Evidence for rangewide panmixia despite multiple barriers to dispersal in a marine mussel

Abstract

Oceanographic features shape the distributional and genetic patterns of marine species by interrupting or promoting connections among populations. Although general patterns commonly arise, distributional ranges and genetic structure are species-specific and do not always comply with the expected trends. By applying a multimarker genetic approach combined with Lagrangian particle simulations (LPS) we tested the hypothesis that oceanographic features along northeastern Atlantic and Mediterranean shores influence dispersal potential and genetic structure of the intertidal mussel Perna perna. Additionally, by performing environmental niche modelling we assessed the potential and realized niche of P. perna along its entire native distributional range and the environmental factors that best explain its realized distribution. Perna perna showed evidence of panmixia across >4,000 km despite several oceanographic breaking points detected by LPS. This is probably the result of a combination of life history traits, continuous habitat availability and stepping-stone dynamics. Moreover, the niche modelling framework depicted minimum sea surface temperatures (SST) as the major factor shaping P. perna distributional range limits along its native areas. Forthcoming warming SST is expected to further change these limits and allow the species to expand its range polewards though this may be accompanied by retreat from warmer areas.

Past climate changes and strong oceanographic barriers structured low‐latitude genetic relics for the golden kelp Laminaria ochroleuca

“…The paradigm of range‐shifting effects of past climate events might not be sufficient to explain the present patterns of diversity, as it may be changed by widespread contemporary dispersal (Silva, Horne, & Castilho, ) or local habitat conditions (Assis et al., ; Lourenço et al., ). For marine organisms, ocean currents influence relative isolation and connectivity of populations (e.g., Coleman, ; Buonomo et al., ; Lourenço et al., ; Pereyra et al. ), keeping or diluting the signatures left by past climate changes (Lourenço et al., ).…”

“…For marine organisms, ocean currents influence relative isolation and connectivity of populations (e.g., Coleman, ; Buonomo et al., ; Lourenço et al., ; Pereyra et al. ), keeping or diluting the signatures left by past climate changes (Lourenço et al., ). Dispersal predictions are increasingly compared with genetic estimates, but not along species ranges (e.g., Alberto et al., ; Billot, Engel, Rousvoal, Kloareg, & Valero, ; Buonomo et al., ; Coleman, ).…”

“…Dispersal predictions are increasingly compared with genetic estimates, but not along species ranges (e.g., Alberto et al., ; Billot, Engel, Rousvoal, Kloareg, & Valero, ; Buonomo et al., ; Coleman, ). Species with restricted dispersal generally hold fine‐scale genetic differentiation (e.g., seaweeds: Assis et al., ; Neiva, Pearson, Valero, & Serrão, ; Robuchon, Le Gall, Mauger, & Valero, ), while those with larger dispersal probabilities (having larval stages) tend to have variable or little phylogeographic structure (e.g., mussels: Lourenço et al., ; pelagic fish: Silva et al., ; benthic fish: Klein et al., ). In benthic marine organisms, depth range shifts, the equivalent to terrestrial altitudinal shifts, may further permit long‐term persistence of ancient gene pools.…”

“…The paradigm of range-shifting effects of past climate events might not be sufficient to explain the present patterns of diversity, as it may be changed by widespread contemporary dispersal (Silva, Horne, & Castilho, 2014) or local habitat conditions Lourenço et al, 2016). For marine organisms, ocean currents influence relative isolation and connectivity of populations (e.g., Coleman, 2013;Buonomo et al, 2016;Lourenço et al, 2017;Pereyra et al 2013), keeping or diluting the signatures left by past climate changes (Lourenço et al, 2017). Dispersal predictions are increasingly compared with genetic estimates, but not along species ranges (e.g., Alberto et al, 2011;Billot, Engel, Rousvoal, Kloareg, & Valero, 2003;Buonomo et al, 2016;Coleman, 2013).…”

Resolving spatial complexities of hybridization in the context of the gray zone of speciation in North American ratsnakes (Pantherophis obsoletuscomplex)

“…Even at the same barrier within related groups of organisms, the timing of divergence and degree of gene flow can be species specific and dependent on when they encountered the barrier (Riddle 2016;Myers et al 2019b). Alternatively, generalist species not as constrained to specific habitats may not show a correlation between genetic variation and landscape features (Joseph and Wilke 2007;Makowsky et al 2009;Lourenço et al 2017).…”