Evaluating life history trade-offs through the presence of linear enamel hypoplasia at Pueblo Bonito and Hawikku: A biocultural study of early life stress and survival in the Ancestral Pueblo Southwest.

ABSTRACT

OBJECTIVES: Due to the indelible nature of enamel, bioarchaeologists use linear enamel hypoplasia (LEH) to detect early investments in surviving stress and have identified an association between LEH presence and constraints in growth and maintenance as well as an increased susceptibility to future stress events. This study evaluates heterogenous frailty and susceptibility to death in relation to episodes of early life stress, as reflected by LEH presence, in the Ancestral Pueblo Southwest. This study hypothesizes that LEH presence will be associated with decreased survivorship and an increased likelihood of mortality in both samples. MATERIALS AND METHODS: This study uses two samples, one from Pueblo Bonito (A.D. 800-1200; n = 28) and the second from Hawikku (A.D. 1300-1680; n = 103). Kaplan-Meier survival analysis with a log-rank test was used to evaluate the effect of LEH presence on survivorship for the two samples. RESULTS: Survival analysis reveals statistically significant differences in mortality risk between individuals with and without LEH for the Hawikku sample, but no significant differences for the Pueblo Bonito sample. CONCLUSION: The results demonstrate differences in the response to early life stress at the Hawikku and Pueblo Bonito sites, likely reflecting context. The Pueblo Bonito sample represents a high-status group, and survival following LEH may be the result of cultural buffering. Hawikku dates to a period associated with increased levels of disease and malnutrition as well as Spanish colonization. This environment may have exacerbated mortality risk for individuals in the region who survived early life stress and signifies the consequences of European colonialism in the New World.