Stress, Life History, and Linear Enamel Hypoplasia: Insights From the Indigenous Populations of the Canary Islands

Abstract

Objectives: This study evaluated the influence of genetic diversity, subsistence strategies, age at death, and their interplay on the prevalence of linear enamel hypoplasias (LEHs) in the indigenous populations of the Canary Islands. Additionally, we test the predictive adaptive hypothesis and the plasticity/constraint hypothesis within this unique archeological context. Methods: LEH incidence, age of occurrence, and the number of stress episodes were assessed macroscopically in a sample of 409 individuals from six of the seven islands comprising the Canarian archipelago during the pre-contact or Indigenous period (2nd–15th century cal CE). Statistical comparisons were made using chi-square and Fisher's exact tests to evaluate LEH prevalence across populations and age groups within each island. To control for potential demographic confounding, hierarchical log-linear (HLL) analysis was applied to explore the combined influence of age, sex, and island of origin on LEH prevalence. Model fit was assessed using likelihood-ratio chi-square tests. Results: Statistically significant differences were found between Gran Canaria and Tenerife, and between them and La Palma. Sexual differences in LEH prevalence were observed among individuals from Gran Canaria and within specific age groups in the other populations. In all indigenous populations, the number of individuals with LEH decreased in the oldest age groups. Conclusions: Our findings suggest that subsistence strategies explain the differences observed among the islands in terms of the various analyzed variables. All the data suggest that the plasticity/constraint hypothesis best fits the Indigenous populations of the Canary Islands, with males being more affected by environmental conditions than females.