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The lowland forests of western and central tropical Africa are separated by several potential biogeographic barriers to dispersal for forest adapted vertebrates. The two primary barriers are (1) the Dahomey Gap, a savanna corridor that... more
The lowland forests of western and central tropical Africa are separated by several potential biogeographic barriers to dispersal for forest adapted vertebrates. The two primary barriers are (1) the Dahomey Gap, a savanna corridor that reaches the coast of southern Ghana, Togo and Benin, and separates the West African rainforest into the Upper (Ghana west to Guinea) and Lower Guinea (Nigeria to Uganda and Angola) forest blocks, and (2) the Lower Niger River, a large delta that separates Western and Eastern Nigeria. Previous studies on terrestrial vertebrates (lizards, mammals and birds) have highlighted a genetic break in the Dahomey Gap/Lower Niger River area although the relative importance of each barrier has not been assessed due to limitations in geographic sampling or properties of the markers used. We compared the phylogeographic history of two co-distributed sister-species of woodpeckers (Campethera caroli and C. nivosa) using data from three loci representing all inheritanc...
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The forest batis, Batis mixta, is a common bird of the forests of the Eastern Arc Mountains of Tanzania and in some adjacent montane and coastal forests. Through new collecting efforts in most of this range we documented a well-marked... more
The forest batis, Batis mixta, is a common bird of the forests of the Eastern Arc Mountains of Tanzania and in some adjacent montane and coastal forests. Through new collecting efforts in most of this range we documented a well-marked change in morphology in the middle of the range. Supplementary genetic studies of the historical population structure suggest connectivity among
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The avian genus Turdus is one of the most speciose and widespread of passerine genera. We investigated phylogenetic relationships within this genus using mitochondrial DNA sequence data from the ND3, ND2 and cytochrome b genes. Our... more
The avian genus Turdus is one of the most speciose and widespread of passerine genera. We investigated phylogenetic relationships within this genus using mitochondrial DNA sequence data from the ND3, ND2 and cytochrome b genes. Our sampling of Turdus included 60 of the 65 extant species currently recognized, as well as all four species from three genera previously shown to
Research Interests: Evolutionary Biology, Genetics, Zoology, Molecular Systematics, Phylogeny, and 12 moreMitochondrial DNA, Maximum Likelihood, Animals, Songbirds, Molecular Phylogenetics and Evolution, Species Distribution, Molecular phylogenetics, Cytochrome B, Cytochrome B Gene, Phylogenetic Tree, Maximum Parsimony, and Molecular Sequence Data
The African bush-shrikes and helmet-shrikes (Malaconotidae sensu [A Complete Checklist of the Birds of the World, third ed., Helm Editions, London, 2003]) include 10 genera and 52 species of predatory passerine birds for which monophyly,... more
The African bush-shrikes and helmet-shrikes (Malaconotidae sensu [A Complete Checklist of the Birds of the World, third ed., Helm Editions, London, 2003]) include 10 genera and 52 species of predatory passerine birds for which monophyly, sister-group, and inter-generic relationships are disputed. To resolve their relationships, we analyzed 2313bp of sequence data obtained from two nuclear introns (myoglobin intron-2, β-fibrinogen intron-5)
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The African genus Hyliota includes three or four species of warbler-like birds of uncertain phylogenetic affinities, as it has historically been placed in different avian families that are now known to represent unrelated lineages:... more
The African genus Hyliota includes three or four species of warbler-like birds of uncertain phylogenetic affinities, as it has historically been placed in different avian families that are now known to represent unrelated lineages: Malaconotidae (bush-shrikes), Platysteiridae (batises and wattle-eyes), Muscicapidae (Old World flycatchers) and Sylviidae (Old-World Warblers). To assess the affinities of Hyliota we sequenced a mitochondrial protein-coding gene
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ABSTRACT: To enhance our current understanding of the evolution of intertidal marine species, we investigated the phylogeographic population structure of the Cape sea urchin Parechinus angulosus using cytochrome c oxidase subunit I (COI)... more
ABSTRACT: To enhance our current understanding of the evolution of intertidal marine species, we investigated the phylogeographic population structure of the Cape sea urchin Parechinus angulosus using cytochrome c oxidase subunit I (COI) mitochondrial and receptor for egg jelly protein 9 (SpREJ9) nuclear DNA (nDNA) sequence data. The species shows variation in colour form, has a wide distribution along the southern African coastline, a broadcast mode of reproduction and probably a fairly long post larval development. ...
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Book Reviews Handbook of the Birds of the World, vol. 16: Tanagers to New World Blackbirds .— Josep del Hoyo , Andrew Elliott , and David Christie , Eds. 2011 . Lynx Edicions , Barcelona, Spain . 894 pp. 81 color plates, >500 photographs, and 766 distribution maps. ISBN 9788496553781 . Hardcover,...more
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Advances in understanding the process of species formation require an integrated perspective that includes the evaluation of spatial, ecological and genetic components. One approach is to focus on multiple stages of divergence within the... more
Advances in understanding the process of species formation require an integrated perspective that includes the evaluation of spatial, ecological and genetic components. One approach is to focus on multiple stages of divergence within the same species. Species that comprise phenotypically different populations segregated in apparently distinct habitats, in which range is presently continuous but was putatively geographically isolated provide an interesting system to study the mechanisms of population divergence. Here, we attempt to elucidate the role of ecology and geography in explaining observed morphological and genetic variation in an understorey-dwelling bird endemic to southeastern Africa, where two subspecies are recognized according to phenotype and habitat affinity. We carried out a range-wide analysis of climatic requirements, morphological and genetic variation across southeast Africa to test the hypothesis that the extent of gene flow among populations of the brown scrub-robin are influenced by their distinct climatic niches. We recovered two distinct trends depending on whether our analyses were hierarchically structured at the subspecies or at the within subspecies level. Between subspecies we found pronounced morphological differentiation associated with strong reproductive isolation (no gene flow) between populations occupying divergent climatic niches characterized by changes in the temperature of the warmest and wettest month. In contrast, within subspecies, we recovered continuous morphological variation with extensive gene flow among populations inhabiting the temperate and sub-tropical forests of southern Africa, despite divergence along the climate axis that is mainly determined by minimum temperature and precipitation of the coldest months. Our results highlight the role of niche divergence as a diversifying force that can promote reproductive isolation in vertebrates.
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Research Interests: Evolutionary Biology, Genetics, Zoology, Geography, Demography, and 19 morePhylogeny, Mitochondrial DNA, Sequence alignment, Animals, Molecular phylogeny, Molecular Phylogenetics and Evolution, Oceania, Species Distribution, Molecular phylogenetics, New Guinea, Columbidae, Oceanic Islands, Species Specificity, Base Sequence, Plate tectonic, Bayes Theorem, Likelihood Functions, Pigeon, and Molecular Sequence Data
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SUMMARY The coevolutionary relationships between avian malaria parasites and their hosts influence the host specificity, geographical distribution and pathogenicity of these parasites. However, to understand fine scale coevolutionary... more
SUMMARY The coevolutionary relationships between avian malaria parasites and their hosts influence the host specificity, geographical distribution and pathogenicity of these parasites. However, to understand fine scale coevolutionary host-parasite relationships, robust and widespread sampling from closely related hosts is needed. We thus sought to explore the coevolutionary history of avian Plasmodium and the widespread African sunbirds, family Nectariniidae. These birds are distributed throughout Africa and occupy a variety of habitats. Considering the role that habitat plays in influencing host-specificity and the role that host-specificity plays in coevolutionary relationships, African sunbirds provide an exceptional model system to study the processes that govern the distribution and diversity of avian malaria. Here we evaluated the coevolutionary histories using a multi-gene phylogeny for Nectariniidae and avian Plasmodium found in Nectariniidae. We then assessed the host-paras...
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The evolution of migration in birds has fascinated biologists for centuries. In this study, we performed phylogenetic-based analyses of Catharus thrushes, a model genus in the study of avian migration, and their close relatives. For these... more
The evolution of migration in birds has fascinated biologists for centuries. In this study, we performed phylogenetic-based analyses of Catharus thrushes, a model genus in the study of avian migration, and their close relatives. For these analyses, we used both mitochondrial and nuclear genes, and the resulting phylogenies were used to trace migratory traits and biogeographic patterns. Our results provide the first robust assessment of relationships within Catharus and relatives and indicate that both mitochondrial and autosomal genes contribute to overall support of the phylogeny. Measures of phylogenetic informativeness indicated that mitochondrial genes provided more signal within Catharus than did nuclear genes, whereas nuclear loci provided more signal for relationships between Catharus and close relatives than did mitochondrial genes. Insertion and deletion events also contributed important support across the phylogeny. Across all taxa included in the study, and for Catharus, possession of long-distance migration is reconstructed as the ancestral condition, and a North American (north of Mexico) ancestral area is inferred. Within Catharus, sedentary behaviour evolved after the first speciation event in the genus and is geographically and temporally correlated with Central American distributions and the final closure of the Central American Seaway. Migratory behaviour subsequently evolved twice in Catharus and is geographically and temporally correlated with a recolonization of North America in the late Pleistocene. By temporally linking speciation events with changes in migratory condition and events in Earth history, we are able to show support for several competing hypotheses relating to the geographic origin of migration.
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We describe the isolation of 10 microsatellite loci from the Great White Pelican using an enrichment protocol. All loci were variable with the number of alleles ranging from 2 to 19, and observed heterozygosity ranging from 0.261 to... more
We describe the isolation of 10 microsatellite loci from the Great White Pelican using an enrichment protocol. All loci were variable with the number of alleles ranging from 2 to 19, and observed heterozygosity ranging from 0.261 to 0.913. Two loci were out of Hardy–Weinberg equilibrium, although in each case this was restricted to one of the two populations screened.
Research Interests: Genetics, Microbiology, Parasitology, Technology, Conservation, and 25 morePolymorphism, Conservation Genetics, Gene Flow, Plant Biology, Medical Microbiology, Plant Breeding, Molecular Breeding, Carnivorous plant ecology, Genetic Diversity, Biological Sciences, Coral Reef, Habitat fragmentation, High Temperature, Great Barrier Reef, Molecular Marker, Linkage Disequilibrium, Genomic Library, Genetic variation, Plant species, Veterinary Sciences, Microsatellite DNA, Breeding System, Biochemistry and cell biology, Molecular Biology Reports, and Simple Sequence Repeat
The Pycnonotidae (bulbuls and greenbuls) comprise approximately 130 species and are widely distributed across Africa and Asia, mainly in evergreen thickets and forest. Recent molecular findings suggest a basal split between the African... more
The Pycnonotidae (bulbuls and greenbuls) comprise approximately 130 species and are widely distributed across Africa and Asia, mainly in evergreen thickets and forest. Recent molecular findings suggest a basal split between the African and the Asian species, although the three African Pycnonotus species are part of the Asian radiation and represent a relative recent immigration to Africa. In this study we investigate the phylogenetic relationships within the African clade, which with the exclusion of Pycnonotus contains approximately 50 species, of which the majority are placed in three large genera Andropadus , Phyllastrephus and Chlorocichla. We use three nuclear markers (myoglobin intron 2, ODC introns 6 and 7 along with intervening exon 7, and β-fibrinogen intron 5), together encompassing 2072 aligned positions, to infer the relationships within the African clade. The resulting tree is generally well supported and indicates that none of the three largest currently recognized genera are monophyletic. For instance, the species included in Andropadus represent three different clades that are not each other's closest relatives. The montane species currently placed in that genus form a strongly supported clade, which is sister to Ixonotus , Thescelocichla, Baeopogon and Chlorocichla , although within this clade the genus Chlorocichla is polyphyletic. The remaining Andropadus species fall into two groups, one of these with A. importunus and A. gracilirostris , which along with Calyptocichla serina form a basal branch in the African greenbul radiation. In support of some previous studies the Leaf-love (Pyrrhurus scandens) is placed within Phyllastrephus. We also propose a new classification that reflects the phylogenetic relationships among African greenbuls.