title: Contesting the presence of wheat in the British Isles 8,000 years ago by assessing ancient DNA authenticity from low-coverage data.
abstract: Contamination with exogenous DNA is a constant hazard to ancient DNA studies, since their validity greatly depend on the ancient origin of the retrieved sequences. Since contamination occurs sporadically, it is fundamental to show positive evidence for the authenticity of ancient DNA sequences even when preventive measures to avoid contamination are implemented. Recently the presence of wheat in the United Kingdom 8000 years before the present has been reported based on an analysis of sedimentary ancient DNA (Smith et al. 2015). Smith et al. did not present any positive evidence for the authenticity of their results due to the small number of sequencing reads that were confidently assigned to wheat. We developed a computational method that compares postmortem damage patterns of a test dataset with bona fide ancient and modern DNA. We applied this test to the putative wheat DNA and find that these reads are most likely not of ancient origin.
authors.affiliation: Research Group for Ancient Genomics and Evolution, Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany.
authors.forename: Clemens L
authors.initials: CL
authors.lastname: Weiß
authors.affiliation: Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0002-7076-8731
authors.initials: M
authors.lastname: Dannemann
authors.affiliation: Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
authors.forename: Kay
authors.initials: K
authors.lastname: Prüfer
authors.affiliation: Research Group for Ancient Genomics and Evolution, Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany.
authors.forename: Hernán A
authors.initials: HA
authors.lastname: Burbano
mesh_terms: D018744:DNA, Plant / Q000235:genetics* / Q000302:isolation & purification*; D005580:Fossils; D008967:Molecular Biology / Q000379:methods; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics* / Q000254:growth & development*; D006113:United Kingdom
chemical_list: D018744:DNA, Plant
keywords: Metagenomics; ancient DNA; authenticity; evolutionary biology; genomics; plant biology