What Mean These Bones?: Studies in Southeastern Bioarchaeology

5. Mississippian Cultual Terminations in Middle Tennessee: What the Bioarchaelogical Evidence Can Tell Us

Health and Cultural Change * 65 bone surface may be raised, extending into the orbit. In porotic hyperostosis , apertures penetrate the external table of the cranial vault, the external table can be thinned, and the diploe is often thickened. Abnormal diploic structure may be visible in radiographs as striations radiating from the inner to the outer tables, the so-called hair-on-end effect. the percentage of crania displaying either cribra orbitalia or porotic hyperostosis in the Sand Prairie series is approximately three times greater than it was in the earlier sample (Table 4-2). The majority of the crania were not intact, although the most poorly preserved and highly fragmented specimens were excluded from the interpopulation comparison . Nevertheless, variation in bone preservation combined with any differential expression of the lesions in the two parts of the cranium where the conditions usually occur, the orbits and posterior vault, could obscure comparisons based on incomplete specimens. When only crania with at least one orbit and much, or all, of the posterior cranial vault are compared, the samples are reduced but the discrepancy in lesion frequency remains: Moorehead phase, N =68, 7 percent affected; Sand Prairie phase, N = 24, 25 percent affected. Three of the six Moorehead phase crania that exhibited the lesions belonged to children who died during their second or third years. These three individuals represented 38 percent of the children in this two-year interval with crania that could be examined for either condition. The affected Sand Prairie phase individuals were generally older at the time of death than their Moorehead phase counterparts. In addition, the lesions typically had a well-remodeled appearance, indicating that the period of nutritionally related stress that resulted in a pathological involvement of bone had occurred earlier in life. (See Martin, Goodman, and Armelagos 1985; Mensforth et al. 1978; Palkovich 1987; and StuartTable 4-2 Skeletons with Cribra Orbitalia or Porotic Hyperostosis Kane Mounds Affected Age N N % N 0-2.9 years 13 3 23 3 3-14.9 years 11 0 0 7 +15 years 74 3 4 31 Total 98 6 6 41 ESLSQ: East St. Louis Stone Quarry ESLSQ Affected N % 1 33 2 29 4 13 7 17 66 * Milner Macadam 1985 for discussions of the importance of differentiating active from inactive lesions.) The greater number of remodeled lesions in the Sand Prairie phase population may reflect the fact that more young children lived through a period of chronic stress, which resulted in skeletal lesions that eventually healed, than survived in the earlier population. Differential survivorship is also suggested by the third-year mortality figures that dropped in the Sand Prairie phase population but continued at an elevated level in the Moorehead phase group. American Bottom and Other Midcontinental Populations Some evidence exists for variation in the mortality and morbidity patterns of populations drawn from different times during Cahokia's long slide to obscurity. It can be safely assumed, however, that the causes underlying any shifts in either mortality or morbidity were many. This uncertainty makes the interpretation of seemingly different patterns rather difficult, particularly when combined with the small size of archaeological skeletal samples and the problems inherent in making inferences about past conditions, human behavior, and the prevalence of pathological conditions in a living population from the frequency of lesions in a nonsurvivor sample. Nevertheless, alterations in the patterning of juvenile deaths and in the age distribution of nutritionally related skeletal lesions may reflect a change in the overall health of young children . Differences in mortality patterns, specifically during the second and third years, may be linked to variation in the age distributions of individuals exhibiting cribra orbitalia and porotic hyperostosis. Taken together, this information raises the possibility that many Sand Prairie phase children survived a period of initial stress, which resulted in bony manifestations of the disease process, only to succumb later to other causes of death. Other indexes of health, such as the combined periostitis and osteomyelitis figures for adults, remained essentially the same during the last two Mississippian phases. These findings underscore the importance of integrating complementary data sets in the assessment of prehistoric community health. In addition, future research should direct especially close attention toward the juvenile segment of American Bottom populations. Lesions resembling those of classic skeletal tuberculosis are particularly significant given previous research conducted within western Illinois. Buikstra and Cook (1978, 1981; Cook 1984) have identified le- Health and Cultural...