Research on mammals in the Guianas of northern South America has had a checkered history. In this... more Research on mammals in the Guianas of northern South America has had a checkered history. In this review, I summarize the notable contributions to mammalogical study in Guyana, Suriname, and French Guiana. These studies began in the mid-18th century with the binomial nomenclature system of scientific classification created by the Swedish naturalist Carl Linnaeus, who described 23 species new to science based on holotype specimens from the Guianas. Notwithstanding popular accounts by amateur naturalists visiting this region, over the next 7 decades there was only sporadic taxonomic work done on Guianan mammals primarily by researchers at European museums. The first comprehensive biological exploration took place in the 1840's during a geographic survey of the boundaries of British Guiana. But it was not until almost half a century later that scientific publications began to regularly document the increasing species diversity in the region, including the prodigious work of Oldfield Thomas at the British Museum of Natural History in London. Another lull in the study of mammals occurred in the mid-1910's to the early 1960's after which foreign researchers began to rediscover the Guianas and their pristine habitats. This biological renaissance is still ongoing and I give a prospectus on the direction of future research in one of the last frontiers of tropical rainforest. An initiative that would be greatly beneficial is the establishment of a university network in the Guianas with graduate-based research to develop a cadre of professional experts on biodiversity and evolution as seen in other countries of South America. This article is protected by copyright. All rights reserved.
We report on the first comprehensive DNA barcoding survey of bats from Jamaica and compare the ge... more We report on the first comprehensive DNA barcoding survey of bats from Jamaica and compare the genetic variation to similar species on South America and Central America. Bats comprise the majority of mammalian diversity in typical lowland forest in the Neotropics, but the Caribbean is one noticeable geographic gap in the International Barcode of Life reference database. Of the 20 known species reported from Jamaica, half were DNA barcoded and were genetically distinct with interspecific variation ranging from 17 to 33%. By contrast, intraspecific variation ranged from 0 to 0.5% indicating that the barcode gap was sufficient in differentiating bat species diversity in Jamaica. The low levels of intraspecific divergence indicate that the populations within each species are relatively homogeneous across the island. There were, however, several cases of high sequence divergence for widely distributed species that occur on both the Caribbean islands and the continental mainland, which wa...
... the high diploid and fundamental number karyotype of Ecto-phylla as the basal lineage followe... more ... the high diploid and fundamental number karyotype of Ecto-phylla as the basal lineage followed by a successivly derived karyotype for Chiro-derma and then a ... The 2n = 26 and FN = 48 karyotype of all species of Chiroderma, V. bidens, and V. nymphaea would be at the node ...
Cases of geographically restricted co-occurring sister taxa are rare and may point to potential d... more Cases of geographically restricted co-occurring sister taxa are rare and may point to potential divergence with gene flow. The two bat species Murina gracilis and M. recondita are both endemic to Taiwan and are putative sister species. To test for non-allopatric divergence and gene flow in these taxa, we generated sequences using Sanger and Next Generation Sequencing, and combined these with microsatellite data for coalescent-based analyses. MtDNA phylogenies supported the reciprocally monophyletic sister relationship between M. gracilis and M. recondita, however, clustering of microsatellite genotypes revealed several cases of species admixture suggesting possible introgression. Sequencing of microsatellite flanking regions revealed that admixture signatures stemmed from microsatellite allele homoplasy rather than recent introgressive hybridization, and also uncovered an unexpected sister relationship between M. recondita and the continental species M. eleryi, to the exclusion of M. gracilis. To dissect the basis of these conflicts between ncDNA and mtDNA, we analysed sequences from 10 anonymous ncDNA loci with *BEAST and isolation-with-migration (IM) and found two distinct clades of M. eleryi, one of which was sister to M. recondita. We conclude that Taiwan was colonized by the ancestor of M. gracilis first, followed by the ancestor of M. recondita after a period of allopatric divergence. After colonization, the mitochondrial genome of M. recondita was replaced by that of the resident M. gracilis. This study illustrates how apparent signatures of sympatric divergence can arise from complex histories of allopatric divergence, colonization and hybridization, thus highlighting the need for rigorous analyses to distinguish between such scenarios. This article is protected by copyright. All rights reserved.
Evolutionary Biology – Concepts, Molecular and Morphological Evolution, 2010
A phylogenetic analysis of loci from the four genetic transmission pathways in mammals (mitochond... more A phylogenetic analysis of loci from the four genetic transmission pathways in mammals (mitochondrial, autosomal, X, and Y sex chromosomes) was used to investigate the evolution of bats in the pantropically distributed family Emballonuridae. The nuclear data sets support a monophyletic clade of species found in the New World. Character optimization of distributional areas suggests that the most recent common
Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been one of the key models in stu... more Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been one of the key models in studies of evolutionary innovation and functional diversification. It has been believed that the RNASE1 gene duplications are correlated with the plant-feeding adaptation of foregut-fermenting herbivores. Here, we characterized RNASE1 genes from Caniformia, which has a simple digestive system and lacks microbial digestion typical of herbivores, in an unprecedented scope based on both gene sequence and tissue expression analyses. Remarkably, the results yielded new hypotheses regarding the evolution and the function of Caniformia RNASE1 genes. Four independent gene duplication events in the families of superfamily Musteloidea, including Procyonidae, Ailuridae, Mephitidae and Mustelidae, were recovered, rejecting previous Mustelidae-specific duplication hypothesis, but supporting Musteloidea duplication hypothesis. Moreover, our analyses revealed pronounced differences among the RNASE1 gene c...
Research on mammals in the Guianas of northern South America has had a checkered history. In this... more Research on mammals in the Guianas of northern South America has had a checkered history. In this review, I summarize the notable contributions to mammalogical study in Guyana, Suriname, and French Guiana. These studies began in the mid-18th century with the binomial nomenclature system of scientific classification created by the Swedish naturalist Carl Linnaeus, who described 23 species new to science based on holotype specimens from the Guianas. Notwithstanding popular accounts by amateur naturalists visiting this region, over the next 7 decades there was only sporadic taxonomic work done on Guianan mammals primarily by researchers at European museums. The first comprehensive biological exploration took place in the 1840's during a geographic survey of the boundaries of British Guiana. But it was not until almost half a century later that scientific publications began to regularly document the increasing species diversity in the region, including the prodigious work of Oldfield Thomas at the British Museum of Natural History in London. Another lull in the study of mammals occurred in the mid-1910's to the early 1960's after which foreign researchers began to rediscover the Guianas and their pristine habitats. This biological renaissance is still ongoing and I give a prospectus on the direction of future research in one of the last frontiers of tropical rainforest. An initiative that would be greatly beneficial is the establishment of a university network in the Guianas with graduate-based research to develop a cadre of professional experts on biodiversity and evolution as seen in other countries of South America. This article is protected by copyright. All rights reserved.
We report on the first comprehensive DNA barcoding survey of bats from Jamaica and compare the ge... more We report on the first comprehensive DNA barcoding survey of bats from Jamaica and compare the genetic variation to similar species on South America and Central America. Bats comprise the majority of mammalian diversity in typical lowland forest in the Neotropics, but the Caribbean is one noticeable geographic gap in the International Barcode of Life reference database. Of the 20 known species reported from Jamaica, half were DNA barcoded and were genetically distinct with interspecific variation ranging from 17 to 33%. By contrast, intraspecific variation ranged from 0 to 0.5% indicating that the barcode gap was sufficient in differentiating bat species diversity in Jamaica. The low levels of intraspecific divergence indicate that the populations within each species are relatively homogeneous across the island. There were, however, several cases of high sequence divergence for widely distributed species that occur on both the Caribbean islands and the continental mainland, which wa...
... the high diploid and fundamental number karyotype of Ecto-phylla as the basal lineage followe... more ... the high diploid and fundamental number karyotype of Ecto-phylla as the basal lineage followed by a successivly derived karyotype for Chiro-derma and then a ... The 2n = 26 and FN = 48 karyotype of all species of Chiroderma, V. bidens, and V. nymphaea would be at the node ...
Cases of geographically restricted co-occurring sister taxa are rare and may point to potential d... more Cases of geographically restricted co-occurring sister taxa are rare and may point to potential divergence with gene flow. The two bat species Murina gracilis and M. recondita are both endemic to Taiwan and are putative sister species. To test for non-allopatric divergence and gene flow in these taxa, we generated sequences using Sanger and Next Generation Sequencing, and combined these with microsatellite data for coalescent-based analyses. MtDNA phylogenies supported the reciprocally monophyletic sister relationship between M. gracilis and M. recondita, however, clustering of microsatellite genotypes revealed several cases of species admixture suggesting possible introgression. Sequencing of microsatellite flanking regions revealed that admixture signatures stemmed from microsatellite allele homoplasy rather than recent introgressive hybridization, and also uncovered an unexpected sister relationship between M. recondita and the continental species M. eleryi, to the exclusion of M. gracilis. To dissect the basis of these conflicts between ncDNA and mtDNA, we analysed sequences from 10 anonymous ncDNA loci with *BEAST and isolation-with-migration (IM) and found two distinct clades of M. eleryi, one of which was sister to M. recondita. We conclude that Taiwan was colonized by the ancestor of M. gracilis first, followed by the ancestor of M. recondita after a period of allopatric divergence. After colonization, the mitochondrial genome of M. recondita was replaced by that of the resident M. gracilis. This study illustrates how apparent signatures of sympatric divergence can arise from complex histories of allopatric divergence, colonization and hybridization, thus highlighting the need for rigorous analyses to distinguish between such scenarios. This article is protected by copyright. All rights reserved.
Evolutionary Biology – Concepts, Molecular and Morphological Evolution, 2010
A phylogenetic analysis of loci from the four genetic transmission pathways in mammals (mitochond... more A phylogenetic analysis of loci from the four genetic transmission pathways in mammals (mitochondrial, autosomal, X, and Y sex chromosomes) was used to investigate the evolution of bats in the pantropically distributed family Emballonuridae. The nuclear data sets support a monophyletic clade of species found in the New World. Character optimization of distributional areas suggests that the most recent common
Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been one of the key models in stu... more Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been one of the key models in studies of evolutionary innovation and functional diversification. It has been believed that the RNASE1 gene duplications are correlated with the plant-feeding adaptation of foregut-fermenting herbivores. Here, we characterized RNASE1 genes from Caniformia, which has a simple digestive system and lacks microbial digestion typical of herbivores, in an unprecedented scope based on both gene sequence and tissue expression analyses. Remarkably, the results yielded new hypotheses regarding the evolution and the function of Caniformia RNASE1 genes. Four independent gene duplication events in the families of superfamily Musteloidea, including Procyonidae, Ailuridae, Mephitidae and Mustelidae, were recovered, rejecting previous Mustelidae-specific duplication hypothesis, but supporting Musteloidea duplication hypothesis. Moreover, our analyses revealed pronounced differences among the RNASE1 gene c...
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