Disparate phylogeographic patterns of molecular genetic variation in four closely related South American small cat species

Tissue specimens from four species of Neotropical small cats (Oncifelis geo ffroyi, N = 38; O. guigna, N = 6; Leopardus tigrinus, N = 32; Lynchailurus colocolo, N = 22) collected from throughout their distribution were examine d for patterns of DNA sequence variation using three mitochondrial genes, 1 6S rRNA, ATP8, and NADH-5. Patterns between and among O. guigna and O. geof froyi individuals were assessed further from size variation at 20 microsate llite loci. Phylogenetic analyses using mitochondrial DNA sequences reveale d monophyletic clustering of the four species, plus evidence of natural hyb ridization between L. tigrinus and L. colocolo in areas of range overlap an d discrete population subdivisions reflecting geographical isolation. Sever al commonly accepted subspecies partitions were affirmed for L. colocolo, b ut not for O. geoffroyi. The lack of geographical substructure in O. geoffr oyi was recapitulated with the microsatellite data, as was the monophyletic clustering of O. guigna and O. geoffroyi individuals. L. tigrinus forms tw o phylogeographic clusters which correspond to L.t. oncilla (from Costa Ric a) and L.t. guttula (from Brazil) and which have mitochondrial DNA (mtDNA) genetic distance estimates comparable to interspecific values between other ocelot lineage species. Using feline-specific calibration rates for mitoch ondrial DNA mutation rates, we estimated that extant lineages of O. guigna diverged 0.4 million years ago (Ma), compared with 1.7 Ma for L. colocolo, 2.0 Ma for O. geoffroyi, and 3.7 Ma for L. tigrinus.