Ancient DNA typing shows that a Bronze Age mummy is a composite of different skeletons

Abstract

Excavations at Cladh Hallan, a Bronze Age-Iron Age settlement on South Uist in the Outer Hebrides off the west coast of Scotland, revealed the skeletons of two adults, a sub-adult and a child buried beneath the foundations of three roundhouses. Osteological and isotopic evidence has shown that the male adult skeleton is a composite made up of parts of at least three different individuals. To test the hypothesis that the female skeleton was also a composite we examined ancient DNA from four of its components: the skull, mandible, right humerus and right femur. Seven polymerase chain reactions (PCRs) were attempted, these covering positions 15,996–16,420, 16–132 and 232–368 of the mitochondrial DNA hypervariable I and II regions. Three PCRs were successful for each sample and a total of 55 sequences were obtained from the cloned products. After exclusion of possible contaminating sequences, the remaining 34 were compared. It was concluded that the mandible, humerus and femur come from different individuals. Insufficient data were obtained to draw conclusions regarding the origin of the skull. The presence of two composite skeletons at Cladh Hallan indicates that the merging of identities may have been a deliberate act, perhaps designed to amalgamate different ancestries into a single lineage.