The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Scott M. Lanyon - One of the best experts on this subject based on the ideXlab platform.
-
Regular ArticleThe Impact of Parsimony Weighting Schemes on Inferred Relationships among Toucans and Neotropical Barbets (Aves: Piciformes)
Molecular Phylogenetics and Evolution, 2000Co-Authors: F. Keith Barker, Scott M. LanyonAbstract:The development of new schemes for weighting DNA sequence data for phylogenetic analysis continues to outpace the development of consensus on the most appropriate weights. The present study is an exploration of the similarities and differences between results from 22 character weighting schemes when applied to a study of barbet and toucan (traditional avian families Capitonidae and Ramphastidae) phylogenetic relationships. The dataset comprises cytochrome b sequences for representatives of all toucan and Neotropical barbet genera, as well as for several genera of Paleotropical barbets. The 22 weighting schemes produced conflicting patterns of relationship among taxa, often with conflicting patterns each receiving strong bootstrap support. Use of multiple weighting schemes helped to identify the source within the dataset (codon position, transitions, transversions) of the various putative phylogenetic signals. Importantly, some phylogenetic hypotheses were consistently supported despite the wide range of weights employed. The use of phylogenetic frameworks to summarize the results of these multiple analyses proved very informative. Relationships among barbets and toucans inferred from these data support the paraphyly of the traditional Capitonidae. Additionally, these data support paraphyly of Neotropical barbets, but rather than indicating a relationship between Semnornis and toucans, as previously suggested by morphological data, most analyses indicate a basal position of Semnornis within the Neotropical radiation. The cytochrome b data also allow inference of relationships among toucans. Supported hypotheses include Ramphastos as the sister to all other toucans, a close relationship of Baillonius and Pteroglossus with these two genera as the sister group to an (Andigena, Selenidera) clade, and the latter four genera as a sister group to Aulacorhynchus.
-
the impact of parsimony weighting schemes on inferred relationships among toucans and neotropical barbets aves piciformes
Molecular Phylogenetics and Evolution, 2000Co-Authors: Keith F Barker, Scott M. LanyonAbstract:The development of new schemes for weighting DNA sequence data for phylogenetic analysis continues to outpace the development of consensus on the most appropriate weights. The present study is an exploration of the similarities and differences between results from 22 character weighting schemes when applied to a study of barbet and toucan (traditional avian families Capitonidae and Ramphastidae) phylogenetic relationships. The dataset comprises cytochrome b sequences for representatives of all toucan and Neotropical barbet genera, as well as for several genera of Paleotropical barbets. The 22 weighting schemes produced conflicting patterns of relationship among taxa, often with conflicting patterns each receiving strong bootstrap support. Use of multiple weighting schemes helped to identify the source within the dataset (codon position, transitions, transversions) of the various putative phylogenetic signals. Importantly, some phylogenetic hypotheses were consistently supported despite the wide range of weights employed. The use of phylogenetic frameworks to summarize the results of these multiple analyses proved very informative. Relationships among barbets and toucans inferred from these data support the paraphyly of the traditional Capitonidae. Additionally, these data support paraphyly of Neotropical barbets, but rather than indicating a relationship between Semnornis and toucans, as previously suggested by morphological data, most analyses indicate a basal position of Semnornis within the Neotropical radiation. The cytochrome b data also allow inference of relationships among toucans. Supported hypotheses include Ramphastos as the sister to all other toucans, a close relationship of Baillonius and Pteroglossus with these two genera as the sister group to an (Andigena, Selenidera) clade, and the latter four genera as a sister group to Aulacorhynchus.
Alexandre Aleixo - One of the best experts on this subject based on the ideXlab platform.
-
Biogeography and spatio-temporal diversification of Selenidera and Andigena Toucans (Aves: Ramphastidae)
Molecular phylogenetics and evolution, 2013Co-Authors: Holly L. Lutz, Jason D. Weckstein, José S. L. Patané, John M. Bates, Alexandre AleixoAbstract:Andean uplift, Plio-Pleistocene climatic fluctuation, and river dynamics in the Amazon basin have all been implicated in the diversification of the South American avifauna. We reconstructed phylogenetic relationships in the genus Selenidera, which has served as a classic case of putative refugial speciation, and the closely related genus Andigena, to better understand the processes driving their diversification. Using mitochondrial and nuclear DNA sequences, we constructed a phylogeny to estimate the pattern and timing of divergence within and between seven lowland Selenidera toucanets and the five species of Andigena mountain-toucans, which together form a single clade. All phylogenetic analyses supported the monophyly of the montane genus Andigena, but indicated that the genus Selenidera is likely paraphyletic with respect to Andigena. Our time tree analysis is consistent with the orogenic uplift of the northern Andean range having initiated the divergence between Selenidera and Andigena, and that the movement and fragmentation of montane habitats in response to Pleistocene climatic oscillations likely influenced diversification within Andigena. Estimated divergence times for lowland Amazonian Selenidera did not support the Last Glacial Maximum (LGM) refuge hypothesis as an important biogeographic factor for the diversification of lineages studied here. The timing of divergence within Selenidera is consistent with the hypothesis that geographic isolation of areas of endemism generated by Amazonian river dynamics during the Plio-Pleistocene contributed to Selenidera speciation and current species distributions.
-
effects of palm heart harvesting on avian frugivores in the atlantic rain forest of brazil
Web Science, 1998Co-Authors: Mauro Galetti, Alexandre AleixoAbstract:1. It has been suggested that palm fruits are keystone resources for frugivores in tropical rain forests, but no study has addressed this hypothesis. The effects of the harvesting of a dominant palm tree Euterpe edulis were studied over 2 years in the Atlantic forest of Brazil. 2. The abundance of 15 large frugivorous birds from five families (Ramphastidae, Cracidae, Cotingidae, Trogonidae and Psittacidae) was estimated using unlimited distance point counts (IPA) and encounter rate. 3. Although all species studied are known to eat Euterpe fruits, only one Cotingidae (Carpornis melanocephalus) and one Ramphastidae (Ramphastos vitellinus) were negatively affected by the removal of this palm from the forest. 4. This result indicates that Euterpe palms in the lowland forests do not fulfil the role of keystone species, because they bear ripe fruits during the period of peak overall fruit availability and because birds may switch their diets to other food sources when palms are removed. 5. Palm-heart exploitation is not recommended in small forest areas, nor in areas where E. edulis bears fruit during the period of overall fruit scarcity. Only long-term monitoring can evaluate the responses of the bird and mammal communities to the harvesting process.
Jason D. Weckstein - One of the best experts on this subject based on the ideXlab platform.
-
Biogeography and spatio-temporal diversification of Selenidera and Andigena Toucans (Aves: Ramphastidae)
Molecular phylogenetics and evolution, 2013Co-Authors: Holly L. Lutz, Jason D. Weckstein, José S. L. Patané, John M. Bates, Alexandre AleixoAbstract:Andean uplift, Plio-Pleistocene climatic fluctuation, and river dynamics in the Amazon basin have all been implicated in the diversification of the South American avifauna. We reconstructed phylogenetic relationships in the genus Selenidera, which has served as a classic case of putative refugial speciation, and the closely related genus Andigena, to better understand the processes driving their diversification. Using mitochondrial and nuclear DNA sequences, we constructed a phylogeny to estimate the pattern and timing of divergence within and between seven lowland Selenidera toucanets and the five species of Andigena mountain-toucans, which together form a single clade. All phylogenetic analyses supported the monophyly of the montane genus Andigena, but indicated that the genus Selenidera is likely paraphyletic with respect to Andigena. Our time tree analysis is consistent with the orogenic uplift of the northern Andean range having initiated the divergence between Selenidera and Andigena, and that the movement and fragmentation of montane habitats in response to Pleistocene climatic oscillations likely influenced diversification within Andigena. Estimated divergence times for lowland Amazonian Selenidera did not support the Last Glacial Maximum (LGM) refuge hypothesis as an important biogeographic factor for the diversification of lineages studied here. The timing of divergence within Selenidera is consistent with the hypothesis that geographic isolation of areas of endemism generated by Amazonian river dynamics during the Plio-Pleistocene contributed to Selenidera speciation and current species distributions.
-
the genus ramphasticola carriker phthiraptera amblycera menoponidae from the toucans piciformes Ramphastidae with description of a new species
Proceedings of the Entomological Society of Washington, 2005Co-Authors: Ronald A Hellenthal, Roger D Price, Jason D. WecksteinAbstract:The diagnostic characteristics of the genus Ramphasticola Carriker are reevaluated. They are of sufficient magnitude to justify the removal of Ramphasticola from synonymy with Myrsidea Waterston and merit its recognition as a distinct genus. The currently recognized three species of Ramphasticola are illustrated and redescribed. A new species, R. moylei, from the type host Ramphastos tucanus cuvieri Wagler in Peru, is described.
-
the genus austrophilopterus ewing phthiraptera philopteridae from toucans toucanets and aracaris piciformes Ramphastidae
Zootaxa, 2005Co-Authors: Roger D Price, Jason D. WecksteinAbstract:Examination of material representing the 24 previously named species and subspecies of Austrophilopterus resulted in recognition of only 6 of these as valid species and 18 as synonymies, including a previously established junior synonym and 17 new synonymies. These 6 species are redescribed and illustrated. One new species, A. thysi, is described from the type host Selenidera gouldii (Natterer).
-
the genus myrsidea waterston phthiraptera menoponidae from the toucans piciformes Ramphastidae with descriptions of three new species
Zootaxa, 2004Co-Authors: Roger Price, Ronald A Hellenthal, Jason D. WecksteinAbstract:Six species of Myrsidea from toucans are redescribed. Three new species are described and illustrated. They and their type hosts are M. witti ex Ramphastos toco toco Statius Muller, M. aleixoi ex Pteroglossus beauharnaesii Wagler, and M. lanei ex P. aracari (L.). Keys are provided for the identification of males and females of these 9 species.
Holly L. Lutz - One of the best experts on this subject based on the ideXlab platform.
-
Biogeography and spatio-temporal diversification of Selenidera and Andigena Toucans (Aves: Ramphastidae)
Molecular phylogenetics and evolution, 2013Co-Authors: Holly L. Lutz, Jason D. Weckstein, José S. L. Patané, John M. Bates, Alexandre AleixoAbstract:Andean uplift, Plio-Pleistocene climatic fluctuation, and river dynamics in the Amazon basin have all been implicated in the diversification of the South American avifauna. We reconstructed phylogenetic relationships in the genus Selenidera, which has served as a classic case of putative refugial speciation, and the closely related genus Andigena, to better understand the processes driving their diversification. Using mitochondrial and nuclear DNA sequences, we constructed a phylogeny to estimate the pattern and timing of divergence within and between seven lowland Selenidera toucanets and the five species of Andigena mountain-toucans, which together form a single clade. All phylogenetic analyses supported the monophyly of the montane genus Andigena, but indicated that the genus Selenidera is likely paraphyletic with respect to Andigena. Our time tree analysis is consistent with the orogenic uplift of the northern Andean range having initiated the divergence between Selenidera and Andigena, and that the movement and fragmentation of montane habitats in response to Pleistocene climatic oscillations likely influenced diversification within Andigena. Estimated divergence times for lowland Amazonian Selenidera did not support the Last Glacial Maximum (LGM) refuge hypothesis as an important biogeographic factor for the diversification of lineages studied here. The timing of divergence within Selenidera is consistent with the hypothesis that geographic isolation of areas of endemism generated by Amazonian river dynamics during the Plio-Pleistocene contributed to Selenidera speciation and current species distributions.
F. Keith Barker - One of the best experts on this subject based on the ideXlab platform.
-
Regular ArticleThe Impact of Parsimony Weighting Schemes on Inferred Relationships among Toucans and Neotropical Barbets (Aves: Piciformes)
Molecular Phylogenetics and Evolution, 2000Co-Authors: F. Keith Barker, Scott M. LanyonAbstract:The development of new schemes for weighting DNA sequence data for phylogenetic analysis continues to outpace the development of consensus on the most appropriate weights. The present study is an exploration of the similarities and differences between results from 22 character weighting schemes when applied to a study of barbet and toucan (traditional avian families Capitonidae and Ramphastidae) phylogenetic relationships. The dataset comprises cytochrome b sequences for representatives of all toucan and Neotropical barbet genera, as well as for several genera of Paleotropical barbets. The 22 weighting schemes produced conflicting patterns of relationship among taxa, often with conflicting patterns each receiving strong bootstrap support. Use of multiple weighting schemes helped to identify the source within the dataset (codon position, transitions, transversions) of the various putative phylogenetic signals. Importantly, some phylogenetic hypotheses were consistently supported despite the wide range of weights employed. The use of phylogenetic frameworks to summarize the results of these multiple analyses proved very informative. Relationships among barbets and toucans inferred from these data support the paraphyly of the traditional Capitonidae. Additionally, these data support paraphyly of Neotropical barbets, but rather than indicating a relationship between Semnornis and toucans, as previously suggested by morphological data, most analyses indicate a basal position of Semnornis within the Neotropical radiation. The cytochrome b data also allow inference of relationships among toucans. Supported hypotheses include Ramphastos as the sister to all other toucans, a close relationship of Baillonius and Pteroglossus with these two genera as the sister group to an (Andigena, Selenidera) clade, and the latter four genera as a sister group to Aulacorhynchus.
