title: Historical introgression drives pervasive mitochondrial admixture between two species of pelagic sharks.
abstract: We use a genomic sampling of both nuclear and mitochondrial DNA markers to examine a pattern of genetic admixture between Carcharhinus galapagensis (Galapagos sharks) and Carcharhinus obscurus (dusky sharks), two well-known and closely related sharks that have been recognized as valid species for more than 100years. We describe widespread mitochondrial-nuclear discordance in which these species are readily distinguishable based on 2152 nuclear single nucleotide polymorphisms from 910 independent autosomal regions, but show pervasive mitochondrial admixture. The species are superficially morphologically cryptic as adults but show marked differences in internal anatomy, as well as niche separation. There was no indication of ongoing hybridization between the species. We conclude that the observed mitochondrial-nuclear discordance is likely due to historical mitochondrial introgression following a range expansion.
authors.affiliation: Department of Biology, College of Charleston, Charleston SC, USA. Electronic address: corrigansl@cofc.edu.
authors.forename: Shannon
authors.initials: S
authors.lastname: Corrigan
authors.affiliation: Institut de Systématique, Évolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, Ecole Pratique des Hautes Etudes, Paris, France; EPHE, PSL Research University, Paris, France; Department of Zoology, University of Cambridge, Cambridge, UK(1).
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Maisano Delser
authors.affiliation: Department of Biology, University of Massachusetts Dartmouth, Dartmouth MA, USA.
authors.forename: Corey
authors.initials: C
authors.lastname: Eddy
authors.affiliation: Marine Ecosystems, Science and Policy, Department of Conservation, Auckland, New Zealand.
authors.forename: Clinton
authors.initials: C
authors.lastname: Duffy
authors.affiliation: Department of Biology, College of Charleston, Charleston SC, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Biology, College of Charleston, Charleston SC, USA; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai, China(1).
authors.forename: Chenhong
authors.initials: C
authors.lastname: Li
authors.affiliation: Laboratory of Molecular Evolution, Center for Bioinformatics and Computational Biology, University of Maryland, College Park MD, USA; National Biodefense Analysis and Countermeasures Center, Fort Detrick, MD, USA(1).
authors.forename: Adam L
authors.initials: AL
authors.lastname: Bazinet
authors.affiliation: Institut de Systématique, Évolution, Biodiversité, ISYEB - UMR 7205 - CNRS, MNHN, UPMC, EPHE, Ecole Pratique des Hautes Etudes, Paris, France; EPHE, PSL Research University, Paris, France.
authors.forename: Stefano
authors.initials: S
authors.lastname: Mona
authors.affiliation: Department of Biology, College of Charleston, Charleston SC, USA; College of Graduate Studies, Medical University of South Carolina, Charleston SC, USA.
authors.forename: Gavin J P
authors.initials: GJP
authors.lastname: Naylor
mesh_terms: D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D005788:Gene Pool; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D008928:Mitochondria / Q000235:genetics*; D010802:Phylogeny; D012754:Sharks / Q000235:genetics*; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial
keywords: Dusky shark; Galapagos shark; Gene capture; Hybridization; Mitonuclear discordance; Population genomics