Speciation with introgression: Phylogeography and systematics of the Ameerega petersi group (Dendrobatidae).

The Tropical Andes contains exceptionally high diversity, much of it arising within the Quaternary period. The complex geology of the Andes and paleoclimate fluctuations within the Quaternary suggest complex speciation scenarios. This, in turn, has contributed to idiosyncratic speciation modes among shallowly diverged Amazonian taxa. Many relationships among these taxa remain poorly resolved. Here we use a sequence capture approach, ultraconserved elements (UCEs), to address the phylogenetic relationships among three recently diverged Peruvian Ameerega poison frog species (A. cainarachi, A. petersi, and A. smaragdina; family Dendrobatidae) and explore a possible mode of speciation in this group. We assess concordance among concatenated phylogenetic tree inference, gene-tree based species tree inference, SNP-based species tree inference, and Bayes factor lineage delimitation to resolve species boundaries. We complement these analyses with assessments of call divergence to address the presence of a prezygotic reproductive barrier. Additionally, we further explore the phylogeographic history of these species of Ameerega with demographic inference, considering evidence for admixture and population expansions. Our results support the synonymy of A. smaragdina as a junior synonym of A. petersi and we find that speciation in this group is characterized by admixture and signatures of a population bottleneck followed by expansion. We invoke the disturbance-vicariance hypothesis to explain the observed patterns and call for more, detailed investigations of in-situ speciation in the Tropical Andes.

Systematics of the Ameerega rubriventris complex (Anura: Dendrobatidae) with descriptions of two new cryptic species from the East-Andean versant of Peru.

We describe two new species of poison frog from central and southern Peru that have been referred to as Ameerega picta, A. hahneli, or A. altamazonica throughout the past thirty years. Our phylogenies generated with genomic data provide strong support that the two new species are successive sisters to two described taxa, A. rubriventris and A. altamazonica, and collectively comprise the Ameerega rubriventris complex. The first new taxon, Ameerega panguana sp. nov., can be distinguished from all other Ameerega by its combination of a unique white venter and an advertisement call of 1-2 notes per second. The second new taxon, Ameerega imasmari sp. nov., is the only cryptically colored Ameerega species that is disttributed across the Fitzcarrald Arch in Southern Peru which possesses a 'peep' advertisement call consisting of 3-4 notes per second and a dominant frequency of 4.3-4.5 kHz. Within the Ameerega rubriventris complex, we observed differences between species in their ventral coloration, tympanum diameter, and call, which suggest that these taxa are reproductively isolated from each other.