Kinship analysis and allelic dropout: a forensic approach on an archaeological case

BACKGROUND

This study relies on the discovery of two pit burials (LTA and LTB) of the Bronze Age Cogotas I archaeological culture (circa 3600-2950 BP) in Spain. LTA was a single burial and LTB contained three skeletal remains of two adults and a newborn or foetus at term.

AIM

The central question posed by this find was whether the LTB tomb constituted a traditional nuclear family (father, mother and son or daughter).

METHODS

Ancient and forensic DNA protocols were employed to obtain reliable results. Autosomal, X-STR markers and mitochondrial DNA were amplified. Subsequently, different kinship probabilities were estimated by means of LR values calculated using the Familias 3 software. Furthermore, an allelic dropout sensitivity test was developed in order to evaluate the influence of allelic dropout phenomena on the results.

RESULTS

It was possible to determine the molecular sex of all individuals and to establish a maternal relationship between the perinatal individual and one of the adults.

CONCLUSION

The remains in the LTB tomb were not a traditional nuclear family (father, mother and son/daughter) and it was probably a tomb where two women, one of them pregnant, were buried.