Using the shape of the basicranial portion of the temporal bone to distinguish between relatively closely-related human populations

Abstract

Variation in cranial morphology is routinely used in archaeology to identify population affinity in human skeletal remains. The shape of the external basicranial portion of the temporal bone, in particular, has been found to have one of the strongest phylogenetic signals in the crania, and so it can be effectively used to distinguish between populations on a large, often global scale. However, its applicability to the analysis of relatively closely-related groups remains largely unexplored. The retention of population signatures in the shape of this portion of the temporal bone is particularly useful for archaeology, as the fragility of the cranium makes analysis of its shape in entirety often difficult. If the shape of the temporal bone can identify differences between relatively closely-related populations with a similar accuracy as for more distantly-related populations, this would significantly aid analyses of population history on a local scale. To test this, we initiated a study that used three-dimensional geometric morphometrics to investigate the shape variation of the temporal bone of two British archaeological populations that were separated both temporally and geographically. The results of a MANOVA found statistically significant shape differences between the two populations and a DFA found that the shape of the temporal bone can correctly classify 84.7% of individuals into their respective population. Therefore, the findings of this study suggest that the shape of the temporal bone can accurately identify differences between two relatively closely-related populations. Future research should focus on examining larger samples from a greater number of populations to determine whether this pattern is widespread.