Phylogenetic analyses of DNA sequences reveal a vastly underestimated radiation of Amazonian Salamanders (Plethodontidae: bolitoglossa), with key implications to the study of plethodontid diversification

Abstract

The recognition of biodiversity is one of the most compelling challenges in biology, because more we know about the things that surrounding more understand about the processes and change our perspective to see the things. Plethodontid salamanders suffer a complex speciation process which radiate mainly in North America and Mesoamerica resulting in 66% of Caudata diversity. For other hand, South American salamanders harbor a little diversity (37 species) which most of them belong to Bolitoglassa, this pattern result by the latter colonization that not allowed to have sufficient time to speciate. However, recent works suggest that South American salamanders diversity are been underestimate, reflecting our knowledge and ignorance of this group. In this context, we study the Amazonian salamanders providing a phylogenetic explanation of molecular variation of different Bolitoglossa samples in the context of radiation of the genus, and evaluate the implications of our results to our understanding of Bolitoglossa species diversity in the Amazon, as well as its diversification and biogeography. Was obtained data from the eight of the nine species distributed in Amazon from near or type locality, generating new sequences from 177 terminals from most amazon populations between Venezuela and Bolivia, and including those previously published. Our sampling represents one of the most complete for the genera (~ 75 % of diversity) to evaluated the phylogenetic relationship of Bolitoglossa. The data was analyzed using Maximum Likelihood with similarity alignment incorporating the indels as binary characters, and Parsimony with dynamic homology and indels as fifth state. The topologies show discordances in the species relationships, but support that the Amazonian salamander diversity are vastly underestimated. Also with the incorporation of species delimitation methods suggest an increase of 300 – 400 % of diversity. The ancestral area reconstruction in both topologies show a unique colonization from Andes to Amazon VII and was the responsible of the radiation of South American salamanders. Our results changes the current paradigm about the diversity and diversification of neotropical salamanders.