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The role of dispersal potential on phylogeographic structure, evidenced by the degree of genetic structure and the presence of coincident genetic and biogeographic breaks, was evaluated in a macrogeographic comparative approach along the north-central coast of Chile, across the biogeographic transition zone at 30°S. Using 2,217 partial sequences of the mitochondrial Cytochrome Oxidase I gene of eight benthic invertebrate species along ca. 2,600 km of coast, we contrasted dispersal potential with genetic structure and determined the concordance between genetic divergence between biogeographic regions and the biogeographic transition zone at 30°S. Genetic diversity and differentiation highly differed between species with high and low dispersal potential. Dispersal potential, sometimes together with biogeographic region, was the factor that best explained the genetic structure of the eight species. The three low dispersal species, and one species assigned to the high dispersal category, had a phylogeographic discontinuity coincident with the biogeographic transition zone at 30°S. Furthermore, coalescent analyses based on the isolation-with-migration model validate that the split between biogeographic regions north and south of 30°S has a historic origin. The signatures of the historic break in high dispersers is parsimoniously explained by the homogenizing effects of gene flow that have erased the genetic signatures, if ever existed, in high dispersers. Of the four species with structure across the break, only two had significant albeit very low levels of asymmetric migration across the transition zone. Historic processes have led to the current biogeographic and phylogeographic structure of marine species with limited dispersal along the north-central coast of Chile, with a strong lasting impact in their genetic structure.

The coast of central Chile is characterized by the occurrence of coastal upwelling during the austral spring and summer seasons, which probably has important consequences for the cross‐shelf transport of larval stages of many species. Three cruises were conducted off the locality of El Quisco during upwelling‐favorable wind periods to determine the surface distribution of epineustonic competent larvae of the gastropod Concholepas concholepas during such events. Contrary to the predictions of a traditional model, where neustonic‐type larvae are transported offshore under such conditions, competent larvae of this species were exclusively found in the area between the shore and the upwelling front. Two additional cruises were conducted during calm periods to determine diel variation in the vertical distribution of C. concholepas competent larvae. The absence of competent larvae at the surface during early night hours suggests a reverse vertical migration. Thus, the retention of C. concholepas competent larvae in the upwelled waters could be the result of the interaction between their reverse diel vertical migration and the typical two‐layer upwelling dynamics.

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