Date of Final Oral Examination (Defense)
Type of Culminating Activity
Master of Arts in Anthropology
Samantha Blatt, Ph.D.
Mark Plew, Ph.D.
Pei-Lin Yu, Ph.D.
A large body of research in bioarchaeology focuses on the changes in the human skeleton associated with the introduction of agriculture. It is assumed that the intensification of agriculture results in an increase in physiological stress and poor health. However, previous studies have shown that stress experiences cannot be generalized by subsistence strategy and prevalence comparisons alone. Rather, age-at and duration of stress events are necessary to construct patterns of health.
Linear enamel hypoplasias (LEH) of subadult permanent dentition serve as a proxy for understanding health and stress in archaeological populations. LEH are defects in enamel, characterized by an increased distance between enamel growth rings, known as perikymata, across the tooth. Since enamel does not remodel, LEH provides a more accurate record of developmental disruption than other skeletal indicators. By analyzing LEH, this project aims to investigate the time and duration of stress events of foragers compared with those of agriculturalists.
The sample is made up of the adult anterior teeth of 40 children of a foraging group (Duff) and two agricultural populations (SunWatch and Buffalo) from the prehistoric Ohio Valley. The ages-at-death of these children have been previously determined using highly accurate dental cellular histology, capable of estimating age to the day. The first step in this project was the microscopic imaging of the surfaces of epoxy cast replicas of the subadult dentition. A scanning electron microscope was used to create 50X photomontages of micrograph images of the replicated tooth surfaces. From these photomontages, LEH from systemic stress was recorded as those that concurrently match among other teeth from the same individual. Individuals with observable defects on two or more teeth were categorized as LEH positive. To calculate the ages at which stress events occurred, perikymata were counted from the occlusal surface of each tooth to the beginning of each identified LEH, then added to cuspal enamel formation times, and initiation times for each tooth. The total number of perikymata within each defect furrow were used to reflect the duration of the stress events. These variables were compared between samples using Fisher’s exact tests, boxplots, pairwise ANOVA tests, and averages.
The results provide a comparative analysis of the changes and continuities in the lifestyles of foragers and agriculturalists in the Ohio Valley. Because their environments were not markedly different, variation in stress events observed between these groups are the result of cultural or nutritional change evidence of which contributes to the evaluation of political or migratory interaction between regional groups. Indeed, it appears that SunWatch children endured the most stress events, although Duff children suffered the longest stress events. Age-at-death among the SunWatch sample was the youngest, therefore their higher frequency of LEH occurrence suggests a decline in quality of health compared to earlier foraging populations. Results are similar to previous studies exploring transitions in health with the rise of agriculture.
Moes, Emily, "Reading Between the Lines: Indicators of Developmental Stress in Prehistoric Ohio Valley Children from Linear Enamel Hypoplasias" (2016). Boise State University Theses and Dissertations. 1109.