| human impacts flatten rainforest-savanna gradient and reduce adaptive diversity in a rainforest bird. | ecological gradients have long been recognized as important regions for diversification and speciation. however, little attention has been paid to the evolutionary consequences or conservation implications of human activities that fundamentally change the environmental features of such gradients. here we show that recent deforestation in west africa has homogenized the rainforest-savanna gradient, causing a loss of adaptive phenotypic diversity in a common rainforest bird, the little greenbul (a ... | 2010 | 20941360 |
| human impacts flatten rainforest-savanna gradient and reduce adaptive diversity in a rainforest bird. | ecological gradients have long been recognized as important regions for diversification and speciation. however, little attention has been paid to the evolutionary consequences or conservation implications of human activities that fundamentally change the environmental features of such gradients. here we show that recent deforestation in west africa has homogenized the rainforest-savanna gradient, causing a loss of adaptive phenotypic diversity in a common rainforest bird, the little greenbul (a ... | 2010 | 20941360 |
| evolutionary consequences of human disturbance in a rainforest bird species from central africa. | relatively little attention has been directed towards understanding the impacts of human disturbance on evolutionary processes that produce and maintain biodiversity. here, we examine the influence of anthropogenic habitat changes on traits typically associated with natural and sexual selection in the little greenbul (andropadus virens), an african rainforest bird species. using satellite remote-sensing and field survey data, we classified habitats into nonhuman-altered mature and human-altered ... | 2008 | 17868295 |
| evolutionary consequences of human disturbance in a rainforest bird species from central africa. | relatively little attention has been directed towards understanding the impacts of human disturbance on evolutionary processes that produce and maintain biodiversity. here, we examine the influence of anthropogenic habitat changes on traits typically associated with natural and sexual selection in the little greenbul (andropadus virens), an african rainforest bird species. using satellite remote-sensing and field survey data, we classified habitats into nonhuman-altered mature and human-altered ... | 2008 | 17868295 |
| genomic divergence across ecological gradients in the central african rainforest songbird (andropadus virens). | the little greenbul, a common rainforest passerine from sub-saharan africa, has been the subject of long-term evolutionary studies to understand the mechanisms leading to rainforest speciation. previous research found morphological and behavioural divergence across rainforest-savannah transition zones (ecotones), and a pattern of divergence with gene flow suggesting divergent natural selection has contributed to adaptive divergence and ecotones could be important areas for rainforests speciation ... | 2017 | 28752944 |
| habitat-dependent song divergence in the little greenbul: an analysis of environmental selection pressures on acoustic signals. | bird song is a sexual trait important in mate choice and known to be shaped by environmental selection. here we investigate the ecological factors shaping song variation across a rainforest gradient in central africa. we show that the little greenbul (andropadus virens), previously shown to vary morphologically across the gradient in fitness-related characters, also varies with respect to song characteristics. acoustic features, including minimum and maximum frequency, and delivery rate of song ... | 2002 | 12389730 |
| testing alternative hypotheses for evolutionary diversification in an african songbird: rainforest refugia versus ecological gradients. | geographic isolation in rainforest refugia and local adaptation to ecological gradients may both be important drivers of evolutionary diversification. however, their relative importance and the underlying mechanisms of these processes remain poorly understood because few empirical studies address both putative processes in a single system. a key question is to what extent is divergence in signals that are important in mate and species recognition driven by isolation in rainforest refugia or by d ... | 2011 | 22023583 |
| testing alternative hypotheses for evolutionary diversification in an african songbird: rainforest refugia versus ecological gradients. | geographic isolation in rainforest refugia and local adaptation to ecological gradients may both be important drivers of evolutionary diversification. however, their relative importance and the underlying mechanisms of these processes remain poorly understood because few empirical studies address both putative processes in a single system. a key question is to what extent is divergence in signals that are important in mate and species recognition driven by isolation in rainforest refugia or by d ... | 2011 | 22023583 |
| predicting bird song from space. | environmentally imposed selection pressures are well known to shape animal signals. changes in these signals can result in recognition mismatches between individuals living in different habitats, leading to reproductive divergence and speciation. for example, numerous studies have shown that differences in avian song may be a potent prezygotic isolating mechanism. typically, however, detailed studies of environmental pressures on variation in animal behavior have been conducted only at small spa ... | 2013 | 24062797 |
| predicting bird song from space. | environmentally imposed selection pressures are well known to shape animal signals. changes in these signals can result in recognition mismatches between individuals living in different habitats, leading to reproductive divergence and speciation. for example, numerous studies have shown that differences in avian song may be a potent prezygotic isolating mechanism. typically, however, detailed studies of environmental pressures on variation in animal behavior have been conducted only at small spa ... | 2013 | 24062797 |
| testing alternative mechanisms of evolutionary divergence in an african rain forest passerine bird. | abstract models of speciation in african rain forests have stressed either the role of isolation or ecological gradients. here we contrast patterns of morphological and genetic divergence in parapatric and allopatric populations of the little greenbul, andropadus virens, within different and similar habitats. we sampled 263 individuals from 18 sites and four different habitat types in upper and lower guinea. we show that despite relatively high rates of gene flow among populations, a. virens has ... | 2005 | 15715832 |
| testing alternative mechanisms of evolutionary divergence in an african rain forest passerine bird. | abstract models of speciation in african rain forests have stressed either the role of isolation or ecological gradients. here we contrast patterns of morphological and genetic divergence in parapatric and allopatric populations of the little greenbul, andropadus virens, within different and similar habitats. we sampled 263 individuals from 18 sites and four different habitat types in upper and lower guinea. we show that despite relatively high rates of gene flow among populations, a. virens has ... | 2005 | 15715832 |
| patterns of variation in mhc class ii beta loci of the little greenbul (andropadus virens) with comments on mhc evolution in birds. | we have isolated major histocompatibility complex (mhc) class ii beta loci from the little greenbul (andropadus virens), an african songbird. we utilized preexisting information about conserved regions of the avian mhc to design primers to amplify a pool of sequences representing multiple loci. from this pool, a unique locus spanning 1109 bp that we designate as anvi-dab1 was cloned and sequenced. we designed locus-specific primers based on this sequence information and amplified six alleles fro ... | 2010 | 16489149 |
| patterns of variation in mhc class ii beta loci of the little greenbul (andropadus virens) with comments on mhc evolution in birds. | we have isolated major histocompatibility complex (mhc) class ii beta loci from the little greenbul (andropadus virens), an african songbird. we utilized preexisting information about conserved regions of the avian mhc to design primers to amplify a pool of sequences representing multiple loci. from this pool, a unique locus spanning 1109 bp that we designate as anvi-dab1 was cloned and sequenced. we designed locus-specific primers based on this sequence information and amplified six alleles fro ... | 2010 | 16489149 |
| habitat-dependent song divergence in the little greenbul: an analysis of environmental selection pressures on acoustic signals. | bird song is a sexual trait important in mate choice and known to be shaped by environmental selection. here we investigate the ecological factors shaping song variation across a rainforest gradient in central africa. we show that the little greenbul (andropadus virens), previously shown to vary morphologically across the gradient in fitness-related characters, also varies with respect to song characteristics. acoustic features, including minimum and maximum frequency, and delivery rate of song ... | 2002 | 12389730 |
| a comparison of variation between a mhc pseudogene and microsatellite loci of the little greenbul (andropadus virens). | we investigated genetic variation of a major histocompatibility complex (mhc) pseudogene (anvi-dab1) in the little greenbul (andropadus virens) from four localities in cameroon and one in ivory coast, west africa. previous microsatellite and mitochondrial dna analyses had revealed little or no genetic differentiation among cameroon localities but significant differentiation between localities in cameroon and ivory coast. | 2005 | 16159389 |
| a comparison of variation between a mhc pseudogene and microsatellite loci of the little greenbul (andropadus virens). | we investigated genetic variation of a major histocompatibility complex (mhc) pseudogene (anvi-dab1) in the little greenbul (andropadus virens) from four localities in cameroon and one in ivory coast, west africa. previous microsatellite and mitochondrial dna analyses had revealed little or no genetic differentiation among cameroon localities but significant differentiation between localities in cameroon and ivory coast. | 2005 | 16159389 |