Competitive mapping allows for the identification and exclusion of human DNA contamination in ancient faunal genomic datasets
Tatiana R. Feuerborn, Eleftheria Palkopoulou, Tom van der Valk, Johanna von Seth, Arielle R. Munters, Patrícia Pečnerová, Marianne Dehasque, Irène Ureña, Erik Ersmark, Vendela Kempe Lagerholm, Maja Krzewińska, Ricardo Varela, Anders Götherström, Love Dalén, David Díez‐del‐Molino
Abstract
BACKGROUND: After over a decade of developments in field collection, laboratory methods and advances in high-throughput sequencing, contamination remains a key issue in ancient DNA research. Currently, human and microbial contaminant DNA still impose challenges on cost-effective sequencing and accurate interpretation of ancient DNA data. RESULTS: Here we investigate whether human contaminating DNA can be found in ancient faunal sequencing datasets. We identify variable levels of human contamination, which persists even after the sequence reads have been mapped to the faunal reference genomes. This contamination has the potential to affect a range of downstream analyses. CONCLUSIONS: We propose a fast and simple method, based on competitive mapping, which allows identifying and removing human contamination from ancient faunal DNA datasets with limited losses of true ancient data. This method could represent an important tool for the ancient DNA field.