Article

Molecular systematics and the role of the "varzea" - "terra-firme" ecotone in the diversification of Xiphorhynchus woodcreepers (Aves : Dendrocolaptidae)

[ "Department of Biological Sciences, and Museum of Natural Science, Louisiana State University, 119 Foster Hall, Baton Rouge, Louisiana 70803, USA"]
The Auk (Impact Factor: 2.63). 01/2009; 119(Jul 2002):621-640. DOI: 10.1642/0004-8038(2002)119[0621:MSATRO]2.0.CO;2

ABSTRACT Se reconstruyó la filogenia de todas las especies conocidas y de muchas de las subespecies de Xiphorhynchus (Dendrocolaptidae) para evaluar los límites de las especies en este género taxonómicamente complejo y para investigar el rol del ecotono entre “várzea” (bosque de inundación) y “terra-firme” (bosque de tierras altas) del Amazonas en su diversificación. Las filogenias fueron inferidas a partir de 2,430 pares de bases de los genes de ADN mitocondrial ND2, ND3 y citocromo b. Todas las estimaciones filogenéticas avalaron la monofilia de todas las especies vivientes de Xiphorhynchus, con excepción del par de especies hermanas X. picus y X. kienerii. Se encontró fuerte respaldo para incluir a Lepidocolaptes fuscus en Xiphorhynchus, confirmando estudios moleculares y anatómicos previos. Los niveles de divergencia en las secuencias entre algunas subespecies de X. guttatus, X. ocellatus y X. spixii alcanzaron o excedieron aquellos encontrados entre especies biológicas cercanamente emparentadas de Xiphorhynchus. Los altos niveles de diferenciación en las secuencias y la parafilia de algunas especies de Xiphorhynchus indicaron que los siguientes taxones deberían ser reconocidos como especies: X. guttatoides, X. chunchotambo y X. elegans. Todas las especies de Xiphorhynchus restringidas a las áreas de bosque de terra-firme de las tierras bajas del Amazonas formaron un grupo monofilético fuertemente respaldado, mientras que las especies restringidas a bosques de várzea aparecieron en la base del clado que contenía a aquellas encontradas en una amplia variedad de hábitats (X. obsoletus) o pertenecieron a un linaje separado que probablemente pueda ser considerado como un género separado (X. kienerii). Estos resultados falsifican la relación de hermandad esperada entre las especies de várzea y terra-firme que se esperaría si el ecotono de várzea y terra-firme hubiera jugado un rol importante en la diferenciación entre poblaciones y en la especiación de Xiphorhynchus. En cambio, las estimaciones filogenéticas sugirieron que la especialización de hábitat de várzea y terra-firme evolucionó temprano en la historia evolutiva de Xiphorhynchus y que las diferenciaciones subsecuentes ocurrieron principalmente en el hábitat de terra-firme.

Full-text

Available from: Alexandre Aleixo, Jun 16, 2015
0 Followers
 · 
230 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Andean uplift played important roles in the historical diversification of Neotropical organisms, both by producing new high-elevation habitats that could be colonized and by isolating organisms on either side of the mountains. Here, we present a molecular phylogeny of Thamnophlius antshrikes, a clade of 30 species whose collective distribution spans nearly the entirety of lowland habitats in tropical South America, the eastern slope foothills of the Andes, and the tepuis of northern South America. Our goal was to examine the role of the Andes in the diversification of lowland and foothill species. Using parsimony and Bayesian ancestral state reconstructions of a three-state distribution character (lowland-restricted, lowland-to-highland, highland-restricted), we found that the Andes were colonized twice independently and the tepuis once from lowland-restricted ancestors. Over the entire evolutionary history of Thamnophilus, the highest transition rates were between highland-restricted and lowland-to-highland distributions, with extremely low rates into and out of lowland-restricted distributions. This pattern suggests lowland-restricted distributions are limited not by physiological constraints, but by other forces, such as competition. These results highlight the need for additional comparative studies in elucidating processes associated with the colonization of high-elevation habitats and the differentiation of populations within them.
    Evolution 03/2007; 61(2):346-67. DOI:10.1111/j.1558-5646.2007.00039.x · 4.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Australo-Papuan Meliphaga honeyeaters have diversified over a wide range of habitats and elevational zones and are one of the few regionally known cryptic avian radiations. Using a combined 1580 bp of mitochondrial and nuclear DNA we investigate the species limits, systematic affinities and biogeographic history of Meliphaga. We also investigate the role of spatial sorting mechanisms, including altitudinal replacement and niche partitioning, as mechanisms underlying the adaptive radiation of this group. Phylogenetic analysis indicates that the genus Meliphaga comprises at least 16 species, three more than recognized in current classifications. The genus divides into two clades; the species-poor lewinii group, and the larger analoga group that has diversified into a wider range of vertical, vegetational and elevational niches. The basal division of each clade into an Australian and New Guinean assemblage was likely induced by the formation of the Arafura Sea during the early Pliocene ( approximately 4 MYA) with a single reinvasion of Australia by the open forest species M. gracilis during the early Pleistocene (1.2-1.5 MYA) via intermittent land bridges or island hopping. Most recent sister species were found to replace each other geographically within the same ecological and elevational zone conforming to the classical allopatric mode of speciation. In contrast, M. orientalis (650-1950 m) and M. analoga (0-1100 m) were found to replace each other altitudinally across ecological zones providing empirical support for altitudinal speciation as a mechanism of diversification in a montane avifauna. We find no evidence of sympatric speciation (co-existing sister lineages) and suggest that spatial segregation within the habitat (niche partitioning) is primarily a mechanism enabling more divergent species to coexist.
    Molecular Phylogenetics and Evolution 02/2007; 42(1):80-91. DOI:10.1016/j.ympev.2006.05.032 · 4.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Among those few hypotheses of Amazonian diversification amenable to falsification by phylogenetic and population genetics methods, three can be singled out because of their general application to vertebrates: the riverine barrier, the refuge, and the Miocene marine incursion hypotheses. I used phylogenetic and population genetics methods to reconstruct the diversification history of the upland (terra-firme) forest superspecies Xiphorhynchus spixii/elegans (Aves: Dendrocolaptidae) in Amazonia, and to evaluate predictions of the riverine barrier, refuge, and Miocene marine incursion hypotheses. Phylogeographic and population genetics analyses of the X. spixiilelegans superspecies indicated that the main prediction of the riverine barrier hypothesis (that sister lineages occur across major rivers) hold only for populations separated by "clear-water" rivers located on the Brazilian shield, in central and eastern Amazonia; in contrast, "white-water" rivers located in western Amazonia did not represent areas of primary divergence for populations of this superspecies. The main prediction derived from the refuge hypothesis (that populations of the X. spixii/elegans superspecies would show signs of past population bottlenecks and recent demographic expansions) was supported only for populations found in western Amazonia, where paleoecological data have failed to support past rainforest fragmentation and expansion of open vegetation types; conversely, populations from the eastern and central parts of Amazonia, where paleoecological data are consistent with an historical interplay between rainforest and open vegetation types, did not show population genetics attributes expected under the refuge hypothesis. Phylogeographic and population genetics data were consistent with the prediction made by the Miocene marine incursion hypothesis that populations of the X. spixii/elegans superspecies found on the Brazilian shield were older than populations from other parts of Amazonia. In contrast, the phylogeny obtained for lineages of this superspecies falsified the predicted monophyly of Brazilian shield populations, as postulated by the Miocene marine incursion hypothesis. In general, important predictions of both riverine barrier and Miocene marine incursion hypotheses were supported, indicating that they are not mutually exclusive; in fact, the data presented herein suggest that an interaction among geology, sea level changes, and hydrography created opportunities for cladogenesis in the X. spixii/elegans superspecies at different temporal and geographical scales.
    Evolution 07/2004; 58(6):1303-17. DOI:10.1554/03-158 · 4.66 Impact Factor