MOLECULAR ZOOGEOGRAPHY OF FRESHWATER FISHES IN THE SOUTHEASTERN UNITED STATES

摘要: Restriction fragment length polymorphisms in mitochondrial DNA (mtDNA) were used to reconstruct evolutionary relationships of conspecific populations four species freshwater fish—Amia calva, Lepomis punctatus, L. gulosus, and microlophus. A suite 14-17 endonucleases was employed assay mtDNAs from 305 specimens collected 14 river drainages extending South Carolina Louisiana. Extensive mtDNA polymorphism observed within each assayed species. In both phenograms Wagner parsimony networks, clones that closely related genetically usually geographically contiguous. Within species, major phylogenetic breaks also distinguished separate geographic regions, demonstrating dispersal gene flow have not been sufficient override influences on population subdivision.—Importantly, there strong patterns congruence across the placements breaks. Three boundary regions characterized by concentrations discontinuities, these zones agree well with previously described zoogeographic boundaries identified a different kind data base—distributional limits species—suggesting common set historical factors may account for phenomena. Repeated episodes eustatic sea level change along relatively static continental morphology are likely causes several drainage isolation coalescence, discussed relation genetic data.—Overall, results exemplify positive role intraspecific analyses play reconstruction. They point out potential inadequacies any interpretations structure fail consider history shaping structure.