Molecular phylogenetics of Doraditos (Aves: Pseudocolopteryx): plumage evolution, cryptic species and moving targets of sexual selection

JORDAN EA; TELLO J; ARETA JI

Congreso; XI Neotropical Ornithological Congress; 2019

Avian plumage evolves under different ?often antagonistic? selective pressures due to a complex interplay between sexual demands and environmental challenges. Elucidating how evolutionary forces have molded plumage and other sexual signals is key to understand phenotypic evolution in birds. Here we built the first species-level phylogenetic analysis of Pseudocolopteryx using mitochondrial (ND2, COI) and nuclear (MYO, ODC) genes to explore the evolutionary processes that fostered intra- and interspecific phenotypic differences. Analyses recovered the monophyly of Pseudocolopteryx (P. sclateri (P. acutipennis (P. dinelliana (P. citreola-P. flaviventris)))), which was sister to Serpophaga nigricans. Ancestral state reconstruction supported a highly dichromatic ancestor of Pseudocolopteryx followed by a general reduction of plumage dichromatism, while bill coloration was dichromatic in all five species. Dichromatism was inversely related to acoustic complexity, possibly due to an evolutionary tradeoff between two competing signal modalities (i.e. visual and auditory), where sexual selection pressures that promoted chromatic conspicuousness in males changed their main target from plumage to acoustic characters during the evolution of Pseudocolopteryx. Modified primary feathers were ancestral in males, and were present in species that perform aerial displays with putative mechanical sounds (P. sclateri, P. acutipennis, P. dinelliana), but absent in those that do not (P. citreola, P. flaviventris). The two cryptic species (P. citreola and P. flaviventris) are sibling species that diverged ca. 60kYA, showing that minimal genetic changes can lead to dramatic vocal differences without obvious morphological changes, and add evidence showing that vocal signals may frequently be more important than visual ones in species recognition systems in the Tyrannidae.