Comment on "Whole-Genome Shotgun Sequencing of Mitochondria from Ancient Hair Shafts"

Gilbert et al. (Reports, 28 September 2007, p. 1927) reported that "hair shafts surpass comparably stored bone as an aDNA source [...] in regard to preservation and concentration of mtDNA." When experimental parameters are carefully controlled for, including adequate sampling, quantitative polymerase chain reaction analysis, and modeling the decay of DNA, the general importance of this claim is not supported.