Phenotyping the ancient world: The physical appearance and ancestry of very degraded samples from a chalcolithic human remains

The genetic study of ancient samples is quite similar to a forensic critical sample analysis with an unknown origin. In both cases, it is not possible to compare the genetic information with other family members, being almost impossible to achieve the individual identification. The prediction of externally visible characteristics (EVC) of an individual and his biogeographical ancestry could definitely be a crucial contribution in a forensic casework. Therefore, the aim of the present work was the molecular study of a very critical sample, a Chalcolithic (3480 +/- 30 YBP) individual found in Asturias, Northern Iberia, intending to discover a possible geographical ancestry for these remains, and the inference of a group of feasible EVCs (hair, skin and iris pigmentation). Given that ancient DNA is often highly damaged, two different methodologies were used in order to determine the biogeographical ancestry of the individual: mitochondrial DNA (HVR-I and -II) and Single Nucleotide Polymorphisms typing. Despite the antiquity of the samples, the genetic information recovered proved of great value. We could determine that the individual had a European ancestry, blond hair, light skin color and brown eyes. Such outcome reveals that it is possible to obtain not only biogeographical but also phenotypic information from a very critical sample.