Molecular analyzes of the tocantins-araguaia interfluve’s birds in the phylogeographic context of the Amazon

The phylogeography has greatly helped in the definition of interspecific limits and times of divergence of taxa in Amazonia, promoting a systematic and taxonomic revision of different groups of organisms, especially birds. However, phylogeographic surveys did not focus on understanding the role of Tocantins-Araguaia Interfluve (TAI) in Amazonian birds’ diversification processes. Hence, we present an unpublished phylogeographic analysis, through the molecular mitochondrial marker ND2 (1045 bp), demonstrating the relationship of TAI with Amazonian interfluvials, in particular the Xingu (CEX) and Belém (CEB) Endemism Centers. Bayesian analyzes and haplotype networks were performed through the set of almost 450 samples from 24 taxa distributed in 17 species for all Amazonian interfluvials. Phylogenetic trees and haplotype networks indicated four distinct phylogeographic patterns: i) No population structure within CEX, ITA and CEB, like Mymotherula axilaris and Dendrocincla fuliginosa, ii) ITA as a contact zone with strong indicative of hybridization events or even introgression between allopatric populations to CEX and CEB, like the complexes Pyrrhura anerythra / coerulescens, Campylopterus largipennis, Dendrocolaptes medius / retentus; iii) the Tocantins River as a phylogeographic barrier isolating CEB populations from ITA/CEX, as for example Formicarius colma, Granatellus pelzelni and Schiffornis turdina; and iv) independent populations between CEX and CEB structured parapatricly within the ITA, like Willisornis vidua. The contact zone condition combined with the presence of phylogeographic breaks and occurrence of population substructures within the ITA demonstrated biogeographic characteristics that define ITA as an not yet known area of biogeographic suture in the Eastern Amazon.