An evaluation of current metric techniques for the determination of population ancestry using the postcranial skeleton

Ancestry determination plays an important part in the identification of human remains. A review of the literature this far showed the cranium has been the focus of the research into ancestry determination due to its significant population variation, however when the cranium is not available other bones have to be used. This study compared the four different FORDISC postcranial functions with a number of alternative metric techniques of ancestry determination from the literature that may be applied to single elements of the postcranial skeleton, namely the femur, pelvis and calcaneus. The alternative tecnqiues used were femoral curvature, femoral torsion, femoral neck axis length, subtrochanteric shape, intercondylar notch height for the femur; Patriquin et al.'s (2002) method for the pelvis and Bidmos' (2006) method for the calcaneus. These methods were applied to a post-medieval London cemetery sample of 52 male and female skeletons. In addition, the consistency of the FORDISC cranial and four postcranial functions was assessed. Assuming an overwhelming predominance of European ancestry in this study sample, FORDISC postcranial function performed worse than other methods requiring similar measurements. Femoral curvature, intercondylar notch height and most of the functions from Patriquin et al.'s (2002) method performed extremely well. Femoral torsion and femoral neck axis length performed poorly. The consistency of ancestry determination using the different FORDISC functions, when applied to a single individual, was extremely poor. Intra and inter observer error assessments were also carried out. The intra and inter observer error analysis showed low levels of measurement error overall but some measurements such as the pelvic measurements were most prone to error.