Abstract
Recent advances in genetic and genomic analysis have greatly improved our understanding of spatial population structure in marine species. However, studies addressing phylogeographic patterns at oceanic spatial scales remain rare. In Atlantic cod (Gadus morhua), existing range‐wide examinations suggest significant transatlantic divergence, although the fine‐scale contemporary distribution of populations and potential for secondary contact are largely unresolved. Here, we explore transatlantic phylogeography in Atlantic cod using a data‐synthesis approach, integrating multiple genome‐wide single‐nucleotide polymorphism (SNP) datasets representative of different regions to create a single range‐wide dataset containing 1,494 individuals from 54 locations and genotyped at 796 common loci. Our analysis highlights significant transatlantic divergence and supports the hypothesis of westward post‐glacial colonization of Greenland from the East Atlantic. Accordingly, our analysis suggests the presence of transatlantic secondary contact off eastern North America and supports existing perspectives on the phylogeographic history of Atlantic cod with an unprecedented combination of genetic and geographic resolution. Moreover, we demonstrate the utility of integrating distinct SNP databases of high comparability.
Highlights
The contemporary distribution of marine species has been shaped by both current and historical patterns in ocean climate and habitat availability (Kettle, Morales‐Muñiz, Roselló‐Izquierdo, Heinrich, & Vøllestad, 2011; Perry, Low, Ellis, & Reynolds, 2005)
During the LGM, one of the Pleistocene’s most severe climatic events, Atlantic cod populations are thought to have retreated into refugia in the East and West Atlantic, and a subsequent westward recolonization of Greenland occurred from the East (Bigg et al, 2008)
The LGM was a crucial event in the phylogeographic history of North Atlantic marine species, as indicated by the observed strong phylo‐ genetic signals
Summary
The contemporary distribution of marine species has been shaped by both current and historical patterns in ocean climate and habitat availability (Kettle, Morales‐Muñiz, Roselló‐Izquierdo, Heinrich, & Vøllestad, 2011; Perry, Low, Ellis, & Reynolds, 2005). Genetic diver‐ gence across ocean basins has been reported in many marine species consistent with the isolation of populations during the Pleistocene (Hewitt, 2003; Maggs et al, 2008), when periods of climatic cooling and glacial advance acted to segregate marine populations into gla‐ cial refugia (Provan & Bennett, 2008). Many shelf sea species persisted in glacial refugia mostly at more southerly latitudes in the East and West Atlantic, before expand‐ ing north during glacial retreat (Hewitt, 2003; Maggs et al, 2008; Provan & Bennett, 2008). As a result of human‐induced climate change, contemporary distributions of marine species are anticipated to shift dramatically once again, with profound ecological and economic consequences (Stanley et al, 2018; Wisz et al, 2015). The analysis of climatically induced changes in past distributions can provide valuable insights into predicted fu‐ ture responses (Beaugrand, Edwards, Raybaud, Goberville, & Kirby, 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
