Early-life Stressors in Pre- and Postcontact Peru: Evidence from Incremental Enamel Microstructures
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Brown, Genevieve
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Abstract
This study seeks to understand how populations in the Lambayeque Valley Complex on the north coast of Peru, were affected by Spanish colonialism through the study of linear enamel hypoplasia (LEH). Here, stress chronologies are compared between two late precontact samples from Huaca Chornancap (1375-1470) and Huaca de los Sacrificios (AD 1470-1532) with a sample from Eten dating to the Early/Middle Colonial era (AD 1535-1620). The three samples represent indigenous Muchik peoples from two distinct contexts (sacrifice victims and postcontact church cemetery). To characterize the timing of early-life stress, high resolution impressions were used to produce tooth crown replicas and studied under an engineer’s measuring microscope. Perikymata were measured from the most occlusal region of the imbricational enamel along the length of each tooth to the cemento-enamel junction. Accentuated perikymata were used as indicators for LEH and identified using z-scores and a moving average. Employing constants for crown initiation and cuspal enamel formation for each tooth and an eight-day periodicity for each perikymata, age-at-defect-formation was calculated. Age-at-defect formation ranged from 1.1 to 4.4 years across the sample. Although there were no statistically significant differences in age-at-defect-formation across the study, the sample from Eten had the widest range of ages and a slightly lower median age-atdefect- formation. This is hypothesized to represent a change in the timing or prevalence of stress during the Colonial era, whether through shifts in weaning patterns or nutrient access.
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LEH, Dental anthropology, Anthropology, Peru, Colonialism, Stress