Anthropology, University of Missouri
Thursday All day, Park Concourse
Sub-adult skeletal remains provide an under-utilized source of information about mortality, fertility, and demographic variation in prehistoric populations. In this study, we examine diachronic patterns of fertility and mortality in the transition from Middle to Late Mississippian periods in Missouri; we then compare them to similar analyses from Woodland and Mississippian populations in west-central Illinois, Arkansas, and Tennessee. We utilize the D0-1/D19+, D5-19/D5+, D30+/D5+, and D1-5/D-10 proportions as relative indicators of population birth, growth, and death rates. Fertility indices (5-19/5+, and 30+/5+) are proxy measures of fertility, and have been demonstrated to be strongly correlated (r2 = .971 and .877) with life-table estimates of crude birthrate and growth rate, respectively. The juvenile death proportion (1-5/1-10) reflects childhood survivorship and is strongly correlated with childhood death rate and crude birth rateWe then examine the relationship between linear enamel hypoplasias, porotic hyperostosis, and cribra orbitalia on sub-adult longevity and survival.
Age-at-death for sub-adults was estimated using dental eruption, epiphyseal fusion, and long-bone length. Death ratios exhibit considerable variability between sites and through time, but temporal trends indicate low but consistent population growth throughout time, before experiencing a population decrease during the Late Mississippian period. Increasing rates of LEH, cribra orbitalia, and porotic hyperostosis through time, combined with Kaplan-Meier survival curves and log-rank tests emphasize the importance of the relationship between sub-adult fertility and mortality in response to changes in subsistence, disease, and social environments.