Out of the blue: adaptive visual pigment evolution accompanies Amazon invasion

Incursions of marine water into South America during the Miocene prompted colonization of freshwater habitats by ancestrally marine species and present a unique opportunity to study the molecular evolution of adaptations to varying environments. Freshwater and marine environments are distinct in both spectra and average intensities of available light. Here, we investigate the molecular evolution of rhodopsin, the photosensitive pigment in the eye that activates in response to light, in a clade of South American freshwater anchovies derived from a marine ancestral lineage. Using likelihood-based comparative sequence analyses, we found evidence for positive selection in the rhodopsin of freshwater anchovy lineages at sites known to be important for aspects of rhodopsin function such as spectral tuning. No evidence was found for positive selection in marine lineages, nor in three other genes not involved in vision. Our results suggest that an increased rate of rhodopsin evolution was driven by diversification into freshwater habitats, thereby constituting a rare example of molecular evolution mirroring large-scale palaeogeographic events.     

Conservation genetics of South American aquatic mammals: an overview of gene diversity,population structure,phylogeography, non‐invasive methods and forensics

• 1 Most aquatic mammals have high dispersal potential, and there are often severe conservation concerns related to their legal or illegal harvesting. Therefore, economic, social and forensic factors often arise in decisions relating to their population management. Molecular markers are essential tools in modern conservation genetics, revealing previously unknown aspects of aquatic mammal behaviour, natural history, population structure and demography. Molecular markers also have been used to define management units, to recognize taxonomic units, to conduct forensic analyses and to control illegal wildlife trade, providing valuable information for decision‐making in wildlife conservation and management.
• 2 We review studies published in peer‐reviewed journals between 1993 and 2010, in which genetic approaches have been applied to conservation‐related issues involving natural populations of 25 species of aquatic mammals in South America. These studies cover just 34% of the 70 aquatic mammal species recorded in South America.
• 3 Most of the studies are related to population structure, phylogeography, gene flow and dispersal movements. In addition, recent findings relate to evolutionarily significant units, management units, forensics and conservation policy.
• 4 Finally, we look to the future and, based on numbers of studies and conservation concerns, suggest which species, geographic areas and genetic studies should be prioritized. Moreover, we discuss constraints on research and suggest collaborative works that would provide critical information towards the effective conservation and management of aquatic mammals in South America.

     

A revision of the Solatium sessile species group (section Geminata pro parte: Solanaceae)

KNAPP, S., 1991. A revision of the Solatium sessile species (sectio Geminata pro parte : Solanaceae ). The taxonomy of the Solanum sessile species group (a part of the large and unwieldy section Geminata) is reviewed, based on detailed field and herbarium studies. Members of the group are found from Mexico to Bolivia in a variety of habitats. Ten species are recognized: S. obovalifolium, S. sessile, S. monadelphum, S. turgidum, S. triste, S. chlamydogynum, S. rovirosanum, S. palmillae, S. oppositifolium and conferliseriatum.     

Review of the science and practice of restoration in Argentina: increasing awareness of the discipline

The objective of this work was to obtain an overview of studies on ecological restoration carried out in Argentina to date. By means of the Scopus database, we performed two literature searches, one in Spanish (restau* and Argentina) and the other in English (restor* and Argentina). Between 1996 and 2013, 105 publications were registered, representing 2% of publications in Biology and Ecology. Most of these appeared in international journals (87%), in English (86%), and 28% were coauthored with researchers from other countries, favoring visibility at an international level. We observed an increase in the number of studies per year over time, with a significant increase beginning in 2008. Of the 18 ecological regions in Argentina, we found studies relating to 12 as well as four studies relating to restoration in urban areas. This review of the literature is intended to increase awareness of restoration in Argentina and help identify current gaps relating either to this subject or to specific ecological regions.     

Late Cenozoic diversification of the austral genus Lagenophora (Astereae,Asteraceae)

Lagenophora (Astereae, Asteraceae) has 14 species in New Zealand, Australia, Asia, southern South America, Gough Island and Tristan da Cunha. Phylogenetic relationships in Lagenophora were inferred using nuclear and plastid DNA regions. Reconstruction of spatio‐temporal evolution was estimated using parsimony, Bayesian inference and likelihood methods, a Bayesian relaxed molecular clock and ancestral area and habitat reconstructions. Our results support a narrow taxonomic concept of Lagenophora including only a core group of species with one clade diversifying in New Zealand and another in South America. The split between the New Zealand and South American Lagenophora dates from 11.2 Mya [6.1–17.4 95% highest posterior density (HPD)]. The inferred ancestral habitats were openings in beech forest and subalpine tussockland. The biogeographical analyses infer a complex ancestral area for Lagenophora involving New Zealand and southern South America. Thus, the estimated divergence times and biogeographical reconstructions provide circumstantial evidence that Antarctica may have served as a corridor for migration until the expansion of the continental ice during the late Cenozoic. The extant distribution of Lagenophora reflects a complex history that could also have involved direct long‐distance dispersal across southern oceans. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 78–95.     

Molecular phylogenetic diversity in the widespread lizard Cercosaura ocellata (Reptilia: Gymnophthalmidae) in South America

For a long time, Cercosaura ocellata was considered polytypic, with three subspecies: C. ocellata ocellata, C. ocellata petersi and C. ocellata bassleri. Recently, C. ocellata bassleri was elevated to full species, based on analysis of a few molecular samples from Peru. This species complex is widely distributed in South America, occurring in Amazonia, Cerrado, Atlantic forest and Pampa biomes. The monophyly and species diversity of C. ocellata are still unstudied. Here, we infer phylogenetic relationships and species diversity of this group analysing 2326 base pairs of three mitochondrial (12S, 16S, and ND4) and one nuclear (c-mos) genes. Our taxon sampling of 115 specimens includes 72 samples of C. ocellata and sequences of other Cercosaura species and closely related Cercosaurinae. Maximum likelihood phylogenetic analysis recovered the monophyly of Cercosaura and that of C. ocellata with strong support. Our analyses suggest that C. ocellata is a complex of cryptic species, which possibly started diversifying in Amazonia.     

Breeding system diversification and evolution in American Poa supersect. Homalopoa (Poaceae: Poeae: Poinae)

Background and Aims Poa subgenus Poa supersect. Homalopoa has diversified extensively in the Americas. Over half of the species in the supersection are diclinous; most of these are from the New World, while a few are from South-East Asia. Diclinism in Homalopoa can be divided into three main types: gynomonoecism, gynodioecism and dioecism. Here the sampling of species of New World Homalopoa is expanded to date its origin and diversification in North and South America and examine the evolution and origin of the breeding system diversity.Methods A total of 124 specimens were included in the matrix, of which 89 are species of Poa supersect. Homalopoa sections Acutifoliae, Anthochloa, Brizoides, Dasypoa, Dioicopoa, Dissanthelium, Homalopoa sensu lato (s.l.), Madropoa and Tovarochloa, and the informal Punapoa group. Bayesian and parsimony analyses were conducted on the data sets based on four markers: the nuclear ribosomal internal tanscribed spacer (ITS) and external transcribed spacer (ETS), and plastid trnT-L and trnL-F. Dating analyses were performed on a reduced Poa matrix and enlarged Poaceae outgroup to utilize fossils as calibration points. A relaxed Bayesian molecular clock method was used.Key Results Hermaphroditism appears to be pleisiomorphic in the monophyletic Poa supersect. Homalopoa, which is suggested to have originated in Eurasia 8·4–4·2 million years ago (Mya). The ancestor of Poa supersect. Homalopoa radiated throughout the New World in the Late Miocene–Early Pliocene, with major lineages originating during the Pliocene to Pleistocene (5–2 Mya). Breeding systems are linked to geographic areas, showing an evolutionary pattern associated with different habitats. At least three major pathways from hermaphroditism to diclinism are inferred in New World Homalopoa: two leading to dioecism, one via gynodioecism in South America and another directly from hermaphroditism in North America, a result that needs to be checked with a broader sampling of diclinous species in North America. A third pathway leads from hermaphroditism to gynomonoecism in Andean species of South America, with strictly pistillate species evolving in the highest altitudes.Conclusions Divergence dating provides a temporal context to the evolution of breeding systems in New World Poa supersect. Homalopoa. The results are consistent with the infrageneric classification in part; monophyletic sections are confirmed, it is proposed to reclassify species of sect. Acutifoliae, Dasypoa and Homalopoa s.l. and it is acknowledged that revision of the infrageneric taxonomy of the gynomonoecious species is needed.     

First reports of Grania (Clitellata: Enchytraeidae) from Africa and South America: molecular phylogeny and descriptions of nine new species

In this article, our knowledge of the geographic distribution of Grania species is expanded by describing seven new species, G rania bekkouchei sp. nov. , G rania brasiliensis sp. nov. , G rania capensis sp. nov. , G rania chilensis sp. nov. , G rania cryptica sp. nov. , G rania hinojosai sp. nov. , and G rania simonae sp. nov. , from poorly investigated regions of the Southern Hemisphere, plus two new species, G rania carolinensis sp. nov. and G rania unitheca sp. nov. , from off the east coast of the USA. An immature achaetous specimen that we call Grania cf. levis was also included. The newly generated data were combined with a previously published data set in order to update the hypothesis of phylogenetic relationships among Grania species. All new species except G . cryptica sp. nov. are supported by both morphological and molecular data. In addition, we find that G . chilensis sp. nov. is structured in at least four distinct populations along the Chilean coast. The species described from South Africa form a monophyletic clade where two are morphologically indistinguishable but diverging in both mitochondrial and nuclear ribosomal genes, and thus we describe them as different species, G . bekkouchei sp. nov. and G . cryptica sp. nov. Among the North Carolinian species, G . unitheca sp. nov. is indicated as a close relative of Grania monospermatheca Erséus & Lasserre, 1976, and G . carolinensis sp. nov. is indicated as a close relative of G. cf. levis. The updated phylogeny is strongly concordant with geographical species distributions, thus supporting a low level of dispersal within this genus, as has previously been hypothesized. © 2015 The Linnean Society of London     

Short-faced bats (Phyllostomidae: Stenodermatina): a Caribbean radiation of strict frugivores

Aim  To test the hypothesis that Caribbean Short-faced bats descended from a single recent ancestor that originated in the continental Neotropics (Mexico, Central America and/or South America).
Location  The Neotropics, including the West Indies.
Methods  New mitochondrial cytochrome b and nuclear Rag2 sequences were combined with published molecular data to estimate phylogenetic relationships and sequence divergence among Short-faced bats. The resulting phylogenies were compared with those compatible with the single-origin hypothesis using two model-based statistical tests. Confidence limits on sequence divergence were estimated using a parametric bootstrap.
Results  All molecular phylogenies revealed two independent Caribbean lineages and showed that continental Short-faced bats share a recent common ancestor. Morphology-based trees compatible with the single-origin hypothesis were significantly worse at explaining the molecular data than any molecular phylogeny.
Main conclusions  The ancestor of all Short-faced bats reached the Antilles in the Miocene, too recently to have used a proposed Oligocene land bridge, and well before the Pleistocene glaciations that are thought to have facilitated dispersal for many bats. After a long period of isolation, Short-faced bats diversified quickly on the Caribbean islands. A single Short-faced lineage then reached the continent and subsequently expanded its range and diversified into the four extant genera. Among bats, independent lineages of aerial insectivores and nectarivores have also recolonized the continent after evolving in the West Indies. The evidence for an insular origin of the short-faced frugivorous radiation completes a dynamic model of Caribbean biogeography that encompasses an entire biological community.     

Molecular genetics and speciation in Elliptio and its relationships to other taxa of North American Unionidae (Bivalvia)

The genetic relationships among 30 populations of 11 species and five genera of North American Unionidae were assessed by using standard allozyme procedures. Emphasis was on relationships among populations and species of Elliptio and Fusconaia. Multi-dimensional scaling based on a matrix of Nei's (1972) genetic distances substantiated the immunoelectrophoretic results of Davis&Fuller 1981, which demonstrated the distinct and divergent taxonomic groups Anodontinae, Margaritiferinae, and Ambleminae, plus die close relationship of Elliptio and Fusconaia , which justifies their inclusion within the same tribe. Genetic distance appears to increase regularly with time since divergence of taxa. The E. complanata species group is an apparently recent radiation and probably is actively radiating today. The I values among species of this group range from 0.90 to 0.99. Considerable heterozygosity, numerous polymorphic loci, and much interpopuladon phenotypic diversity was also recorded for this group. Some taxa mat have been considered synonyms are demonstrated to be valid species. Reasons for the low genetic distances among unionid taxa are discussed. Standard allozyme analyses are shown to be of great value for assessing relationships among unionid taxa.     

Phylogenetic analysis of Chloraeinae (Orchidaceae) based on plastid and nuclear DNA sequences

The phylogenetic relationships of subtribe Chloraeinae, a group of terrestrial orchids endemic to southern South America, have not been satisfactorily investigated. A previous molecular phylogenetic analysis based on plastid DNA supported the monophyly of Chloraeinae and Gavilea, but showed that Chloraea is non‐monophyletic and that the sole species of Bipinnula analysed is sister to Geoblasta. However, that analysis included only 18 of the 73 species belonging to this subtribe. Here, the phylogenetic relationships of Chloraeinae were assessed by analysing aproximately 7500 bp of nucleotide sequences from nuclear ribosomal internal transcribed spacer (ITS) and plastid DNA (rbcL, matK, trnL‐trnF, rpoB‐trnC) for 42 species representing all four currently accepted genera of Chloraeinae and appropriate outgroups. Nuclear and plastid data were analysed separately and in combination using two different methods, namely parsimony and Bayesian inference. Our analyses support the monophyly of Chloraeinae and their inclusion in an expanded concept of Cranichideae, but none of the genera of Chloraeinae that includes more than one species is monophyletic. Gavilea and Bipinnula are paraphyletic, with Chloraea chica nested in Gavilea and Geoblasta penicillata in Bipinnula. As currently delimited, Chloraea is polyphyletic. The taxonomic changes proposed recently are for the most part not justifiable on phylogenetic grounds, except for recognition of the monotypic genus Correorchis. The lack of resolution for the relationships among species of ‘core’Chloraea suggests a relatively recent diversification of this group. The current generic classification is in need or revision, but additional study is advisable before carrying out further taxonomic changes. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 258–277.     

Contrasting patterns of naturalized plant richness in the Americas: Numbers are higher in the North but expected to rise sharply in the South

With increasing availability of plant distribution data, the information about global plant diversity is improving rapidly. Recently, Ulloa Ulloa et al. (2017) presented the first comprehensive overview of the native vascular flora of the Americas, yielding a total count of 124,993 native species. Of these, 51,241 occur in North America and 82,052 in South America. By combining these data with the information in the Global Naturalized Alien Flora (GloNAF) database of naturalized alien floras, we point out that for a complete picture of the regional and continental plant richness, the naturalized alien species need to be considered. Ignoring this novel component of regional floras can lead to an inaccurate picture of overall change in biodiversity in the Anthropocene. We show that North and South America might face contrasting challenges in terms of potential threats to biodiversity posed by alien plant species, because of the different past and present dynamics of invasions and predictions of future development. In total, there are 7,042 naturalized alien plants occurring in the Americas, with 6,122 recorded in North America and 2,677 in South America; if only introductions from other continents are considered additions to the native continental flora make up 6.9 and 1.4 %, respectively. Nevertheless, predictions of naturalized plant trajectories based on global trade dynamics and climate change suggest that considerable increases in naturalized plant numbers are expected in the next 20 years for emerging South American economies, which could reverse the present state.     

Molecular and karyotypic phylogeography in the Neotropical Hoplias malabaricus (Erythrinidae) fish in eastern Brazil

The sedentary, predatory characin Hoplias malabaricus has one of the widest distributions of freshwater fishes in South America and is characterized by seven karyomorphs (A–G) that occur in sympatric and allopatric populations. Karyotypical patterns of variation in wild populations have been interpreted as evidence of multiple lineages within this nominal species, a possibility that may limit the validity of experimental data for particular karyomorphs. This study used the phylogeographic and genealogical concordance between cytogenetic (N = 49) and molecular (mitochondrial DNA) (N = 73) data on 17 samples, collected in 12 basins from south‐eastern and north‐eastern Brazil, to assess the systematic value of cytogenetic data. Cytogenetic patterns show a sex chromosome system in the 2n = 40F karyomorph. Molecular and cytogenetic data indicate a long, independent evolutionary history of karyomorphs and a coastal origin of continental populations in south‐eastern Brazil. The lack of fit with molecular clock expectations of divergence between groups is likely to be due to strong demographic fluctuations during the evolution of this species complex. The results indicate that karyotypical identification provides a reliable baseline for placing experimental studies on Hoplias spp. in a phylogenetic context.     

NEOSQUIRREL: a data set of ecological knowledge on Neotropical squirrels

相似文献   

A cladistic analysis of the Solatium sessile species group (section Geminata pro parte: Solanaceae)

The Solanum sessile species group is one of eight putatively monophyletic subgroups of the large and diverse Solanum section Geminata. The species group comprises ten species of mostly northern South American trees and shrubs. Characters and character states peculiar to Solanum are discussed in detail. A cladistic analysis of the sessile group yielded four equally parsimonious trees which represent two basic tree topologies. The consensus cladogram is composed of three main clades. Biogeographic analysis using the consensus tree revealed no components in common to the three clades. Possible geographical scenarios are discussed with reference to the geological history of northern South America.     

Molecular diversification of salamanders of the tropical American genus Bolitoglossa (Caudata: Plethodontidae) and its evolutionary and biogeographical implications

The largest genus of salamanders, Bolitoglossa (Plethodontidae), is widespread in tropical America, where it occurs in diverse habitats and elevations, from high elevation grasslands to lowland rain forest . It has the most extensive geographical range of any salamander genus. While most species occur in Middle America, it ranges throughout most of tropical South America as well. Phylogenetic analysis of 1196 bp of two mitochondrial genes (cytochrome b , 16S RNA) from 55 species offers strong support for the monophyly of the genus and sorts the species into a number of clades. Taking into account morphology, distribution, general ecology, and prior systematic and taxonomic studies, we recognize seven subgenera, four of them new: Bolitoglossa Duméril, Bibron et Duméril, 1854, Eladinea Miranda Ribeiro, 1937, Magnadigita Taylor, 1944, Mayamandra , Nanotriton , Oaxakia and Pachymandra . All South American and some lower Middle American species are included in a single well -supported clade, Eladinea . At the species level our analyses uncover the existence of large genetic diversity within morphologically homogeneous taxa. We propose the new combination: B. (Eladinea) paraensis (Unterstein, 1930) stat. nov. , for Brazilian salamanders previously included under B. altamazonica . We evaluate evidence for the multiple colonization of the tropical lowlands by morphologically derived species groups. South America was invaded by members of one clade, Eladinea , which we infer to have dispersed to South America prior to closure of the Panamanian Portal. Despite the relatively long history of salamanders in South America, that continent now accounts for a relatively small proportion of the lineages and species of neotropical salamanders.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 81 , 325–346.