Efeitos do ambiente na estruturação genética e fenotípica no complexo de espécies de anuros boana calcarata-fasciata na bacia amazônica

Abstract

The Amazon basin harbors a megadiversity of species and environments, representing a relevant natural laboratory to investigate the effects of microevolutionary processes and environmental variation on species diversification. The use of integrative approaches combining phenotypic and genetic variation to examine the divergence between lineages has increased our knowledge on the mechanisms causing species diversification in this mega diverse region. Here, we investigated the relative influence of environmental variation and geographic distance on the genetic and morphological differentiation of the Amazonian treefrog species complex Boana calcarata-fasciata (Anura, Hylidae). We analyzed the genetic variation of the 16S mtDNA gene from 413 individuals collected in flooded and non-flooded forest localities in Amazonia, 167 of which were newly generated samples from Brazil. We then estimated phylogenetic relationships and conducted species delimitation analyses on the complete molecular dataset to define the main intraspecific lineages to focus our phenotypic and environmental approach. We collected morphological data for the head shape and size of a sub-sample of 66 individuals using 3D models built from high-resolution photography. Using comparative phylogenetic methods, we tested for phylogenetic signal, evolutionary model that better explain the mode and time of the morphological diversification, and the influence of environmental variables on the morphological variation. We also verified the relationships among environmental, geographical, and genetic distances with morphological and genetic variation using dbRDA and partial Mantel tests. We found a high cryptic diversity, with a correspondent three-fold increase in the number of evolutionary units within the species complex, unveiling the phylogenetic relationships and taxonomic position of the newly generated Brazilian samples. We found evidence of subtle morphological differences in body size and head shape that diverged in a different mode and time compared to the genetic structuration. Furthermore, we showed that diverse and dissimilar factors differentially influence the morphological and genetic variation within the species complex, but historical and current environmental conditions, mainly vegetation cover, precipitation, and velocity of climate change had essential roles in morphological diversification, likely suggesting a case of parallel morphological evolution.