A Pilot Study of Isotopic Analysis for the Geographic Provenance of Aged Human Skeletal Remains

To evaluate the potential of stable isotope analysis for determining the geographic provenance of aged human remains, and to assess its effectiveness as a screening tool in forensic identification when prior information is limited.

Enamel samples from twelve aged human remains were analyzed for strontium isotopes (⁸⁷Sr/⁸⁶Sr) and stable carbon and oxygen isotopes (δ¹³C, δ¹⁸O). Geographic assignment was conducted using the assignR package by integrating isotopic data with global isoscapes to generate probabilistic provenance maps.

The ⁸⁷Sr/⁸⁶Sr ratios of enamel samples ranged from 0.708 647 to 0.717 172, while δ¹³C and δ¹⁸O values indicated substantial inter-individual variation in diet and environmental conditions. Isotopic assignment effectively excluded incompatible regions and significantly narrowed the range of possible origins. Among the twelve individuals, eight showed concordance between isotopic predictions and known places of origin, demonstrating the method's relatively high accuracy.

Multi-isotope analysis provides an effective approach for determining the geographic provenance of aged human remains, particularly in cases where DNA evidence is unavailable or limited. The reliability of isotopic assignments depends on the quality of isoscapes, individual life history, the preservation state of samples, and rigorous laboratory quality control. Future work should focus on improving baseline datasets, standardizing analytical protocols, and integrating multidisciplinary data to enhance the precision and applicability of isotope-based provenance methods.