Isotopic Determination of Region of Origin in Modern Peoples: Applications for Identification of U.S. War-Dead From the Vietnam Conflict
FLORIDA UNIV GAINESVILLE
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This study is novel in that it is the first of its kind to compile a reference sample of isotopic values associated with known natal regions to be utilized in forensic work. Stable isotopes of carbon, oxygen, strontium, and lead were examined to determine if natal origins could be assessed isotopically between Southeast Asian and American dental remains as well as regionally within the United States. Teeth believed to be of East Asian origin were compared to the extracted third molars of recent American dental patients. Living subjects completed surveys detailing physiological, behavioral, and residential information that affect isotope values. The least squares means for all isotope values examined exhibited significant differences between the East Asian and American cohorts. Based on this information, a discriminant function was created that correctly classified individuals, through resubstitution and cross-validation, as belonging to one of these two groups by 95 or better. American strontium values displayed a distinct trend toward homogenization, with the mean value for Sr87Sr86 varying only slightly from that of seawater. In order to identify natal origin among Americans, nine regions were created within the United States based on O18 values. Good discrimination was noted between the mountain states and the southern states. A discriminant function analysis proved disappointing though, and additional sampling from most states is needed to improve the statistical robusticity of the model. The results of this study will have wide-reaching effects across the medico-legal spectrum. This body of research will serve as the foundation for a database of modern, human, geolocational isotope values that will assist not only in the identification of fallen servicemen and women, but in the identification of victims of mass fatality incidents, undocumented aliens who perish attempting entry into the U.S., and local skeletal Jane and John Doe cases.
- Sociology and Law
- Anatomy and Physiology