bioRxiv preprint doi: https://doi.org/10.1101/2021.05.07.443120; this version posted May 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Standardized nuclear markers advance metazoan taxonomy Lars Dietz1, Jonas Eberle1,2, Christoph Mayer1, Sandra Kukowka1, Claudia Bohacz1, Hannes Baur3, Marianne Espeland1, Bernhard A. Huber1, Carl Hutter4, Ximo Mengual1, Ralph S. Peters1, Miguel Vences5, Thomas Wesener1, Keith Willmott6, Bernhard Misof1,7, Oliver Niehuis8, Dirk Ahrens*1 1Zoological Research Museum Alexander Koenig, Bonn, Germany 2Paris-Lodron-University, Salzburg, Austria 3Naturhistorisches Museum Bern/ Institute of Ecology and Evolution, University of Bern, Switzerland 4Museum of Natural Sciences and Department of Biological Sciences, Louisiana State University, Baton Rouge, USA 5Technische Universität Braunschweig, Germany 6Florida Museum of Natural History, University of Florida, Gainesville, USA 7Rheinische Friedrich-Wilhelms-Universität Bonn, Germany 8Abt. Evolutionsbiologie und Ökologie, Institut für Biologie I, Albert-Ludwigs-Universität Freiburg, Germany *Corresponding author. Email:
[email protected] Abstract Species are the fundamental units of life and their recognition is essential for science and society. DNA barcoding, the use of a single and often mitochondrial gene, has been increasingly employed as a universal approach for the identification of animal species. However, this approach faces several challenges. Here, we demonstrate with empirical data from a number of metazoan animal lineages that multiple nuclear-encoded markers, so called universal single-copy orthologs (USCOs) performs much better than the single barcode gene to discriminate closely related species. Overcoming the general shortcomings of mitochondrial DNA barcodes, USCOs also accurately assign samples to higher taxonomic levels.