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Complex niche divergence underlies lineage diversification in Oophaga poison frogs
Author(s) -
PossoTerranova Andrés,
Andrés José A.
Publication year - 2016
Publication title -
journal of biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 158
eISSN - 1365-2699
pISSN - 0305-0270
DOI - 10.1111/jbi.12799
Subject(s) - biology , ecological niche , ecology , lineage (genetic) , niche , phylogenetic tree , clade , range (aeronautics) , vicariance , biogeography , taxon , evolutionary biology , habitat , gene , biochemistry , materials science , composite material
Aim Despite the incredible diversity of lowland tropical rain forests, we still have limited understanding of the drivers of speciation in these ecoregions. Here, we investigated the relative contribution of geographical and environmental factors to the diversification of a Neotropical genus of poison frogs ( Oophaga ). Location Central and South America, including regions from southern Nicaragua to northern Ecuador. Methods We generated gene genealogies ( 12S, 16S, COI , CytB and tRNA ‐val , SIAH 1, H3 and Rag 1) and used species phylogenetic methods ( MDC and * beast ) to generate a robust phylogeny of Oophaga frogs. Then, we combined the resulting phylogenetic hypothesis with detailed geographical data and environmental niche modelling ( ENM ) to test the role of geographical isolation, climatic niche divergence and altitudinal gradients. Results Gene genealogies were discordant and did not show exclusive genealogical patterns; however, species tree resolved the phylogenetic relationship among Oophaga species with strong node support (> 0.9 ML / BPP ). Geographical ranges showed little overlap between distantly related species. However, within the South American and Central American clades, sister taxa showed substantially overlapping ranges. Analyses of ecological disparity ( DTT ) indicated a departure from a neutral (Brownian) model of evolution, and age‐range correlations, predicted niche occupancy profiles, and Seeva analyses showed that different species tend to evolve under different potential climatic niches. Main conclusions Oophaga frogs originated in Central America and reached South America after the closure of the Panama Isthmus. The South‐ and Central‐American clades of this genus have convergently evolved to similar patterns of geographical distribution and niche occupancy. Within clades, sister taxa showed parapatric distributions replacing each other along elevational gradients as predicted by the models of divergence along continuous ecological gradients. Accordingly, we found strong shifts in climatic niches throughout the history of these two clades. However, the largest niche shifts seem to post‐date the final elevation of the Talamanca and northern Andes. Overall, our data suggest that speciation along climatic gradients on a structured landscape has been a major evolutionary force behind the diversification of Oophag a poison frogs.