Vocal anatomy evolution associated with the acoustic diversity in Bokermannohyla Faivovich, Haddad, Garcia, Frost, Campbell & Wheeller, 2005 (Anura, Hylidae, Cophomantini)

Abstract

Phenotypic evolution of different organisms has been widely studied in light comparative phylogenetic methods, of which allow comparisons between phenotypes under a phylogeny. Anurans show complex behavioral phenotypes, being one of them, important in mechanisms of speciation, the vocal communication, that consists mainly in the emission of stereotyped signals such as the advertisement call. Given this, there are a considerable number of studies attempting to understand the evolution of vocalizations in different anuran groups. However, considering that acoustic signals are produced from anatomical structures (larynx and associated components) of the vocal apparatus when inhaling or exhaling air, the acoustic complexity can be shaped accordingly, resulting in correlated evolutionary responses with respect to sexual or natural selection. Even though, studies encompassing the vocal apparatus characterization are scarce and, consequently, there are no macro evolutionary studies considering the eventual correlation between vocal apparatus and acoustic signals. Moreover, homology delimitation between acoustic units is not as trivial as considered in the literature, which points to the need to evaluate every aspect involved in the vocalization behavior. The model genus - Bokermannohyla - shows a considerable acoustic diversity, highlighting the applicability of the comparative methods in order to understand evolutionary patterns in the genus' vocal communication and the possible underlying mechanisms. Therefore, the present proposal represents the first endeavor to characterize in details the vocal apparatus and corresponding acoustic signals in the genus, so it could be possible to delimit homologies accurately between these characters. From this, make an attempt to detect evolutionary patterns considering the eventual correlation between vocal apparatus and advertisement calls, to evaluate if differences or similarities in the former express evolutionary changes or conservationism in the latter through the phylogenetic structure of the genus.