Is the parana river a geographic barrier that promotes forest bird speciation?

LAVINIA, P; GARCIA, N. ; TUBARO, PABLO L.; LIJTMAER, DARIO A.; ADRIAN S. DI GIACOMO; CABANNE, G. S.; KOPUCHIAN, CECILIA; CAMPAGNA, LEONARDO

Puerto Iguazú

Congreso; Ornithological Congress of the Americas; 2017

Aves Argentinas

The riverine barriers hypothesis establishes that large rivers represent geographic barriers to gene flow for different organisms, leading to differentiation that could result in the origin of new species. Initially, this hypothesis was enunciated in the context of the Amazon River basin; an area which includes the largest rivers in the Neotropics. In this project, we asses if the Paraná River in the Del Plata basin, the second in importance in South-America, could be acting as barrier for east-west dispersion and gene flow forforest bird species. We have analyzed seven species that have described subspecies based on morphological differences between populations on either side of the Paraná River. We used a genomic approach (double digest RAD-Seq) to assess the genetic divergence between populations distributed on both sides of the river. We found clear genetic differentiation concordant with the current course of the Paraná River only in one species (Thamnophilus caerulescens). We discuss the possible influence of the paleo-river in another five species (Cyclarhis gujanensis, Cyanocompsa brissonii, Colaptes melanochloros, Thraupis sayaca and Lepidocolaptes angustirostris) that showed population structure with an East/West split not concordant with the current Paraná River location. We also found weak population structure in Coryphospingus cucullatus, with no association with the Paraná River. Finally, we analyzed these results taking into account the divergence time in each case in the context of the geologic andpaleo-ecologic history of the region; and considering the biology, ecology and behavioral features of each species.