Robb, Kasey, 2008. Adaptation to the Pacific Island environment. An investigation of non-specific indicators of stress in prehistoric human skeletal remains.
Goodman et al. (1988) explain that stress focuses on the cost and limits of adaptation. This study investigated non-specific indicators of stress in human skeletal remains from seven prehistoric sites in the Pacific islands as an attempt to gauge the success or failure of adaptation to an island environment. The samples used in this study represent both colonising and established populations and are spread geographically throughout the Pacific islands. The Pacific island environment varies in the distribution of biota, including important nutritional sources and vectors for disease transmission (particularly malaria) that all have implications for the adaptability of prehistoric populations to their island environment. The study of cortical thickness in Pacific island samples has not previously been included with the investigation of other non-specific indicators of stress and therefore allows comparisons of patterns of appositional growth both between and within populations. In the current study both inter and intra sample comparisons of cortical thickness, maximum femoral length and linear enamel hypoplasia were made to assess if there were any differences in patterns of growth disruption in subadults (n=17) and adults (n=100). No significant correlations were determined between the nonspecific indicators of stress and the temporal and spatial distributions of the samples. This is because there was very little variation in results between samples. Within all the samples there was evidence of an age related decline in cortical thickness and sexual dimorphism of cortical thickness and maximum femoral length. There was no evidence that incidences of childhood stress affect the adult attainment of their genetic potential for growth. Subadult measures of cortical thickness in neonates showed increased values when compared to modern reference standards but the adult means clustered around the minimum recommended cortical thickness for modern healthy populations. These results suggest a difference between prehistoric and modern growth patterns but show no evidence for chronic ill-health. Overall, the indicators used in the current study showed very similar results and therefore do not reflect evidence for differential adaptation to the Pacific island environment through time and across the island groups. This could have been the result of small sample sizes or the limitations of bioarchaeological studies and needs to be further investigated with the use of other non-specific indicators of stress and evidence of disease in Pacific island samples.
Goodman, A.H., R.B. Thomas, A.C. Swedlund, and G.J. Armelagos. 1988. Biocultural Perspectives on Stress in Prehistoric, Historical and Contemporary Population Research. Yearbook of PhysicalAnthropology 31:169-202.