Article

Temporal and spatial diversification of Pteroglossus araçaris (AVES: Ramphastidae) in the neotropics: constant rate of diversification does not support an increase in radiation during the Pleistocene.

Department of Biology, Northwestern University, Evanston, IL 60208, USA.
Molecular Phylogenetics and Evolution (Impact Factor: 4.02). 11/2010; 58(1):105-15. DOI: 10.1016/j.ympev.2010.10.016
Source: PubMed

ABSTRACT We use the small-bodied toucan genus Pteroglossus to test hypotheses about diversification in the lowland Neotropics. We sequenced three mitochondrial genes and one nuclear intron from all Pteroglossus species and used these data to reconstruct phylogenetic trees based on maximum parsimony, maximum likelihood, and Bayesian analyses. These phylogenetic trees were used to make inferences regarding both the pattern and timing of diversification for the group. We used the uplift of the Talamanca highlands of Costa Rica and western Panama as a geologic calibration for estimating divergence times on the Pteroglossus tree and compared these results with a standard molecular clock calibration. Then, we used likelihood methods to model the rate of diversification. Based on our analyses, the onset of the Pteroglossus radiation predates the Pleistocene, which has been predicted to have played a pivotal role in diversification in the Amazon rainforest biota. We found a constant rate of diversification in Pteroglossus evolutionary history, and thus no support that events during the Pleistocene caused an increase in diversification. We compare our data to other avian phylogenies to better understand major biogeographic events in the Neotropics. These comparisons support recurring forest connections between the Amazonian and Atlantic forests, and the splitting of cis/trans Andean species after the final uplift of the Andes. At the subspecies level, there is evidence for reciprocal monophyly and groups are often separated by major rivers, demonstrating the important role of rivers in causing or maintaining divergence. Because some of the results presented here conflict with current taxonomy of Pteroglossus, new taxonomic arrangements are suggested.

2 Followers
 · 
153 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The growing knowledge on paleogeography and the recent applications of molecular biology and phylogeography to the study of the Amazonian biota have provided a framework for testing competing hypotheses of biotic diversification in this region. Here, we reconstruct the spatio-temporal context of diversification of a widespread understory polytypic Amazonian bird species (Thamnophilus aethiops) and contrast it with different hypotheses of diversification and the taxonomy currently practiced in the group. Sequences of mtDNA (cytochrome b and ND2) and nuclear (β-fibrinogen introns 5 and 7 and the Z-liked Musk4) genes, adding up to 4,093 bp of 89 individuals covering the Amazonian, Andean, and Atlantic forest populations of T. aethiops were analyzed. Phylogenetic and population genetics analyses revealed ten reciprocally monophyletic and genetically isolated or nearly-isolated lineages in T. aethiops, highlighting several inconsistencies between taxonomy and evolutionary history in this group. Our data suggest that the diversification of T. aethiops started in the Andean highlands, and then proceeded into the Amazonian lowlands probably after the consolidation of the modern Amazonian drainage. The main cladogenetic events in T. aethiops may be related to the formation and structuring of large Amazonian rivers during the Late Miocene - Early Pleistocene, coinciding with the dates proposed for other lineages of Amazonian organisms. Population genetics data do not support climatic fluctuations as a major source of diversification in T. aethiops. Even though not entirely concordant with paleobiogeographic models derived from phylogenies of other vertebrate lineages, our results support a prominent role for rivers as major drivers of diversification in Amazonia, while underscoring that different diversification scenarios are probably related to the distinct evolutionary origins of groups being compared.
    Molecular Phylogenetics and Evolution 10/2014; DOI:10.1016/j.ympev.2014.09.023 · 4.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The genus Xiphorhynchus is a species rich avian group widely distributed in Neotropical forests of Central and South America. Although recent molecular studies have improved our understanding of the spatial patterns of genetic diversity in some species of this genus, most are still poorly known, including their taxonomy. Here, we address the historical diversification and phylogenetic relationships of the X. guttatus / susurrans complex, using data from two mitochondrial (cyt b and ND2) and one nuclear (β-fibint7) genes. Phylogenetic relationships were inferred with both gene trees and a Bayesian-based species tree under a coalescent framework (∗BEAST). With exception of the nuclear β-fibint7 gene that produced an unresolved tree, both mtDNA and the species tree showed a similar topology and were congruent in recovering five main clades with high statistical support. These clades, however, are not fully concordant with traditional delimitation of some X. guttatus subspecies, since X. g. polystictus, X. g. guttatus, and X. connectens are not supported as distinct clades. Interestingly, these three taxa are more closely related to the mostly trans-Andean X. susurrans than the other southern and western Amazonian subspecies of X. guttatus, which constitutes a paraphyletic species. Timing estimates based on the species tree indicated that diversification in X. guttatus occurred between the end of the Pliocene and early Pleistocene, likely associated with the formation of the modern Amazon River and its main southern tributaries (Xingu, Tocantins, and Madeira), in addition to climate-induced changes in the distribution of rainforest biomes. Our study supports with an enlarged dataset a previous proposal for recognizing at least three species level taxa in the X. guttatus / susurrans complex: X. susurrans, X. guttatus, and X. guttatoides. Copyright © 2015 Elsevier Inc. All rights reserved.
    Molecular Phylogenetics and Evolution 02/2015; 85. DOI:10.1016/j.ympev.2015.02.004 · 4.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: AimTo assess geographical and temporal patterns of diversification in Metallura hummingbirds, particularly with respect to topographical barriers and climatic variation between different populations.LocationTropical Andes.Methods We estimated a multilocus phylogeny for all nine species of Metallura and evaluated phylogeographical patterns within Metallura tyrianthina using mitochondrial DNA sequences from across its range (n = 192). We tested mechanisms of diversification using climatic classification of sampling sites, coalescent-based dating, lineages-through-time plots and dispersal–vicariance analysis.ResultsMetallura consists of two main clades: (1) the tree line specialists in the M. aeneocauda superspecies; and (2) a habitat-generalist clade that includes M. tyrianthina and M. iracunda. Metallura phoebe was recovered as sister to the tree line clade in some analyses. In both clades, there was marked genetic structure across topographical barriers and almost no structure between climatically distinct regions in the absence of barriers. The tree line clade exhibited deeper divergences in the Central Andes than elsewhere, and a south-to-north history of diversification, whereas the habitat-generalist clade showed deeper divergences in the Northern Andes and a history of southward expansion. A pure-birth model explained the steady net rate of diversification of Metallura hummingbirds through the Pliocene and the Pleistocene.Main conclusionsIsolation across topographical barriers best explained the genetic structure in M. tyrianthina. The two Metallura clades expanded from opposite ends of the Andes, leading to asynchronous divergence across common topographical barriers. Cycles of expansion followed by isolation may explain the preponderance of idiosyncratic area relationships that are typical of Andean clades. Geoclimatic dynamism during the Pleistocene caused Metallura and other Andean bird clades to undergo radical range shifts, including dispersal across topographical barriers, that became key to their diversification.
    Journal of Biogeography 12/2014; 42(4). DOI:10.1111/jbi.12452 · 4.97 Impact Factor

Full-text

Download
83 Downloads
Available from
May 16, 2014