, a microscopic approach makes it possible to more consistently identify patterns of growth and growth disruption in greater detail than that possible with traditional macroscopic techniques. Such microscopic studies are being increasingly explored in bioarchaeology, but this area of investigation has not seen extensive application to zooarchaeological material. Consequently, enamel defects in general have not been integrated as heavily in this field. A species of particular importance within the modern context of climate change is the barren-ground caribou (Rangifer tarandus groenlandicus). This species has been a crucial species to the human populations throughout the Arctic for thousands of years, and herd fluctuations have in the past shaped the human experience. The study of past stress in these populations could provide significant historical insight into herd patterns, which would have impacted subsistence and mobility patterns, and traditional use of these animals among both past and contemporary human populations. This paper presents the results of a pilot study using the Olympus LEXT Laser-Scanning Confocal Microscope OLS4000 to evaluate enamel growth in an archaeological caribou tooth from the LdFa-1 site (a large caribou hunting site located in the deep interior of southern Baffin Island). Our study demonstrates the potential of this technology to capture enamel surface microstructures and to provide greater insight into the fine patterns of growth arrest within this zooarchaeological context.

Bioarchaeology as a field of study can contribute important insights to our understanding of how stress-related phenomena experienced in childhood influence later life conditions. One area that is especially effective is looking at the dental enamel surface microstructures reflecting patterns of growth and growth disruption. Since dental enamel grows incrementally, and because it does not remodel once formed, a record of growth disruption (formed during childhood) is preserved for the rest of an individuals' life. Enamel surface defects are commonly observed macroscopically as enamel hypoplasia. However, this method does not capture the smaller defects reflecting a disruption in only a few of the growth lines visible on the tooth surface. Previous approaches to the assessment of these structures have included scanning electron microscopes and polarized light microscopes with photomontaging and z-stacking capacity. This paper presents the application of the Olympus LEXT 3D Laser Measuring Microscope OLS4000 and Olympus LEXT analytical software to capture and examine dental enamel surface microstructures. The use of the LEXT for these purposes is critically assessed, and the strengths and challenges discussed. Recommendations are made for future application of this instrument to bioarchaeological research.

Objectives: In the 14th century AD, medieval Europe was severely affected by the Great European Famine as well as repeated bouts of disease, including the Black Death, causing major demographic shifts. This high volatility led to increased mobility and migration due to new labor and economic opportunities, as evidenced by documentary and stable isotope data. This study uses ancient DNA (aDNA) isolated from skeletal remains to examine whether evidence for large-scale population movement can be gleaned from the complete mitochondrial genomes of 264 medieval individuals from England (London) and Denmark. Materials and Methods: Using a novel library-conserving approach to targeted capture, we recovered 264 full mitochondrial genomes from the petrous portion of the temporal bones and teeth and compared genetic diversity across the medieval period within and between English (London) and Danish populations and with contemporary populations through population pairwise Φ ST analysis. Results: We find no evidence of significant differences in genetic diversity spatially or temporally in our dataset, yet there is a high degree of haplotype diversity in our medieval samples with little exact sequence sharing. Discussion: The mitochondrial genomes of both medieval Londoners and medieval Danes suggest high mitochondrial diversity before, during and after the Black Death. While our mitochondrial genomic data lack geographically correlated signals, these data could be the result of high, continual female migration before and after the Black Death or may simply indicate a large female effective population size unaffected by the upheaval of the medieval period. Either scenario suggests a genetic resiliency in areas of northwestern medieval Europe.

The influence of early life stress on later life experiences has become a major focus of research in medicine and more recently in bioarchaeology. Dental enamel, which preserves a record of childhood stress events, represents an important resource for this investigation when paired with the information from adult skeletal remains, such as age at death. The purpose of this research was to use a life history approach to the exploration of sex differences in the relationship between childhood stress and adult longevity by examining accentuated striae of Retzius (AS). A medieval Danish sample (n = 70) drawn from the rural cemetery of Sejet and the urban cemetery of Ole Wormsgade was considered for AS and age at death. The results suggest sex differences in survivorship, with more stress being associated with reduced survivorship in males and increased survivorship in females. A consideration of AS formation time also suggests a difference in the impact of developmental timing between males and females. These results are interpreted in terms of differential frailty and selective mortality, drawing in both biomedical and cultural perspectives.