The Black and Caspian Seas have experienced alternating periods of isolation and interconnection over many Milankovitch climate oscillations and most recently became separated when the meltwater overflow from the Caspian Sea ceased at the end of the last glaciation. Climate-induced habitat changes have indisputably had profound impacts on distribution and demography of aquatic species, yet uncertainties remain about the relative roles of isolation and dispersal in the response of species shared between the Black and Caspian Sea basins. We examined these issues using phylogeographical analysis of an anadromous cyprinid fish Rutilus frisii. Bayesian coalescence analyses of sequence variation at two nuclear and one mitochondrial genes suggest that the Black and Caspian Seas supported separate populations of R. frisii during the last glaciation. Parameter estimates from the fitted isolation-with-migration model showed that their separation was not complete, however, and that the two populations continued to exchange genes in both directions. These analyses also suggested that majority of migrations occurred during the Pleistocene, showing that the variation shared between the Black and Caspian Seas is the result of ancient dispersal along the temporary natural connections between the basins, rather than of incomplete lineage sorting or recent human-mediated dispersal. Gene flow between the refugial populations was therefore an important source of genetic variation, and we suggest that it facilitated the evolutionary response of the populations to changing climate.

Department of Vertebrate Evolutionary Biology and Genetics Laboratory of Fish Genetics Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic CZ 27721 Libéchov Czech Republic

References provided by Crossref.org

A dynamic history of admixture from Mediterranean and Carpathian glacial refugia drives genomic diversity in the bank vole

Back from the brink: the Holocene history of the Carpathian barbel Barbus carpathicus

Human-aided dispersal has altered but not erased the phylogeography of the tench

See more in PubMed

GENBANK
EU285029, EU285030, EU285031, EU285032, EU285033, EU285034, EU285035, EU285036, EU285037, EU285038, EU285039, EU285040, EU285041, EU285042, EU285043, EU285044, EU285045, EU285046, EU285047, EU285048, EU285049, EU285050, EU285051, EU285052, EU285053, EU285054, EU285055, EU285056