Codweb: Whole-genome sequencing uncovers extensive reticulations fueling adaptation among Atlantic, Arctic, and Pacific gadids

• Published in: Science Advances
• Main Authors: Árnason, Einar, Halldórsdóttir, Katrín
• Other Authors: Líf- og umhverfisvísindadeild (HÍ), Faculty of Life and Environmental Sciences (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 2019
• Subjects: Gadidae; Pacific cod; Walleye pollock; Atlantic cod; Þorskur; Ufsi; Þorskfiskar; Erfðarannsóknir; Arctic; Pacific; Svala; Atlantic Arctic; atlantic cod; Atlantic-Arctic; Iceland; Pacific Arctic
• Online Access: https://hdl.handle.net/20.500.11815/2104; https://doi.org/10.1126/sciadv.aat8788

Publisher's version (útgefin grein) Introgressive hybridization creates networks of genetic relationships across species. Among marine fish of the Gadidae family, Pacific cod and walleye pollock are separate invasions of an Atlantic cod ancestor into the Pacific. Cods are ecological success stories, and their ecologies allow them to support the largest fisheries of the world. The enigmatic walleye pollock differs morphologically, behaviorally, and ecologically from its relatives, representing a niche shift. Here, we apply whole-genome sequencing to Pacific, Arctic, and Atlantic gadids and reveal extensive introgression among them with the ABBA-BABA test and pseudolikelihood phylogenetic network analysis. We propose that walleye pollock resulted from extensive adaptive introgression or homoploid hybrid speciation. The path of evolution of these taxa is more web than a tree. Their ability to invade and expand into new habitats and become ecologically successful may depend on genes acquired through adaptive introgression or hybrid speciation. This work was supported by a grant from the Svala Árnadóttir private fund, by a grant from the University of Iceland Research Fund, by institutional funds from R.C. Lewontin, and by a Grant of Excellence from the Icelandic Science Foundation (no. 185151-051). A Peer Reviewed