Ancient DNA: The quest for the best

Abstract

It is the dream of all researchers working with ancient DNA to identify prior to DNA extraction from bone the specimens or specific zones within them that contain the highest proportion of endogenous DNA. As it impacts the sacrifice of precious ancient specimens and the financial support needed for the analyses, the question is of high importance to the scientific field of palaeogenomics. The “Holy Grail” of palaeogenomics was reached when Cristina Gamba et al. (2014) discovered that it was in the petrosal part of the temporal bone, the densest part of the mammalian skeleton, where DNA is exceptionally well preserved. As a consequence, osteological collections experienced a rush from palaeogenomicists to “harvest” these precious bone parts. In this issue of Molecular Ecology Resources, Alberti et al. (2018) describe the discovery of another promising source of relatively well-preserved endogenous DNA, that they had identified through computed tomography (CT scans), the outermost layer of cortical bone. These bones being larger and more abundant than petrous bones, this discovery increases markedly the source material for high-quality palaeogenomic studies and releases the pressure on osteological collections.