Sex estimation of sub-adult human remains and determination of geographic origin: New perspectives and methodologies

Abstract

Forensic anthropology has long established the use of sex estimation and assessment of geographical origin in the identification of unidentified subjects, including victims of human rights atrocities and migrant diasporas. This research explores and develops innovative anthropological methods for the application of the recent advances in geometric morphometry and ancient DNA (aDNA) to the above post-mortem approaches of identification. The aim of this research is to develop novel standards for diagnosing sex and geographic origins useful for the identification of unknown human remains. Phase I of the project involves the use of 3D digitization and geometric morphometric approaches to increase the accuracy in sub-adult sex estimation and to analyze size, shape and degree of maturation of skeletal elements to detect patterns of similarities and differences between sexes. A representative sample of a population of known origin was generated using contemporary human skeletal remains of Italian sub-adults who died during the 1990s. Bone surfaces were digitized using a 3D laser scanner and 3D landmarks and semi-landmarks were developed to capture the variation of skeletal morphology. GPA and PCA will be used as multivariate analyses. Phase II focuses on geographic origin and uses 20 modern samples from different geographic origins and taphonomic contexts. An aDNA protocol was used to maximize the results in degraded modern bones. DNA extraction, library and sequenced using a Shotgun-sequencing approach were carried out in genomics laboratories at UCD. The geographic information will be predicted by comparing the results obtained by means of SNP genotypes with databases of known populations. This approach enables the attribution of the samples to different regions and creates a basis for personal identification.