WorldWideScience

Sample records for biogeography

  1. Biogeography

    Science.gov (United States)

    Quattrochi, Dale A.; Arnold, James E. (Technical Monitor)

    2002-01-01

    As a field of study, biogeography may be considered a bricolage - it has been constructed from many different facets from an array of research disciplines including biology, botany, zoology, geography, and geology. Biogeography focuses on the study of the constantly changing ranges of plants and animals, over multitude of space and time scales. It also includes the study of the structure and dynamics of biotic communities and ecosystems as they relate to both natural and anthropogenic processes. As it exists today, biogeography is an interdisciplinary research area founded in both the biological and Earth sciences. From a purely biological perspective, biogeography may be perceived as one of two types of studies: 1. biotic distributions and broad scales, and interpretations of the evolutionary and dispersal history of a single taxon or a few taxa; or 2. biotic distributions at local-to-regional scales, and interpretations of these distributions in relation to contemporary environments and rates of immigration or extinction. The first type of study is what is most usually associated with the term "biogeography" as disciplinary research field. It is conventionally termed "classical biogeography" because it reflects the continuity of research foci on which biogeography was founded in the nineteenth-century. The second type of biogeographical study has more modern day roots and is termed "geographical ecology" to reflect the theoretical predilections of ecologists and population biologists. Geographical ecology for all intents has become merged with ecology and exists as a sub discipline within this larger field of study.

  2. The Great Cacti: Ethnobotany & Biogeography

    Directory of Open Access Journals (Sweden)

    David A. Hooper

    2010-08-01

    Full Text Available Review of The Great Cacti: Ethnobotany & Biogeography. David Yetman. 2007. The University of Arizona, Tucson. Pp. 320, 366 color photographs, 17 maps. $59.95 (cloth. ISBN 9780816524310.

  3. Biogeography based Satellite Image Classification

    CERN Document Server

    Panchal, V K; Kaur, Navdeep; Kundra, Harish

    2009-01-01

    Biogeography is the study of the geographical distribution of biological organisms. The mindset of the engineer is that we can learn from nature. Biogeography Based Optimization is a burgeoning nature inspired technique to find the optimal solution of the problem. Satellite image classification is an important task because it is the only way we can know about the land cover map of inaccessible areas. Though satellite images have been classified in past by using various techniques, the researchers are always finding alternative strategies for satellite image classification so that they may be prepared to select the most appropriate technique for the feature extraction task in hand. This paper is focused on classification of the satellite image of a particular land cover using the theory of Biogeography based Optimization. The original BBO algorithm does not have the inbuilt property of clustering which is required during image classification. Hence modifications have been proposed to the original algorithm and...

  4. An horizon scan of biogeography

    DEFF Research Database (Denmark)

    Dawson, Michael; Algar, Adam; Antonelli, Alexandre;

    2013-01-01

    The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may present itself relatively infrequently. Each biennial meeting of the International Biogeography Society showcases ideas solicited and developed largely during the preceding year, by individuals or teams...... from across the breadth of the discipline. Here, we highlight challenges, developments, and opportunities in biogeography from that biennial synthesis. We note the realized and potential impact of rapid data accumulation in several fields, a renaissance for inter‐disciplinary research, the importance......‐deductive branches and establish a greater role within and outside academia....

  5. Constrained Multiobjective Biogeography Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Hongwei Mo

    2014-01-01

    Full Text Available Multiobjective optimization involves minimizing or maximizing multiple objective functions subject to a set of constraints. In this study, a novel constrained multiobjective biogeography optimization algorithm (CMBOA is proposed. It is the first biogeography optimization algorithm for constrained multiobjective optimization. In CMBOA, a disturbance migration operator is designed to generate diverse feasible individuals in order to promote the diversity of individuals on Pareto front. Infeasible individuals nearby feasible region are evolved to feasibility by recombining with their nearest nondominated feasible individuals. The convergence of CMBOA is proved by using probability theory. The performance of CMBOA is evaluated on a set of 6 benchmark problems and experimental results show that the CMBOA performs better than or similar to the classical NSGA-II and IS-MOEA.

  6. Constrained multiobjective biogeography optimization algorithm.

    Science.gov (United States)

    Mo, Hongwei; Xu, Zhidan; Xu, Lifang; Wu, Zhou; Ma, Haiping

    2014-01-01

    Multiobjective optimization involves minimizing or maximizing multiple objective functions subject to a set of constraints. In this study, a novel constrained multiobjective biogeography optimization algorithm (CMBOA) is proposed. It is the first biogeography optimization algorithm for constrained multiobjective optimization. In CMBOA, a disturbance migration operator is designed to generate diverse feasible individuals in order to promote the diversity of individuals on Pareto front. Infeasible individuals nearby feasible region are evolved to feasibility by recombining with their nearest nondominated feasible individuals. The convergence of CMBOA is proved by using probability theory. The performance of CMBOA is evaluated on a set of 6 benchmark problems and experimental results show that the CMBOA performs better than or similar to the classical NSGA-II and IS-MOEA.

  7. An horizon scan of biogeography

    Directory of Open Access Journals (Sweden)

    Michael N Dawson

    2013-07-01

    Full Text Available The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may present itself relatively infrequently. Each biennial meeting of the International Biogeography Society showcases ideas solicited and developed largely during the preceding year, by individuals or teams from across the breadth of the discipline. Here, we highlight challenges, developments, and opportunities in biogeography from that biennial synthesis. We note the realized and potential impact of rapid data accumulation in several fields, a renaissance for inter-disciplinary research, the importance of recognizing the evolution-ecology continuum across spatial and temporal scales and at different taxonomic, phylogenetic and functional levels, and re-exploration of classical assumptions and hypotheses using new tools. However, advances are taxonomically and geographically biased, key theoretical frameworks await tools to handle, or strategies to simplify, the biological complexity seen in empirical systems. Current threats to biodiversity require unprecedented integration of knowledge and development of predictive capacity that may enable biogeography to unite its descriptive and hypothetico-deductive branches and establish a greater role within and outside academia.

  8. Conservation biogeography - foundations, concepts and challenges

    DEFF Research Database (Denmark)

    Richardson, Timothy; Whittaker, R.J.; Whittaker, Robert J.

    2010-01-01

    Conservation biogeography involves the application of biogeographical principles, theories, and analyses to problems regarding biodiversity conservation. The field was formally defined in 2005, and considerable research has been conducted in the ensuing 5 years. This editorial sets the context...... for 16 contributions in a special issue of Diversity and Distributions on developments and challenges in conservation biogeography. Papers are grouped into the following main themes: species distribution modelling; data requirements; approaches for assigning conservation priorities; approaches...... for integrating information from numerous disparate sources; special challenges involving invasive species; and the crucial issue of determining how elements of biodiversity are likely to respond to rapid climate change. One paper provides a synthesis of requirements for a robust conservation biogeography...

  9. Evolution and biogeography of gymnosperms.

    Science.gov (United States)

    Wang, Xiao-Quan; Ran, Jin-Hua

    2014-06-01

    Living gymnosperms comprise only a little more than 1000 species, but represent four of the five main lineages of seed plants, including cycads, ginkgos, gnetophytes and conifers. This group has huge ecological and economic value, and has drawn great interest from the scientific community. Here we review recent advances in our understanding of gymnosperm evolution and biogeography, including phylogenetic relationships at different taxonomic levels, patterns of species diversification, roles of vicariance and dispersal in development of intercontinental disjunctions, modes of molecular evolution in different genomes and lineages, and mechanisms underlying the formation of large nuclear genomes. It is particularly interesting that increasing evidence supports a sister relationship between Gnetales and Pinaceae (the Gnepine hypothesis) and the contribution of recent radiations to present species diversity, and that expansion of retrotransposons is responsible for the large and complex nuclear genome of gymnosperms. In addition, multiple coniferous genera such as Picea very likely originated in North America and migrated into the Old World, further indicating that the center of diversity is not necessarily the place of origin. The Bering Land Bridge acted as an important pathway for dispersal of gymnosperms in the Northern Hemisphere. Moreover, the genome sequences of conifers provide an unprecedented opportunity and an important platform for the evolutionary studies of gymnosperms, and will also shed new light on evolution of many important gene families and biological pathways in seed plants.

  10. A second horizon scan of biogeography

    DEFF Research Database (Denmark)

    Dawson, Michael N.; Axmacher, Jan C.; Beierkuhnlein, Carl

    2016-01-01

    time; moreover, what appears to be a Golden Age may sometimes have an undesirable 'Midas touch'. Contexts within and outwith biogeography-e.g., methods, knowledge, climate, biodiversity, politics-are continually changing, and at times it can be challenging to establish or maintain relevance. In so many...

  11. Conference program and abstracts. International Biogeography Society 6th Biennial Meeting – 9-13 January 2013, Miami, Florida, USA

    Directory of Open Access Journals (Sweden)

    Joaquín Hortal

    2012-12-01

    Full Text Available Proceedings of the Sixth biennial conference of the International Biogeography Society, an international and interdisciplinary society contributing to the advancement of all studies of the geography of nature. Held at Miami, Florida, USA, 9 – 13 January 2013.Abstracts include:(i the Opening, MacArthur & Wilson Award and Alfred Russel Award Plenary Lectures;(ii four symposia entitled "Island Biogeography: New Syntheses", "Beyond Bergmann: New perspectives on the biogeography of traits", "The Convergence of Conservation Paleontology and Biogeography" and "Predicting species and biodiversity in a warmer world: are we doing a good job?";(iii oral presentations from contributed papers on Phylogeography, Marine Biogeography, Biogeography of the Anthropocene, Hot Topics in biogeography, Island Biogeography, Neotropical Biogeography, Global Change Biogeography, Historical and Paleo-biogeography, Conservation Biogeography and Global-Scale Biogeography; and(iv contributions presented as posters on Phylogeography, Geospatial techniques and land cover, Biodiversity gradients and macroecology, Biogeography of traits, Island Biogeography, Neotropical Biogeography, Conservation Biogeography, Disturbance and Disease Biogeography, Climate Change Biogeography and Historical and Paleo-Biogeography.

  12. Intercontinental and intracontinental biogeography patterns and methods

    Institute of Scientific and Technical Information of China (English)

    Jun WEN; Qiu-Yun (Jenny) XIANG; Hong QIAN; Jian-hua LI; Xiao-Quan WANG; Stefanie M. ICKERT-BOND

    2009-01-01

    @@ The study of biogeography has benefited from the exponential increase of DNA sequence data from recent molecular systematic studies, the development of analytical methods in the last decade concerning divergence time estimation and geographic area analyses, and the availability of large-scale distribution data of species in many groups of organisms. The underlying principle of divergence time estimation from DNA and protein data is that sequence divergence depends on the product of evolutionary rate and time. With their molecular clock hypothesis, Zuckerkandl and Pauling (1965) separated rates of molecular evolution from time by incorporating fossil evidence. Originally, a constant rate of sequence evolution was assumed, but soon it became evident that many data sets do not obey the constant rate assumption of a strict molecular clock.

  13. Sympatry inference and network analysis in biogeography.

    Science.gov (United States)

    Dos Santos, Daniel A; Fernández, Hugo R; Cuezzo, María Gabriela; Domínguez, Eduardo

    2008-06-01

    A new approach for biogeography to find patterns of sympatry, based on network analysis, is proposed. Biogeographic analysis focuses basically on sympatry patterns of species. Sympatry is a network (= relational) datum, but it has never been analyzed before using relational tools such as Network Analysis. Our approach to biogeographic analysis consists of two parts: first the sympatry inference and second the network analysis method (NAM). The sympatry inference method was designed to propose sympatry hypothesis, constructing a basal sympatry network based on punctual data, independent of a priori distributional area determination. In this way, two or more species are considered sympatric when there is interpenetration and relative proximity among their records of occurrence. In nature, groups of species presenting within-group sympatry and between-group allopatry constitute natural units (units of co-occurrence). These allopatric units are usually connected by intermediary species. The network analysis method (NAM) that we propose here is based on the identification and removal of intermediary species to segregate units of co-occurrence, using the betweenness measure and the clustering coefficient. The species ranges of the units of co-occurrence obtained are transferred to a map, being considered as candidates to areas of endemism. The new approach was implemented on three different real complex data sets (one of them a classic example previously used in biogeography) resulting in (1) independence of predefined spatial units; (2) definition of co-occurrence patterns from the sympatry network structure, not from species range similarities; (3) higher stability in results despite scale changes; (4) identification of candidates to areas of endemism supported by strictly endemic species; (5) identification of intermediary species with particular biological attributes.

  14. Concentric Circular Antenna Array Synthesis Using Biogeography Based Optimization

    Directory of Open Access Journals (Sweden)

    Urvinder Singh

    2012-03-01

    Full Text Available Biogeography based optimization (BBO is a new stochastic force based on the science of biogeography. Biogeography is the schoolwork of geographical allotment of biological organisms. BBO utilizes migration operator to share information between the problem solutions. The problem solutions are known as habitats and sharing of features is called migration. In this paper, BBO algorithm is developed to optimize the current excitations of concentric circular antenna arrays (CCAA. Concentric Circular Antenna Array (CCAA has numerous attractive features that make it essential in mobile and communication applications. The goal of the optimization is to reduce the side lobe levels and the primary lobe beam width as much as possible. To confirm the capabilities of BBO, three different CCAA antennas of different sizes are taken. The results obtained by BBO are compared with the Real coded Genetic Algorithm (RGA, Craziness based Particle Swarm Optimization (CRPSO and Hybrid Evolutionary Programming (HEP.

  15. The Biogeography of Putative Microbial Antibiotic Production.

    Directory of Open Access Journals (Sweden)

    Hélène Morlon

    Full Text Available Understanding patterns in the distribution and abundance of functional traits across a landscape is of fundamental importance to ecology. Mapping these distributions is particularly challenging for species-rich groups with sparse trait measurement coverage, such as flowering plants, insects, and microorganisms. Here, we use likelihood-based character reconstruction to infer and analyze the spatial distribution of unmeasured traits. We apply this framework to a microbial dataset comprised of 11,732 ketosynthase alpha gene sequences extracted from 144 soil samples from three continents to document the spatial distribution of putative microbial polyketide antibiotic production. Antibiotic production is a key competitive strategy for soil microbial survival and performance. Additionally, novel antibiotic discovery is highly relevant to human health, making natural antibiotic production by soil microorganisms a major target for bioprospecting. Our comparison of trait-based biogeographical patterns to patterns based on taxonomy and phylogeny is relevant to our basic understanding of microbial biogeography as well as the pressing need for new antibiotics.

  16. Marine cyanophages exhibit local and regional biogeography.

    Science.gov (United States)

    Marston, Marcia F; Taylor, Samantha; Sme, Noel; Parsons, Rachel J; Noyes, Timothy J E; Martiny, Jennifer B H

    2013-05-01

    Biogeographic patterns have been demonstrated for a wide range of microorganisms. Nevertheless, the biogeography of marine viruses has been slower to emerge. Here we investigate biogeographic patterns of marine cyanophages that infect Synechococcus sp. WH7803 across multiple spatial and temporal scales. We compared cyanophage myoviral communities from nine coastal sites in Southern New England (SNE), USA, one site in Long Island NY, and four sites from Bermuda's inshore waters by assaying cyanophage isolates using the myoviral g43 DNA polymerase gene. Cyanophage community composition varied temporally at each of the sites. Further, 6 years of sampling at one Narragansett Bay site revealed annual seasonal variations in community composition, driven by the seasonal reoccurrence of specific viral taxa. Although the four Bermuda communities were similar to one another, they were significantly different than the North American coastal communities, with almost no overlap of taxa between the two regions. Among the SNE sites, cyanophage community composition also varied significantly and was correlated with the body of water sampled (e.g. Narragansett Bay, Cape Cod Bay, Vineyard Sound), although here, the same viral taxa were found at multiple sites. This study demonstrates that marine cyanophages display striking seasonal and spatial biogeographic patterns.

  17. Countryside biogeography of Neotropical reptiles and amphibians.

    Science.gov (United States)

    Mendenhall, Chase D; Frishkoff, Luke O; Santos-Barrera, Georgina; Pacheco, Jesús; Mesfun, Eyobed; Mendoza Quijano, Fernando; Ehrlich, Paul R; Ceballos, Gerardo; Daily, Gretchen C; Pringle, Robert M

    2014-04-01

    The future of biodiversity and ecosystem services depends largely on the capacity of human-dominated ecosystems to support them, yet this capacity remains largely unknown. Using the framework of countryside biogeography, and working in the Las Cruces system of Coto Brus, Costa Rica, we assessed reptile and amphibian assemblages within four habitats that typify much of the Neotropics: sun coffee plantations (12 sites), pasture (12 sites), remnant forest elements (12 sites), and a larger, contiguous protected forest (3 sites in one forest). Through analysis of 1678 captures of 67 species, we draw four primary conclusions. First, we found that the majority of reptile (60%) and amphibian (70%) species in this study used an array of habitat types, including coffee plantations and actively grazed pastures. Second, we found that coffee plantations and pastures hosted rich, albeit different and less dense, reptile and amphibian biodiversity relative to the 326-ha Las Cruces Forest Reserve and neighboring forest elements. Third, we found that the small ribbons of "countryside forest elements" weaving through farmland collectively increased the effective size of a 326-ha local forest reserve 16-fold for reptiles and 14-fold for amphibians within our 236-km2 study area. Therefore, countryside forest elements, often too small for most remote sensing techniques to identify, are contributing -95% of the available habitat for forest-dependent reptiles and amphibians in our largely human-dominated study region. Fourth, we found large and pond-reproducing amphibians to prefer human-made habitats, whereas small, stream-reproducing, and directly developing species are more dependent on forest elements. Our investigation demonstrates that tropical farming landscapes can support substantial reptile and amphibian biodiversity. Our approach provides a framework for estimating the conservation value of the complex working landscapes that constitute roughly half of the global land surface

  18. BIOGEOGRAPHY. The dispersal of alien species redefines biogeography in the Anthropocene.

    Science.gov (United States)

    Capinha, César; Essl, Franz; Seebens, Hanno; Moser, Dietmar; Pereira, Henrique Miguel

    2015-06-12

    It has been argued that globalization in human-mediated dispersal of species breaks down biogeographic boundaries, yet empirical tests are still missing. We used data on native and alien ranges of terrestrial gastropods to analyze dissimilarities in species composition among 56 globally distributed regions. We found that native ranges confirm the traditional biogeographic realms, reflecting natural dispersal limitations. However, the distributions of gastropods after human transport are primarily explained by the prevailing climate and, to a smaller extent, by distance and trade relationships. Our findings show that human-mediated dispersal is causing a breakdown of biogeographic barriers, and that climate and to some extent socioeconomic relationships will define biogeography in an era of global change.

  19. Biogeography of sulfate-reducing prokaryotes in river floodplains

    NARCIS (Netherlands)

    Miletto, M.; Loy, A.; Antheunisse, A.M.; Loeb, R.; Bodelier, P.L.E.; Laanbroek, R.

    2008-01-01

    In this study, a large-scale field survey was conducted to describe the biogeography of sulfate-reducing prokaryotes (SRPs) in river floodplains. Fingerprints obtained with three methods, i.e. 16S rRNA gene-based oligonucleotide microarray, dsrB-based denaturing gradient gel electrophoresis (DGGE) a

  20. Hydrography shapes bacterial biogeography of the deep Arctic Ocean.

    Science.gov (United States)

    Galand, Pierre E; Potvin, Marianne; Casamayor, Emilio O; Lovejoy, Connie

    2010-04-01

    It has been long debated as to whether marine microorganisms have a ubiquitous distribution or patterns of biogeography, but recently a consensus for the existence of microbial biogeography is emerging. However, the factors controlling the distribution of marine bacteria remain poorly understood. In this study, we combine pyrosequencing and traditional Sanger sequencing of the 16S rRNA gene to describe in detail bacterial communities from the deep Arctic Ocean. We targeted three separate water masses, from three oceanic basins and show that bacteria in the Arctic Ocean have a biogeography. The biogeographical distribution of bacteria was explained by the hydrography of the Arctic Ocean and subsequent circulation of its water masses. Overall, this first taxonomic description of deep Arctic bacteria communities revealed an abundant presence of SAR11 (Alphaproteobacteria), SAR406, SAR202 (Chloroflexi) and SAR324 (Deltaproteobacteria) clusters. Within each cluster, the abundance of specific phylotypes significantly varied among water masses. Water masses probably act as physical barriers limiting the dispersal and controlling the diversity of bacteria in the ocean. Consequently, marine microbial biogeography involves more than geographical distances, as it is also dynamically associated with oceanic processes. Our ocean scale study suggests that it is essential to consider the coupling between microbial and physical oceanography to fully understand the diversity and function of marine microbes.

  1. A Theory of Island Biogeography for Exotic Species.

    Science.gov (United States)

    Burns, Kevin C

    2015-10-01

    The theory of island biogeography has played a pivotal role in the way ecologists view communities. However, it does not account for exotic species explicitly, which limits its use as a conservation tool. Here, I present the results of a long-term study of plant communities inhabiting an archipelago of small islands off the coast of New Zealand and derive a modified version of the theory of island biogeography to predict differences in the turnover and diversity of native and exotic species. Empirical results showed that, although species richness of both native and exotic plant species increased with island area, native species consistently outnumbered exotic species. Species turnover increased with species richness in both groups. However, opposite to species-area patterns, turnover increased more rapidly with species richness in exotic species. Empirical results were consistent with the modified version of the theory of island biogeography, which distinguishes exotic species from native species by decoupling extinction rates of exotic species from island area, because they are represented by only small populations at the initial stages of invasion. Overall results illustrate how the theory of island biogeography can be modified to reflect the dynamics of exotic species as they invade archipelagos, expanding its use as a conservation tool.

  2. Biogeography and ecology of southern Portuguese butterflies and burnets (Lepidoptera)

    NARCIS (Netherlands)

    Schmitt, T.

    2003-01-01

    Biogeography and ecology of southern Portuguese butterflies and burnets (Lepidoptera) During several visits to the western part of the Algarve (southern Portugal), the author mapped the butterflies and burnets of this region. In total, I observed 58 butterfly species (51 Papilionoidea, 7 Hesperiidae

  3. Using historical biogeography to test for community saturation.

    Science.gov (United States)

    Pinto-Sánchez, Nelsy Rocío; Crawford, Andrew J; Wiens, John J

    2014-09-01

    Saturation is the idea that a community is effectively filled with species, such that no more can be added without extinctions. This concept has important implications for many areas of ecology, such as species richness, community assembly, invasive species and climate change. Here, we illustrate how biogeography can be used to test for community saturation, when combined with data on local species richness, phylogeny and climate. We focus on a clade of frogs (Terrarana) and the impact of the Great American Biotic Interchange on patterns of local richness in Lower Middle America and adjacent regions. We analyse data on species richness at 83 sites and a time-calibrated phylogeny for 363 species. We find no evidence for saturation, and show instead that biotic interchange dramatically increased local richness in the region. We suggest that historical biogeography offers thousands of similar long-term natural experiments that can be used to test for saturation.

  4. Biogeography of photoautotrophs in the high polar biome

    Directory of Open Access Journals (Sweden)

    Stephen Brian Pointing

    2015-09-01

    Full Text Available The global latitudinal gradient in biodiversity weakens in the high polar biome and so an alternative explanation for distribution of Arctic and Antarctic photoautotrophs is required. Here we identify how temporal, microclimate and evolutionary drivers of biogeography are important, rather than the macroclimate features that drive plant diversity patterns elsewhere. High polar ecosystems are biologically unique, with a more central role for bryophytes, lichens and microbial photoautotrophs over that of vascular plants. Constraints on vascular plants arise mainly due to stature and ontogenetic barriers. Conversely non-vascular plant and microbial photoautotroph distribution is correlated with favourable microclimates and the capacity for poikilohydric dormancy. Contemporary distribution also depends on evolutionary history, with adaptive and dispersal traits as well as legacy influencing biogeography. We highlight the relevance of these findings to predicting future impacts on polar plant diversity and to the current status of plants in Arctic and Antarctic conservation policy frameworks.

  5. Spikemoss patterns : Systematics and historical biogeography of Selaginellaceae

    OpenAIRE

    Weststrand, Stina

    2016-01-01

    Selaginellaceae, spikemosses, is a heterosporous plant family belonging to the lycophytes. With an estimated age of some 350 million years, the family is historically important as one of the oldest known groups of vascular plants. Selaginellaceae is herbaceous with a worldwide distribution. However, the majority of the ca. 750 species in the single genus Selaginella are found in the tropics and subtropics. This thesis aims at elucidating the systematics and historical biogeography of Selagine...

  6. Optimization of nonlinear controller with an enhanced biogeography approach

    Directory of Open Access Journals (Sweden)

    Mohammed Salem

    2014-07-01

    Full Text Available This paper is dedicated to the optimization of nonlinear controllers basing of an enhanced Biogeography Based Optimization (BBO approach. Indeed, The BBO is combined to a predator and prey model where several predators are used with introduction of a modified migration operator to increase the diversification along the optimization process so as to avoid local optima and reach the optimal solution quickly. The proposed approach is used in tuning the gains of PID controller for nonlinear systems. Simulations are carried out over a Mass spring damper and an inverted pendulum and has given remarkable results when compared to genetic algorithm and BBO.

  7. Advances and Limitations of Disease Biogeography Using Ecological Niche Modeling.

    Science.gov (United States)

    Escobar, Luis E; Craft, Meggan E

    2016-01-01

    Mapping disease transmission risk is crucial in public and animal health for evidence based decision-making. Ecology and epidemiology are highly related disciplines that may contribute to improvements in mapping disease, which can be used to answer health related questions. Ecological niche modeling is increasingly used for understanding the biogeography of diseases in plants, animals, and humans. However, epidemiological applications of niche modeling approaches for disease mapping can fail to generate robust study designs, producing incomplete or incorrect inferences. This manuscript is an overview of the history and conceptual bases behind ecological niche modeling, specifically as applied to epidemiology and public health; it does not pretend to be an exhaustive and detailed description of ecological niche modeling literature and methods. Instead, this review includes selected state-of-the-science approaches and tools, providing a short guide to designing studies incorporating information on the type and quality of the input data (i.e., occurrences and environmental variables), identification and justification of the extent of the study area, and encourages users to explore and test diverse algorithms for more informed conclusions. We provide a friendly introduction to the field of disease biogeography presenting an updated guide for researchers looking to use ecological niche modeling for disease mapping. We anticipate that ecological niche modeling will soon be a critical tool for epidemiologists aiming to map disease transmission risk, forecast disease distribution under climate change scenarios, and identify landscape factors triggering outbreaks.

  8. Statistical Mechanics Approximation of Biogeography-Based Optimization.

    Science.gov (United States)

    Ma, Haiping; Simon, Dan; Fei, Minrui

    2016-01-01

    Biogeography-based optimization (BBO) is an evolutionary algorithm inspired by biogeography, which is the study of the migration of species between habitats. This paper derives a mathematical description of the dynamics of BBO based on ideas from statistical mechanics. Rather than trying to exactly predict the evolution of the population, statistical mechanics methods describe the evolution of statistical properties of the population fitness. This paper uses the one-max problem, which has only one optimum and whose fitness function is the number of 1s in a binary string, to derive equations that predict the statistical properties of BBO each generation in terms of those of the previous generation. These equations reveal the effect of migration and mutation on the population fitness dynamics of BBO. The results obtained in this paper are similar to those for the simple genetic algorithm with selection and mutation. The paper also derives equations for the population fitness dynamics of general separable functions, and we find that the results obtained for separable functions are the same as those for the one-max problem. The statistical mechanics theory of BBO is shown to be in good agreement with simulation.

  9. A Predictive Model for Investigating Seagrass Paleoecology, Biogeography and Diversity

    Science.gov (United States)

    Sewall, J. O.; Clementz, M. T.

    2008-12-01

    Seagrasses are highly productive components of coastal ecosystems that play significant roles in the flow of nutrients and the modulation of physical conditions within the world's oceans. However, in spite of the significant role seagrasses play today, the fossil record contains little evidence of the distribution and abundance of seagrass species in the past and many questions about their biology, ecology, and evolutionary history remain. We have developed, and present here, a parameter driven numerical model of global seagrass biogeography and diversity appropriate for paleontological and paleoecological investigations. The global distribution of seagrasses in our model is dependent on four input parameters, water temperature, water salinity, water depth, and photosynthetically available radiation at depth. With these limited inputs, our model captures both the location and biodiversity of modern seagrass distributions well. The simplicity of our model and its robust representation of modern conditions give it tremendous flexibility for applications throughout the ~70 Ma long history of seagrasses. Paleo ocean temperatures, salinity, water depths, and incident radiation are available from paleoclimatic/proxy datasets and/or numerical simulations of past environmental/climatic conditions, thus permitting investigations into time specific seagrass biogeography and diversity throughout its evolutionary history. In addition, the simplicity of our model allows for theoretical investigations of seagrass paleoecology and response to environmental changes. Both applications will contribute significantly to furthering our understanding of seagrasses, seagrass dominated ecosystems, and the roles they have played in the earth system over the past 70 Ma.

  10. Biogeography as critical nursing pedagogy: Breathing life into nurse education.

    Science.gov (United States)

    Kyle, Richard G; Atherton, Iain M

    2016-09-01

    Insights from the social sciences, including geography, sociology, and anthropology, have long been incorporated into pre-registration nursing programmes. However, scholars have suggested that their inclusion has been sporadic and lacks clear theoretical rationale. In this paper we argue anew that the social sciences - and particularly, human geography - could be central to nurse education. Specifically, we recast the concept of 'biogeography' drawn from human geography that emphasises the interplay between life (bio) and place (geo) to propose pedagogy that theoretically justifies and practically enables the inclusion of the social sciences in nurse education. Biogeography can breathe new life into nursing curricula by animating our students through the cultivation of three 'spirits of nursing'. First, a 'spirit of empathy' that can shatter patient-professional dualisms by facilitating person-centred and place-sensitive care. Second, a 'spirit of engagement' that situates practice in social structures awakening a desire to effect change by fomenting an acute sense of social justice. Third, a 'spirit of enquiry' that holds in critical tension the theory-practice gap by fostering continual questioning and pursuit of evidence. In so doing, biogeographical pedagogy releases the latent potential of the social sciences to revitalise nurse education, reinvigorate our students, and renew ourselves as nurse educators.

  11. Advances and Limitations of Disease Biogeography Using Ecological Niche Modeling

    Science.gov (United States)

    Escobar, Luis E.; Craft, Meggan E.

    2016-01-01

    Mapping disease transmission risk is crucial in public and animal health for evidence based decision-making. Ecology and epidemiology are highly related disciplines that may contribute to improvements in mapping disease, which can be used to answer health related questions. Ecological niche modeling is increasingly used for understanding the biogeography of diseases in plants, animals, and humans. However, epidemiological applications of niche modeling approaches for disease mapping can fail to generate robust study designs, producing incomplete or incorrect inferences. This manuscript is an overview of the history and conceptual bases behind ecological niche modeling, specifically as applied to epidemiology and public health; it does not pretend to be an exhaustive and detailed description of ecological niche modeling literature and methods. Instead, this review includes selected state-of-the-science approaches and tools, providing a short guide to designing studies incorporating information on the type and quality of the input data (i.e., occurrences and environmental variables), identification and justification of the extent of the study area, and encourages users to explore and test diverse algorithms for more informed conclusions. We provide a friendly introduction to the field of disease biogeography presenting an updated guide for researchers looking to use ecological niche modeling for disease mapping. We anticipate that ecological niche modeling will soon be a critical tool for epidemiologists aiming to map disease transmission risk, forecast disease distribution under climate change scenarios, and identify landscape factors triggering outbreaks. PMID:27547199

  12. Phylogeny and Biogeography of Cyanobacteria and Their Produced Toxins

    Directory of Open Access Journals (Sweden)

    Agostinho Antunes

    2013-11-01

    Full Text Available Phylogeny is an evolutionary reconstruction of the past relationships of DNA or protein sequences and it can further be used as a tool to assess population structuring, genetic diversity and biogeographic patterns. In the microbial world, the concept that everything is everywhere is widely accepted. However, it is much debated whether microbes are easily dispersed globally or whether they, like many macro-organisms, have historical biogeographies. Biogeography can be defined as the science that documents the spatial and temporal distribution of a given taxa in the environment at local, regional and continental scales. Speciation, extinction and dispersal are proposed to explain the generation of biogeographic patterns. Cyanobacteria are a diverse group of microorganisms that inhabit a wide range of ecological niches and are well known for their toxic secondary metabolite production. Knowledge of the evolution and dispersal of these microorganisms is still limited, and further research to understand such topics is imperative. Here, we provide a compilation of the most relevant information regarding these issues to better understand the present state of the art as a platform for future studies, and we highlight examples of both phylogenetic and biogeographic studies in non-symbiotic cyanobacteria and cyanotoxins.

  13. Advances and Limitations of Disease Biogeography Using Ecological Niche Modeling

    Directory of Open Access Journals (Sweden)

    Luis E Escobar

    2016-08-01

    Full Text Available Mapping disease transmission risk is crucial in public and animal health for evidence based decision-making. Ecology and epidemiology are highly related disciplines that may contribute to improvements in mapping disease, which can be used to answer health related questions. Ecological niche modeling is increasingly used for understanding the biogeography of diseases in plants, animals, and humans. However, epidemiological applications of niche modeling approaches can fail to generate robust study designs, generating incomplete or incorrect inferences. This manuscript is an overview of the history and conceptual bases behind ecological niche modeling, specifically as applied to epidemiology and public health; it does not pretend to be an exhaustive and detailed description of ecological niche modeling literature and methods. Instead, this review includes selected state-of-the-science approaches and tools, providing a short guide to designing studies incorporating information on the type and quality of the input data (i.e., occurrences and environmental variables, identification and justification of the extent of the study area, and encourages users to explore and test diverse algorithms for more informed conclusions. We provide a friendly introduction to the field of disease biogeography presenting an updated guide for researchers looking to use ecological niche modeling for disease mapping. We anticipate that ecological niche modeling will soon be a critical tool for epidemiologists aiming to map disease transmission risk, forecast disease distribution under climate change scenarios, and identify landscape factors triggering outbreaks.

  14. Studies on phylogeny and biogeography of damselflies (Odonata) with emphasis on the Argiolestidae

    NARCIS (Netherlands)

    Kalkman, Vincent J.

    2013-01-01

    he papers in which are part of this theses describe the global diversity and conservation status of damselflies and dragonflies, contain a moleculair revision of the damselflies and discuss the biogeography of damselflies and dragonflies in the Australasian region.

  15. Complex System Optimization Using Biogeography-Based Optimization

    Directory of Open Access Journals (Sweden)

    Dawei Du

    2013-01-01

    Full Text Available Complex systems are frequently found in modern industry. But with their multisubsystems, multiobjectives, and multiconstraints, the optimization of complex systems is extremely hard. In this paper, a new algorithm adapted from biogeography-based optimization (BBO is introduced for complex system optimization. BBO/Complex is the combination of BBO with a multiobjective ranking system, an innovative migration approach, and effective diversity control. Based on comparisons with three complex system optimization algorithms (multidisciplinary feasible (MDF, individual discipline feasible (IDF, and collaborative optimization (CO on four real-world benchmark problems, BBO/Complex demonstrates competitive performance. BBO/Complex provides the best performance in three of the benchmark problems and the second best in the fourth problem.

  16. Floristics and biogeography of vegetation in seasonally dry tropical regions

    DEFF Research Database (Denmark)

    Dexter, K.G.; Smart, B.; Baldauf, C.

    2015-01-01

    To provide an inter-continental overview of the floristics and biogeography of drought-adapted tropical vegetation formations, we compiled a dataset of inventory plots in South America (n=93), Africa (n=84), and Asia (n=92) from savannas (subject to fire), seasonally dry tropical forests (not...... generally subject to fire), and moist forests (no fire). We analysed floristic similarity across vegetation formations within and between continents. Our dataset strongly suggests that different formations tend to be strongly clustered floristically by continent, and that among continents, superficially...... similar vegetation formations (e.g. savannas) are floristically highly dissimilar. Neotropical moist forest, savanna and seasonally dry tropical forest are floristically distinct, but elsewhere there is no clear floristic division of savanna and seasonally dry tropical forest, though moist and dry...

  17. Biogeography in the air: fungal diversity over land and oceans

    Directory of Open Access Journals (Sweden)

    J. Fröhlich-Nowoisky

    2012-03-01

    Full Text Available Biogenic aerosols are relevant for the Earth system, climate, and public health on local, regional, and global scales. Up to now, however, little is known about the diversity and biogeography of airborne microorganisms. We present the first DNA-based analysis of airborne fungi on global scales, showing pronounced geographic patterns and boundaries. In particular we find that the ratio of species richness between Basidiomycota and Ascomycota is much higher in continental air than in marine air. This may be an important difference between the "blue ocean" and "green ocean" regimes in the formation of clouds and precipitation, for which fungal spores can act as nuclei. Our findings also suggest that air flow patterns and the global atmospheric circulation are important for the understanding of global changes in biodiversity.

  18. Biogeography in the air: fungal diversity over land and oceans

    Directory of Open Access Journals (Sweden)

    J. Fröhlich-Nowoisky

    2011-07-01

    Full Text Available Biogenic aerosols are relevant for the Earth system, climate, and public health on local, regional, and global scales. Up to now, however, little is known about the diversity and biogeography of airborne microorganisms. We present the first DNA-based analysis of airborne fungi on global scales, showing pronounced geographic patterns and boundaries. In particular we found that the ratio of species richness between Basidiomycota and Ascomycota is much higher in continental air than in marine air. This may be an important difference between the "blue ocean" and "green ocean" regimes in the formation of clouds and precipitation, for which fungal spores can act as nuclei. Our findings also suggest that air flow patterns and the global atmospheric circulation are important for the evolution of microbial ecology and for the understanding of global changes in biodiversity.

  19. Phylogenetic biogeography and taxonomy of disjunctly distributed bryophytes

    Institute of Scientific and Technical Information of China (English)

    Jochen HEINRICHS; J(o)rn HENTSCHEL; Kathrin FELDBERG; Andrea BOMBOSCH; Harald SCHNEIDER

    2009-01-01

    More than 200 research papers on the molecular phylogeny and phylogenetic biogeography of bryophytes have been published since the beginning of this millenium. These papers corroborated assumptions of a complex ge-netic structure of morphologically circumscribed bryophytes, and raised reservations against many morphologically justified species concepts, especially within the mosses. However, many molecular studies allowed for corrections and modifications of morphological classification schemes. Several studies reported that the phylogenetic structure of disjunctly distributed bryophyte species reflects their geographical ranges rather than morphological disparities. Molecular data led to new appraisals of distribution ranges and allowed for the reconstruction of refugia and migra-tion routes. Intercontinental ranges of bryophytes are often caused by dispersal rather than geographical vicariance. Many distribution patterns of disjunct bryophytes are likely formed by processes such as short distance dispersal, rare long distance dispersal events, extinction, recolonization and diversification.

  20. A biogeography-based optimization for optimum discrete design of skeletal structures

    Science.gov (United States)

    Jalili, Shahin; Hosseinzadeh, Yousef; Taghizadieh, Nasser

    2016-09-01

    This article presents a modified biogeography-based optimization (MBBO) algorithm for optimum design of skeletal structures with discrete variables. The main idea of the biogeography-based optimization (BBO) algorithm is based on the science of biogeography, in which each habitat is a possible solution for the optimization problem in the search space. This algorithm consists of two main operators: migration and mutation. The migration operator helps the habitats to exploit the search space, while the mutation operator guides habitats to escape from the local optimum. To enhance the performance of the standard algorithm, some modifications are made and an MBBO algorithm is presented. The performance of the MBBO algorithm is evaluated by optimizing five benchmark design examples, and the obtained results are compared with other methods in the literature. The numerical results demonstrate that the MBBO algorithm is able to show very competitive results and has merits in finding optimum designs.

  1. Global phylogeny and biogeography of grammitid ferns (Polypodiaceae).

    Science.gov (United States)

    Sundue, Michael A; Parris, Barbara S; Ranker, Tom A; Smith, Alan R; Fujimoto, Erin L; Zamora-Crosby, Delia; Morden, Clifford W; Chiou, Wen-Liang; Chen, Cheng-Wei; Rouhan, Germinal; Hirai, Regina Y; Prado, Jefferson

    2014-12-01

    We examined the global historical biogeography of grammitid ferns (Polypodiaceae) within a phylogenetic context. We inferred phylogenetic relationships of 190 species representing 31 of the 33 currently recognized genera of grammitid ferns by analyzing DNA sequence variation of five plastid DNA regions. We estimated the ages of cladogenetic events on an inferred phylogeny using secondary fossil calibration points. Historical biogeographical patterns were inferred via ancestral area reconstruction. Our results supported four large-scale phylogenetic and biogeographic patterns: (1) a monophyletic grammitid clade that arose among Neotropical polypod ancestors about 31.4 Ma; (2) a paraphyletic assemblage of clades distributed in the Neotropics and the Afro-Malagasy region; (3) a large clade distributed throughout the Asia-Malesia-Pacific region that originated about 23.4 Ma; and, (4) an Australian or New Zealand origin of the circumaustral genus Notogrammitis. Most genera were supported as monophyletic except for Grammitis, Oreogrammitis, Radiogrammitis, and Zygophlebia. Grammitid ferns are a well-supported monophyletic group with two biogeographically distinct lineages: a primarily Neotropical grade exhibiting several independent successful colonizations to the Afro-Malagasy region and a primarily Paleotropical clade exhibiting multiple independent dispersals to remote Pacific islands and temperate, austral regions.

  2. Biogeography and Adaptive evolution of Streptomyces Strains from saline environments

    Science.gov (United States)

    Zhao, Fei; Qin, Yu-Hua; Zheng, Xin; Zhao, Hong-Wei; Chai, Dong-Yan; Li, Wei; Pu, Ming-Xiang; Zuo, Xing-Sheng; Qian, Wen; Ni, Ping; Zhang, Yong; Mei, Han; He, Song-Tao

    2016-01-01

    The genus Streptomyces is a widespread genus within the phylum Actinobacteria and has been isolated from various environments worldwide. However, little is known about whether biogeography affects distributional pattern of Streptomyces in salty environments. Such information is essential for understanding the ecology of Streptomyces. Here we analyzed four house-keeping genes (16S rRNA, rpoB, recA and atpD) and salty-tolerance related genes (ectA-ectD) of 38 Streptomyces strains isolated from saline environments in Yunnan and Xinjiang Provinces of western China. The obtained Streptomyces strains were classified into three operational taxonomic units, each comprising habitat-specific geno- and ecotype STs. In combination with expressional variations of salty-tolerance related genes, the statistical analyses showed that spatial distance and environmental factors substantially influenced Streptomyces distribution in saline environments: the former had stronger influence at large spatial scales (>700 km), whereas the latter was influential at large (>700 km) and small spatial scales (ectoine and hydroxyectoine than strains from salt mines, which could help them resist to salinity in the hypersaline environments. PMID:27596681

  3. Reconstructing ancestral ranges in historical biogeography: properties and prospects

    Institute of Scientific and Technical Information of China (English)

    Kristin S. LAMM; Benjamin D. REDELINGS

    2009-01-01

    Recent years have witnessed a proliferation of quantitative methods for biogeographic inference. In particular, novel parametric approaches represent exciting new opportunities for the study of range evolution. Here, we review a selection of current methods for biogeographic analysis and discuss their respective properties. These methods include generalized parsimony approaches, weighted ancestral area analysis, dispersal-vicariance analysis, the dispersal-extinction-cladogenesis model and other maximum likelihood approaches, and Bayesian stochastic mapping of ancestral ranges, including a novel approach to inferring range evolution in the context of island biogeography. Some of these methods were developed specifically for problems of ancestral range reconstruction, whereas others were designed for more general problems of character state reconstruction and subsequently applied to the study of ancestral ranges. Methods for reconstructing ancestral history on a phylogenetic tree differ not only in the types of ancestral range states that are allowed, but also in the various historical events that may change the ancestral ranges. We explore how the form of allowed ancestral ranges and allowed transitions can both affect the outcome of ancestral range estimation. Finally, we mention some promising avenues for future work in the development of model-based approaches to biogeographic analysis.

  4. Biogeography of thermophilic phototrophic bacteria belonging to Roseiflexus genus.

    Science.gov (United States)

    Gaisin, Vasil A; Grouzdev, Denis S; Namsaraev, Zorigto B; Sukhacheva, Marina V; Gorlenko, Vladimir M; Kuznetsov, Boris B

    2016-03-01

    Isolated environments such as hot springs are particularly interesting for studying the microbial biogeography. These environments create an 'island effect' leading to genetic divergence. We studied the phylogeographic pattern of thermophilic anoxygenic phototrophic bacteria, belonging to the Roseiflexus genus. The main characteristic of the observed pattern was geographic and geochronologic fidelity to the hot springs within Circum-Pacific and Alpine-Himalayan-Indonesian orogenic belts. Mantel test revealed a correlation between genetic divergence and geographic distance among the phylotypes. Cluster analysis revealed a regional differentiation of the global phylogenetic pattern. The phylogeographic pattern is in correlation with geochronologic events during the break up of Pangaea that led to the modern configuration of continents. To our knowledge this is the first geochronological scenario of intercontinental prokaryotic taxon divergence. The existence of the modern phylogeographic pattern contradicts with the existence of the ancient evolutionary history of the Roseiflexus group proposed on the basis of its deep-branching phylogenetic position. These facts indicate that evolutionary rates in Roseiflexus varied over a wide range.

  5. Microbial Biogeography and Core Microbiota of the Rat Digestive Tract

    Science.gov (United States)

    Li, Dongyao; Chen, Haiqin; Mao, Bingyong; Yang, Qin; Zhao, Jianxin; Gu, Zhennan; Zhang, Hao; Chen, Yong Q.; Chen, Wei

    2017-01-01

    As a long-standing biomedical model, rats have been frequently used in studies exploring the correlations between gastrointestinal (GI) bacterial biota and diseases. In the present study, luminal and mucosal samples taken along the longitudinal axis of the rat digestive tract were subjected to 16S rRNA gene sequencing-based analysis to determine the baseline microbial composition. Results showed that the community diversity increased from the upper to lower GI segments and that the stratification of microbial communities as well as shift of microbial metabolites were driven by biogeographic location. A greater proportion of lactate-producing bacteria (such as Lactobacillus, Turicibacter and Streptococcus) were found in the stomach and small intestine, while anaerobic Lachnospiraceae and Ruminococcaceae, fermenting carbohydrates and plant aromatic compounds, constituted the bulk of the large-intestinal core microbiota where topologically distinct co-occurrence networks were constructed for the adjacent luminal and mucosal compartments. When comparing the GI microbiota from different hosts, we found that the rat microbial biogeography might represent a new reference, distinct from other murine animals. Our study provides the first comprehensive characterization of the rat GI microbiota landscape for the research community, laying the foundation for better understanding and predicting the disease-related alterations in microbial communities. PMID:28374781

  6. Species tree estimation and the historical biogeography of heroine cichlids.

    Science.gov (United States)

    Hulsey, C Darrin; Keck, Benjamin P; Hollingsworth, Phillip R

    2011-01-01

    Heroine cichlids are major components of the fish faunas in both Central America and the Caribbean. To examine the evolutionary patterns of how cichlids colonized both of these regions, we reconstructed the phylogenetic relationships among 23 cichlid lineages. We used three phylogenetically novel nuclear markers (Dystropin b, Myomesin1, and Wnt7b) in combination with sequence data from seven other gene regions (Nd2, Rag1, Enc1, Sreb2, Ptr, Plagl2, and Zic1) to elucidate the species tree of these cichlids. The species examined represent major heroine lineages in South America, Central America, and the Greater Antilles. The individual gene trees of these groups were topologically quite discordant. Therefore, we combined the genetic partitions and inferred the species tree using both concatenation and a coalescent-based Bayesian method. The two resulting phylogenetic topologies were largely concordant but differed in two fundamental ways. First, more nodes in the concatenated tree were supported with substantial or 100% Bayesian posterior support than in the coalescent-based tree. Second, there was a minor, but biogeographically critical, topological difference between the concatenated and coalescent-based trees. Nevertheless, both analyses recovered topologies consistent with the Greater Antillean heroines being phylogenetically nested within the largely Central American heroine radiation. This study suggests that reconstructions of cichlid phylogeny and historical biogeography should account for the vagaries of individual gene histories.

  7. Biogeography of dinoflagellate cysts in northwest Atlantic estuaries.

    Science.gov (United States)

    Price, Andrea M; Pospelova, Vera; Coffin, Michael R S; Latimer, James S; Chmura, Gail L

    2016-08-01

    Few biogeographic studies of dinoflagellate cysts include the near-shore estuarine environment. We determine the effect of estuary type, biogeography, and water quality on the spatial distribution of organic-walled dinoflagellate cysts from the Northeast USA (Maine to Delaware) and Canada (Prince Edward Island). A total of 69 surface sediment samples were collected from 27 estuaries, from sites with surface salinities >20. Dinoflagellate cysts were examined microscopically and compared to environmental parameters using multivariate ordination techniques. The spatial distribution of cyst taxa reflects biogeographic provinces established by other marine organisms, with Cape Cod separating the northern Acadian Province from the southern Virginian Province. Species such as Lingulodinium machaerophorum and Polysphaeridinium zoharyi were found almost exclusively in the Virginian Province, while others such as Dubridinium spp. and Islandinium? cezare were more abundant in the Acadian Province. Tidal range, sea surface temperature (SST), and sea surface salinity (SSS) are statistically significant parameters influencing cyst assemblages. Samples from the same type of estuary cluster together in canonical correspondence analysis when the estuaries are within the same biogeographic province. The large geographic extent of this study, encompassing four main estuary types (riverine, lagoon, coastal embayment, and fjord), allowed us to determine that the type of estuary has an important influence on cyst assemblages. Due to greater seasonal variations in SSTs and SSSs in estuaries compared to the open ocean, cyst assemblages show distinct latitudinal trends. The estuarine context is important for understanding present-day species distribution, the factors controlling them, and to better predict how they may change in the future.

  8. Evolution and biogeography of Haemonchus contortus, linking faunal dynamics in space and time

    Science.gov (United States)

    History is the foundation that informs about the nuances of faunal assembly that are essential in understanding the dynamic nature of the host-parasite interface. All of our knowledge begins and ends with evolution, ecology and biogeography as these interacting facets determine the history of biodi...

  9. Does biogeography have a future in a globalized world with globalized faunas?

    NARCIS (Netherlands)

    Schram, F.R.

    2008-01-01

    The study of biogeography was once a pillar of evolution science. Both Darwin and especially Wallace found great inspiration from the consideration of animal distributions. However, what is to happen to this discipline in a time of global trade, mass movement of people and goods, and the resulting g

  10. Studies on the Ecology, Biogeography and Evolution of Palms (Arecaceae) with Focus on the Americas

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.

    The palm family (Arecaceae) increasingly serves as a model system to study the ecology and evolution of tropical ecosystems. This volume covers a wide range of topics in the areas of palm community ecology, macroecology, biogeography, and phylogeny, with a focus on the bridge between ecological...

  11. Improving the Projections of Vegetation Biogeography by Integrating Climate Envelope Models and Dynamic Global Vegetation Models

    Science.gov (United States)

    Case, M. J.; Kim, J. B.

    2015-12-01

    Assessing changes in vegetation is increasingly important for conservation planning in the face of climate change. Dynamic global vegetation models (DGVMs) are important tools for assessing such changes. DGVMs have been applied at regional scales to create projections of range expansions and contractions of plant functional types. Many DGVMs use a number of algorithms to determine the biogeography of plant functional types. One such DGVM, MC2, uses a series of decision trees based on bioclimatic thresholds while others, such as LPJ, use constraining emergent properties with a limited set of bioclimatic threshold-based rules. Although both approaches have been used widely, we demonstrate that these biogeography outputs perform poorly at continental scales when compared to existing potential vegetation maps. Specifically, we found that with MC2, the algorithm for determining leaf physiognomy is too simplistic to capture arid and semi-arid vegetation in much of the western U.S., as well as is the algorithm for determining the broadleaf and needleleaf mix in the Southeast. With LPJ, we found that the bioclimatic thresholds used to allow seedling establishment are too broad and fail to capture regional-scale biogeography of the plant functional types. In response, we demonstrate a new approach to determining the biogeography of plant functional types by integrating the climatic thresholds produced for individual tree species by a series of climate envelope models with the biogeography algorithms of MC2 and LPJ. Using this approach, we find that MC2 and LPJ perform considerably better when compared to potential vegetation maps.

  12. Molecular biogeography of Europe: Pleistocene cycles and postglacial trends

    Directory of Open Access Journals (Sweden)

    Schmitt Thomas

    2007-04-01

    Full Text Available Abstract The climatic cycles with subsequent glacial and intergalcial periods have had a great impact on the distribution and evolution of species. Using genetic analytical tools considerably increased our understanding of these processes. In this review I therefore give an overview of the molecular biogeography of Europe. For means of simplification, I distinguish between three major biogeographical entities: (i "Mediterranean" with Mediterranean differentiation and dispersal centres, (ii "Continental" with extra-Mediterranean centres and (iii "Alpine" and/or "Arctic" with recent alpine and/or arctic distribution patterns. These different molecular biogeographical patterns are presented using actual examples. Many "Mediterranean" species are differentiated into three major European genetic lineages, which are due to glacial isolation in the three major Mediterranean peninsulas. Postglacial expansion in this group of species is mostly influenced by the barriers of the Pyrenees and the Alps with four resulting main patterns of postglacial range expansions. However, some cases are known with less than one genetic lineage per Mediterranean peninsula on the one hand, and others with a considerable genetic substructure within each of the Mediterranean peninsulas, Asia Minor and the Maghreb. These structures within the Mediterranean sub-centres are often rather strong and in several cases even predate the Pleistocene. For the "Continental" species, it could be shown that the formerly supposed postglacial spread from eastern Palearctic expansion centres is mostly not applicable. Quite the contrary, most of these species apparently had extra-Mediterranean centres of survival in Europe with special importance of the perialpine regions, the Carpathian Basin and parts of the Balkan Peninsula. In the group of "Alpine" and/or "Arctic" species, several molecular biogeographical patterns have been found, which support and improve the postulates based on

  13. Models of oceanic island biogeography: changing perspectives on biodiversity dynamics in archipelagoes

    Directory of Open Access Journals (Sweden)

    Lawrence R Heaney

    2013-12-01

    Full Text Available Models of biogeographic processes can both enhance and inhibit our ability to ask questions that guide our understanding of patterns and processes. The two ‘traditional’ models of island biogeography, the Equilibrium Model and the Vicariance Model, raise important and insightful questions about relevant processes, but both fail to raise many crucial questions. An example involving the non-volant mammals of the Philippine archipelago shows that both models highlight some, but not all, relevant patterns and processes. The more recently proposed General Dynamic Model successfully combines many of the positive aspects of the two traditional models, but leaves some important questions unasked. We pose a number of questions here that may help guide further development of models of island biogeography.

  14. On the Convergence of Biogeography-Based Optimization for Binary Problems

    Directory of Open Access Journals (Sweden)

    Haiping Ma

    2014-01-01

    Full Text Available Biogeography-based optimization (BBO is an evolutionary algorithm inspired by biogeography, which is the study of the migration of species between habitats. A finite Markov chain model of BBO for binary problems was derived in earlier work, and some significant theoretical results were obtained. This paper analyzes the convergence properties of BBO on binary problems based on the previously derived BBO Markov chain model. Analysis reveals that BBO with only migration and mutation never converges to the global optimum. However, BBO with elitism, which maintains the best candidate in the population from one generation to the next, converges to the global optimum. In spite of previously published differences between genetic algorithms (GAs and BBO, this paper shows that the convergence properties of BBO are similar to those of the canonical GA. In addition, the convergence rate estimate of BBO with elitism is obtained in this paper and is confirmed by simulations for some simple representative problems.

  15. Design of Large Thinned Arrays Using Different Biogeography-Based Optimization Migration Models

    Directory of Open Access Journals (Sweden)

    Sotirios K. Goudos

    2016-01-01

    Full Text Available Array thinning is a common discrete-valued combinatorial optimization problem. Evolutionary algorithms are suitable techniques for above-mentioned problem. Biogeography-Based Optimization (BBO, which is inspired by the science of biogeography, is a stochastic population-based evolutionary algorithm (EA. The original BBO uses a linear migration model to describe how species migrate from one island to another. Other nonlinear migration models have been proposed in the literature. In this paper, we apply BBO with four different migration models to five different large array design cases. Additionally we compare results with five other popular algorithms. The problems dimensions range from 150 to 300. The results show that BBO with sinusoidal migration model generally performs better than the other algorithms. However, these results are considered to be indicative and do not generally apply to all optimization problems in antenna design.

  16. Contrasting biogeography of endemic and alien terrestrial species in the Canary Islands

    OpenAIRE

    Vilà, Montserrat

    2006-01-01

    Endemics and alien organisms can be considered two faces of the same coin, since management of both groups of taxa have strongly interrelated conservation implications. Islands are rich in endemic species and are also very vulnerable to biological invasions. We analysed the biogeography and taxonomy of endemic and alien terrestrial species in the Canary Islands including fungi, lichens, bryophytes, vascular plants, arthropods, molluscs, annelids and vertebrates. By using the plant dataset we ...

  17. Biodiversity and biogeography pattern of benthic communities in the coastal basins of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sivadas, S.K.; Ingole, B.S.

    . Values of + range from high, when several different orders are represented by a single species, but some genera are species rich whereas the ranges are low when all the species belong to different families but the same order (Clarke & Warwick 2001... species in similar genera or families to each other then taxonomic dissimilarity is low, whilst if they do not share many evolutionary branches the dissimilarity will remain large (Clarke et al. 2006). The biogeography pattern was then determined...

  18. Fishes of the Vitória-Trindade Chain: Biodiversity, Biogeography and Evolution

    OpenAIRE

    Pinheiro,Hudson Tercio

    2016-01-01

    Studies on the ecology and biogeography of seamounts and oceanic islands have advanced substantially in the last 60 years. However, few seamounts have been scientifically characterized, with basic aspects of their biodiversity still unknown and many hypotheses not empirically tested. Consequently, the role of seamounts in the evolution for marine species is still unclear. In the south Atlantic, the Vitória-Trindade Chain (VTC) extends ca. 1,200 km offshore the Brazilian coast. For a long time...

  19. Oceanic island biogeography through the lens of the general dynamic model: assessment and prospect

    DEFF Research Database (Denmark)

    Borregaard, Michael; Amorim, Isabel; Borges, Paulo;

    2016-01-01

    and in developing and enhancing ecological–evolutionary understanding of oceanic island systems through the lens of the GDM. In particular, we focus on four main themes: (i) macroecological tests using a space-for-time rationale; (ii) extensions of theory to islands following different patterns of ontogeny; (iii...... demonstrate the vitality of the field of island biogeography by identifying a range of potentially productive lines for future research....

  20. Vegetation ecology meets ecosystem science: Permanent grasslands as a functional biogeography case study.

    Science.gov (United States)

    Violle, Cyrille; Choler, Philippe; Borgy, Benjamin; Garnier, Eric; Amiaud, Bernard; Debarros, Guilhem; Diquelou, Sylvain; Gachet, Sophie; Jolivet, Claudy; Kattge, Jens; Lavorel, Sandra; Lemauviel-Lavenant, Servane; Loranger, Jessy; Mikolajczak, Alexis; Munoz, François; Olivier, Jean; Viovy, Nicolas

    2015-11-15

    The effect of biodiversity on ecosystem functioning has been widely acknowledged, and the importance of the functional roles of species, as well as their diversity, in the control of ecosystem processes has been emphasised recently. However, bridging biodiversity and ecosystem science to address issues at a biogeographic scale is still in its infancy. Bridging this gap is the primary goal of the emerging field of functional biogeography. While the rise of Big Data has catalysed functional biogeography studies in recent years, comprehensive evidence remains scarce. Here, we present the rationale and the first results of a country-wide initiative focused on the C3 permanent grasslands. We aimed to collate, integrate and process large databases of vegetation relevés, plant traits and environmental layers to provide a country-wide assessment of ecosystem properties and services which can be used to improve regional models of climate and land use changes. We outline the theoretical background, data availability, and ecoinformatics challenges associated with the approach and its feasibility. We provide a case study of upscaling of leaf dry matter content averaged at ecosystem level and country-wide predictions of forage digestibility. Our framework sets milestones for further hypothesis testing in functional biogeography and earth system modelling.

  1. Voltage Profile Enhancement and Reduction of Real Power loss by Hybrid Biogeography Based Artificial Bee Colony algorithm

    Directory of Open Access Journals (Sweden)

    K. Lenin

    2014-04-01

    Full Text Available This paper presents Hybrid Biogeography algorithm for solving the multi-objective reactive power dispatch problem in a power system. Real Power Loss minimization and maximization of voltage stability margin are taken as the objectives. Artificial bee colony optimization (ABC is quick and forceful algorithm for global optimization. Biogeography-Based Optimization (BBO is a new-fangled biogeography inspired algorithm. It mainly utilizes the biogeography-based relocation operator to share the information among solutions. In this work, a hybrid algorithm with BBO and ABC is projected, and named as HBBABC (Hybrid Biogeography based Artificial Bee Colony Optimization, for the universal numerical optimization problem. HBBABC merge the searching behavior of ABC with that of BBO. Both the algorithms have different solution probing tendency like ABC have good exploration probing tendency while BBO have good exploitation probing tendency.  HBBABC used to solve the reactive power dispatch problem and the proposed technique has been tested in standard IEEE30 bus test system.

  2. Novel migration operators of biogeography-based optimization and Markov analysis

    DEFF Research Database (Denmark)

    Guo, Weian; Wang, Lei; Si, Chenyong;

    2016-01-01

    Biogeography-based optimization (BBO) is a nature-inspired optimization algorithm and has been developed in both theory and practice. In canonical BBO, migration operator is crucial to affect algorithm’s performance. In migration operator, a good solution has a large probability to be selected......, a number of benchmark tests are carried out to empirically assess the performance of the proposed migration operators, on both low-dimensional and high-dimensional numerical optimization problems. The comparison results demonstrate that the proposed migration operators are feasible and effective to enhance...

  3. Revealing the secrets of African annonaceae : systematics, evolution and biogeography of the syncarpous genera Isolona and Monodora

    NARCIS (Netherlands)

    Couvreur, T.L.P.

    2008-01-01

    The goal of this PhD project was to study the evolution, systematics and biogeography of two African genera from the pan-tropical Annonaceae family: Isolona and Monodora. Both genera are unique within the family in that the female reproductive parts (or carpels) are fused into a single unit. All oth

  4. Molecular phylogenetics and historical biogeography amid shifting continents in the cockles and giant clams (Bivalvia: Cardiidae).

    Science.gov (United States)

    Herrera, Nathanael D; Ter Poorten, Jan Johan; Bieler, Rüdiger; Mikkelsen, Paula M; Strong, Ellen E; Jablonski, David; Steppan, Scott J

    2015-12-01

    Reconstructing historical biogeography of the marine realm is complicated by indistinct barriers and, over deeper time scales, a dynamic landscape shaped by plate tectonics. Here we present the most extensive examination of model-based historical biogeography among marine invertebrates to date. We conducted the largest phylogenetic and molecular clock analyses to date for the bivalve family Cardiidae (cockles and giant clams) with three unlinked loci for 110 species representing 37 of the 50 genera. Ancestral ranges were reconstructed using the dispersal-extinction-cladogenesis (DEC) method with a time-stratified paleogeographic model wherein dispersal rates varied with shifting tectonics. Results were compared to previous classifications and the extensive paleontological record. Six of the eight prior subfamily groupings were found to be para- or polyphyletic. Cardiidae originated and subsequently diversified in the tropical Indo-Pacific starting in the Late Triassic. Eastern Atlantic species were mainly derived from the tropical Indo-Mediterranean region via the Tethys Sea. In contrast, the western Atlantic fauna was derived from Indo-Pacific clades. Our phylogenetic results demonstrated greater concordance with geography than did previous phylogenies based on morphology. Time-stratifying the DEC reconstruction improved the fit and was highly consistent with paleo-ocean currents and paleogeography. Lastly, combining molecular phylogenetics with a rich and well-documented fossil record allowed us to test the accuracy and precision of biogeographic range reconstructions.

  5. Integrating multiple lines of evidence into historical biogeography hypothesis testing: a Bison bison case study.

    Science.gov (United States)

    Metcalf, Jessica L; Prost, Stefan; Nogués-Bravo, David; DeChaine, Eric G; Anderson, Christian; Batra, Persaram; Araújo, Miguel B; Cooper, Alan; Guralnick, Robert P

    2014-02-22

    One of the grand goals of historical biogeography is to understand how and why species' population sizes and distributions change over time. Multiple types of data drawn from disparate fields, combined into a single modelling framework, are necessary to document changes in a species's demography and distribution, and to determine the drivers responsible for change. Yet truly integrated approaches are challenging and rarely performed. Here, we discuss a modelling framework that integrates spatio-temporal fossil data, ancient DNA, palaeoclimatological reconstructions, bioclimatic envelope modelling and coalescence models in order to statistically test alternative hypotheses of demographic and potential distributional changes for the iconic American bison (Bison bison). Using different assumptions about the evolution of the bioclimatic niche, we generate hypothetical distributional and demographic histories of the species. We then test these demographic models by comparing the genetic signature predicted by serial coalescence against sequence data derived from subfossils and modern populations. Our results supported demographic models that include both climate and human-associated drivers of population declines. This synthetic approach, integrating palaeoclimatology, bioclimatic envelopes, serial coalescence, spatio-temporal fossil data and heterochronous DNA sequences, improves understanding of species' historical biogeography by allowing consideration of both abiotic and biotic interactions at the population level.

  6. Does the legacy of historical biogeography shape current invasiveness in pines?

    Science.gov (United States)

    Gallien, Laure; Saladin, Bianca; Boucher, Florian C; Richardson, David M; Zimmermann, Niklaus E

    2016-02-01

    Why are some introduced species more successful at establishing and spreading than others? Until now, characteristics of extant species have been intensively investigated to answer this question. We propose to gain new insights on species invasiveness by exploring the long-term biogeographic and evolutionary history of lineages. We exemplify our approach using one of the best-studied invasive plant genera, Pinus. We notably estimated the historical biogeography of pines and the rates of trait evolution in pines. These estimates were analysed with regard to species invasiveness status. The results revealed that currently invasive species belong to lineages that were particularly successful at colonizing new regions in the past. We also showed that highly mobile lineages had faster rates of niche evolution, but that these rates are poor proxies for species adaptive potential in invaded regions (estimated by niche shift among native and invaded regions). In summary, working at the interface of ecology, historical biogeography and evolutionary history offers stimulating perspectives to improve our understanding of the drivers of invasion success.

  7. A Biogeography-Based Optimization Algorithm Hybridized with Tabu Search for the Quadratic Assignment Problem.

    Science.gov (United States)

    Lim, Wee Loon; Wibowo, Antoni; Desa, Mohammad Ishak; Haron, Habibollah

    2016-01-01

    The quadratic assignment problem (QAP) is an NP-hard combinatorial optimization problem with a wide variety of applications. Biogeography-based optimization (BBO), a relatively new optimization technique based on the biogeography concept, uses the idea of migration strategy of species to derive algorithm for solving optimization problems. It has been shown that BBO provides performance on a par with other optimization methods. A classical BBO algorithm employs the mutation operator as its diversification strategy. However, this process will often ruin the quality of solutions in QAP. In this paper, we propose a hybrid technique to overcome the weakness of classical BBO algorithm to solve QAP, by replacing the mutation operator with a tabu search procedure. Our experiments using the benchmark instances from QAPLIB show that the proposed hybrid method is able to find good solutions for them within reasonable computational times. Out of 61 benchmark instances tested, the proposed method is able to obtain the best known solutions for 57 of them.

  8. Niche partitioning and biogeography of high light adapted Prochlorococcus across taxonomic ranks in the North Pacific.

    Science.gov (United States)

    Larkin, Alyse A; Blinebry, Sara K; Howes, Caroline; Lin, Yajuan; Loftus, Sarah E; Schmaus, Carrie A; Zinser, Erik R; Johnson, Zackary I

    2016-07-01

    The distribution of major clades of Prochlorococcus tracks light, temperature and other environmental variables; yet, the drivers of genomic diversity within these ecotypes and the net effect on biodiversity of the larger community are poorly understood. We examined high light (HL) adapted Prochlorococcus communities across spatial and temporal environmental gradients in the Pacific Ocean to determine the ecological drivers of population structure and diversity across taxonomic ranks. We show that the Prochlorococcus community has the highest diversity at low latitudes, but seasonality driven by temperature, day length and nutrients adds complexity. At finer taxonomic resolution, some 'sub-ecotype' clades have unique, cohesive responses to environmental variables and distinct biogeographies, suggesting that presently defined ecotypes can be further partitioned into ecologically meaningful units. Intriguingly, biogeographies of the HL-I sub-ecotypes are driven by unique combinations of environmental traits, rather than through trait hierarchy, while the HL-II sub-ecotypes appear ecologically similar, thus demonstrating differences among these dominant HL ecotypes. Examining biodiversity across taxonomic ranks reveals high-resolution dynamics of Prochlorococcus evolution and ecology that are masked at phylogenetically coarse resolution. Spatial and seasonal trends of Prochlorococcus communities suggest that the future ocean may be comprised of different populations, with implications for ecosystem structure and function.

  9. A Biogeography-Based Optimization Algorithm Hybridized with Tabu Search for the Quadratic Assignment Problem

    Directory of Open Access Journals (Sweden)

    Wee Loon Lim

    2016-01-01

    Full Text Available The quadratic assignment problem (QAP is an NP-hard combinatorial optimization problem with a wide variety of applications. Biogeography-based optimization (BBO, a relatively new optimization technique based on the biogeography concept, uses the idea of migration strategy of species to derive algorithm for solving optimization problems. It has been shown that BBO provides performance on a par with other optimization methods. A classical BBO algorithm employs the mutation operator as its diversification strategy. However, this process will often ruin the quality of solutions in QAP. In this paper, we propose a hybrid technique to overcome the weakness of classical BBO algorithm to solve QAP, by replacing the mutation operator with a tabu search procedure. Our experiments using the benchmark instances from QAPLIB show that the proposed hybrid method is able to find good solutions for them within reasonable computational times. Out of 61 benchmark instances tested, the proposed method is able to obtain the best known solutions for 57 of them.

  10. Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia.

    Directory of Open Access Journals (Sweden)

    Benny K K Chan

    Full Text Available The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007 and C. newmani sp. nov.. These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.

  11. Where did the chili get its spice? Biogeography of capsaicinoid production in ancestral wild chili species.

    Science.gov (United States)

    Tewksbury, Joshua J; Manchego, Carlos; Haak, David C; Levey, Douglas J

    2006-03-01

    The biogeography of pungency in three species of wild chili in the chaco and surrounding highland habitats of southeastern Bolivia is described. We report that Capsicum chacoense, C. baccatum, and C. eximium are polymorphic for production of capsaicin and its analogs, such that completely pungent and completely nonpungent individuals co-occur in some populations. In C. chacoense, the density of plants and the proportion of pungent plants increased with elevation. Above 900 m, all individuals in all populations except two were pungent; nonpungent individuals in at least one of the two polymorphic populations were likely a result of spreading by humans. The occurrence of pungent and nonpungent individuals in three species of ancestral Capsicum and the geographic variation of pungency within species suggest that production of capsaicin and its analogs entails both costs and benefits, which shift from one locality to another. Determining the selection pressures behind such shifts is necessary to understand the evolution of pungency in chilies.

  12. A Modified Biogeography-Based Optimization for the Flexible Job Shop Scheduling Problem

    Directory of Open Access Journals (Sweden)

    Yuzhen Yang

    2015-01-01

    Full Text Available The flexible job shop scheduling problem (FJSSP is a practical extension of classical job shop scheduling problem that is known to be NP-hard. In this paper, an effective modified biogeography-based optimization (MBBO algorithm with machine-based shifting is proposed to solve FJSSP with makespan minimization. The MBBO attaches great importance to the balance between exploration and exploitation. At the initialization stage, different strategies which correspond to two-vector representation are proposed to generate the initial habitats. At global phase, different migration and mutation operators are properly designed. At local phase, a machine-based shifting decoding strategy and a local search based on insertion to the habitat with best makespan are introduced to enhance the exploitation ability. A series of experiments on two well-known benchmark instances are performed. The comparisons between MBBO and other famous algorithms as well as BBO variants prove the effectiveness and efficiency of MBBO in solving FJSSP.

  13. Barrier displacement on a neutral landscape: Towards a theory of continental biogeography

    Science.gov (United States)

    Albert, James S.; Schoolmaster, Donald; Tagliacollo, Victor; Duke-Sylvester, Scott M.

    2017-01-01

    Macroevolutionary theory posits three processes leading to lineage diversification and the formation of regional biotas: dispersal (species geographic range expansion), speciation (species lineage splitting), and extinction (species lineage termination). The Theory of Island Biogeography (TIB) predicts species richness values using just two of these processes; dispersal and extinction. Yet most species on Earth live on continents or continental shelves, and the dynamics of evolutionary diversification at regional and continental scales are qualitatively different from those that govern the formation of species richness on biogeographic islands. Certain geomorphological processes operating perennially on continental platforms displace barriers to gene flow and organismal dispersal, and affect all three terms of macroevolutionary diversification. For example, uplift of a dissected landscape and river capture both merge and separate portions of adjacent areas, allowing dispersal and larger geographic ranges, vicariant speciation and smaller geographic ranges, and extinction when range sizes are subdivided below a minimum persistence threshold.

  14. Hybridizing artificial bee colony with biogeography-based optimization for constrained mechanical design problems

    Institute of Scientific and Technical Information of China (English)

    蔡绍洪; 龙文; 焦建军

    2015-01-01

    A novel hybrid algorithm named ABC-BBO, which integrates artificial bee colony (ABC) algorithm with biogeography-based optimization (BBO) algorithm, is proposed to solve constrained mechanical design problems. ABC-BBO combined the exploration of ABC algorithm with the exploitation of BBO algorithm effectively, and hence it can generate the promising candidate individuals. The proposed hybrid algorithm speeds up the convergence and improves the algorithm’s performance. Several benchmark test functions and mechanical design problems are applied to verifying the effects of these improvements and it is demonstrated that the performance of this proposed ABC-BBO is superior to or at least highly competitive with other population-based optimization approaches.

  15. Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia).

    Science.gov (United States)

    Chan, Benny K K; Chen, H-N; Dando, P R; Southward, A J; Southward, E C

    2016-01-01

    The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007) and C. newmani sp. nov.). These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.

  16. An attempt to revisit the global biogeography of limno-terrestrial Tardigrada

    Directory of Open Access Journals (Sweden)

    Philip J.A. PUGH

    2007-09-01

    Full Text Available The major increase in distribution records of limno-terrestrial tardigrades over the last ten years has enabled us to reassess the global biogeography of the Tardigrada using cluster analysis, principal components analysis and parsimony analysis of endemism (PAE. Although the new clustergram topology shows a close correlation with those we originally presented in 1998, the PAE outputs warrant a radical reinterpretation of the results as they imply that the Laurasian fauna is derived and the Gondwanan groups basal. The distribution of endemic tardigrade genera and families provides some support for this argument though the findings should be viewed with some caution as PAE has its detractors and has not been previously applied on a 'global' scale.

  17. The unified neutral theory of biodiversity and biogeography at age ten.

    Science.gov (United States)

    Rosindell, James; Hubbell, Stephen P; Etienne, Rampal S

    2011-07-01

    A decade has now passed since Hubbell published The Unified Neutral Theory of Biodiversity and Biogeography. Neutral theory highlights the importance of dispersal limitation, speciation and ecological drift in the natural world and provides quantitative null models for assessing the role of adaptation and natural selection. Significant advances have been made in providing methods for understanding neutral predictions and comparing them with empirical data. In this review, we describe the current state-of-the-art techniques and ideas in neutral theory and how these are of relevance to ecology. The future of neutral theory is promising, but its concepts must be applied more broadly beyond the current focus on species-abundance distributions.

  18. Phylogeny and Biogeography of Thuja L. (Cupressaceae), an Eastern Asian and North American Disjunct Genus

    Institute of Scientific and Technical Information of China (English)

    Jian-Hua LI; Qiao-Ping XIANG

    2005-01-01

    In order to develop better insights into biogeographic patterns of eastern Asian and North American disjunct plant genera, sequences of nuclear ribosomal DNA internal transcribed spacer (nr DNA ITS) region were used to estimate interspecific relationships of Thuja L. (Cupressaceae) and infer its biogeography based on the phylogeny. According to the phylogenetic analysis, two clades were recognized. The first clade included Thuja plicata D. Don (western North America) and T. koraiensis Nakai (northeastern Asia), and the second one contained T. occidentalis (Gord.) Carr. (Japan). The ancestral area of Thuja was inferred to be eastern Asia, and two dispersal events were responsible for the modern distribution of Thuja in North America. Both the North Atlantic land bridge and Bering land bridge were possible routes for the migration of ancestral populations to North America.

  19. Natural Image Enhancement Using a Biogeography Based Optimization Enhanced with Blended Migration Operator

    Directory of Open Access Journals (Sweden)

    J. Jasper

    2014-01-01

    Full Text Available This paper addresses a novel and efficient algorithm for solving optimization problem in image processing applications. Image enhancement (IE is one of the complex optimization problems in image processing. The main goal of this paper is to enhance color images such that the eminence of the image is more suitable than the original image from the perceptual viewpoint of human. Traditional methods require prior knowledge of the image to be enhanced, whereas the aim of the proposed biogeography based optimization (BBO enhanced with blended migration operator (BMO algorithm is to maximize the objective function in order to enhance the image contrast by maximizing the parameters like edge intensity, edge information, and entropy. Experimental results are compared with the current state-of-the-art approaches and indicate the superiority of the proposed technique in terms of subjective and objective evaluation.

  20. Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica

    Directory of Open Access Journals (Sweden)

    Byron Adams

    2014-06-01

    Full Text Available The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems.

  1. A Hybrid Grey Based KOHONEN Model and Biogeography-Based Optimization for Project Portfolio Selection

    Directory of Open Access Journals (Sweden)

    Farshad Faezy Razi

    2014-01-01

    Full Text Available The problem of selection and the best option are the main subject of operation research science in decision-making theory. Selection is a process that scrutinizes and investigates several quantitative and qualitative, and most often incompatible, factors. One of the most fundamental management issues in multicriteria selection literature is the multicriteria adoption of the projects portfolio. In such decision-making condition, manager is seeking for the best combination to build up a portfolio among the existing projects. In the present paper, KOHONEN algorithm was first employed to build up a portfolio of the projects. Next, each portfolio was evaluated using grey relational analysis (GRA and then scheduled risk of the project was predicted using Mamdani fuzzy inference method. Finally, the multiobjective biogeography-based optimization algorithm was utilized for drawing risk and rank Pareto analysis. A case study is used concurrently to show the efficiency of the proposed model.

  2. The general dynamic model of island biogeography revisited on the level of major plant families

    DEFF Research Database (Denmark)

    Lenzner, Bernd; Beierkuhnlein, Carl; Patrick, Weigelt

    2016-01-01

    Aim: The general dynamic model (GDM) proposed by Whittaker et al. (2008) is a widely accepted theoretical framework in island biogeography. In this study, we explore whether GDM predictions hold when overall plant diversity is deconstructed into major plant families. Location: 101 islands from 14...... oceanic archipelagos worldwide. Methods: Occurrence data for all species of nine large, cosmopolitan flowering plant families were used to test predictions derived from the GDM. We analyzed the effects of island area and age on species richness as well as number and percentage of single-island endemic...... species per family using mixed-effect models. Results: Total species and endemic richness as well as the percentage of endemic species showed a hump-shaped relationship with island age. The overall pattern was mainly driven by few species-rich plant families. Varying patterns were found for individual...

  3. Biogeography of Parasitic Nematode Communities in the Galapagos Giant Tortoise: Implications for Conservation Management.

    Directory of Open Access Journals (Sweden)

    Guillaume Fournié

    Full Text Available The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host.

  4. The taxonomy, biogeography and conservation of the myrmecophilous Chrysoritis butterflies (Lepidoptera: Lycaenidae in South Africa

    Directory of Open Access Journals (Sweden)

    R.F. Terblanche

    2003-12-01

    Full Text Available The relevance and integration of scientific knowledge to conservation management of the locally popular and highly endemic butterfly genus Chrysoritis are investigated within the research fields of taxonomy and biogeography. The butterfly genus Chrysoritis contains at least 41 species endemic to South Africa. The taxonomy of Chrysoritis has reached a state where revisions could easily result in a plethora of names between “lumping and splitting”. In practice, the state of the taxonomy of these butterflies on species level may alter their conservation priority. The two most species rich species groups in Chrysoritis have different centres of endemism, however, a butterfly atlas becomes a necessity to reveal more about their biogeography. There is an absence of butterfly species lists in many of our National Parks and Nature Reserves. Legislation should facilitate rather than limit the valuable role of the amateur lepidopterist to add distribution records. In turn, the amateur lepidopterists should adapt and make an effort to explore unknown localities, apart from monitoring butterflies at their well-known localities. The red listing of localised butterflies in South Africa, including a number of Chrysoritis species, is in need of an urgent review in the light of the most recent IUCN categories. A species such as Chrysoritis dicksoni should be protected by law - but at its known localities. The scenario that real conservation action is only needed if the last known locality of a butterfly is threatened, should be abolished. A paradigm shift to conserve the metapopulations of the highly endemic Chrysoritis genus and not merely a few of its species as items that appear on lists, seems necessary.

  5. Projected impacts of climate change and ocean acidification on the global biogeography of planktonic foraminifera

    Directory of Open Access Journals (Sweden)

    T. Roy

    2014-06-01

    Full Text Available Planktonic foraminifera are a major contributor to the deep carbonate-flux and the planktonic biomass of the global ocean. Their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically-based foraminifer model that incorporates three known major physiological drivers of foraminifer biogeography – temperature, food and light – we investigate (i the global redistribution of planktonic foraminifera under anthropogenic climate change, and (ii the alteration of the carbonate chemistry of foraminifer habitat with ocean acidification. The present-day and future (2090–2100 3-D distributions of foraminifera are simulated using temperature, plankton biomass, and light from an Earth system model forced with historical and a future (IPCC A2 high CO2 emission scenario. The broadscale patterns of present day foraminifer biogeography are well reproduced. Foraminifer abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. In the tropics, the geographical shifts are driven by temperature, while the vertical shifts are driven by both temperature and food availability. In the high-latitudes, vertical shifts are driven by food availability, while geographical shifts are driven by both food availability and temperature. Changes in the marine carbon cycle would be expected in response to (i the large-scale rearrangements in foraminifer abundance, and (ii the reduction of the carbonate concentration in the habitat range of planktonic foraminifers: from 10–30 μmol kg−1 in the polar/subpolar regions to 30–70 μmol kg−1 in the subtropical/tropical regions. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of their habitat drops below the calcite saturation horizon.

  6. Parameters Identification of Fluxgate Magnetic Core Adopting the Biogeography-Based Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Wenjuan Jiang

    2016-06-01

    Full Text Available The main part of the magnetic fluxgate sensor is the magnetic core, the hysteresis characteristic of which affects the performance of the sensor. When the fluxgate sensors are modelled for design purposes, an accurate model of hysteresis characteristic of the cores is necessary to achieve good agreement between modelled and experimental data. The Jiles-Atherton model is simple and can reflect the hysteresis properties of the magnetic material precisely, which makes it widely used in hysteresis modelling and simulation of ferromagnetic materials. However, in practice, it is difficult to determine the parameters accurately owing to the sensitivity of the parameters. In this paper, the Biogeography-Based Optimization (BBO algorithm is applied to identify the Jiles-Atherton model parameters. To enhance the performances of the BBO algorithm such as global search capability, search accuracy and convergence rate, an improved Biogeography-Based Optimization (IBBO algorithm is put forward by using Arnold map and mutation strategy of Differential Evolution (DE algorithm. Simulation results show that IBBO algorithm is superior to Genetic Algorithm (GA, Particle Swarm Optimization (PSO algorithm, Differential Evolution algorithm and BBO algorithm in identification accuracy and convergence rate. The IBBO algorithm is applied to identify Jiles-Atherton model parameters of selected permalloy. The simulation hysteresis loop is in high agreement with experimental data. Using permalloy as core of fluxgate probe, the simulation output is consistent with experimental output. The IBBO algorithm can identify the parameters of Jiles-Atherton model accurately, which provides a basis for the precise analysis and design of instruments and equipment with magnetic core.

  7. Molecular systematic and historical biogeography of the armored Neotropical catfishes Hypoptopomatinae and Neoplecostominae (Siluriformes: Loricariidae).

    Science.gov (United States)

    Chiachio, Márcio Cesar; Oliveira, Claudio; Montoya-Burgos, Juan I

    2008-11-01

    The Neotropics possess the greatest freshwater fish diversity of the world, rendering the study of their evolutionary history extremely challenging. Loricariidae catfishes are one of the most diverse components of the Neotropical ichthyofauna and despite a long history of classification, major issues still need elucidation. Based on a nuclear gene, we present a robust phylogeny of two former loricariid subfamilies: Hypoptopomatinae and Neoplecostominae. Our results show that Neoplecostominae is nested within Hypoptopomatinae, and is the sister group to the former Otothyrini tribe. According to our results, supplemented by morphological observations, we erect two new subfamilies, the Otothyrinae and a new Hypoptopomatinae, and modify the Neoplecostominae by including the genus Pseudotocinclus. The uncovered evolutionary relationships allow a detailed analysis of their historical biogeography. We tested two Dispersal-Extinction-Cladogenesis models for inferring the distribution range evolution of the new subfamilies, and show that the model having no constrains performs better than a model constraining long-range dispersal. The Maximum Likelihood reconstructions of ancestral ranges showed a marked division between the Amazonian origin of the Hypoptopomatinae and the eastern coastal Brazil+Upper Paraná origin of the Neoplecostominae and Otothyrinae. Markedly few instances of dispersal across the border separating the Amazon basin and the Paraná-Paraguay+eastern coastal Brazil+Uruguay were reconstructed. This result is in clear contrast with the historical biogeography of many Neotropical fishes, including other Loricariidae. Part of the dispersal limitation may be explained by divergent ecological specialization: lowland rivers versus mountain streams habitats. Moreover, because most species of the new subfamilies are small, we hypothesize that body size-related effects might limit their dispersal, like predation and energetic cost to migration. Finally

  8. Comprehensive species set revealing the phylogeny and biogeography of Feliformia (Mammalia, Carnivora) based on mitochondrial DNA

    Science.gov (United States)

    Ma, Jian-Zhang

    2017-01-01

    Extant Feliformia species are one of the most diverse radiations of Carnivora (~123 species). Despite substantial recent interest in their conservation, diversification, and systematic study, no previous phylogeny contains a comprehensive species set, and no biogeography of this group is available. Here, we present a phylogenetic estimate for Feliformia with a comprehensive species set and establish a historical biogeography based on mitochondrial DNA. Both the Bayesian and maximum likelihood phylogeny for Feliformia are elucidated in our analyses and are strongly consistent with many groups recognized in previous studies. The mitochondrial phylogenetic relationships of Felidae were for the first time successfully reconstructed in our analyses with strong supported. When divergence times and dispersal/vicariance histories were compared with historical sea level changes, four dispersal and six vicariance events were identified. These vicariance events were closely related with global sea level changes. The transgression of sea into the lowland plains between Eurasia and Africa may have caused the vicariance in these regions. A fall in the sea level during late Miocene to Pliocene produced the Bering strait land bridge, which assisted the migration of American Feliformia ancestors from Asia to North America. In contrast with the ‘sweepstakes hypothesis’, our results suggest that the climate cooling during 30–27 Ma assisted Feliformia migration from the African mainland to Madagascar by creating a short-lived ice bridge across the Mozambique Channel. Lineages-through-time plots revealed a large increase in lineages since the Mid-Miocene. During the Mid-Miocene Climatic Optimum, the ecosystems and population of Feliformia rapidly expanded. Subsequent climate cooling catalyzed immigration, speciation, and the extinction of Feliformia. PMID:28358848

  9. The diversity and biogeography of the communities of Actinobacteria in the forelands of glaciers at a continental scale

    Science.gov (United States)

    Zhang, Binglin; Wu, Xiukun; Zhang, Gaosen; Li, Shuyan; Zhang, Wei; Chen, Ximing; Sun, Likun; Zhang, Baogui; Liu, Guangxiu; Chen, Tuo

    2016-05-01

    Glacier forelands, where the initially exposed area is unvegetated with minimal human influence, are an ideal place for research on the distributions and biogeography of microbial communities. Actinobacteria produce many bioactive substances and have important roles in soil development and biogeochemical cycling. However, little is known about the distribution and biogeography of Actinobacteria in glacier forelands. Therefore, we investigated the patterns of diversity and the biogeography of actinobacterial communities of the inhabited forefields of 5 glaciers in China. Of the bacteria, the mean relative abundance of Actinobacteria was 13.1%, and 6 classes were identified in the phylum Actinobacteria. The dominant class was Actinobacteria (57%), which was followed in abundance by Acidimicrobiia (19%) and Thermoleophilia (19%). When combined, the relative abundance of the other three classes, the MB-A2-108, Nitriliruptoria and Rubrobacteria, was only 2.4%. A biogeographic pattern in the forelands of the 5 glaciers in China was not detected for actinobacterial communities. Compared with 7 other actinobacterial communities found in the forelands of glaciers globally, those in the Southern Hemisphere were significantly different from those in the Northern Hemisphere. Moreover, the communities were significantly different on the separate continents of the Northern Hemisphere. The dissimilarity of the actinobacterial communities increased with geographic distance (r = 0.428, p = 0.0003). Because of environmental factors, the effect of geography was clear when the distance exceeded a certain continent-level threshold. With the analysis of indicator species, we found that each genus had a geographic characteristic, which could explain why the communities with greater diversity were more strongly affected by biogeography.

  10. Improving the performance of the Egyptian second testing nuclear research reactor using interval type-2 fuzzy logic controller tuned by modified biogeography-based optimization

    Energy Technology Data Exchange (ETDEWEB)

    Sayed, M.M., E-mail: M.M.Sayed@ieee.org; Saad, M.S.; Emara, H.M.; Abou El-Zahab, E.E.

    2013-09-15

    Highlights: • A modified version of the BBO was proposed. • A novel method for interval type-2 FLC design tuned by MBBO was proposed. • The performance of the ETRR-2 was improved by using IT2FLC tuned by MBBO. -- Abstract: Power stabilization is a critical issue in nuclear reactors. The conventional proportional derivative (PD) controller is currently used in the Egyptian second testing research reactor (ETRR-2). In this paper, we propose a modified biogeography-based optimization (MBBO) algorithm to design the interval type-2 fuzzy logic controller (IT2FLC) to improve the performance of the Egyptian second testing research reactor (ETRR-2). Biogeography-based optimization (BBO) is a novel evolutionary algorithm that is based on the mathematical models of biogeography. Biogeography is the study of the geographical distribution of biological organisms. In the BBO model, problem solutions are represented as islands, and the sharing of features between solutions is represented as immigration and emigration between the islands. A modified version of the BBO is applied to design the IT2FLC to get the optimal parameters of the membership functions of the controller. We test the optimal IT2FLC obtained by modified biogeography-based optimization (MBBO) using the integral square error (ISE) and is compared with the currently used PD controller.

  11. Certain investigations on the reduction of side lobe level of an uniform linear antenna array using biogeography based optimization technique with sinusoidal migration model and simplified-BBO

    Indian Academy of Sciences (India)

    T S Jeyali Laseetha; R Sukanesh

    2014-02-01

    In this paper, we propose biogeography based optimization technique, with linear and sinusoidal migration models and simplified biogeography based optimization (S-BBO), for uniformly spaced linear antenna array synthesis to maximize the reduction of side lobe level (SLL). This paper explores biogeography theory. It generalizes two migration models in BBO namely, linear migration model and sinusoidal migration model. The performance of SLL reduction in ULA is investigated. Our performance study shows that among the two, sinusoidal migration model is a promising candidate for optimization. In our work, simplified – BBO algorithmis also deployed. This determines an optimum set value for amplitude excitations of antenna array elements that generate a radiation pattern with maximum side lobe level reduction. Our detailed investigation also shows that sinusoidal migration model of BBO performs better compared to the other evolutionary algorithms discussed in this paper.

  12. Microbial biogeography of wine grapes is conditioned by cultivar, vintage, and climate.

    Science.gov (United States)

    Bokulich, Nicholas A; Thorngate, John H; Richardson, Paul M; Mills, David A

    2014-01-01

    Wine grapes present a unique biogeography model, wherein microbial biodiversity patterns across viticultural zones not only answer questions of dispersal and community maintenance, they are also an inherent component of the quality, consumer acceptance, and economic appreciation of a culturally important food product. On their journey from the vineyard to the wine bottle, grapes are transformed to wine through microbial activity, with indisputable consequences for wine quality parameters. Wine grapes harbor a wide range of microbes originating from the surrounding environment, many of which are recognized for their role in grapevine health and wine quality. However, determinants of regional wine characteristics have not been identified, but are frequently assumed to stem from viticultural or geological factors alone. This study used a high-throughput, short-amplicon sequencing approach to demonstrate that regional, site-specific, and grape-variety factors shape the fungal and bacterial consortia inhabiting wine-grape surfaces. Furthermore, these microbial assemblages are correlated to specific climatic features, suggesting a link between vineyard environmental conditions and microbial inhabitation patterns. Taken together, these factors shape the unique microbial inputs to regional wine fermentations, posing the existence of nonrandom "microbial terroir" as a determining factor in regional variation among wine grapes.

  13. Molecular phylogeny and biogeography of the widely distributed Amanita species, A. muscaria and A. pantherina.

    Science.gov (United States)

    Oda, Takashi; Tanaka, Chihiro; Tsuda, Mitsuya

    2004-08-01

    The molecular phylogeny and biogeography of two widely distributed Amanita species, A. muscaria and A. pantherina, were studied based on specimens from diverse localities. Analyses of both a partial sequence of the ITS region of nuclear DNA and a partial sequence of the beta-tubulin gene were able to resolve specimens of each species. Analyses revealed a greater divergence of the beta-tubulin region than the ITS region. Based on molecular phylogeny of the combination of the ITS and beta-tubulin regions, A. muscaria could be separated into at least three groups (Eurasian, Eurasian subalpine, and North American), and A. pantherina could be separated into at least two groups (North American and Eurasian). We hypothesize that the speciation of A. muscaria occurred in Eurasia with subsequent migration to North America via land bridges. However, it is impossible to determine whether A. pantherina moved from Eurasia to North America or vice versa. For both A. muscaria and A. pantherina, the intracontinental relationships of both Eurasia and North America were closer than the relationships between eastern Asia and eastern North America.

  14. Local-global overlap in diversity informs mechanisms of bacterial biogeography.

    Science.gov (United States)

    Livermore, Joshua A; Jones, Stuart E

    2015-11-01

    Spatial variation in environmental conditions and barriers to organism movement are thought to be important factors for generating endemic species, thus enhancing global diversity. Recent microbial ecology research suggested that the entire diversity of bacteria in the global oceans could be recovered at a single site, thus inferring a lack of bacterial endemism. We argue this is not the case in the global ocean, but might be in other bacterial ecosystems with higher dispersal rates and lower global diversity, like the human gut. We quantified the degree to which local and global bacterial diversity overlap in a diverse set of ecosystems. Upon comparison of observed local-global diversity overlap with predictions from a neutral biogeography model, human-associated microbiomes (gut, skin, mouth) behaved much closer to neutral expectations whereas soil, lake and marine communities deviated strongly from the neutral expectations. This is likely a result of differences in dispersal rate among 'patches', global diversity of these systems, and local densities of bacterial cells. It appears that overlap of local and global bacterial diversity is surprisingly large (but likely not one-hundred percent), and most importantly this overlap appears to be predictable based upon traditional biogeographic parameters like community size, global diversity, inter-patch environmental heterogeneity and patch connectivity.

  15. On the historical biogeography of global Galliformes: ancestral range and diversification patterns

    Institute of Scientific and Technical Information of China (English)

    Youhua; Chen

    2014-01-01

    Background: In this study, the ancestral distributional ranges and the tempo of diversification patterns of global Galliformes were investigated.Methods: Different diversification models characterizing possible tempo patterns were fitted and compared onto the phylogenetic tree for the 197 Galliforme species, consisting of a constant-speciation and constant-extinction model(CONSTANT), a decreasing-speciation and constant-extinction model(SPVAR), a constant-speciation and increasing-extinction model(EXVAR) and a decreasing-speciation and increasing-extinction model(BOTHVAR).Ancestral range reconstruction was conducted using the dispersal-extinction-cladogenesis model.Results: A constant-diversification-rate(CONSTANT) model best quantified the historical speciation patterns of this avian assemblage through model selection. Clade age and species richness are significantly and positively correlated. The most recent common ancestor for Galliformes species was originally found in the disjunctive regions between Southeast Asia and North America. High-frequency dispersal events were identified across the whole evolutionary time.Conclusions: The constant diversification rate for global Galliforme species implied that there were no diversification rate-shifting trends for Galliformes species. The present study may contribute to the understanding of the ecology and diversity patterns of Galliformes from the perspective of historical biogeography, although some limitations existed.

  16. Metacommunity versus biogeography: a case study of two groups of neotropical vegetation-dwelling arthropods.

    Directory of Open Access Journals (Sweden)

    Thiago Gonçalves-Souza

    Full Text Available Biogeography and metacommunity ecology provide two different perspectives on species diversity. Both are spatial in nature but their spatial scales do not necessarily match. With recent boom of metacommunity studies, we see an increasing need for clear discrimination of spatial scales relevant for both perspectives. This discrimination is a necessary prerequisite for improved understanding of ecological phenomena across scales. Here we provide a case study to illustrate some spatial scale-dependent concepts in recent metacommunity studies and identify potential pitfalls. We presented here the diversity patterns of Neotropical lepidopterans and spiders viewed both from metacommunity and biogeographical perspectives. Specifically, we investigated how the relative importance of niche- and dispersal-based processes for community assembly change at two spatial scales: metacommunity scale, i.e. within a locality, and biogeographical scale, i.e. among localities widely scattered along a macroclimatic gradient. As expected, niche-based processes dominated the community assembly at metacommunity scale, while dispersal-based processes played a major role at biogeographical scale for both taxonomical groups. However, we also observed small but significant spatial effects at metacommunity scale and environmental effects at biogeographical scale. We also observed differences in diversity patterns between the two taxonomical groups corresponding to differences in their dispersal modes. Our results thus support the idea of continuity of processes interactively shaping diversity patterns across scales and emphasize the necessity of integration of metacommunity and biogeographical perspectives.

  17. Pole-to-pole biogeography of surface and deep marine bacterial communities.

    Science.gov (United States)

    Ghiglione, Jean-François; Galand, Pierre E; Pommier, Thomas; Pedrós-Alió, Carlos; Maas, Elizabeth W; Bakker, Kevin; Bertilson, Stefan; Kirchmanj, David L; Lovejoy, Connie; Yager, Patricia L; Murray, Alison E

    2012-10-23

    The Antarctic and Arctic regions offer a unique opportunity to test factors shaping biogeography of marine microbial communities because these regions are geographically far apart, yet share similar selection pressures. Here, we report a comprehensive comparison of bacterioplankton diversity between polar oceans, using standardized methods for pyrosequencing the V6 region of the small subunit ribosomal (SSU) rRNA gene. Bacterial communities from lower latitude oceans were included, providing a global perspective. A clear difference between Southern and Arctic Ocean surface communities was evident, with 78% of operational taxonomic units (OTUs) unique to the Southern Ocean and 70% unique to the Arctic Ocean. Although polar ocean bacterial communities were more similar to each other than to lower latitude pelagic communities, analyses of depths, seasons, and coastal vs. open waters, the Southern and Arctic Ocean bacterioplankton communities consistently clustered separately from each other. Coastal surface Southern and Arctic Ocean communities were more dissimilar from their respective open ocean communities. In contrast, deep ocean communities differed less between poles and lower latitude deep waters and displayed different diversity patterns compared with the surface. In addition, estimated diversity (Chao1) for surface and deep communities did not correlate significantly with latitude or temperature. Our results suggest differences in environmental conditions at the poles and different selection mechanisms controlling surface and deep ocean community structure and diversity. Surface bacterioplankton may be subjected to more short-term, variable conditions, whereas deep communities appear to be structured by longer water-mass residence time and connectivity through ocean circulation.

  18. Review of the systematics, distribution, biogeography and natural history of Moroccan amphibians.

    Science.gov (United States)

    Beukema, Wouter; De Pous, Philip; Donaire-Barroso, David; Boaerts, Sergé; Garcia-Porta, Joan; Escoriza, Daniel; Arribas, Oscar J; El Mouden, El Hassan; Carranza, Salvador

    2013-01-01

    The amphibian fauna of the Kingdom of Morocco was traditionally regarded as poor and closely related to its European counterpart. However, an increase in research during the last decades revealed a considerable degree of endemism amongst Moroccan amphibians, as well as phenotypic and genotypic inter- and intraspecific divergence. Despite this increase in knowledge, a comprehensible overview is lacking while several systematic issues have remained unresolved. We herein present a contemporary overview of the distribution, taxonomy and biogeography of Moroccan amphibians. Fourteen fieldtrips were made by the authors and colleagues between 2000 and 2012, which produced a total of 292 new distribution records. Furthermore, based on the results of the present work, we (i) review the systematics of the genus Salamandra in Morocco, including the description of a new subspecies from the Rif- and Middle Atlas Mountains, Salamandra algira splendens ssp. nov.; (ii) present data on intraspecific morphological variability of Pelobates varaldiiand Pleurodeles waltl in Morocco; (iii) attempt to resolve the phylogenetic position of Bufo brongersmai and erect a new genus for this species, Barbarophryne gen. nov.; (iv) summarize and assess the availability of tadpole-specific characteristics and bioacoustical data, and (v) summarize natural history data.

  19. Advancing global marine biogeography research with open-source GIS software and cloud-computing

    Science.gov (United States)

    Fujioka, Ei; Vanden Berghe, Edward; Donnelly, Ben; Castillo, Julio; Cleary, Jesse; Holmes, Chris; McKnight, Sean; Halpin, patrick

    2012-01-01

    Across many scientific domains, the ability to aggregate disparate datasets enables more meaningful global analyses. Within marine biology, the Census of Marine Life served as the catalyst for such a global data aggregation effort. Under the Census framework, the Ocean Biogeographic Information System was established to coordinate an unprecedented aggregation of global marine biogeography data. The OBIS data system now contains 31.3 million observations, freely accessible through a geospatial portal. The challenges of storing, querying, disseminating, and mapping a global data collection of this complexity and magnitude are significant. In the face of declining performance and expanding feature requests, a redevelopment of the OBIS data system was undertaken. Following an Open Source philosophy, the OBIS technology stack was rebuilt using PostgreSQL, PostGIS, GeoServer and OpenLayers. This approach has markedly improved the performance and online user experience while maintaining a standards-compliant and interoperable framework. Due to the distributed nature of the project and increasing needs for storage, scalability and deployment flexibility, the entire hardware and software stack was built on a Cloud Computing environment. The flexibility of the platform, combined with the power of the application stack, enabled rapid re-development of the OBIS infrastructure, and ensured complete standards-compliance.

  20. Cognitive radio adaptation for power consumption minimization using biogeography-based optimization

    Science.gov (United States)

    Qi, Pei-Han; Zheng, Shi-Lian; Yang, Xiao-Niu; Zhao, Zhi-Jin

    2016-12-01

    Adaptation is one of the key capabilities of cognitive radio, which focuses on how to adjust the radio parameters to optimize the system performance based on the knowledge of the radio environment and its capability and characteristics. In this paper, we consider the cognitive radio adaptation problem for power consumption minimization. The problem is formulated as a constrained power consumption minimization problem, and the biogeography-based optimization (BBO) is introduced to solve this optimization problem. A novel habitat suitability index (HSI) evaluation mechanism is proposed, in which both the power consumption minimization objective and the quality of services (QoS) constraints are taken into account. The results show that under different QoS requirement settings corresponding to different types of services, the algorithm can minimize power consumption while still maintaining the QoS requirements. Comparison with particle swarm optimization (PSO) and cat swarm optimization (CSO) reveals that BBO works better, especially at the early stage of the search, which means that the BBO is a better choice for real-time applications. Project supported by the National Natural Science Foundation of China (Grant No. 61501356), the Fundamental Research Funds of the Ministry of Education, China (Grant No. JB160101), and the Postdoctoral Fund of Shaanxi Province, China.

  1. Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

    Science.gov (United States)

    Coleman-Derr, Devin; Desgarennes, Damaris; Fonseca-Garcia, Citlali; Gross, Stephen; Clingenpeel, Scott; Woyke, Tanja; North, Gretchen; Visel, Axel; Partida-Martinez, Laila P; Tringe, Susannah G

    2016-01-01

    Desert plants are hypothesized to survive the environmental stress inherent to these regions in part thanks to symbioses with microorganisms, and yet these microbial species, the communities they form, and the forces that influence them are poorly understood. Here we report the first comprehensive investigation of the microbial communities associated with species of Agave, which are native to semiarid and arid regions of Central and North America and are emerging as biofuel feedstocks. We examined prokaryotic and fungal communities in the rhizosphere, phyllosphere, leaf and root endosphere, as well as proximal and distal soil samples from cultivated and native agaves, through Illumina amplicon sequencing. Phylogenetic profiling revealed that the composition of prokaryotic communities was primarily determined by the plant compartment, whereas the composition of fungal communities was mainly influenced by the biogeography of the host species. Cultivated A. tequilana exhibited lower levels of prokaryotic diversity compared with native agaves, although no differences in microbial diversity were found in the endosphere. Agaves shared core prokaryotic and fungal taxa known to promote plant growth and confer tolerance to abiotic stress, which suggests common principles underpinning Agave-microbe interactions.

  2. The biogeography of soil archaeal communities on the eastern Tibetan Plateau

    Science.gov (United States)

    Shi, Yu; Adams, Jonathan M.; Ni, Yingying; Yang, Teng; Jing, Xin; Chen, Litong; He, Jin-Sheng; Chu, Haiyan

    2016-12-01

    The biogeographical distribution of soil bacterial communities has been widely investigated. However, there has been little study of the biogeography of soil archaeal communities on a regional scale. Here, using high-throughput sequencing, we characterized the archaeal communities of 94 soil samples across the eastern Tibetan Plateau. Thaumarchaeota was the predominant archael phylum in all the soils, and Halobacteria was dominant only in dry soils. Archaeal community composition was significantly correlated with soil moisture content and C:N ratio, and archaeal phylotype richness was negatively correlated with soil moisture content (r = ‑0.47, P community pattern. These results indicate that soil moisture and C:N ratio are the key factors structuring soil archaeal communities on the eastern Tibetan Plateau. Our findings suggest that archaeal communities have adjusted their distributions rapidly enough to reach range equilibrium in relation to past environmental changes e.g. in water availability and soil nutrient status. This responsiveness may allow better prediction of future responses of soil archaea to environmental change in these sensitive ecosystems.

  3. Biogeography rather than association with cyanobacteria structures symbiotic microbial communities in the marine sponge Petrosia ficiformis

    Science.gov (United States)

    Burgsdorf, Ilia; Erwin, Patrick M.; López-Legentil, Susanna; Cerrano, Carlo; Haber, Markus; Frenk, Sammy; Steindler, Laura

    2014-01-01

    The sponge Petrosia ficiformis is ubiquitous in the Mediterranean Sea and Eastern Atlantic Ocean, hosting a diverse assemblage of bacteria, including, in illuminated sites, cyanobacteria. Two closely related sponge color morphs have been described, one inside caves and at their entrance (white/pink), and one on the rocky cliffs (violet). The presence of the different morphs and their ubiquity in the Mediterranean (from North-West to South-East) provides an opportunity to examine which factors mostly affect the associated microbial communities in this species: (i) presence of phototrophic symbionts or (ii) biogeography. 16S rRNA gene tag pyrosequencing data of the microbial communities revealed that Chloroflexi, Gammaproteobacteria, and Acidobacteria dominated the bacterial communities of all sponges analyzed. Chlorophyll a content, TEM observations and DNA sequence data confirmed the presence of the cyanobacterium Synechococcus feldmannii in violet and pink morphs of P. ficiformis and their absence in white color morphs. Rather than cyanobacterial symbionts (i.e., color morphs) accounting for variability in microbial symbiont communities, a biogeographic trend was observed between P. ficiformis collected in Israel and Italy. Analyses of partial 18S rRNA and mitochondrial cytochrome c oxidase subunit I (COX1) gene sequences revealed consistent genetic divergence between the violet and pink-white morphotypes of P. ficiformis. Overall, data indicated that microbial symbiont communities were more similar in genetically distinct P. ficiformis from the same location, than genetically similar P. ficiformis from distant locations. PMID:25346728

  4. Biogeography rather than association with cyanobacteria structures symbiotic microbial communities in the marine sponge Petrosia ficiformis.

    Science.gov (United States)

    Burgsdorf, Ilia; Erwin, Patrick M; López-Legentil, Susanna; Cerrano, Carlo; Haber, Markus; Frenk, Sammy; Steindler, Laura

    2014-01-01

    The sponge Petrosia ficiformis is ubiquitous in the Mediterranean Sea and Eastern Atlantic Ocean, hosting a diverse assemblage of bacteria, including, in illuminated sites, cyanobacteria. Two closely related sponge color morphs have been described, one inside caves and at their entrance (white/pink), and one on the rocky cliffs (violet). The presence of the different morphs and their ubiquity in the Mediterranean (from North-West to South-East) provides an opportunity to examine which factors mostly affect the associated microbial communities in this species: (i) presence of phototrophic symbionts or (ii) biogeography. 16S rRNA gene tag pyrosequencing data of the microbial communities revealed that Chloroflexi, Gammaproteobacteria, and Acidobacteria dominated the bacterial communities of all sponges analyzed. Chlorophyll a content, TEM observations and DNA sequence data confirmed the presence of the cyanobacterium Synechococcus feldmannii in violet and pink morphs of P. ficiformis and their absence in white color morphs. Rather than cyanobacterial symbionts (i.e., color morphs) accounting for variability in microbial symbiont communities, a biogeographic trend was observed between P. ficiformis collected in Israel and Italy. Analyses of partial 18S rRNA and mitochondrial cytochrome c oxidase subunit I (COX1) gene sequences revealed consistent genetic divergence between the violet and pink-white morphotypes of P. ficiformis. Overall, data indicated that microbial symbiont communities were more similar in genetically distinct P. ficiformis from the same location, than genetically similar P. ficiformis from distant locations.

  5. Interactions between hydrology and water chemistry shape bacterioplankton biogeography across boreal freshwater networks.

    Science.gov (United States)

    Niño-García, Juan Pablo; Ruiz-González, Clara; Del Giorgio, Paul A

    2016-07-01

    Disentangling the mechanisms shaping bacterioplankton communities across freshwater ecosystems requires considering a hydrologic dimension that can influence both dispersal and local sorting, but how the environment and hydrology interact to shape the biogeography of freshwater bacterioplankton over large spatial scales remains unexplored. Using Illumina sequencing of the 16S ribosomal RNA gene, we investigate the large-scale spatial patterns of bacterioplankton across 386 freshwater systems from seven distinct regions in boreal Québec. We show that both hydrology and local water chemistry (mostly pH) interact to shape a sequential structuring of communities from highly diverse assemblages in headwater streams toward larger rivers and lakes dominated by fewer taxa. Increases in water residence time along the hydrologic continuum were accompanied by major losses of bacterial richness and by an increased differentiation of communities driven by local conditions (pH and other related variables). This suggests that hydrology and network position modulate the relative role of environmental sorting and mass effects on community assembly by determining both the time frame for bacterial growth and the composition of the immigrant pool. The apparent low dispersal limitation (that is, the lack of influence of geographic distance on the spatial patterns observed at the taxonomic resolution used) suggests that these boreal bacterioplankton communities derive from a shared bacterial pool that enters the networks through the smallest streams, largely dominated by mass effects, and that is increasingly subjected to local sorting of species during transit along the hydrologic continuum.

  6. Phylogeny and biogeography of Alyssum (Brassicaceae) based on nuclear ribosomal ITS DNA sequences

    Indian Academy of Sciences (India)

    Yan Li; Yan Kong; Zhe Zhang; Yanqiang Yin; Bin Liu; Guanghui Lv; Xiyong Wang

    2014-08-01

    The genus Alyssum consists of about 195 species native to Europe, Asia and northern Africa. All species were assigned to six sections. Previous molecular phylogeny studies indicate that Alyssum is polyphyletic. However, the divergence time and dispersal of the genus are not well studied. In this study, the phylogenetic relationships within the genus Alyssum were studied with nrDNA ITS sequences obtained from five sections. The divergence time was estimated by fossil calibration and the biogeography was examined by spread analysis. The phylogeny indicated two main lineages: lineage 1 includes the section of Alyssum, Gamosepalum and Psilonema; lineage 2 includes the section of Odontarrhena, Meniocus and Clypeola. The phylogenetic relationship was not congruent with the previous sectional classifications. The age of Alyssum was dated to the upper Miocene. Molecular data suggested the diversification of Alyssum in Mediterranean areas and wide-ranging distribution such as North Africa, eastward into Central Asia and immigration into North America. Climatic aridification and arid/semiarid areas established in the Pliocene/Pleistocene could have provided favourable conditions for the migration and diversification of Alyssum.

  7. Breakthroughs in the biodiversity, biogeography, biostratigraphy, and basin analysis of the Beaufort group

    Science.gov (United States)

    Hancox, P. J.; Rubidge, B. S.

    2001-08-01

    Over the past decade researchers working on the rocks of the Beaufort Group in the main Karoo Basin of South Africa have vastly increased our understanding of this important Permo-Triassic sequence. Many new fossil forms have been discovered, allowing for breakthroughs into the biodiversity, biogeography and biostratigraphy of the group. Taxonomic and phylogenetic advances are many and varied, and cover most of the vertebrate taxa, but with emphasis placed on the temnospondyl amphibians, archosauriforms and non-mammalian synapsids, in particular the anomodontia. Biostratigraphic breakthroughs have centered on the Middle Permian Eodicynodon and Tapinocephalus assemblage zones, the Late Permian Dicynodon Assemblage Zone, and the Triassic Lystrosaurus and Cynognathus assemblage zones. Correlation of these biozones with better dated sequences in Europe, Russia and China has allowed for many chronostratigraphic refinements, which are in turn vital for sequence stratigraphical analysis of the basin fill. Based on fossil data, both the lower (Ecca-Beaufort) and upper (Beaufort-Molteno) contacts of the group have been proved to be highly diachronous. The refined chronostratigraphic framework has also allowed for a better analysis of the basin evolution through time, particularly in terms of the correlation of external stimuli that affect basin sedimentation patterns.

  8. Historical biogeography of two cosmopolitan families of flowering plants: Annonaceae and Rhamnaceae.

    Science.gov (United States)

    Richardson, J E; Chatrou, L W; Mols, J B; Erkens, R H J; Pirie, M D

    2004-10-29

    Annonaceae are a pantropically distributed family found predominantly in rainforests, so they are megathermal taxa, whereas Rhamnaceae are a cosmopolitan family that tend to be found in xeric regions and may be classified as mesothermal. Phylogenetic analyses of these families are presented based on rbcL and trnL-F plastid DNA sequences. Likelihood ratio tests revealed rate heterogeneity in both phylogenetic trees and they were therefore made ultrametric using non-parametric rate smoothing and penalized likelihood. Divergence times were then estimated using fossil calibration points. The historical biogeography of these families that are species rich in different biomes is discussed and compared with other published reconstructions. Rhamnaceae and most lineages within Annonaceae are too young to have had their distribution patterns influenced by break-up of previously connected Gondwanan landmasses. Contrasts in the degree of geographical structure between these two families may be explained by differences in age and dispersal capability. In both groups, long-distance dispersal appears to have played a more significant role in establishing modern patterns than had previously been assumed. Both families also contain examples of recent diversification of species-rich lineages. An understanding of the processes responsible for shaping the distribution patterns of these families has contributed to our understanding of the historical assembly of the biomes that they occupy.

  9. Molecular phylogeny and biogeography of the weevil subfamily Platypodinae reveals evolutionarily conserved range patterns.

    Science.gov (United States)

    Jordal, Bjarte H

    2015-11-01

    Platypodinae is a peculiar weevil subfamily of species that cultivate fungi in tunnels excavated in dead wood. Their geographical distribution is generally restricted, with genera confined to a single continent or large island, which provides a useful system for biogeographical research. This study establishes the first detailed molecular phylogeny of the group, with the aim of testing hypotheses on classification, diversification, and biogeography. A phylogeny was reconstructed based on 3648 nucleotides from COI, EF-1α, CAD, ArgK, and 28S. Tree topology was well resolved and indicated a strong correlation with geography, more so than predicted by previous morphology-based classifications. Tesserocerini was paraphyletic, with Notoplatypus as the sister group to a clade consisting of three main lineages of Tesserocerini and the recently evolved Platypodini. Austroplatypus formed the sister group to all remaining Platypodini and hence confirmed its separate status from Platypus. The Indo-Australian genera of Platypodini were strikingly paraphyletic, suggesting that the taxonomy of this tribe needs careful revision. Ancestral-area reconstructions in Lagrange and S-DIVA were ambiguous for nodes roughly older than 80 Ma. More recent events were firmly assessed and involved post-Gondwanan long-distance dispersal. The Neotropics was colonized three times, all from the Afrotropical region, with the latest event less than 25 Ma that included the ancestor of all Neotropical Platypodini.

  10. Biogeography of planktonic and benthic cyanobacteria in coastal waters of the Big Island, Hawai'i.

    Science.gov (United States)

    Chamberlain, Samuel D; Kaplan, Katherine A; Modanu, Maria; Sirianni, Katherine M; Annandale, Senifa; Hewson, Ian

    2014-07-01

    Cyanobacteria are biogeochemically significant constituents of coral reef ecosystems; however, little is known about biotic and abiotic factors influencing the abundance and composition of cyanobacterial communities in fringing coral reef waters. To understand the patterns of cyanobacterial biogeography in relation to coastal environmental factors, we examined the diversity of planktonic and benthic cyanobacteria at 12 sites along the west coast of Hawaii's Big Island. We found distinct cyanobacterial communities in sediments compared to the water column. In both sediments and water, community structure was strongly related to overall biomass (chlorophyll a concentration), although both these communities corresponded to different sets of biotic/abiotic variables. To examine the influence of freshwater input on planktonic cyanobacterial communities, we conducted a mesocosm experiment where seawater was amended with freshwater from two sources representing high- and low-human population influence. Planktonic cyanobacterial abundance decreased over time in mesocosms, although chlorophyll a concentration significantly increased with time, indicating cyanobacteria were likely outcompeted by other phytoplankton in incubations. Our results show that cyanobacterial community structure may be affected by runoff from terrestrial habitats, but that the composition of cyanobacterial communities inhabiting these locations is also structured by factors not measured in this study.

  11. Biodiversity and biogeography of rhizobia associated with common bean (Phaseolus vulgaris L.) in Shaanxi Province.

    Science.gov (United States)

    Wang, Li; Cao, Ying; Wang, En Tao; Qiao, Ya Juan; Jiao, Shuo; Liu, Zhen Shan; Zhao, Liang; Wei, Ge Hong

    2016-05-01

    The biodiversity and biogeography of rhizobia associated with bean in Shaanxi Province were investigated. A total of 194 bacterial isolates from bean nodules collected from 13 sampling sites were characterized based on phylogenetic analyses of the 16S rRNA gene, the housekeeping genes recA, glnII and atpD, and the symbiotic genes nodC and nifH. Fifteen genospecies belonging to the genera Rhizobium, Agrobacterium, Ensifer, Bradyrhizobium and Ochrobactrum were defined among the isolates, with Rhizobium sp. II, Agrobacterium sp. II, E. fredii and R. phaseoli being the dominant groups. Four symbiotic gene lineages corresponding to Rhizobium sp. I, Rhizobium sp. II, R. phaseoli and B. liaoningense were detected in the nodC and nifH sequence analyses, indicating different origins for the symbiotic genes and their co-evolution with the chromosome of the bacteria. Moreover, the Ensifer isolates harbored symbiotic genes closely related to bean-nodulating Pararhizobium giardinii, indicating possible lateral gene transfer from Rhizobium to Ensifer. Correlation of rhizobial community composition with moisture, temperature, intercropping, soil features and nutrients were detected. All the results demonstrated a great diversity of bean rhizobia in Shaanxi that might be due to the adaptable evolution of the bean-nodulating rhizobia subjected to the diverse ecological conditions in the area.

  12. Phylogenetic position, origin and biogeography of Palearctic and Socotran blind-snakes (Serpentes: Typhlopidae).

    Science.gov (United States)

    Kornilios, P; Giokas, S; Lymberakis, P; Sindaco, R

    2013-07-01

    The majority of the family Typhlopidae occurs in the Neotropic, Australasian, Indo-Malayan and Afrotropic ecoregions. They show a restricted distribution in the western Palearctic, where they include few native species, i.e. Rhinotyphlops simoni, R. episcopus and Typhlops vermicularis. A unique species among typhlopids is T. socotranus, found in Socotra, one of the most endemic-rich archipelagoes. In this study we determine the phylogenetic position of the above mentioned species and discuss their systematics, origin and biogeography. For this purpose we use three protein-coding nuclear markers (AMEL-amelogenin, BDNF-brain-derived neurotrophic factor and NT3-neurotrophin 3) to construct a time-calibrated phylogeny of the family Typhlopidae. Our results show that T. socotranus is a sister-species to T. vermicularis, while R. simoni and R. episcopus are sister-species to each other and are found within the African clade of the family, although they are geographically distributed in west Asia. Additionally we discuss several hypotheses on their origin, as well as the occurence of typhlopids in Eurasia.

  13. The Monogenean Parasite Fauna of Cichlids: A Potential Tool for Host Biogeography

    Directory of Open Access Journals (Sweden)

    Antoine Pariselle

    2011-01-01

    Full Text Available We discuss geographical distribution and phylogeny of Dactylogyridea (Monogenea parasitizing Cichlidae to elucidate their hosts' history. Although mesoparasitic Monogenea (Enterogyrus spp. show typical vicariant distribution, ectoparasitic representatives from different continents are not considered sister taxa, hence their distribution cannot result from vicariance alone. Because of the close host-parasite relationship, this might indicate that present-day cichlid distribution may also reflect dispersal through coastal or brackish waters. Loss of ectoparasites during transoceanic migration, followed by lateral transfer from other fish families might explain extant host-parasite associations. Because of its mesoparasitic nature, hence not subject to salinity variations of the host's environment, Enterogyrus could have survived marine migrations, intolerable for ectoparasites. Host-switches and salinity transitions may be invoked to explain the pattern revealed by a preliminary morphological phylogeny of monogenean genera from Cichlidae and other selected Monogenea genera, rendering the parasite distribution explicable under both vicariance and dispersal. Testable hypotheses are put forward in this parasitological approach to cichlid biogeography. Along with more comprehensive in-depth morphological phylogeny, comparison with molecular data, clarifying dactylogyridean evolution on different continents and from various fish families, and providing temporal information on host-parasite history, are needed to discriminate between the possible scenarios.

  14. On the historical biogeography of global Galliformes:ancestral range and diversification patterns

    Institute of Scientific and Technical Information of China (English)

    Youhua Chen

    2014-01-01

    Background:In this study, the ancestral distributional ranges and the tempo of diversification patterns of global Galliformes were investigated. Methods:Different diversification models characterizing possible tempo patterns were fitted and compared onto the phylogenetic tree for the 197 Galliforme species, consisting of a constant-speciation and constant-extinction model (CONSTANT), a decreasing-speciation and constant-extinction model (SPVAR), a constant-speciation and increasing-extinction model (EXVAR) and a decreasing-speciation and increasing-extinction model (BOTHVAR). Ancestral range reconstruction was conducted using the dispersal-extinction-cladogenesis model. Results:A constant-diversification-rate (CONSTANT) model best quantified the historical speciation patterns of this avian assemblage through model selection. Clade age and species richness are significantly and positively correlated. The most recent common ancestor for Galliformes species was originally found in the disjunctive regions between Southeast Asia and North America. High-frequency dispersal events were identified across the whole evolutionary time. Conclusions:The constant diversification rate for global Gal iforme species implied that there were no diversification rate-shifting trends for Galliformes species. The present study may contribute to the understanding of the ecology and diversity patterns of Galliformes from the perspective of historical biogeography, although some limitations existed.

  15. Middle Eocene rodents from Peruvian Amazonia reveal the pattern and timing of caviomorph origins and biogeography.

    Science.gov (United States)

    Antoine, Pierre-Olivier; Marivaux, Laurent; Croft, Darin A; Billet, Guillaume; Ganerød, Morgan; Jaramillo, Carlos; Martin, Thomas; Orliac, Maëva J; Tejada, Julia; Altamirano, Ali J; Duranthon, Francis; Fanjat, Grégory; Rousse, Sonia; Gismondi, Rodolfo Salas

    2012-04-07

    The long-term isolation of South America during most of the Cenozoic produced a highly peculiar terrestrial vertebrate biota, with a wide array of mammal groups, among which caviomorph rodents and platyrrhine primates are Mid-Cenozoic immigrants. In the absence of indisputable pre-Oligocene South American rodents or primates, the mode, timing and biogeography of these extraordinary dispersals remained debated. Here, we describe South America's oldest known rodents, based on a new diverse caviomorph assemblage from the late Middle Eocene (approx. 41 Ma) of Peru, including five small rodents with three stem caviomorphs. Instead of being tied to the Eocene/Oligocene global cooling and drying episode (approx. 34 Ma), as previously considered, the arrival of caviomorphs and their initial radiation in South America probably occurred under much warmer and wetter conditions, around the Mid-Eocene Climatic Optimum. Our phylogenetic results reaffirm the African origin of South American rodents and support a trans-Atlantic dispersal of these mammals during Middle Eocene times. This discovery further extends the gap (approx. 15 Myr) between first appearances of rodents and primates in South America.

  16. Congruent and synchronic patterns in biogeography and speciation among seabirds, pinnipeds, and cestodes.

    Science.gov (United States)

    Hoberg, E P

    1992-08-01

    Congruence in biogeographic patterns among diverse assemblages of taxa indicates uniformity in the historical determinants of biotic distributions. Comparisons of host and parasite phylogenies and the elucidation of distributional area relationships are requisite components of analyses in historical biogeography. Host-parasite associations with broad geographic ranges are often archaic and have been structured largely by coevolutionary processes. In contrast, the origins and radiation of the primary cestode faunas of some seabirds (Alcataenia spp./Alcidae) and pinnipeds (Anophryocephalus spp./Phocidae and Otariidae) are associated with colonization. These young colonizing faunas, in the Holarctic Region, were influenced by a common history during the late Pliocene and Pleistocene epochs. Periodic range contraction, with isolation in refugial centers, and subsequent expansion into postglacial habitats for hosts and parasites coincided with the cyclic pattern of stadials and interstadials. During the past 2-3 million years following colonization, these dramatic climatic fluctuations strongly influenced the continuity of ecological associations in marine habitats and appear to have been the determinants of congruent and synchronic patterns of speciation among these disparate taxa of marine homeotherms and eucestodes.

  17. Hacia una biogeografía evolutiva Towards an evolutionary biogeography

    Directory of Open Access Journals (Sweden)

    UANJ MORRONE

    2007-12-01

    Full Text Available La proliferación de métodos en las últimas décadas ha llevado a algunos autores a cuestionar si la biogeografía es una disciplina coherente. Las biotas son mosaicos complejos debidos a dispersión (expansión de las distribuciones y vicarianza (fragmentación de las distribuciones, teniendo historias complejas y reticuladas, que necesariamente deben estudiarse a través de la integración de diferentes metodologías. Un análisis biogeográfico evolutivo involucraría cinco etapas: (1 reconocimiento de componentes bióticos (conjuntos de taxa integrados espacio-temporalmente debido a una historia común, mediante la panbiogeografía y métodos para identificar áreas de endemismo; (2 contrastación de los componentes bióticos e identificación de los eventos vicariantes que los fragmentaron, mediante la biogeografía cladística y filogeografía comparada; (3 establecimiento de un arreglo jerárquico de los componentes en un sistema biogeográfico de reinos, regiones, dominios, provincias y distritos; (4 identificación de los cenocrones (conjuntos de taxa con edad y orígenes similares, datados mediante la filogeografía intraespecífica, relojes moleculares y fósiles; y (5 formulación de un escenario geobiótico, que explique la evolución de los componentes y cenocrones, integrando información geológica y tectónicaThe proliferation of methods in the last decades has led some authors to question whether biogeography is a coherent discipline. Biotas are complex mosaics due to dispersal (expansion of distributions and vicariance (fragmentation of distributions, having complex, reticulate histories, which necessarily need to be studied through the integration of different methodologies. An evolutionary biogeographical analysis may involve five steps: (1 recognition of biotic components (sets of spatio-temporally integrated taxa due to common history, through panbiogeography and methods used to identify areas of endemism; (2

  18. Evolution and Biogeography of Haemonchus contortus: Linking Faunal Dynamics in Space and Time.

    Science.gov (United States)

    Hoberg, E P; Zarlenga, D S

    2016-01-01

    History is the foundation that informs about the nuances of faunal assembly that are essential in understanding the dynamic nature of the host-parasite interface. All of our knowledge begins and ends with evolution, ecology and biogeography, as these interacting facets determine the history of biodiverse systems. These components, relating to Haemonchus, can inform about the complex history of geographical distribution, host association and the intricacies of host-parasite associations that are played out in physiological and behavioural processes that influence the potential for disease and our capacity for effective control in a rapidly changing world. Origins and evolutionary diversification among species of the genus Haemonchus and Haemonchus contortus occurred in a complex crucible defined by shifts in environmental structure emerging from cycles of climate change and ecological perturbation during the late Tertiary and through the Quaternary. A history of sequential host colonization associated with waves of dispersal bringing assemblages of ungulates from Eurasia into Africa and processes emerging from ecosystems in collision and faunal turnover defined the arena for radiation among 12 recognized species of Haemonchus. Among congeners, the host range for H. contortus is exceptionally broad, including species among artiodactyls of 40 genera representing 5 families (and within 12 tribes of Bovidae). Broad host range is dramatically reflected in the degree to which translocation, introduction and invasion with host switching, has characterized an expanding distribution over time in North America, South America, southern Eurasia, Australia and New Zealand, coincidental with agriculture, husbandry and global colonization by human populations driven particularly by European exploration after the 1500s. African origins in xeric to mesic habitats of the African savannah suggest that historical constraints linked to ecological adaptations (tolerances and

  19. Phylogeny of Acridocarpus-Brachylophon (Malpighiaceae): implications for tertiary tropical floras and Afroasian biogeography.

    Science.gov (United States)

    Davis, Charles C; Bell, Charles D; Fritsch, Peter W; Mathews, Sarah

    2002-12-01

    A major tenet of African Tertiary biogeography posits that lowland rainforest dominated much of Africa in the late Cretaceous and was replaced by xeric vegetation as a response to continental uplift and consequent widespread aridification beginning in the late Paleogene. The aridification of Africa is thought to have been a major factor in the extinction of many African humid-tropical lineages, and in the present-day disparity of species diversity between Africa and other tropical regions. This primarily geologically based model can be tested with independent phylogenetic evidence from widespread African plant groups containing both humid- and xeric-adapted species. We estimated the phylogeny and lineage divergence times within one such angiosperm group, the acridocarpoid clade (Malpighiaceae), with combined ITS, ndhF, and trnL-F data from 15 species that encompass the range of morphological and geographic variation within the group. Dispersal-vicariance analysis and divergence-time estimates suggest that the basal acridocarpoid divergence occurred between African and Southeast Asian lineages approximately 50 million years ago (mya), perhaps after a southward ancestral retreat from high-latitude tropical forests in response to intermittent Eocene cooling. Dispersion of Aeridocarpus from Africa to Madagascar is inferred between approximately 50 and 35 mya, when lowland humid tropical forest was nearly continuous between these landmasses. A single dispersal event within Acridocarpus is inferred from western Africa to eastern Africa between approximately 23 and 17 mya, coincident with the widespread replacement of humid forests by savannas in eastern Africa. Although the spread of xeric environments resulted in the extinction of many African plant groups, our data suggest that for others it provided an opportunity for further diversification.

  20. Biogeography and molecular diversity of coral symbionts in the genus Symbiodinium around the Arabian Peninsula

    KAUST Repository

    Ziegler, Maren

    2017-01-02

    Aim: Coral reefs rely on the symbiosis between scleractinian corals and intracellular, photosynthetic dinoflagellates of the genus Symbiodinium making the assessment of symbiont diversity critical to our understanding of ecological resilience of these ecosystems. This study characterizes Symbiodinium diversity around the Arabian Peninsula, which contains some of the most thermally diverse and understudied reefs on Earth. Location: Shallow water coral reefs throughout the Red Sea (RS), Sea of Oman (SO), and Persian/Arabian Gulf (PAG). Methods: Next-generation sequencing of the ITS2 marker gene was used to assess Symbiodinium community composition and diversity comprising 892 samples from 46 hard and soft coral genera. Results: Corals were associated with a large diversity of Symbiodinium, which usually consisted of one or two prevalent symbiont types and many types at low abundance. Symbiodinium communities were strongly structured according to geographical region and to a lesser extent by coral host identity. Overall symbiont communities were composed primarily of species from clade A and C in the RS, clade A, C, and D in the SO, and clade C and D in the PAG, representing a gradual shift from C- to D-dominated coral hosts. The analysis of symbiont diversity in an Operational Taxonomic Unit (OTU)-based framework allowed the identification of differences in symbiont taxon richness over geographical regions and host genera. Main conclusions: Our study represents a comprehensive overview over biogeography and molecular diversity of Symbiodinium in the Arabian Seas, where coral reefs thrive in one of the most extreme environmental settings on the planet. As such our data will serve as a baseline for further exploration into the effects of environmental change on host-symbiont pairings and the identification and ecological significance of Symbiodinium types from regions already experiencing \\'Future Ocean\\' conditions.

  1. Defining and dividing the greater Caribbean: insights from the biogeography of shorefishes.

    Science.gov (United States)

    Robertson, D Ross; Cramer, Katie L

    2014-01-01

    The Greater Caribbean biogeographic region is the high-diversity heart of the Tropical West Atlantic, one of four global centers of tropical marine biodiversity. The traditional view of the Greater Caribbean is that it is limited to the Caribbean, West Indies, southwest Gulf of Mexico and tip of Florida, and that, due to its faunal homogeneity, lacks major provincial subdivisions. In this scenario the northern 2/3 of the Gulf of Mexico and southeastern USA represent a separate temperate, "Carolinian" biogeographic region. We completed a comprehensive re-assessment of the biogeography of the Greater Caribbean by comparing the distributions of 1,559 shorefish species within 45 sections of shelf waters of the Greater Caribbean and adjacent areas. This analysis shows that that the Greater Caribbean occupies a much larger area than usually thought, extending south to at least Guyana, and north to encompass the entire Carolinian area. Rather than being homogenous, the Greater Caribbean is divided into three major provinces, each with a distinctive, primarily tropical fauna: (1) a central, tropical province comprising the West Indies, Bermuda and Central America; (2) a southern, upwelling-affected province spanning the entire continental shelf of northern South America; and (iii) a northern, subtropical province that includes all of the Gulf of Mexico, Florida and southeastern USA. This three-province pattern holds for both reef- and soft bottom fishes, indicating a general response by demersal fishes to major variation in provincial shelf environments. Such environmental differences include latitudinal variation in sea temperature, availability of major habitats (coral reefs, soft bottom shorelines, and mangroves), and nutrient additions from upwelling areas and large rivers. The three-province arrangement of the Greater Caribbean broadly resembles and has a similar environmental basis to the provincial arrangement of its sister biogeographic region, the Tropical Eastern

  2. Defining and dividing the greater Caribbean: insights from the biogeography of shorefishes.

    Directory of Open Access Journals (Sweden)

    D Ross Robertson

    Full Text Available The Greater Caribbean biogeographic region is the high-diversity heart of the Tropical West Atlantic, one of four global centers of tropical marine biodiversity. The traditional view of the Greater Caribbean is that it is limited to the Caribbean, West Indies, southwest Gulf of Mexico and tip of Florida, and that, due to its faunal homogeneity, lacks major provincial subdivisions. In this scenario the northern 2/3 of the Gulf of Mexico and southeastern USA represent a separate temperate, "Carolinian" biogeographic region. We completed a comprehensive re-assessment of the biogeography of the Greater Caribbean by comparing the distributions of 1,559 shorefish species within 45 sections of shelf waters of the Greater Caribbean and adjacent areas. This analysis shows that that the Greater Caribbean occupies a much larger area than usually thought, extending south to at least Guyana, and north to encompass the entire Carolinian area. Rather than being homogenous, the Greater Caribbean is divided into three major provinces, each with a distinctive, primarily tropical fauna: (1 a central, tropical province comprising the West Indies, Bermuda and Central America; (2 a southern, upwelling-affected province spanning the entire continental shelf of northern South America; and (iii a northern, subtropical province that includes all of the Gulf of Mexico, Florida and southeastern USA. This three-province pattern holds for both reef- and soft bottom fishes, indicating a general response by demersal fishes to major variation in provincial shelf environments. Such environmental differences include latitudinal variation in sea temperature, availability of major habitats (coral reefs, soft bottom shorelines, and mangroves, and nutrient additions from upwelling areas and large rivers. The three-province arrangement of the Greater Caribbean broadly resembles and has a similar environmental basis to the provincial arrangement of its sister biogeographic region, the

  3. Paraphyly of Cinclodes fuscus (Aves: Passeriformes: Furnariidae): Implications for taxonomy and biogeography

    Science.gov (United States)

    Sanin, Camilo; Cadena, Carlos Daniel; Maley, James M.; Lijtmaer, Dario A.; Tubaro, Pablo L.; Chesser, R. Terry

    2009-01-01

    The Andes are a hotspot of global avian diversity, but studies on the historical diversification of Andean birds remain relatively scarce. Evolutionary studies on avian lineages with Andean–Patagonian distributions have focused on reconstructing species-level phylogenies, whereas no detailed phylogeographic studies on widespread species have been conducted. Here, we describe phylogeographic patterns in the Bar-winged Cinclodes (Cinclodes fuscus), a widespread and common species of ovenbird (Furnariidae) that breeds from Tierra del Fuego to the northern Andes. Traditionally, C. fuscus has been considered a single species composed of nine subspecies, but its long and narrow range suggests the possibility of considerable genetic variation among populations. Sequences of two mitochondrial genes revealed three discrete and geographically coherent groups of C. fuscus, occupying the southern, central, and northern Andes. Surprisingly, phylogenetic analyses indicated that these groups were more closely related to other species of Cinclodes than to each other. Relationships of the southern and northern C. fuscus clades to other species of Cinclodes were straightforward; in combination with available information on plumage, behavioral, and vocal variation, this suggests that each should be recognized as a distinct biological species. The central Andean group was paraphyletic with respect to C. oustaleti, and relationships among these taxa and C. olrogi were poorly resolved. We suggest that the central Andean C. fuscus should also be considered a different species, pending new information to clarify species limits in this group. These new phylogenetic data, along with recently developed methods, allowed us to review the biogeography of the genus, confirming southern South America and the central Andes as important areas for the diversification of these birds.

  4. Macroevolutionary dynamics and historical biogeography of primate diversification inferred from a species supermatrix.

    Directory of Open Access Journals (Sweden)

    Mark S Springer

    Full Text Available Phylogenetic relationships, divergence times, and patterns of biogeographic descent among primate species are both complex and contentious. Here, we generate a robust molecular phylogeny for 70 primate genera and 367 primate species based on a concatenation of 69 nuclear gene segments and ten mitochondrial gene sequences, most of which were extracted from GenBank. Relaxed clock analyses of divergence times with 14 fossil-calibrated nodes suggest that living Primates last shared a common ancestor 71-63 Ma, and that divergences within both Strepsirrhini and Haplorhini are entirely post-Cretaceous. These results are consistent with the hypothesis that the Cretaceous-Paleogene mass extinction of non-avian dinosaurs played an important role in the diversification of placental mammals. Previous queries into primate historical biogeography have suggested Africa, Asia, Europe, or North America as the ancestral area of crown primates, but were based on methods that were coopted from phylogeny reconstruction. By contrast, we analyzed our molecular phylogeny with two methods that were developed explicitly for ancestral area reconstruction, and find support for the hypothesis that the most recent common ancestor of living Primates resided in Asia. Analyses of primate macroevolutionary dynamics provide support for a diversification rate increase in the late Miocene, possibly in response to elevated global mean temperatures, and are consistent with the fossil record. By contrast, diversification analyses failed to detect evidence for rate-shift changes near the Eocene-Oligocene boundary even though the fossil record provides clear evidence for a major turnover event ("Grande Coupure" at this time. Our results highlight the power and limitations of inferring diversification dynamics from molecular phylogenies, as well as the sensitivity of diversification analyses to different species concepts.

  5. Biogeography and change among regional coral communities across the Western Indian Ocean.

    Directory of Open Access Journals (Sweden)

    Timothy R McClanahan

    Full Text Available Coral reefs are biodiverse ecosystems structured by abiotic and biotic factors operating across many spatial scales. Regional-scale interactions between climate change, biogeography and fisheries management remain poorly understood. Here, we evaluated large-scale patterns of coral communities in the western Indian Ocean after a major coral bleaching event in 1998. We surveyed 291 coral reef sites in 11 countries and over 30° of latitude between 2004 and 2011 to evaluate variations in coral communities post 1998 across gradients in latitude, mainland-island geography and fisheries management. We used linear mixed-effect hierarchical models to assess total coral cover, the abundance of four major coral families (acroporids, faviids, pocilloporids and poritiids, coral genus richness and diversity, and the bleaching susceptibility of the coral communities. We found strong latitudinal and geographic gradients in coral community structure and composition that supports the presence of a high coral cover and diversity area that harbours temperature-sensitive taxa in the northern Mozambique Channel between Tanzania, northern Mozambique and northern Madagascar. Coral communities in the more northern latitudes of Kenya, Seychelles and the Maldives were generally composed of fewer bleaching-tolerant coral taxa and with reduced richness and diversity. There was also evidence for continued declines in the abundance of temperature-sensitive taxa and community change after 2004. While there are limitations of our regional dataset in terms of spatial and temporal replication, these patterns suggest that large-scale interactions between biogeographic factors and strong temperature anomalies influence coral communities while smaller-scale factors, such as the effect of fisheries closures, were weak. The northern Mozambique Channel, while not immune to temperature disturbances, shows continued signs of resistance to climate disturbances and remains a priority for

  6. Out of Africa: Phylogeny and biogeography of the widespread genus Acanthodactylus (Reptilia: Lacertidae).

    Science.gov (United States)

    Tamar, Karin; Carranza, Salvador; Sindaco, Roberto; Moravec, Jiří; Trape, Jean-François; Meiri, Shai

    2016-10-01

    Acanthodactylus lizards are among the most diverse and widespread diurnal reptiles in the arid regions spanning from North Africa across to western India. Acanthodactylus constitutes the most species-rich genus in the family Lacertidae, with over 40 recognized species inhabiting a wide variety of dry habitats. The genus has seldom undergone taxonomic revisions, and although there are a number of described species and species-groups, their boundaries, as well as their interspecific relationships, remain largely unresolved. We constructed a multilocus phylogeny, combining data from two mitochondrial (12S, cytb) and three nuclear (MC1R, ACM4, c-mos) markers for 302 individuals belonging to 36 known species, providing the first large-scale time-calibrated molecular phylogeny of the genus. We evaluated phylogenetic relationships between and within species-groups, and assessed Acanthodactylus biogeography across its known range. Acanthodactylus cladogenesis is estimated to have originated in Africa due to vicariance and dispersal events from the Oligocene onwards. Radiation started with the separation into three clades: the Western and scutellatus clades largely distributed in North Africa, and the Eastern clade occurring mostly in south-west Asia. Most Acanthodactylus species diverged during the Miocene, possibly as a result of regional geological instability and climatic changes. We support most of the current taxonomic classifications and phylogenetic relationships, and provide genetic validity for most species. We reveal a new distinct blanfordii species-group, suggest new phylogenetic positions (A. hardyi, A. masirae), and synonymize several species and subspecies (A. lineomaculatus, A. boskianus khattensis and A. b. nigeriensis) with their phylogenetically closely-related species. We recommend a thorough systematic revision of taxa, such as A. guineensis, A. grandis, A. dumerilii, A. senegalensis and the pardalis and erythrurus species-groups, which exhibit high

  7. Biogeography of pelagic bacterioplankton across an antagonistic temperature-salinity gradient in the Red Sea

    KAUST Repository

    Ngugi, David

    2011-12-01

    The Red Sea is a unique marine ecosystem with contrasting gradients of temperature and salinity along its north-to-south axis. It is an extremely oligotrophic environment that is characterized by perpetual year-round water column stratification, high annual solar irradiation, and negligible riverine and precipitation inputs. In this study, we investigated whether the contemporary environmental conditions shape community assemblages by pyrosequencing 16S rRNA genes of bacteria in surface water samples collected from the northeastern half of this water body. A combined total of 1855 operational taxonomic units (OTUs) were recovered from the \\'small-cell\\' and \\'large-cell\\' fractions. Here, a few major OTUs affiliated with Cyanobacteria and Proteobacteria accounted for â93% of all sequences, whereas a tail of \\'rare\\' OTUs represented most of the diversity. OTUs allied to Surface 1a/b SAR11 clades and Prochlorococcus related to the high-light-adapted (HL2) ecotype were the most widespread and predominant sequence types. Interestingly, the frequency of taxa that are typically found in the upper mesopelagic zone was significantly elevated in the northern transects compared with those in the central, presumably as a direct effect of deep convective mixing in the Gulf of Aqaba and water exchange with the northern Red Sea. Although temperature was the best predictor of species richness across all major lineages, both spatial and environmental distances correlated strongly with phylogenetic distances. Our results suggest that the bacterial diversity of the Red Sea is as high as in other tropical seas and provide evidence for fundamental differences in the biogeography of pelagic communities between the northern and central regions. © 2011 Blackwell Publishing Ltd.

  8. Phylogenetic analyses provide insights into the historical biogeography and evolution of Brachyrhaphis fishes.

    Science.gov (United States)

    Ingley, Spencer J; Reina, Ruth G; Bermingham, Eldredge; Johnson, Jerald B

    2015-08-01

    The livebearing fish genus Brachyrhaphis (Poeciliidae) has become an increasingly important model in evolution and ecology research, yet the phylogeny of this group is not well understood, nor has it been examined thoroughly using modern phylogenetic methods. Here, we present the first comprehensive phylogenetic analysis of Brachyrhaphis by using four molecular markers (3mtDNA, 1nucDNA) to infer relationships among species in this genus. We tested the validity of this genus as a monophyletic group using extensive outgroup sampling based on recent phylogenetic hypotheses of Poeciliidae. We also tested the validity of recently described species of Brachyrhaphis that are part of the B. episcopi complex in Panama. Finally, we examined the impact of historical events on diversification of Brachyrhaphis, and made predictions regarding the role of different ecological environments on evolutionary diversification where known historical events apparently fail to explain speciation. Based on our results, we reject the monophyly of Brachyrhaphis, and question the validity of two recently described species (B. hessfeldi and B. roswithae). Historical biogeography of Brachyrhaphis generally agrees with patterns found in other freshwater taxa in Lower Central America, which show that geological barriers frequently predict speciation. Specifically, we find evidence in support of an 'island' model of Lower Central American formation, which posits that the nascent isthmus was partitioned by several marine connections before linking North and South America. In some cases where historic events (e.g., vicariance) fail to explain allopatric species breaks in Brachyrhaphis, ecological processes (e.g., divergent predation environments) offer additional insight into our understanding of phylogenetic diversification in this group.

  9. Biotic interactions overrule plant responses to climate, depending on the species' biogeography.

    Directory of Open Access Journals (Sweden)

    Astrid Welk

    Full Text Available This study presents an experimental approach to assess the relative importance of climatic and biotic factors as determinants of species' geographical distributions. We asked to what extent responses of grassland plant species to biotic interactions vary with climate, and to what degree this variation depends on the species' biogeography. Using a gradient from oceanic to continental climate represented by nine common garden transplant sites in Germany, we experimentally tested whether congeneric grassland species of different geographic distribution (oceanic vs. continental plant range type responded differently to combinations of climate, competition and mollusc herbivory. We found the relative importance of biotic interactions and climate to vary between the different components of plant performance. While survival and plant height increased with precipitation, temperature had no effect on plant performance. Additionally, species with continental plant range type increased their growth in more benign climatic conditions, while those with oceanic range type were largely unable to take a similar advantage of better climatic conditions. Competition generally caused strong reductions of aboveground biomass and growth. In contrast, herbivory had minor effects on survival and growth. Against expectation, these negative effects of competition and herbivory were not mitigated under more stressful continental climate conditions. In conclusion we suggest variation in relative importance of climate and biotic interactions on broader scales, mediated via species-specific sensitivities and factor-specific response patterns. Our results have important implications for species distribution models, as they emphasize the large-scale impact of biotic interactions on plant distribution patterns and the necessity to take plant range types into account.

  10. Global biogeography of reef fishes: a hierarchical quantitative delineation of regions.

    Science.gov (United States)

    Kulbicki, Michel; Parravicini, Valeriano; Bellwood, David R; Arias-Gonzàlez, Ernesto; Chabanet, Pascale; Floeter, Sergio R; Friedlander, Alan; McPherson, Jana; Myers, Robert E; Vigliola, Laurent; Mouillot, David

    2013-01-01

    Delineating regions is an important first step in understanding the evolution and biogeography of faunas. However, quantitative approaches are often limited at a global scale, particularly in the marine realm. Reef fishes are the most diversified group of marine fishes, and compared to most other phyla, their taxonomy and geographical distributions are relatively well known. Based on 169 checklists spread across all tropical oceans, the present work aims to quantitatively delineate biogeographical entities for reef fishes at a global scale. Four different classifications were used to account for uncertainty related to species identification and the quality of checklists. The four classifications delivered converging results, with biogeographical entities that can be hierarchically delineated into realms, regions and provinces. All classifications indicated that the Indo-Pacific has a weak internal structure, with a high similarity from east to west. In contrast, the Atlantic and the Eastern Tropical Pacific were more strongly structured, which may be related to the higher levels of endemism in these two realms. The "Coral Triangle", an area of the Indo-Pacific which contains the highest species diversity for reef fishes, was not clearly delineated by its species composition. Our results show a global concordance with recent works based upon endemism, environmental factors, expert knowledge, or their combination. Our quantitative delineation of biogeographical entities, however, tests the robustness of the results and yields easily replicated patterns. The similarity between our results and those from other phyla, such as corals, suggests that our approach may be of broad utility in describing and understanding global marine biodiversity patterns.

  11. Bacterial community structure on two alpine debris-covered glaciers and biogeography of Polaromonas phylotypes.

    Science.gov (United States)

    Franzetti, Andrea; Tatangelo, Valeria; Gandolfi, Isabella; Bertolini, Valentina; Bestetti, Giuseppina; Diolaiuti, Guglielmina; D'Agata, Carlo; Mihalcea, Claudia; Smiraglia, Claudio; Ambrosini, Roberto

    2013-08-01

    High-elevation cold environments are considered ideal places to test hypotheses about mechanisms of bacterial colonization and succession, and about bacterial biogeography. Debris-covered glaciers (glaciers whose ablation area is mainly covered by a continuous layer of rock debris fallen from the surrounding mountains) have never been investigated in this respect so far. We used the Illumina technology to analyse the V5 and V6 hypervariable regions of the bacterial 16S rRNA gene amplified from 38 samples collected in July and September 2009 at different distances from the terminus on two debris-covered glaciers (Miage and Belvedere--Italian Alps). Heterotrophic taxa-dominated communities and bacterial community structure changed according to ice ablation rate, organic carbon content of the debris and distance from the glacier terminus. Bacterial communities therefore change during downwards debris transport, and organic carbon of these recently exposed substrates is probably provided more by allochthonous deposition of organic matter than by primary production by autotrophic organisms. We also investigated whether phylotypes of the genus Polaromonas, which is ubiquitous in cold environments, do present a biogeographical distribution by analysing the sequences retrieved in this study together with others available in the literature. We found that the genetic distance among phylotypes increased with geographic distance; however, more focused analyses using discrete distance classes revealed that both sequences collected at sites <100 km and at sites 9400-13,500 km to each other were more similar than those collected at other distance classes. Evidences of biogeographic distribution of Polaromonas phylotypes were therefore contrasting.

  12. Biogeography of the deep-sea galatheid squat lobsters of the Pacific Ocean

    Science.gov (United States)

    Macpherson, Enrique; Richer de Forges, Bertrand; Schnabel, Kareen; Samadi, Sarah; Boisselier, Marie-Catherine; Garcia-Rubies, Antoni

    2010-02-01

    We analyzed the distribution patterns of the galatheid squat lobsters (Crustacea, Decapoda, Galatheidae) of the Pacific Ocean. We used the presence/absence data of 402 species along the continental slope and continental rise (200-2000 m) obtained from 54 cruises carried out in areas around the Philippines, Indonesia, Solomon, Vanuatu, New Caledonia, Fiji, Tonga, Wallis and Futuna and French Polynesia. The total number of stations was ca. 3200. We also used published data from other expeditions carried out in the Pacific waters, and from an exhaustive search of ca. 600 papers on the taxonomy and biogeography of Pacific species. We studied the existence of biogeographic provinces using multivariate analyses, and present data on latitudinal and longitudinal patterns of species richness, rate of endemism and the relationship between body sizes with the size of the geographic ranges. Latitudinal species richness along the Western and Eastern Pacific exhibited an increase from higher latitudes towards the Equator. Longitudinal species richness decreased considerably from the Western to the Central Pacific. Size frequency distribution for body size was strongly shifted toward small sizes and endemic species were significantly smaller than non-endemics. This study concludes that a clear separation exists between the moderately poor galatheid fauna of the Eastern Pacific and the rich Western and Central Pacific faunas. Our results also show that the highest numbers of squat lobsters are found in the Coral Sea (Solomon-Vanuatu-New Caledonia islands) and Indo-Malay-Philippines archipelago (IMPA). The distribution of endemism along the Pacific Ocean indicates that there are several major centres of diversity, e.g. Coral Sea, IMPA, New Zealand and French Polynesia. The high proportion of endemism in these areas suggests that they have evolved independently.

  13. Diversity and composition of the copepod communities associated with megafauna around a cold seep in the Gulf of Mexico with remarks on species biogeography

    NARCIS (Netherlands)

    Plum, C.; Gollner, S.; Martinez Arbizu, P.; Bright, M.

    2015-01-01

    In order to characterize the copepod communitiesassociated with tubeworm and mussel aggregations around ahydrocarbon seep in the Green Canyon of the Gulf of Mexico,diversity, abundance, and community composition were analyzed.Also analyzed were species biogeography and the potentialconnectivity to o

  14. The world bacterial biogeography and biodiversity through databases: a case study of NCBI Nucleotide Database and GBIF Database.

    Science.gov (United States)

    Selama, Okba; James, Phillip; Nateche, Farida; Wellington, Elizabeth M H; Hacène, Hocine

    2013-01-01

    Databases are an essential tool and resource within the field of bioinformatics. The primary aim of this study was to generate an overview of global bacterial biodiversity and biogeography using available data from the two largest public online databases, NCBI Nucleotide and GBIF. The secondary aim was to highlight the contribution each geographic area has to each database. The basis for data analysis of this study was the metadata provided by both databases, mainly, the taxonomy and the geographical area origin of isolation of the microorganism (record). These were directly obtained from GBIF through the online interface, while E-utilities and Python were used in combination with a programmatic web service access to obtain data from the NCBI Nucleotide Database. Results indicate that the American continent, and more specifically the USA, is the top contributor, while Africa and Antarctica are less well represented. This highlights the imbalance of exploration within these areas rather than any reduction in biodiversity. This study describes a novel approach to generating global scale patterns of bacterial biodiversity and biogeography and indicates that the Proteobacteria are the most abundant and widely distributed phylum within both databases.

  15. The World Bacterial Biogeography and Biodiversity through Databases: A Case Study of NCBI Nucleotide Database and GBIF Database

    Directory of Open Access Journals (Sweden)

    Okba Selama

    2013-01-01

    Full Text Available Databases are an essential tool and resource within the field of bioinformatics. The primary aim of this study was to generate an overview of global bacterial biodiversity and biogeography using available data from the two largest public online databases, NCBI Nucleotide and GBIF. The secondary aim was to highlight the contribution each geographic area has to each database. The basis for data analysis of this study was the metadata provided by both databases, mainly, the taxonomy and the geographical area origin of isolation of the microorganism (record. These were directly obtained from GBIF through the online interface, while E-utilities and Python were used in combination with a programmatic web service access to obtain data from the NCBI Nucleotide Database. Results indicate that the American continent, and more specifically the USA, is the top contributor, while Africa and Antarctica are less well represented. This highlights the imbalance of exploration within these areas rather than any reduction in biodiversity. This study describes a novel approach to generating global scale patterns of bacterial biodiversity and biogeography and indicates that the Proteobacteria are the most abundant and widely distributed phylum within both databases.

  16. Molecular assessment of the phylogeny and biogeography of a recently diversified endemic group of South American canids (Mammalia: Carnivora: Canidae

    Directory of Open Access Journals (Sweden)

    Ligia Tchaicka

    Full Text Available Abstract To investigate the evolution and biogeography of an endemic group of South American foxes, we examined mitochondrial DNA control region sequences for 118 individuals belonging to all six extant species of the genus Lycalopex. Phylogenetic and molecular dating analyses supported the inference that this genus has undergone a very recent and rapid radiation, stemming from a common ancestor that lived ca. 1 million years ago. The Brazilian endemic L. vetulus was supported as the most basal species in this genus, whereas the most internal group is comprised by the recently diverged (ca. 350,000 years ago Andean/Patagonian species L. griseus and L. culpaeus. We discuss the inferred phylogenetic relationships and divergence times in the context of the current geographic distributions of these species, and the likely effects of Pleistocene climatic changes on the biogeography of this group. Furthermore, a remarkable finding was the identification of multiple individuals classified as L. gymnocercus bearing mtDNA haplotypes clearly belonging to L. griseus, sampled in regions where the latter is not known to occur. At a minimum, this result implies the need to clarify the present-day geographic distribution of each of these fox species, while it may also indicate an ongoing hybridization process between them. Future testing of this hypothesis with in-depth analyses of these populations is thus a priority for understanding the history, evolutionary dynamics and present-day composition of this endemic Neotropical genus.

  17. Biogeography in Cellana (Patellogastropoda, Nacellidae) with Special Emphasis on the Relationships of Southern Hemisphere Oceanic Island Species

    Science.gov (United States)

    Nakano, Tomoyuki; Palma, Alvaro; Poulin, Elie

    2017-01-01

    Oceanic islands lacking connections to other land are extremely isolated from sources of potential colonists and have acquired their biota mainly through dispersal from geographically distant areas. Hence, isolated island biota constitutes interesting models to infer biogeographical mechanisms of dispersal, colonization, differentiation, and speciation. Limpets of the genus Cellana (Nacellidae: Patellogastropoda) show limited dispersal capacity but are broadly distributed across the Indo-Pacific including many endemic species in isolated oceanic islands. Here, we examined main distributional patterns and geographic boundaries among Cellana lineages with special emphasis in the relationships of Southern Hemisphere oceanic islands species. Phylogenetic reconstructions based on mtDNA (COI) recognized three main clades in Cellana including taxa from different provinces of the Indo-Pacific. Clear genetic discontinuities characterize the biogeography of Cellana and several lineages are associated to particular areas of the Indo-Pacific supporting the low dispersal capacity of the genus across recognized biogeographical barriers in the region. However, evolutionary relationships within Cellana suggest that long-distance dispersal processes have been common in the history of the genus and probably associated to the origin of the species in Hawaii and Juan Fernández Archipelago. Therefore, the presence of Cellana species in geographically distant Southern Hemisphere oceanic islands, such as the Juan Fernández Archipelago, suggests that long-distance dispersal mediated by rafting may have played an important role in the biogeography of the genus. PMID:28099466

  18. Biogeography and potential exchanges among the atlantic Equatorial belt cold-seep faunas.

    Directory of Open Access Journals (Sweden)

    Karine Olu

    Full Text Available Like hydrothermal vents along oceanic ridges, cold seeps are patchy and isolated ecosystems along continental margins, extending from bathyal to abyssal depths. The Atlantic Equatorial Belt (AEB, from the Gulf of Mexico to the Gulf of Guinea, was one focus of the Census of Marine Life ChEss (Chemosynthetic Ecosystems program to study biogeography of seep and vent fauna. We present a review and analysis of collections from five seep regions along the AEB: the Gulf of Mexico where extensive faunal sampling has been conducted from 400 to 3300 m, the Barbados accretionary prism, the Blake ridge diapir, and in the Eastern Atlantic from the Congo and Gabon margins and the recently explored Nigeria margin. Of the 72 taxa identified at the species level, a total of 9 species or species complexes are identified as amphi-Atlantic. Similarity analyses based on both Bray Curtis and Hellinger distances among 9 faunal collections, and principal component analysis based on presence/absence of megafauna species at these sites, suggest that within the AEB seep megafauna community structure is influenced primarily by depth rather than by geographic distance. Depth segregation is observed between 1000 and 2000 m, with the middle slope sites either grouped with those deeper than 2000 m or with the shallower sites. The highest level of community similarity was found between the seeps of the Florida escarpment and Congo margin. In the western Atlantic, the highest degree of similarity is observed between the shallowest sites of the Barbados prism and of the Louisiana slope. The high number of amphi-atlantic cold-seep species that do not cluster according to biogeographic regions, and the importance of depth in structuring AEB cold-seep communities are the major conclusions of this study. The hydrothermal vent sites along the Mid Atlantic Ridge (MAR did not appear as "stepping stones" for dispersal of the AEB seep fauna, however, the south MAR and off axis regions

  19. Implications of rbcL phylogeny for historical biogeography of genus Mercurialis L.: Estimating age and center of origin

    Directory of Open Access Journals (Sweden)

    Jovanović V.

    2010-01-01

    Full Text Available The aim of this study was to address questions concerning the historical biogeography of the genus Mercurialis in the subfamily Acalyphoideae. Applying a molecular clock to obtained rbcL phylogeny, we estimated the minimal age of divergence of genus Mercurialis to ~65-66 Ma, placing it at the Cretaceous/Paleogene boundary. We used ancestral area analysis and dispersal-vicariance analysis to infer the center of origin of the genus. Contrary to previous hypothesis, our results show that Mercurialis originated in Indomalaya and migrated westward, while the Mediterranean area was most probably the center of ecological diversification and further speciation. Evolutionary events of vicariance and dispersals were reconstructed in a proposed scenario of divergence of Mercurialis within Acalyphoideae. .

  20. Oceanic archipelagos: a perspective on the geodynamics and biogeography of the World’s smallest biotic provinces

    Directory of Open Access Journals (Sweden)

    Kostas Triantis

    2016-07-01

    Full Text Available Since the contributions of Charles Darwin and Alfred Russel Wallace, oceanic archipelagos have played a central role in the development of biogeography. However, despite the critical influence of oceanic islands on ecological and evolutionary theory, our focus has remained limited to either the island-level of specific archipelagos or single archipelagos. Recently, it was proposed that oceanic archipelagos qualify as biotic provinces, with diversity primarily reflecting a balance between speciation and extinction, with colonization having a minor role. Here we focus on major attributes of the archipelagic geological dynamics that can affect diversity at both the island and the archipelagic level. We also re-affirm that oceanic archipelagos are appropriate spatiotemporal units to frame analyses in order to understand large scale patterns of biodiversity.

  1. Multilocus sequence analysis for assessment of phylogenetic diversity and biogeography in Thalassospira bacteria from diverse marine environments.

    Science.gov (United States)

    Lai, Qiliang; Liu, Yang; Yuan, Jun; Du, Juan; Wang, Liping; Sun, Fengqin; Shao, Zongze

    2014-01-01

    Thalassospira bacteria are widespread and have been isolated from various marine environments. Less is known about their genetic diversity and biogeography, as well as their role in marine environments, many of them cannot be discriminated merely using the 16S rRNA gene. To address these issues, in this report, the phylogenetic analysis of 58 strains from seawater and deep sea sediments were carried out using the multilocus sequence analysis (MLSA) based on acsA, aroE, gyrB, mutL, rpoD and trpB genes, and the DNA-DNA hybridization (DDH) and average nucleotide identity (ANI) based on genome sequences. The MLSA analysis demonstrated that the 58 strains were clearly separated into 15 lineages, corresponding to seven validly described species and eight potential novel species. The DDH and ANI values further confirmed the validity of the MLSA analysis and eight potential novel species. The MLSA interspecies gap of the genus Thalassospira was determined to be 96.16-97.12% sequence identity on the basis of the combined analyses of the DDH and MLSA, while the ANIm interspecies gap was 95.76-97.20% based on the in silico DDH analysis. Meanwhile, phylogenetic analyses showed that the Thalassospira bacteria exhibited distribution pattern to a certain degree according to geographic regions. Moreover, they clustered together according to the habitats depth. For short, the phylogenetic analyses and biogeography of the Thalassospira bacteria were systematically investigated for the first time. These results will be helpful to explore further their ecological role and adaptive evolution in marine environments.

  2. Biogeography and evolutionary diversification in one of the most widely distributed and species rich genera of the Pacific.

    Science.gov (United States)

    Cantley, Jason T; Markey, Adrienne S; Swenson, Nathan G; Keeley, Sterling C

    2016-01-01

    The historical biogeography of many lineages-of both terrestrial and marine ocean habitats-remains poorly investigated even though remote ocean habitat covers approximately 66% of the Earth's surface. One such lineage with poorly understood biogeographic affinities across vast ocean habitat is the genus Coprosma (Rubiaceae) with numerous species, and a widespread and disjunct distribution among the far-flung insular localities of multiple Pacific Islands. Here, the first taxonomically robust phylogeny for Coprosma s.s. was dated using molecular clock techniques and indicated Coprosma s.s. diverged from its sister genus Nertera likely during or shortly after the Oligocene Marine Transgression of New Zealand. Diversification of the five major clades identified occurred in New Zealand during the Miocene, which was then followed by multiple independent dispersals from New Zealand to various localities in many directions. The pattern of Coprosma's distribution in the Pacific appears stochastic both temporally and spatially, but evolution of an orange to red fruit colour prior to nearly all inferred dispersals hints at endozoochory by birds. The number of inferred long-distance dispersals of Coprosma s.s. (>30), and number of repeated dispersals to the same insular locality from unrelated Coprosma s.s. sublineages (>8) is perhaps the most currently known for a remote Pacific-centred genus investigated to date. A New Zealand origin for a Pacific-wide dispersal of taxa is not novel, but the manner in which the temporal and spatial distribution for Coprosma s.s. was achieved contributes to a novel understanding of the historical biogeography of widespread Pacific genera that have origins in the Southern Hemisphere.

  3. Diversity, relationships, and biogeography of the lambeosaurine dinosaurs from the European Archipelago, with description of the New Aralosaurin Canardia garonnensis.

    Science.gov (United States)

    Prieto-Márquez, Albert; Dalla Vecchia, Fabio M; Gaete, Rodrigo; Galobart, Angel

    2013-01-01

    We provide a thorough re-evaluation of the taxonomic diversity, phylogenetic relationships, and historical biogeography of the lambeosaurine hadrosaurids from the European Archipelago. Previously published occurrences of European Lambeosaurinae are reviewed and new specimens collected from upper Maastrichtian strata of the south-central Pyrenees are described. No support is found for the recognition of European saurolophines in the available hadrosaurid materials recovered so far from this area. A new genus and species of basal lambeosaurine, Canardia garonnensis, is described on the basis of cranial and appendicular elements collected from upper Maastrichtian strata of southern France. C. garonnensis differs from all other hadrosaurids, except Aralosaurus tuberiferus, in having maxilla with prominent subrectangular rostrodorsal flange; it differs from A. tuberiferus in a few maxillary and prefrontal characters. Together with A. tuberiferus, C. garonnensis integrates the newly recognized tribe Aralosaurini. Inference of lambeosaurine interrelationships via maximum parsimony analysis indicates that the other three known European lambeosaurines are representatives of two additional subclades (tribes) of these hadrosaurids: Tsintaosaurini (Pararhabdodon isonensis) and Lambeosaurini (the Arenysaurus ardevoli-Blasisaurus canudoi clade). The tribes Aralosaurini, Tsintaosaurini, Lambeosaurini, and Parasaurolophini are formally defined and diagnosed for the first time. Three event-based quantitative methods of ancestral range reconstruction were implemented to infer the historical biogeography of European lambeosaurines: Dispersal-Vicariance Analysis, Bayesian Binary MCMC, and Dispersal-Extinction-Cladogenesis. The results of these analyses, coupled with the absence of pre-Maastrichtian lambeosaurines in the Mesozoic vertebrate fossil record of Europe, favor the hypothesis that aralosaurins and tsintaosaurins were Asian immigrants that reached the Ibero-Armorican island

  4. Diversity, Relationships, and Biogeography of the Lambeosaurine Dinosaurs from the European Archipelago, with Description of the New Aralosaurin Canardia garonnensis

    Science.gov (United States)

    Prieto-Márquez, Albert; Dalla Vecchia, Fabio M.; Gaete, Rodrigo; Galobart, Àngel

    2013-01-01

    We provide a thorough re-evaluation of the taxonomic diversity, phylogenetic relationships, and historical biogeography of the lambeosaurine hadrosaurids from the European Archipelago. Previously published occurrences of European Lambeosaurinae are reviewed and new specimens collected from upper Maastrichtian strata of the south-central Pyrenees are described. No support is found for the recognition of European saurolophines in the available hadrosaurid materials recovered so far from this area. A new genus and species of basal lambeosaurine, Canardia garonnensis, is described on the basis of cranial and appendicular elements collected from upper Maastrichtian strata of southern France. C. garonnensis differs from all other hadrosaurids, except Aralosaurus tuberiferus, in having maxilla with prominent subrectangular rostrodorsal flange; it differs from A. tuberiferus in a few maxillary and prefrontal characters. Together with A. tuberiferus, C. garonnensis integrates the newly recognized tribe Aralosaurini. Inference of lambeosaurine interrelationships via maximum parsimony analysis indicates that the other three known European lambeosaurines are representatives of two additional subclades (tribes) of these hadrosaurids: Tsintaosaurini (Pararhabdodon isonensis) and Lambeosaurini (the Arenysaurus ardevoli-Blasisaurus canudoi clade). The tribes Aralosaurini, Tsintaosaurini, Lambeosaurini, and Parasaurolophini are formally defined and diagnosed for the first time. Three event-based quantitative methods of ancestral range reconstruction were implemented to infer the historical biogeography of European lambeosaurines: Dispersal-Vicariance Analysis, Bayesian Binary MCMC, and Dispersal-Extinction-Cladogenesis. The results of these analyses, coupled with the absence of pre-Maastrichtian lambeosaurines in the Mesozoic vertebrate fossil record of Europe, favor the hypothesis that aralosaurins and tsintaosaurins were Asian immigrants that reached the Ibero-Armorican island

  5. Biogeografía marina de Chile continental Marine biogeography of continental Chile

    Directory of Open Access Journals (Sweden)

    PATRICIO A. CAMUS

    2001-09-01

    literature review on the marine biogeography of Chile and related subjects, with the following objectives: (a to summarize the oceanographic, climatic and geomorphologic characteristics of the Chilean continental coast; (b to discuss 27 biogeographic classifications published for the Chilean coast, analyzing both the procedures and criteria used by their authors, along with their main conclusions and agreements; (c to assess the vicariant and dispersal processes associated with the displacement and modification of the regional biotas, regarding the available antecedentes on the prevailing conditions and main events during the Tertiary and Quaternary periods; and (d to propose a scenario of biogeographic change based on historical determinants and their influence on the formation, character, and dynamics of biotas along the Chilean coast, emphasizing the identification and biogeographic nature of the main spatial units. From the preceding information, I propose a hypothesis of biogeographic classification for the level of biotas, not necessarily coincident with prior studies at lower levels such as flora or fauna. This classification identifies three major spatial units: a southern area which comprises an austral biota (Magellan Province, a northern area which comprises a warm-temperate biota (Peruvian Province, and a non transitional, Intermediate Area including mixed components of biota and exhibiting a poor biogeographic definition of both its character and hierarchical rank. I also discuss the different nature of two transitional zones located at the boundaries of the Intermediate Area, a southward induced transition and a northward contact transition, likely produced by the migration of biotas and glacial-tectonic events, respectively

  6. The biogeography of kelps (Laminariales, Phaeophyceae): a global analysis with new insights from recent advances in molecular phylogenetics

    Science.gov (United States)

    Bolton, John J.

    2010-12-01

    Despite their ecological and economic importance, no summary of kelp global biogeography has been produced for almost two decades. The circumscription of the order Laminariales and familial and generic relationships in the group have changed considerably recently, in the light of molecular data. A global summary and geographical analysis of kelp species and their distributions (112 species in 33 genera) is presented. These data are analysed and discussed from the perspective of the new consensus of relationships within the group, and likely evolutionary events. The putative ancestors of the kelps occur and are overwhelmingly most diverse, in the cooler waters of northern Japan. The biogeographical evidence suggests three main lines of subsequent evolution: (a) a diversification producing the four ‘derived’ families Alariaceae, Costariceae, Laminariaceae, and Lessoniaceae and most extant genera in the temperate northern Pacific, probably during the Miocene. (b) The evolution of an Arctic flora which invaded the North Atlantic following the opening of the Bering Strait ca. 5.5 Ma. (c) At least four separate crossings, by different genera, of tropical regions from Northern to Southern Hemisphere (and one in the opposite direction). The recorded impacts of man on these distributions have thus far been minimal, with the notable exceptions of Undaria pinnatifida and species of Saccharina (grown in aquaculture systems for human food). Most genera are monospecific, with many confined to either the western or eastern temperate North Pacific, whereas the distribution of the most species-rich genera ( Alaria, Laminaria, Saccharina) includes the Arctic, and they are widespread in the North Atlantic. This rapid species-level evolution is hypothesised to have been promoted by the relatively recent invasion of the Atlantic by these taxa. The crossing of the tropics has occurred in warm-temperate species some of which occur and are sometimes abundant, in deeper water in today

  7. The historical biogeography of Pteroglossus aracaris (Aves, Piciformes, Ramphastidae based on Bayesian analysis of mitochondrial DNA sequences

    Directory of Open Access Journals (Sweden)

    Sérgio L. Pereira

    2008-01-01

    Full Text Available Most Neotropical birds, including Pteroglossus aracaris, do not have an adequate fossil record to be used as time constraints in molecular dating. Hence, the evolutionary timeframe of the avian biota can only be inferred using alternative time constraints. We applied a Bayesian relaxed clock approach to propose an alternative interpretation for the historical biogeography of Pteroglossus based on mitochondrial DNA sequences, using different combinations of outgroups and time constraints obtained from outgroup fossils, vicariant barriers and molecular time estimates. The results indicated that outgroup choice has little effect on the Bayesian posterior distribution of divergence times within Pteroglossus , that geological and molecular time constraints seem equally suitable to estimate the Bayesian posterior distribution of divergence times for Pteroglossus , and that the fossil record alone overestimates divergence times within the fossil-lacking ingroup. The Bayesian estimates of divergence times suggest that the radiation of Pteroglossus occurred from the Late Miocene to the Pliocene (three times older than estimated by the “standard” mitochondrial rate of 2% sequence divergence per million years, likely triggered by Andean uplift, multiple episodes of marine transgressions in South America, and formation of present-day river basins. The time estimates are in agreement with other Neotropical taxa with similar geographic distributions.

  8. Biogeography-Based Combinatorial Strategy for Efficient Autonomous Underwater Vehicle Motion Planning and Task-Time Management

    Institute of Scientific and Technical Information of China (English)

    S.M.Zadeh; D.M.W Powers; K. Sammut; A.M. Yazdani

    2016-01-01

    Autonomous Underwater Vehicles (AUVs) are capable of conducting various underwater missions and marine tasks over long periods of time. In this study, a novel conflict-free motion-planning framework is introduced. This framework enhances AUV mission performance by completing the maximum number of highest priority tasks in a limited time through a large-scale waypoint cluttered operating field and ensuring safe deployment during the mission. The proposed combinatorial route-path-planner model takes advantage of the Biogeography- Based Optimization (BBO) algorithm to satisfy the objectives of both higher- and lower-level motion planners and guarantee the maximization of mission productivity for a single vehicle operation. The performance of the model is investigated under different scenarios, including cost constraints in time-varying operating fields. To demonstrate the reliability of the proposed model, the performance of each motion planner is separately assessed and statistical analysis is conducted to evaluate the total performance of the entire model. The simulation results indicate the stability of the proposed model and the feasibility of its application to real-time experiments.

  9. A Simultaneous Biogeography based Optimal Placement of DG Units and Capacitor Banks in Distribution Systems with Nonlinear Loads

    Science.gov (United States)

    Sadeghi, Hassan; Ghaffarzadeh, Navid

    2016-09-01

    This paper uses a new algorithm namely biogeography based optimization (BBO) intended for the simultaneous placement of the distributed generation (DG) units and the capacitor banks in the distribution network. The procedure of optimization has been conducted in the presence of nonlinear loads (a cause of harmonic injection). The purpose of simultaneous optimal placement of the DG and the capacitor is the reduction of active and reactive losses. The difference in the values of loss reduction at different levels of the load have been included in the objective function and the considered objective function includes the constraints of voltage, size and the number of DG units and capacitor banks and the allowable range of the total harmonic distortion (THD) of the total voltage in accordance with the IEEE 519 standards. In this paper the placement has been performed on two load types ie constant and mixed power, moreover the effects of load models on the results and the effects of optimal placement on reduction of the THD levels have also been analyzed. The mentioned cases have been studied on a 33 bus radial distribution system.

  10. Erwinia amylovora novel plasmid pEI70: complete sequence, biogeography, and role in aggressiveness in the fire blight phytopathogen.

    Directory of Open Access Journals (Sweden)

    Pablo Llop

    Full Text Available Comparative genomics of several strains of Erwinia amylovora, a plant pathogenic bacterium causal agent of fire blight disease, revealed that its diversity is primarily attributable to the flexible genome comprised of plasmids. We recently identified and sequenced in full a novel 65.8 kb plasmid, called pEI70. Annotation revealed a lack of known virulence-related genes, but found evidence for a unique integrative conjugative element related to that of other plant and human pathogens. Comparative analyses using BLASTN showed that pEI70 is almost entirely included in plasmid pEB102 from E. billingiae, an epiphytic Erwinia of pome fruits, with sequence identities superior to 98%. A duplex PCR assay was developed to survey the prevalence of plasmid pEI70 and also that of pEA29, which had previously been described in several E. amylovora strains. Plasmid pEI70 was found widely dispersed across Europe with frequencies of 5-92%, but it was absent in E. amylovora analyzed populations from outside of Europe. Restriction analysis and hybridization demonstrated that this plasmid was identical in at least 13 strains. Curing E. amylovora strains of pEI70 reduced their aggressiveness on pear, and introducing pEI70 into low-aggressiveness strains lacking this plasmid increased symptoms development in this host. Discovery of this novel plasmid offers new insights into the biogeography, evolution and virulence determinants in E. amylovora.

  11. Erwinia amylovora novel plasmid pEI70: complete sequence, biogeography, and role in aggressiveness in the fire blight phytopathogen.

    Science.gov (United States)

    Llop, Pablo; Cabrefiga, Jordi; Smits, Theo H M; Dreo, Tanja; Barbé, Silvia; Pulawska, Joanna; Bultreys, Alain; Blom, Jochen; Duffy, Brion; Montesinos, Emilio; López, María M

    2011-01-01

    Comparative genomics of several strains of Erwinia amylovora, a plant pathogenic bacterium causal agent of fire blight disease, revealed that its diversity is primarily attributable to the flexible genome comprised of plasmids. We recently identified and sequenced in full a novel 65.8 kb plasmid, called pEI70. Annotation revealed a lack of known virulence-related genes, but found evidence for a unique integrative conjugative element related to that of other plant and human pathogens. Comparative analyses using BLASTN showed that pEI70 is almost entirely included in plasmid pEB102 from E. billingiae, an epiphytic Erwinia of pome fruits, with sequence identities superior to 98%. A duplex PCR assay was developed to survey the prevalence of plasmid pEI70 and also that of pEA29, which had previously been described in several E. amylovora strains. Plasmid pEI70 was found widely dispersed across Europe with frequencies of 5-92%, but it was absent in E. amylovora analyzed populations from outside of Europe. Restriction analysis and hybridization demonstrated that this plasmid was identical in at least 13 strains. Curing E. amylovora strains of pEI70 reduced their aggressiveness on pear, and introducing pEI70 into low-aggressiveness strains lacking this plasmid increased symptoms development in this host. Discovery of this novel plasmid offers new insights into the biogeography, evolution and virulence determinants in E. amylovora.

  12. Mitochondrial DNA phylogeography of the Mesoamerican spiny-tailed lizards (Ctenosaura quinquecarinata complex): historical biogeography, species status and conservation.

    Science.gov (United States)

    Hasbún, Carlos Roberto; Gómez, Africa; Köhler, Gunther; Lunt, David H

    2005-09-01

    Through the examination of past and present distributions of plants and animals, historical biogeographers have provided many insights on the dynamics of the massive organismal exchange between North and South America. However, relatively few phylogeographic studies have been attempted in the land bridge of Mesoamerica despite its importance to better understand the evolutionary forces influencing this biodiversity 'hotspot'. Here we use mitochondrial DNA sequence data from fresh samples and formalin-fixed museum specimens to investigate the genetic and biogeographic diversity of the threatened Mesoamerican spiny-tailed lizards of the Ctenosaura quinquecarinata complex. Species boundaries and their phylogeographic patterns are examined to better understand their disjunct distribution. Three monophyletic, allopatric lineages are established using mtDNA phylogenetic and nested clade analyses in (i) northern: México, (ii) central: Guatemala, El Salvador and Honduras, and (iii) southern: Nicaragua and Costa Rica. The average sequence divergence observed between lineages varied between 2.0% and 3.7% indicating that they do not represent a very recent split and the patterns of divergence support the recently established nomenclature of C. quinquecarinata, Ctenosaura flavidorsalis and Ctenosaura oaxacana. Considering the geological history of Mesoamerica and the observed phylogeographic patterns of these lizards, major evolutionary episodes of their radiation in Mesoamerica are postulated and are indicative of the regions' geological complexity. The implications of these findings for the historical biogeography, taxonomy and conservation of these lizards are discussed.

  13. Molecular Phylogeny and Historical Biogeography of the Neotropical Swarm-Founding Social Wasp Genus Synoeca (Hymenoptera: Vespidae)

    Science.gov (United States)

    Menezes, Rodolpho Santos Telles; Brady, Seán Gary; Carvalho, Antônio Freire; Del Lama, Marco Antonio; Costa, Marco Antônio

    2015-01-01

    The Neotropical Region harbors high biodiversity and many studies on mammals, reptiles, amphibians and avifauna have investigated the causes for this pattern. However, there is a paucity of such studies that focus on Neotropical insect groups. Synoeca de Saussure, 1852 is a Neotropical swarm-founding social wasp genus with five described species that is broadly and conspicuously distributed throughout the Neotropics. Here, we infer the phylogenetic relationships, diversification times, and historical biogeography of Synoeca species. We also investigate samples of the disjoint populations of S. septentrionalis that occur in both northwestern parts of South America through Central American and the Brazilian Atlantic rainforests. Our results showed that the interspecific relationships for Synoeca could be described as follows: (S. chalibea + S. virginea) + (S. cyanea + (S. septentrionalis/S. surinama)). Notably, samples of S. septentrionalis and S. surinama collected in the Atlantic Forest were interrelated and may be the result of incomplete lineage sorting and/or mitochondrial introgression among them. Our Bayesian divergence dating analysis revealed recent Plio-Pleistocene diversification in Synoeca. Moreover, our biogeographical analysis suggested an Amazonian origin of Synoeca, with three main dispersal events subsequently occurring during the Plio-Pleistocene. PMID:25738705

  14. EDENetworks: a user-friendly software to build and analyse networks in biogeography, ecology and population genetics.

    Science.gov (United States)

    Kivelä, Mikko; Arnaud-Haond, Sophie; Saramäki, Jari

    2015-01-01

    The recent application of graph-based network theory analysis to biogeography, community ecology and population genetics has created a need for user-friendly software, which would allow a wider accessibility to and adaptation of these methods. EDENetworks aims to fill this void by providing an easy-to-use interface for the whole analysis pipeline of ecological and evolutionary networks starting from matrices of species distributions, genotypes, bacterial OTUs or populations characterized genetically. The user can choose between several different ecological distance metrics, such as Bray-Curtis or Sorensen distance, or population genetic metrics such as FST or Goldstein distances, to turn the raw data into a distance/dissimilarity matrix. This matrix is then transformed into a network by manual or automatic thresholding based on percolation theory or by building the minimum spanning tree. The networks can be visualized along with auxiliary data and analysed with various metrics such as degree, clustering coefficient, assortativity and betweenness centrality. The statistical significance of the results can be estimated either by resampling the original biological data or by null models based on permutations of the data.

  15. Phylogeny of the Labeoninae (Teleostei, Cypriniformes) based on nuclear DNA sequences and implications on character evolution and biogeography

    Institute of Scientific and Technical Information of China (English)

    Lanping ZHENG; Junxing YANG; Xiaoyong CHEN

    2012-01-01

    The Labeoninae is a subfamily of the family Cyprinidae,Order Cypriniformes.Oromandibular morphology within the Labeoninae is the greatest among cyprinid fishes.Although several phylogenetic studies about labeonines have been undertaken the results have been inconsistent and a comprehensive phylogeny is needed.Further,an incongruence between morphological and molecular phylogeny requires a systematic exploration of the significance of morphological characters on the basis of the molecular phylogeny.In this study,a total of 292 nucleotide sequences from 73 individuals (representing 24 genera and 73 species) of Labeoninae were analyzed.The results of the phylogenetic analysis indicate that there are four major clades within Labeoninae and three monophyletic lineages within the fourth clade.Results of the character evolution show that all oromandibular morphological characters are homoplastically distributed on the molecular phylogenetic tree and suggests that these characters evolved several times during the history of labeonines.In particular,the labeonine,a specific disc on the lower lip,has been acquired three times and reversed twice.These morphological characters do not have systematic significance but can be useful for taxonomy.The results of biogeography suggest that the Labeoninae originated from Southeast Asia and separately dispersed to Africa,East Asia and South Asia.

  16. Phylogeny and biogeography of the New World siskins and goldfinches: rapid, recent diversification in the Central Andes.

    Science.gov (United States)

    Beckman, Elizabeth J; Witt, Christopher C

    2015-06-01

    Time-calibrated molecular phylogenies can help us to understand the origins of the diverse and unique Andean avifauna. Previous studies have shown that the tempo of diversification differed between the Andes and adjacent lowland regions of South America. Andean taxa were found to have speciated more recently and to have avoided the decelerated diversification that is typical of Neotropical lowland clades. The South American siskins, a Pleistocene finch radiation, may typify this Andean pattern. We investigated the phylogenetic biogeography of all the New World siskins and goldfinches in new detail. To understand the specific role of the Andes in siskin diversification, we asked: (1) Was diversification faster in Andean siskin lineages relative to non-Andean ones? (2) Did siskin lineages move into and out of the Andes at different rates? We found that siskin lineages in the Andes had higher diversification rates and higher outward dispersal rates than siskin lineages outside the Andes. We conclude that páramo expansion and contraction in response to Pleistocene climatic cycles caused accelerated diversification and outward dispersal in Andean siskins. The younger average age of bird species in the Andes compared to lowland South America may be attributable to bursts of recent diversification in siskins and several other vagile, open-habitat clades.

  17. Biogeography-based combinatorial strategy for efficient autonomous underwater vehicle motion planning and task-time management

    Science.gov (United States)

    Zadeh, S. M.; Powers, D. M. W.; Sammut, K.; Yazdani, A. M.

    2016-12-01

    Autonomous Underwater Vehicles (AUVs) are capable of spending long periods of time for carrying out various underwater missions and marine tasks. In this paper, a novel conflict-free motion planning framework is introduced to enhance underwater vehicle's mission performance by completing maximum number of highest priority tasks in a limited time through a large scale waypoint cluttered operating field, and ensuring safe deployment during the mission. The proposed combinatorial route-path planner model takes the advantages of the Biogeography-Based Optimization (BBO) algorithm toward satisfying objectives of both higher-lower level motion planners and guarantees maximization of the mission productivity for a single vehicle operation. The performance of the model is investigated under different scenarios including the particular cost constraints in time-varying operating fields. To show the reliability of the proposed model, performance of each motion planner assessed separately and then statistical analysis is undertaken to evaluate the total performance of the entire model. The simulation results indicate the stability of the contributed model and its feasible application for real experiments.

  18. Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology

    Directory of Open Access Journals (Sweden)

    Dirk-Martin Scheel

    2014-05-01

    Full Text Available Extinctions and declines of large marine vertebrates have major ecological impacts and are of critical concern in marine environments. The Caribbean monk seal, Monachus tropicalis, last definitively reported in 1952, was one of the few marine mammal species to become extinct in historical times. Despite its importance for understanding the evolutionary biogeography of southern phocids, the relationships of M.tropicalis to the two living species of critically endangered monk seals have not been resolved. In this study we present the first molecular data for M. tropicalis, derived from museum skins. Phylogenetic analysis of cytochrome b sequences indicates that M. tropicalis was more closely related to the Hawaiian rather than the Mediterranean monk seal. Divergence time estimation implicates the formation of the Panamanian Isthmus in the speciation of Caribbean and Hawaiian monk seals. Molecular, morphological and temporal divergence between the Mediterranean and “New World monk seals” (Hawaiian and Caribbean is profound, equivalent to or greater than between sister genera of phocids. As a result, we classify the Caribbean and Hawaiian monk seals together in a newly erected genus, Neomonachus. The two genera of extant monk seals (Monachus and Neomonachus represent old evolutionary lineages each represented by a single critically endangered species, both warranting continuing and concerted conservation attention and investment if they are to avoid the fate of their Caribbean relative.

  19. Amplicon-Based Pyrosequencing Reveals High Diversity of Protistan Parasites in Ships' Ballast Water: Implications for Biogeography and Infectious Diseases.

    Science.gov (United States)

    Pagenkopp Lohan, K M; Fleischer, R C; Carney, K J; Holzer, K K; Ruiz, G M

    2016-04-01

    Ships' ballast water (BW) commonly moves macroorganisms and microorganisms across the world's oceans and along coasts; however, the majority of these microbial transfers have gone undetected. We applied high-throughput sequencing methods to identify microbial eukaryotes, specifically emphasizing the protistan parasites, in ships' BW collected from vessels calling to the Chesapeake Bay (Virginia and Maryland, USA) from European and Eastern Canadian ports. We utilized tagged-amplicon 454 pyrosequencing with two general primer sets, amplifying either the V4 or V9 domain of the small subunit (SSU) of the ribosomal RNA (rRNA) gene complex, from total DNA extracted from water samples collected from the ballast tanks of bulk cargo vessels. We detected a diverse group of protistan taxa, with some known to contain important parasites in marine systems, including Apicomplexa (unidentified apicomplexans, unidentified gregarines, Cryptosporidium spp.), Dinophyta (Blastodinium spp., Euduboscquella sp., unidentified syndinids, Karlodinium spp., Syndinium spp.), Perkinsea (Parvilucifera sp.), Opisthokonta (Ichthyosporea sp., Pseudoperkinsidae, unidentified ichthyosporeans), and Stramenopiles (Labyrinthulomycetes). Further characterization of groups with parasitic taxa, consisting of phylogenetic analyses for four taxa (Cryptosporidium spp., Parvilucifera spp., Labyrinthulomycetes, and Ichthyosporea), revealed that sequences were obtained from both known and novel lineages. This study demonstrates that high-throughput sequencing is a viable and sensitive method for detecting parasitic protists when present and transported in the ballast water of ships. These data also underscore the potential importance of human-aided dispersal in the biogeography of these microbes and emerging diseases in the world's oceans.

  20. Hybrid Differential Evolution with Biogeography-Based Optimization for Design of a Reconfigurable Antenna Array with Discrete Phase Shifters

    Directory of Open Access Journals (Sweden)

    Xiangtao Li

    2011-01-01

    Full Text Available Multibeam antenna arrays have important applications in communications and radar. This paper presents a new method of designing a reconfigurable antenna with quantized phase excitations using a new hybrid algorithm, called DE/BBO. The reconfigurable design problem is to find the element excitation that will result in a sector pattern main beam with low sidelobes with additional requirement that the same excitation amplitudes applied to the array with zero-phase should be in a high directivity, low sidelobe pencil-shaped main beam. In order to reduce the effect of mutual coupling between the antenna-array elements, the dynamic range ratio is minimized. Additionally, compared with the continuous realization and subsequent quantization, experimental results indicate that the performance of the discrete realization of the phase excitation value can be improved. In order to test the performances of hybrid differential evolution with biogeography-based optimization, the results of some state-of-art algorithms are considered, for the purposed of comparison. Experiment results indicate the better performance of the DE/BBO.

  1. Molecular phylogeny and historical biogeography of the neotropical swarm-founding social wasp genus Synoeca (Hymenoptera: Vespidae.

    Directory of Open Access Journals (Sweden)

    Rodolpho Santos Telles Menezes

    Full Text Available The Neotropical Region harbors high biodiversity and many studies on mammals, reptiles, amphibians and avifauna have investigated the causes for this pattern. However, there is a paucity of such studies that focus on Neotropical insect groups. Synoeca de Saussure, 1852 is a Neotropical swarm-founding social wasp genus with five described species that is broadly and conspicuously distributed throughout the Neotropics. Here, we infer the phylogenetic relationships, diversification times, and historical biogeography of Synoeca species. We also investigate samples of the disjoint populations of S. septentrionalis that occur in both northwestern parts of South America through Central American and the Brazilian Atlantic rainforests. Our results showed that the interspecific relationships for Synoeca could be described as follows: (S. chalibea + S. virginea + (S. cyanea + (S. septentrionalis/S. surinama. Notably, samples of S. septentrionalis and S. surinama collected in the Atlantic Forest were interrelated and may be the result of incomplete lineage sorting and/or mitochondrial introgression among them. Our Bayesian divergence dating analysis revealed recent Plio-Pleistocene diversification in Synoeca. Moreover, our biogeographical analysis suggested an Amazonian origin of Synoeca, with three main dispersal events subsequently occurring during the Plio-Pleistocene.

  2. Comparative study of migration operator for Biogeography-Based Optimization%生物地理学优化算法中迁移算子的比较

    Institute of Scientific and Technical Information of China (English)

    吴斌; 林锦国; 崔志勇

    2012-01-01

    Biogeography-Based Optimization (BBO) algorithm is a new kind of optimization algorithm based on biogeography. It is designed based on the migration strategy of species to solve global optimization problem. The migration and mutation operators play the key role in the BBO. Four migration patterns based on the selection model for the islands (which is guiding high emigration rate or high immigration rate) and the scale of migration (single or part variable) are analyzed and discussed. To compare the performance of the four migration operators, 13 experiments are carried out on a set of well-known benchmark global optimization problems. Simulation results show that the partial immigration strategy outperforms other three operators.%生物地理学优化算法(Biogeography-Based Optimization,BBO)是一种模仿物种迁移规律的智能优化算法,其中迁移算子是影响优化效果的关键环节.基于迁移地的选择模式(以迁出率高的栖息地为主导或者以迁入率高的栖息地为主导)和迁移量的规模(单变量和部分变量),提出了BBO算法中可能存在的四种迁移方式.通过对13个经典实例的实验仿真,比较4种迁移算子的优化结果,阐明了产生差异的原因.实验结果表明,迁入主导的部分迁移式算子优化效果最好.

  3. Biogeography and Photosynthetic Biomass of Arctic Marine Pico-Eukaroytes during Summer of the Record Sea Ice Minimum 2012.

    Science.gov (United States)

    Metfies, Katja; von Appen, Wilken-Jon; Kilias, Estelle; Nicolaus, Anja; Nöthig, Eva-Maria

    2016-01-01

    Information on recent photosynthetic biomass distribution and biogeography of Arctic marine pico-eukaryotes (0.2-3 μm) is needed to better understand consequences of environmental change for Arctic marine ecosystems. We analysed pico-eukaryote biomass and community composition in Fram Strait and large parts of the Central Arctic Ocean (Nansen Basin, Amundsen Basin) using chlorophyll a (Chl a) measurements, automated ribosomal intergenic spacer analysis (ARISA) and 454-pyrosequencing. Samples were collected during summer 2012, the year with the most recent record sea ice minimum. Chl a concentrations were highest in eastern Fram Strait and pico-plankton accounted for 60-90% of Chl a biomass during the observation period. ARISA-patterns and 454-pyrosequencing revealed that pico-eukaryote distribution is closely related to water mass distribution in the euphotic zone of the Arctic Ocean. Phaeocystaceae, Micromonas sp., Dinophyceae and Syndiniales constitute a high proportion of sequence reads, while sequence abundance of autotrophic Phaeocystaceae and mixotrophic Micromonas sp. was inversely correlated. Highest sequence abundances of Phaeocystaceae were observed in the warm Atlantic Waters in Fram Strait, while Micromonas sp. dominated the abundant biosphere in the arctic halocline. Our results are of particular interest considering existing hypotheses that environmental conditions in Nansen Basin might become more similar to the current conditions in Fram Strait. We propose that in response, biodiversity and biomass of pico-eukaryotes in Nansen Basin could resemble those currently observed in Fram Strait in the future. This would significantly alter biogeochemical cycles in a large part of the Central Arctic Ocean.

  4. Historical biogeography and diversification of truffles in the Tuberaceae and their newly identified southern hemisphere sister lineage.

    Directory of Open Access Journals (Sweden)

    Gregory Bonito

    Full Text Available Truffles have evolved from epigeous (aboveground ancestors in nearly every major lineage of fleshy fungi. Because accelerated rates of morphological evolution accompany the transition to the truffle form, closely related epigeous ancestors remain unknown for most truffle lineages. This is the case for the quintessential truffle genus Tuber, which includes species with socio-economic importance and esteemed culinary attributes. Ecologically, Tuber spp. form obligate mycorrhizal symbioses with diverse species of plant hosts including pines, oaks, poplars, orchids, and commercially important trees such as hazelnut and pecan. Unfortunately, limited geographic sampling and inconclusive phylogenetic relationships have obscured our understanding of their origin, biogeography, and diversification. To address this problem, we present a global sampling of Tuberaceae based on DNA sequence data from four loci for phylogenetic inference and molecular dating. Our well-resolved Tuberaceae phylogeny shows high levels of regional and continental endemism. We also identify a previously unknown epigeous member of the Tuberaceae--the South American cup-fungus Nothojafnea thaxteri (E.K. Cash Gamundí. Phylogenetic resolution was further improved through the inclusion of a previously unrecognized Southern hemisphere sister group of the Tuberaceae. This morphologically diverse assemblage of species includes truffle (e.g. Gymnohydnotrya spp. and non-truffle forms that are endemic to Australia and South America. Southern hemisphere taxa appear to have diverged more recently than the Northern hemisphere lineages. Our analysis of the Tuberaceae suggests that Tuber evolved from an epigeous ancestor. Molecular dating estimates Tuberaceae divergence in the late Jurassic (~156 million years ago, with subsequent radiations in the Cretaceous and Paleogene. Intra-continental diversification, limited long-distance dispersal, and ecological adaptations help to explain patterns of

  5. Biogeography and Photosynthetic Biomass of Arctic Marine Pico-Eukaroytes during Summer of the Record Sea Ice Minimum 2012.

    Directory of Open Access Journals (Sweden)

    Katja Metfies

    Full Text Available Information on recent photosynthetic biomass distribution and biogeography of Arctic marine pico-eukaryotes (0.2-3 μm is needed to better understand consequences of environmental change for Arctic marine ecosystems. We analysed pico-eukaryote biomass and community composition in Fram Strait and large parts of the Central Arctic Ocean (Nansen Basin, Amundsen Basin using chlorophyll a (Chl a measurements, automated ribosomal intergenic spacer analysis (ARISA and 454-pyrosequencing. Samples were collected during summer 2012, the year with the most recent record sea ice minimum. Chl a concentrations were highest in eastern Fram Strait and pico-plankton accounted for 60-90% of Chl a biomass during the observation period. ARISA-patterns and 454-pyrosequencing revealed that pico-eukaryote distribution is closely related to water mass distribution in the euphotic zone of the Arctic Ocean. Phaeocystaceae, Micromonas sp., Dinophyceae and Syndiniales constitute a high proportion of sequence reads, while sequence abundance of autotrophic Phaeocystaceae and mixotrophic Micromonas sp. was inversely correlated. Highest sequence abundances of Phaeocystaceae were observed in the warm Atlantic Waters in Fram Strait, while Micromonas sp. dominated the abundant biosphere in the arctic halocline. Our results are of particular interest considering existing hypotheses that environmental conditions in Nansen Basin might become more similar to the current conditions in Fram Strait. We propose that in response, biodiversity and biomass of pico-eukaryotes in Nansen Basin could resemble those currently observed in Fram Strait in the future. This would significantly alter biogeochemical cycles in a large part of the Central Arctic Ocean.

  6. Population structure, historical biogeography and demographic history of the alpine toad Scutiger ningshanensis in the Tsinling Mountains of Central China.

    Directory of Open Access Journals (Sweden)

    Hongzhe Meng

    Full Text Available Population genetic structure, historical biogeography and historical demography of the alpine toad Scutiger ningshanensis were studied using the combined data mtDNA cytochrome b (cyt b and the mtDNA cytochrome c oxidase subunit I (COI as the molecular markers. This species has high genetic variation. There was a significant genetic differentiation among most populations. Three lineages were detected. The phylogenetic relationship analyses and the SAMOVA (spatial analysis of molecular variance results showed significant phylogeographic structure. 82.15% genetic variation occurred among populations whereas differentiation within populations only contributed 17.85% to the total. Mantel test results showed a significant correlation between the pairwise calculated genetic distance and pairwise calculated geographical distance of the populations (regression coefficient  = 0.001286, correlation coefficient  = 0.77051, p (rrand≥robs  = 0.0185<0.05, indicating the existence of isolation-by-distance pattern of genetic divergence for cyt b + COI sequence, which suggests that the distribution of genetic variation is due to geographical separation rather than natural selection. The population expansion or contraction and genetic differentiation between populations or lineages could be explained by topography and the repetitive uplifts of the Tsinling Mountains and the climatic cycles during the late Pliocene and Pleistocene. S. ningshanensis experienced a rapid population expansion about 40,000 years before present. The current decline in population size was probably caused by anthropogenic disturbance. Current populations of S. ningshanensis are from different refugia though the location of these refugia could not be determined in our study. Topography, climatic changes and repetitive population expansion/contraction together led to the high level of genetic variation in S. ningshanensis. A total of three management units (MUs was determined

  7. Phylogeny of Acronychia (Rutaceae and First Insights into Its Historical Biogeography and the Evolution of Fruit Characters.

    Directory of Open Access Journals (Sweden)

    Laura Holzmeyer

    Full Text Available The genus Acronychia (Citrus family, Rutaceae contains 49 species of trees and shrubs that are found mainly in rain forest. The genus has a large distributional range from mainland southern Asia to Australia and New Caledonia, but most species are endemic to either New Guinea or Australia. This study aimed to provide the first detailed molecular phylogeny of Acronychia and use it to test the taxonomic value of fruit morphological characters, and infer the historical biogeography of the genus.Phylogenetic analyses (Bayesian Inference, Maximum Likelihood were undertaken on nucleotide sequence data from two plastid (psbA-trnH, trnL-trnF and three nuclear markers (ETS, ITS, NIAi3 from 29 Acronychia species (59% of the genus and representatives of related genera.The results indicate that the South-East Asian genus Maclurodendron is nested phylogenetically within Acronychia and must be synonymized to render Acronychia monophyletic. Fruit morphological characters have been used previously to infer relationships within Acronychia and our analyses show that these characters are informative for some subclades but are homoplasious for the group as a whole. Apocarpous fruits are the ancestral state in Acronychia and subapocarpous and fully syncarpous fruits are derived. The unisexual flowers of Maclurodendron are derived from bisexual flowers, which are found in all species of Acronychia as well as its relatives. Acronychia probably first evolved on Australia with range expansion to New Guinea via stepping-stone dispersal or direct land connections within the Sahul Shelf, followed by two independent dispersals to areas west of New Guinea. Most species of Acronychia occur in either Australia or New Guinea, but no species occurs in both regions. This is surprising given the close proximity of the landmasses, but might be explained by ecological factors.

  8. In the wake of invasion: tracing the historical biogeography of the South American cricetid radiation (Rodentia, Sigmodontinae.

    Directory of Open Access Journals (Sweden)

    Rafael N Leite

    Full Text Available The Great American Biotic Interchange (GABI was greatly influenced by the completion of the Isthmus of Panama and impacted the composition of modern faunal assemblages in the Americas. However, the contribution of preceding events has been comparatively less explored, even though early immigrants in the fossil records are evidence for waif dispersals. The cricetid rodents of the subfamily Sigmodontinae are a classic example of a species-rich South American radiation resulting from an early episode of North American invasion. Here, we provide a temporal and spatial framework to address key aspects of the historical biogeography and diversification of this diverse mammal group by using mitochondrial and nuclear DNA datasets coupled with methods of divergence time estimation, ancestral area reconstruction and comparative phylogenetics. Relaxed-clock time estimates indicate that divergence of the Sigmodontinae began in the middle-late Miocene (ca. 12-9 Ma. Dispersal-vicariance analyses point to the arrival of a single lineage of northern invaders with a widespread ancestral distribution and imply that the initial differentiation between Central and South America gave rise to the most basal groups within the subfamily. These two major clades diversified in the late Miocene followed by the radiation of main tribes until the early Pliocene. Within the Oryzomyalia, tribes diverged initially in eastern South America whereas multiple dispersals into the Andes promoted further diversification of the majority of modern genera. A comparatively uniform background tempo of diversification explains the species richness of sigmodontines across most nodes, except for two akodontine genera with recent increases in diversification rates. The bridging of the Central American seaway and episodes of low sea levels likely facilitated the invasion of South America long before the onset of the post-Isthmian phase of the GABI.

  9. In the wake of invasion: tracing the historical biogeography of the South American cricetid radiation (Rodentia, Sigmodontinae).

    Science.gov (United States)

    Leite, Rafael N; Kolokotronis, Sergios-Orestis; Almeida, Francisca C; Werneck, Fernanda P; Rogers, Duke S; Weksler, Marcelo

    2014-01-01

    The Great American Biotic Interchange (GABI) was greatly influenced by the completion of the Isthmus of Panama and impacted the composition of modern faunal assemblages in the Americas. However, the contribution of preceding events has been comparatively less explored, even though early immigrants in the fossil records are evidence for waif dispersals. The cricetid rodents of the subfamily Sigmodontinae are a classic example of a species-rich South American radiation resulting from an early episode of North American invasion. Here, we provide a temporal and spatial framework to address key aspects of the historical biogeography and diversification of this diverse mammal group by using mitochondrial and nuclear DNA datasets coupled with methods of divergence time estimation, ancestral area reconstruction and comparative phylogenetics. Relaxed-clock time estimates indicate that divergence of the Sigmodontinae began in the middle-late Miocene (ca. 12-9 Ma). Dispersal-vicariance analyses point to the arrival of a single lineage of northern invaders with a widespread ancestral distribution and imply that the initial differentiation between Central and South America gave rise to the most basal groups within the subfamily. These two major clades diversified in the late Miocene followed by the radiation of main tribes until the early Pliocene. Within the Oryzomyalia, tribes diverged initially in eastern South America whereas multiple dispersals into the Andes promoted further diversification of the majority of modern genera. A comparatively uniform background tempo of diversification explains the species richness of sigmodontines across most nodes, except for two akodontine genera with recent increases in diversification rates. The bridging of the Central American seaway and episodes of low sea levels likely facilitated the invasion of South America long before the onset of the post-Isthmian phase of the GABI.

  10. Biogeography and molar morphology of Pleistocene African elephants: new evidence from Elandsfontein, Western Cape Province, South Africa

    Science.gov (United States)

    Smith, Kathlyn M.; Stynder, Deano D.

    2015-05-01

    Elandsfontein (EFT) is a Middle Pleistocene archaeological/paleontological site located in the Western Cape Province of South Africa. The largest herbivore in the assemblage is Loxodonta atlantica zulu, an extinct member of the genus that includes modern African elephants. No Elephas recki specimens were recovered at EFT, despite their common occurrence in other regions of Africa at the same time. Because E. recki and L. atlantica molars are similar in appearance, but the two species are traditionally viewed as dominating different regions of Africa during the Pleistocene, isolated molars may on occasions have been assessed to species level on the basis of geography rather than morphology. The last morphologic evaluation of EFT elephants was conducted in the 1970s, and revisiting this issue with new specimens provides added insight into the evolution of elephants in Africa. Reevaluating morphological characteristics of EFT elephant molars, through qualitative and quantitative description and comparison with Middle Pleistocene E. recki recki, L. atlantica atlantica, and L. atlantica zulu molar morphology, corroborates assessment of EFT elephants as L. a. zulu. Two recently discovered, previously undescribed molars from EFT show that molars of L. a. zulu exhibit greater variation in enamel thickness, lamellar frequency, and occlusal surface morphology than previously reported. An update of the Pleistocene biogeography of Loxodonta and Elephas indicates that fossil remains of both are often found at the same localities in eastern Africa. Their rare co-occurrences in the north and south, however, suggest geographic separation of the two genera in at least some regions of Africa, which may have been based on habitat preference.

  11. The ecology, biogeography, history and future of two globally important weeds: Cardiospermum halicacabum Linn. and C. grandiflorum Sw

    Directory of Open Access Journals (Sweden)

    Enelge Gildenhuys

    2013-10-01

    establishment potential. This review opens the door to better understand the global biogeography of the genus Cardiospermum, with direct implications for management, while also highlighting gaps in current research.

  12. Diversity and biogeography of rhizobia isolated from root nodules of Glycine max grown in Hebei Province, China.

    Science.gov (United States)

    Li, Qin Qin; Wang, En Tao; Zhang, Yun Zeng; Zhang, Yan Ming; Tian, Chang Fu; Sui, Xin Hua; Chen, Wen Feng; Chen, Wen Xin

    2011-05-01

    A total of 215 rhizobial strains were isolated and analyzed with 16S rRNA gene, 16S-23S intergenic spacer, housekeeping genes atpD, recA, and glnII, and symbiotic genes nifH and nodC to understand the genetic diversity of soybean rhizobia in Hebei province, China. All the strains except one were symbiotic bacteria classified into nine genospecies in the genera of Bradyrhizobium and Sinorhizobium. Surveys on the distribution of these rhizobia in different regions showed that Bradyrhizobium japonicum and Bradyrhizobium elkanii strains were found only in neutral to slightly alkaline soils whereas Bradyrhizobium yuanmingense, Bradyrhizobium liaoningense-related strains and strains of five Sinorhizobium genospecies were found in alkaline-saline soils. Correspondence and canonical correspondence analyses on the relationship of rhizobial distribution and their soil characteristics reveal that high soil pH, electrical conductivity, and potassium content favor distribution of the B. yuanmingense and the five Sinorhizobium species but inhibit B. japonicum and B. elkanii. High contents of available phosphorus and organic matters benefit Sinorhizobium fredii and B. liaoningense-related strains and inhibit the others groups mentioned above. The symbiotic gene (nifH and nodC) lineages among B. elkanii, B. japonicum, B. yuanmingense, and Sinorhizobium spp. were observed in the strains, signifying that vertical gene transfer was the main mechanism to maintain these genes in the soybean rhizobia. However, lateral transfer of symbiotic genes commonly in Sinorhizobium spp. and rarely in Bradyrhizobium spp. was also detected. These results showed the genetic diversity, the biogeography, and the soil determinant factors of soybean rhizobia in Hebei province of China.

  13. Around the World in Eight Million Years: Historical Biogeography and Evolution of the Spray Zone Spider Amaurobioides (Araneae: Anyphaenidae)

    Science.gov (United States)

    Opell, Brent D.; Haddad, Charles R.; Raven, Robert J.; Soto, Eduardo M.; Ramírez, Martín J.

    2016-01-01

    Closely related organisms with transoceanic distributions have long been the focus of historical biogeography, prompting the question of whether long-distance dispersal, or tectonic-driven vicariance shaped their current distribution. Regarding the Southern Hemisphere continents, this question deals with the break-up of the Gondwanan landmass, which has also affected global wind and oceanic current patterns since the Miocene. With the advent of phylogenetic node age estimation and parametric bioinformatic advances, researchers have been able to disentangle historical evolutionary processes of taxa with greater accuracy. In this study, we used the coastal spider genus Amaurobioides to investigate the historical biogeographical and evolutionary processes that shaped the modern-day distribution of species of this exceptional genus of spiders. As the only genus of the subfamily Amaurobioidinae found on three Southern Hemisphere continents, its distribution is well-suited to study in the context of Gondwanic vicariance versus long-distance, transoceanic dispersal. Ancestral species of the genus Amaurobioides appear to have undergone several long-distance dispersal events followed by successful establishments and speciation, starting from the mid-Miocene through to the Pleistocene. The most recent common ancestor of all present-day Amaurobioides species is estimated to have originated in Africa after arriving from South America during the Miocene. From Africa the subsequent dispersals are likely to have taken place predominantly in an eastward direction. The long-distance dispersal events by Amaurobioides mostly involved transoceanic crossings, which we propose occurred by rafting, aided by the Antarctic Circumpolar Current and the West Wind Drift. PMID:27732621

  14. Comparison of Genetic Algorithm, Particle Swarm Optimization and Biogeography-based Optimization for Feature Selection to Classify Clusters of Microcalcifications

    Science.gov (United States)

    Khehra, Baljit Singh; Pharwaha, Amar Partap Singh

    2016-06-01

    Ductal carcinoma in situ (DCIS) is one type of breast cancer. Clusters of microcalcifications (MCCs) are symptoms of DCIS that are recognized by mammography. Selection of robust features vector is the process of selecting an optimal subset of features from a large number of available features in a given problem domain after the feature extraction and before any classification scheme. Feature selection reduces the feature space that improves the performance of classifier and decreases the computational burden imposed by using many features on classifier. Selection of an optimal subset of features from a large number of available features in a given problem domain is a difficult search problem. For n features, the total numbers of possible subsets of features are 2n. Thus, selection of an optimal subset of features problem belongs to the category of NP-hard problems. In this paper, an attempt is made to find the optimal subset of MCCs features from all possible subsets of features using genetic algorithm (GA), particle swarm optimization (PSO) and biogeography-based optimization (BBO). For simulation, a total of 380 benign and malignant MCCs samples have been selected from mammogram images of DDSM database. A total of 50 features extracted from benign and malignant MCCs samples are used in this study. In these algorithms, fitness function is correct classification rate of classifier. Support vector machine is used as a classifier. From experimental results, it is also observed that the performance of PSO-based and BBO-based algorithms to select an optimal subset of features for classifying MCCs as benign or malignant is better as compared to GA-based algorithm.

  15. Genetic diversity of parasitic dinoflagellates in the genus amoebophrya and its relationship to parasite biology and biogeography.

    Science.gov (United States)

    Kim, Sunju; Park, Myung Gil; Kim, Keun-Yong; Kim, Chang-Hoon; Yih, Wonho; Park, Jong Soo; Coats, D Wayne

    2008-01-01

    genetic diversity in Amoebophrya strains does not always reflect parasite biology or biogeography.

  16. Biogeography, host specificity, and molecular phylogeny of the basidiomycetous yeast Phaffia rhodozyma and its sexual form, Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Libkind, Diego; Ruffini, Alejandra; van Broock, Maria; Alves, Leonor; Sampaio, José Paulo

    2007-02-01

    Phaffia rhodozyma (sexual form, Xanthophyllomyces dendrorhous) is a basidiomycetous yeast that has been found in tree exudates in the Northern Hemisphere at high altitudes and latitudes. This yeast produces astaxanthin, a carotenoid pigment with biotechnological importance because it is used in aquaculture for fish pigmentation. We isolated X. dendrorhous from the Southern Hemisphere (Patagonia, Argentina), where it was associated with fruiting bodies of Cyttaria hariotii, an ascomycetous parasite of Nothofagus trees. We compared internal transcribed spacer (ITS)-based phylogenies of P. rhodozyma and its tree host (Betulaceae, Corneaceae, Fagaceae, and Nothofagaceae) and found them to be generally concordant, suggesting that different yeast lineages colonize different trees and providing an explanation for the phylogenetic distance observed between the type strains of P. rhodozyma and X. dendrorhous. We hypothesize that the association of Xanthophyllomyces with Cyttaria derives from a previous association of the yeast with Nothofagus, and the sister relationship between Nothofagaceae and Betulaceae plus Fagaceae correlates with the phylogeny of X. dendrorhous strains originating from these three plant families. The two most basal strains of X. dendrorhous are those isolated from Cornus, an ancestral genus in the phylogenetic analysis of the host trees. Thus, we question previous conclusions that P. rhodozyma and X. dendrorhous represent different species since the polymorphisms detected in the ITS and intergenic spacer sequences can be attributed to intraspecific variation associated with host specificity. Our study provides a deeper understanding of Phaffia biogeography, ecology, and molecular phylogeny. Such knowledge is essential for the comprehension of many aspects of the biology of this organism and will facilitate the study of astaxanthin production within an evolutionary and ecological framework.

  17. The discovery of new deep-sea hydrothermal vent communities in the southern ocean and implications for biogeography.

    Directory of Open Access Journals (Sweden)

    Alex D Rogers

    2012-01-01

    Full Text Available Since the first discovery of deep-sea hydrothermal vents along the Galápagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8°C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp., stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae, bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more

  18. Transferring and implementing the general dynamic model of oceanic island biogeography at the scale of island fragments: the role of geological age and topography in plant diversification in the Canaries

    DEFF Research Database (Denmark)

    Otto, Rüdiger; Whittaker, Robert J.; von Gaisberg, Markus;

    2016-01-01

    Aim The general dynamic model (GDM) of oceanic island biogeography integrates rates of immigration, speciation and extinction in relation to a humped trajectory of island area and topographic complexity through time, based on a simplified island ontogeny. In practice, many islands have more compl...

  19. Ecology and biogeography of megafauna and macrofauna at the first known deep-sea hydrothermal vents on the ultraslow-spreading Southwest Indian Ridge

    Science.gov (United States)

    Copley, J. T.; Marsh, L.; Glover, A. G.; Hühnerbach, V.; Nye, V. E.; Reid, W. D. K.; Sweeting, C. J.; Wigham, B. D.; Wiklund, H.

    2016-12-01

    The Southwest Indian Ridge is the longest section of very slow to ultraslow-spreading seafloor in the global mid-ocean ridge system, but the biogeography and ecology of its hydrothermal vent fauna are previously unknown. We collected 21 macro- and megafaunal taxa during the first Remotely Operated Vehicle dives to the Longqi vent field at 37° 47‧S 49° 39‧E, depth 2800 m. Six species are not yet known from other vents, while six other species are known from the Central Indian Ridge, and morphological and molecular analyses show that two further polychaete species are shared with vents beyond the Indian Ocean. Multivariate analysis of vent fauna across three oceans places Longqi in an Indian Ocean province of vent biogeography. Faunal zonation with increasing distance from vents is dominated by the gastropods Chrysomallon squamiferum and Gigantopelta aegis, mussel Bathymodiolus marisindicus, and Neolepas sp. stalked barnacle. Other taxa occur at lower abundance, in some cases contrasting with abundances at other vent fields, and δ13C and δ15N isotope values of species analysed from Longqi are similar to those of shared or related species elsewhere. This study provides baseline ecological observations prior to mineral exploration activities licensed at Longqi by the United Nations.

  20. An integrative systematic revision and biogeography of Rhynchocalamus snakes (Reptilia, Colubridae with a description of a new species from Israel

    Directory of Open Access Journals (Sweden)

    Karin Tamar

    2016-12-01

    Full Text Available Background The colubrid snakes of the genus Rhynchocalamus are seldom studied and knowledge of their ecology and life history is scarce. Three species of Rhynchocalamus are currently recognized, R. satunini (from Turkey eastwards to Iran, R. arabicus (Yemen and Oman, and R. melanocephalus (from the Sinai Peninsula northwards to Turkey. All are slender, secretive, mainly nocturnal and rare fossorial snakes. This comprehensive study is the first to sample all known Rhynchocalamus species in order to review the intra-generic phylogenetic relationships and historical biogeography of the genus. Methods We revised the systematics of Rhynchocalamus using an integrative approach and evaluated its phylogeography. The phylogenetic position within the Colubridae and the phylogenetic relationships within the genus were inferred using 29 individuals belonging to the three known species, with additional sampling of two other closely-related genera, Muhtarophis and Lytorhynchus. We analysed three mitochondrial (12S, 16S, cytb and one nuclear (c-mos gene fragments. Phylogenetic trees were reconstructed using maximum likelihood and Bayesian inference methods; the latter method also used to provide the first time-calibrated molecular phylogeny of the genus. We generated a nuclear network and carried out a topology test and species delimitation analysis. Morphological comparisons were used to differentiate among species and to describe a new species from Israel. The studied material was comprised of 108 alcohol-preserved specimens, 15 photographs, and data from the literature for the examination of 17 mensural, 14 meristic, and two categorical characters. Results The molecular results support Rhynchocalamus as monophyletic, and as having split from its sister genus Lytorhynchus during the Late Oligocene. The three recognized species of Rhynchocalamus comprise four independently evolving groups. The molecular results reveal that the genus began to diverge during

  1. Systematics, biogeography, and character evolution of the legume tribe Fabeae with special focus on the middle-Atlantic island lineages

    Directory of Open Access Journals (Sweden)

    Schaefer Hanno

    2012-12-01

    Full Text Available Abstract Background Tribe Fabeae comprises about 380 legume species, including some of the most ancient and important crops like lentil, pea, and broad bean. Breeding efforts in legume crops rely on a detailed knowledge of closest wild relatives and geographic origin. Relationships within the tribe, however, are incompletely known and previous molecular results conflicted with the traditional morphology-based classification. Here we analyse the systematics, biogeography, and character evolution in the tribe based on plastid and nuclear DNA sequences. Results Phylogenetic analyses including c. 70% of the species in the tribe show that the genera Vicia and Lathyrus in their current circumscription are not monophyletic: Pisum and Vavilovia are nested in Lathyrus, the genus Lens is nested in Vicia. A small, well-supported clade including Vicia hirsuta, V. sylvatica, and some Mediterranean endemics, is the sister group to all remaining species in the tribe. Fabeae originated in the East Mediterranean region in the Miocene (23–16 million years ago (Ma and spread at least 39 times into Eurasia, seven times to the Americas, twice to tropical Africa and four times to Macaronesia. Broad bean (V. faba and its sister V. paucijuga originated in Asia and might be sister to V. oroboides. Lentil (Lens culinaris ssp. culinaris is of Mediterranean origin and together with eight very close relatives forms a clade that is nested in the core Vicia, where it evolved c. 14 Ma. The Pisum clade is nested in Lathyrus in a grade with the Mediterranean L. gloeosperma, L. neurolobus, and L. nissolia. The extinct Azorean endemic V. dennesiana belongs in section Cracca and is nested among Mediterranean species. According to our ancestral character state reconstruction results, ancestors of Fabeae had a basic chromosome number of 2n=14, an annual life form, and evenly hairy, dorsiventrally compressed styles. Conclusions Fabeae evolved in the Eastern Mediterranean in the

  2. Evolution and biogeography of an emerging quasispecies: diversity patterns of the fish Viral Hemorrhagic Septicemia virus (VHSv).

    Science.gov (United States)

    Pierce, Lindsey R; Stepien, Carol A

    2012-05-01

    Viral Hemorrhagic Septicemia virus (VHSv) is an RNA rhabdovirus that causes one of the most important finfish diseases, affecting over 70 marine and freshwater species. It was discovered in European cultured fish in 1938 and since has been described across the Northern Hemisphere. Four strains and several substrains have been hypothesized, whose phylogenetic relationships and evolutionary radiation are evaluated here in light of a quasispecies model, including an in-depth analysis of the novel and especially virulent new substrain (IVb) that first appeared in the North American Laurentian Great Lakes in 2003. We analyze the evolutionary patterns, genetic diversity, and biogeography of VHSv using all available RNA sequences from the glycoprotein (G), nucleoprotein (N), and non-virion (Nv) genes, with Maximum Likelihood and bayesian approaches. Results indicate that the G gene evolves at an estimated rate of μ=2.58×10(-4) nucleotide substitutions per site per year, the N gene at μ=4.26×10(-4), and Nv fastest at μ=1.25×10(-3). Phylogenetic trees from the three genes largely are congruent, distinguishing strains I-IV as reciprocally monophyletic with high bootstrap and posterior probability support. VHSv appears to have originated from a marine ancestor in the North Atlantic Ocean, diverging into two primary clades: strain IV in North America (the Northwestern Atlantic Ocean), and strains I-III in the Northeastern Atlantic region (Europe). Strain II may comprise the basal group of the latter clade and diverged in Baltic Sea estuarine waters; strains I and III appear to be sister groups (according to the G and Nv genes), with the former mostly in European freshwaters and the latter in North Sea marine/estuarine waters. Strain IV is differentiated into three monophyletic substrains, with IVa infecting Northeastern Pacific salmonids and many marine fishes (with 44 unique G gene haplotypes), IVb endemic to the freshwater Great Lakes (11 haplotypes), and a newly

  3. Biogeography, biodiversity and fluid dependence of deep-sea cold-seep communities at active and passive margins

    Science.gov (United States)

    Sibuet, Myriam; Olu, Karine

    1998-01-01

    To date, several cold-seep areas which fuel chemosynthesis-based benthic communities have been explored, mainly by deployment of manned submersibles. They are located in the Atlantic and in the Eastern and Western Pacific oceans and in the Mediterranean Sea, in depths ranging between 400 and 6000 m in different geological contexts in passive and active margins. Our study is based on a review of the existent literature on 24 deep cold seeps. The geographic distribution of seeps, the variations of origin and composition of fluids, and rates of fluid flow are presented as they are important factors which explain the spatial heterogeneity and the biomass of biological communities. Methane-rich fluid of thermogenic and/or biogenic origin is the principal source of energy for high-productive communities; however, production of sulphide by sulphate reduction in the sediment also has a major role. The dominant seep species are large bivalves belonging to the families Vesicomyidae or Mytilidae. Other symbiont-containing species occur belonging to Solemyidae, Thyasiridae, Lucinidae bivalves, Pogonophora worms, Cladorhizidae and Hymedesmiidae sponges. Most of the symbiont-containing cold-seep species are new to science. Different symbiont-containing species rely on sulphide or methane oxidation, or both, via chemoautotrophic endosymbiotic bacteria. A total of 211 species, from which 64 are symbiont-containing species, have been inventoried. Patterns in biodiversity and biogeography are proposed. A large majority of the species are endemic to a seep area and the symbiont-containing species are mainly endemic to the cold-seep ecosystem. A comparison of species found in other deep chemosynthesis-based ecosystems, hydrothermal vents, whale carcass and shipwreck reduced habitats, reveals from the existing data, that only 13 species, of which five are symbiont-containing species occur, at both seeps and hydrothermal vents. The species richness of cold-seep communities decreases

  4. Parsimony analysis of endemism (PAE and studies of Mexican biogeography PAE y el estudio de la biogeografía de México

    Directory of Open Access Journals (Sweden)

    A. Townsend Peterson

    2008-12-01

    Full Text Available Parsimony analysis of endemism (PAE has become a popular analytical approach in efforts to map the biogeography of Mexican biotas. Although attractive, the technique has serious drawbacks that make correct inferences of biogeographic history unlikely, which has been noted amply in the broader literature.El PAE se ha convertido en un método popular en los esfuerzos por resumir, en forma de mapas, la biogeografía de la biota de México. A pesar de su atractivo, la técnica tiene problemas serios que impiden que las conclusiones resultantes sean las correctas. Estos problemas se han hecho ampliamente evidentes en la literatura sobre este campo.

  5. Phylogeny of the genus Willemia (Collembola: Hypogastruridae) and biogeography of the W. buddenbrocki-group with description of a new species from Ivory Coast (western Africa).

    Science.gov (United States)

    Zon, Serge Déméango; Bedos, Anne; D'Haese, Cyrille A

    2015-06-29

    Willemia tondoh sp. nov. from the Ivory Coast (western Africa) is described and illustrated. The new species is the 14th in the buddenbrocki-group and is defined with two large globular sensilla placed in a cavity and covered in part by tegumental fold on antennal segment IV, 7 chaetae on antennal segment I, postantennal organ with 9 vesicles, s-chaetae subcylindrical and acuminate on abdominal terga and chaetae a1 absent on abdominal sternum IV. A phylogeny for all the 46 species of the genus Willemia is proposed. Based on the phylogentic framework, the biogeography of the buddenbrocki-group is discussed. An identification key for all 46 known species of the genus is provided.

  6. Mammalian Biogeography and the Latitudinal Climatic Gradient in Western North America During the Paleocene Evolutionary Radiation of Mammals (Invited)

    Science.gov (United States)

    Fox, D. L.; Rose, P.

    2010-12-01

    significant negative relationship with paleolatitude. For both analyses, results are similar at the genus levels. In eight species that occur in four or more regions, none demonstrate a statistically significant increase in m1 area with latitude. Thus, despite climatic gradients in the mid-Paleocene that were similar to modern gradients, mammals in the region during the Paleocene appear to violate two essentially canonical biogeographic patterns seen in modern mammals and diverse other organisms, potentially ruling out climate as a long-term control on these patterns. The contrasts between the biogeography of modern and mid-Paleocene mammals in the region could result from distinct community ecology of faunas dominated by extinct “archaic” clades of mammals, ongoing ecological recovery after the Cretaceous-Paleogene extinction, and/or the modern biogeographic patterns being geologically recent or episodic phenomenon and not long-term characteristics of the geographic distribution of mammalian species richness or body size.

  7. Biogeography of Mediterranean Invasions

    Science.gov (United States)

    Groves, R. H.; di Castri, F.

    The Mediterranean basin, California, Chile, the western Cape of South Africa, and southern Australia share a Mediterranean climate characterized by cool, wet winters and hot, dry summers. These five regions have differing patterns of human settlement, but similarities in natural vegetation and some faunal assemblages. These likenesses are enhanced with time by an increasing level of biotic exchange among the regions. An initiative of a subcommittee of SCOPE (Scientific Committee on Problems of the Environment), which realized that the integrity of many natural ecosystems is being threatened by the ingress of invasive species, this book uniquely documents the introduced floras and faunas, especially plants, buds, and mammals, in these five regions of Mediterranean climate, and aims to increase our understanding of the ecology of biological invasions. In doing so, it points a way to more effectively manage the biota of these regions.

  8. Do the historical biogeography and evolutionary history of the digenean Margotrema spp. across central Mexico mirror those of their freshwater fish hosts (Goodeinae?

    Directory of Open Access Journals (Sweden)

    Andrés Martínez-Aquino

    Full Text Available Host-parasite systems provide an ideal platform to study evolution at different levels, including codivergence in a historical biogeography context. In this study we aim to describe biogeographic and codivergent patterns and associated processes of the Goodeinae freshwater fish and their digenean parasite (Margotrema spp. over the last 6.5 Ma (million years, identifying the main factors (host and/or hydrogeomorphology that influenced the evolution of Margotrema. We obtained a species tree for Margotrema spp. using DNA sequence data from mitochondrial and nuclear molecular markers (COI and ITS1, respectively and performed molecular dating to discern divergence events within the genus. The dispersal-extinction-cladogenesis (DEC model was used to describe the historical biogeography of digeneans and applied to cophylogenetic analyses of Margotrema and their goodeine hosts. Our results showed that the evolutionary history of Margotrema has been shaped in close association with its geographic context, especially with the geological history of central Mexico during the Pleistocene. Host-specificity has been established at three levels of historical association: a Species-Species, represented by Xenotaenia resolanae-M. resolanae exclusively found in the Cuzalapa River Basin; b Species-Lineage, represented by Characodon audax-M. bravoae Lineage II, exclusive to the Upper and Middle Mezquital River Basin, and c Tribe-Lineage, including two instances of historical associations among parasites and hosts at the taxonomical level of tribe, one represented by Ilyodontini-M. bravoae Lineage I (distributed across the Ayuquila and Balsas River Basins, and another comprised of Girardinichthyini/Chapalichthyini-M. bravoae Lineage III, found only in the Lerma River Basin. We show that the evolutionary history of the parasites is, on several occasions, in agreement with the phylogenetic and biogeographic history of their hosts. A series of biogeographic and host

  9. Do the historical biogeography and evolutionary history of the digenean Margotrema spp. across central Mexico mirror those of their freshwater fish hosts (Goodeinae)?

    Science.gov (United States)

    Martínez-Aquino, Andrés; Ceccarelli, Fadia Sara; Eguiarte, Luis E; Vázquez-Domínguez, Ella; de León, Gerardo Pérez-Ponce

    2014-01-01

    Host-parasite systems provide an ideal platform to study evolution at different levels, including codivergence in a historical biogeography context. In this study we aim to describe biogeographic and codivergent patterns and associated processes of the Goodeinae freshwater fish and their digenean parasite (Margotrema spp.) over the last 6.5 Ma (million years), identifying the main factors (host and/or hydrogeomorphology) that influenced the evolution of Margotrema. We obtained a species tree for Margotrema spp. using DNA sequence data from mitochondrial and nuclear molecular markers (COI and ITS1, respectively) and performed molecular dating to discern divergence events within the genus. The dispersal-extinction-cladogenesis (DEC) model was used to describe the historical biogeography of digeneans and applied to cophylogenetic analyses of Margotrema and their goodeine hosts. Our results showed that the evolutionary history of Margotrema has been shaped in close association with its geographic context, especially with the geological history of central Mexico during the Pleistocene. Host-specificity has been established at three levels of historical association: a) Species-Species, represented by Xenotaenia resolanae-M. resolanae exclusively found in the Cuzalapa River Basin; b) Species-Lineage, represented by Characodon audax-M. bravoae Lineage II, exclusive to the Upper and Middle Mezquital River Basin, and c) Tribe-Lineage, including two instances of historical associations among parasites and hosts at the taxonomical level of tribe, one represented by Ilyodontini-M. bravoae Lineage I (distributed across the Ayuquila and Balsas River Basins), and another comprised of Girardinichthyini/Chapalichthyini-M. bravoae Lineage III, found only in the Lerma River Basin. We show that the evolutionary history of the parasites is, on several occasions, in agreement with the phylogenetic and biogeographic history of their hosts. A series of biogeographic and host

  10. Introduction to the Arizona Sky Island Arthropod Project (ASAP): Systematics, Biogeography, Ecology, and Population Genetics of Arthropods of the Madrean Sky Islands.

    Science.gov (United States)

    Moore, Wendy; Meyer, Wallace M; Eble, Jeffrey A; Franklin, Kimberly; Wiens, John F; Brusca, Richard C

    2013-01-01

    The Arizona Sky Island Arthropod Project (ASAP) is a new multi-disciplinary research program at the University of Arizona that combines systematics, biogeography, ecology, and population genetics to study origins and patterns of arthropod diversity along elevation gradients and among mountain ranges in the Madrean Sky Island Region. Arthropods represent taxonomically and ecologically diverse organisms that drive key ecosystem processes in this mountain archipelago. Using data from museum specimens and specimens we obtain during long-term collecting and monitoring programs, ASAP will document arthropod species across Arizona's Sky Islands to address a number of fundamental questions about arthropods of this region. Baseline data will be used to determine climatic boundaries for target species, which will then be integrated with climatological models to predict future changes in arthropod communities and distributions in the wake of rapid climate change. ASAP also makes use of the natural laboratory provided by the Sky Islands to investigate ecological and genetic factors that influence diversification and patterns of community assembly. Here, we introduce the project, outline overarching goals, and describe preliminary data from the first year of sampling ground-dwelling beetles and ants in the Santa Catalina Mountains.

  11. Early Pleistocene lineages of Bagre bagre (Linnaeus, 1766 (Siluriformes: Ariidae, from the Atlantic coast of South America, with insights into the demography and biogeography of the species

    Directory of Open Access Journals (Sweden)

    Wemerson C. da Silva

    Full Text Available ABSTRACT Coastal and marine environments are characterized by a lack of evident physical barriers or geographic isolation, and it may be difficult to understand how divergence can arise and be sustained in marine environments. The identification of 'soft' barriers is a crucial step towards the understanding of gene flow in marine environments. The marine catfishes of the family Ariidae are a demersal group with restricted migratory behavior, no pelagic larval stages, and mechanisms of larval retention, representing a potentially useful model for the understanding of historical processes of allopatric speciation in the marine environment. In the present study, two lineages of the Coco sea catfish, Bagre bagre , were recognized from their complete segregation at both mitochondrial and morphological levels. One lineage is distributed between Venezuela and the northern coast of Brazil, including the semiarid northeast coast, while the second lineage is found on the eastern coast of Brazil, including the humid northeast coast. Based on distribution area, habitats preference, and genetic variability, inferences are made in relation to biogeography and demography of lineages in Atlantic coast of South America.

  12. Morphology-based phylogeny and biogeography of Wockia (Lepidoptera: Urodidae) with description of a new species from Japan and South Korea.

    Science.gov (United States)

    Sohn, Jae-Cheon

    2014-04-01

    Wockia, one of the six genera within the lepidopteran family Urodidae, currently includes nine species distributed in Holarctic, Oriental, and Neotropical regions. A new species of the genus, W. magna sp. nov., is described from Japan and South Korea. This is the first record of Urodidae from Japan. A cladistic analysis was constructed based on 27 morphological characters from five ingroup species and two outgroup taxa. A single most parsimonious tree was found (length = 38, CI = 71, RI = 70). The resulting tree failed to recover the monophyly of Wockia chewbacca and a clade Wockia sensu stricto, including four congeners from North America, temperate East Asia and Southeast Asia. Wockia sensu stricto was resolved as monophyletic and was divided into two subgroups, one including W. asperipunctella and W. magna, and the other including W. koreana and W. variata. The sister-group relationship of W. asperipunctella and W. magna was moderately supported. Synapomorphies of Wockia sensu stricto are provided from the resulting phylogeny. Systematic definitions of Wockia and other allied genera are revised. Optimal ancestral area reconstruction implemented in DIVA resulted in different hypotheses for Wockia, depending on how to constrain the maximum number of areas. The maximum area number set as two yielded a more likely scenario suggesting that Wockia sensu stricto originated in temperate East Asia and then dispersed into the Oriental region, North America, and Europe. A working hypothesis and other equally possible alternative explanations for the biogeography of Wockia are provided.

  13. Probabilistic historical biogeography: new models for founder-event speciation, imperfect detection, and fossils allow improved accuracy and model-testing

    Directory of Open Access Journals (Sweden)

    Nicholas Joseph Matzke

    2013-12-01

    Full Text Available Historical biogeography has been characterized by a large diversity of methods and unresolved debates about which processes, such as dispersal or vicariance, are most important for explaining distributions. A new R package, BioGeoBEARS, implements many models in a common likelihood framework, so that standard statistical model selection procedures can be applied to let the data choose the best model. Available models include a likelihood version of DIVA (“DIVALIKE”, LAGRANGE’s DEC model, and BAYAREA, as well as “+J” versions of these models which include founder-event speciation, an important process left out of most inference methods. I use BioGeoBEARS on a large sample of island and non-island clades (including two fossil clades to show that founder-event speciation is a crucial process in almost every clade, and that most published datasets reject the non-J models currently in widespread use. BioGeoBEARS is open-source and freely available for installation at the Comprehensive R Archive Network at http://CRAN.R-project.org/package=BioGeoBEARS. A step-by-step tutorial is available at http://phylo.wikidot.com/biogeobears.

  14. Evolutionary dynamics and biogeography of Musaceae reveal a correlation between the diversification of the banana family and the geological and climatic history of Southeast Asia.

    Science.gov (United States)

    Janssens, Steven B; Vandelook, Filip; De Langhe, Edmond; Verstraete, Brecht; Smets, Erik; Vandenhouwe, Ines; Swennen, Rony

    2016-06-01

    Tropical Southeast Asia, which harbors most of the Musaceae biodiversity, is one of the most species-rich regions in the world. Its high degree of endemism is shaped by the region's tectonic and climatic history, with large differences between northern Indo-Burma and the Malayan Archipelago. Here, we aim to find a link between the diversification and biogeography of Musaceae and geological history of the Southeast Asian subcontinent. The Musaceae family (including five Ensete, 45 Musa and one Musella species) was dated using a large phylogenetic framework encompassing 163 species from all Zingiberales families. Evolutionary patterns within Musaceae were inferred using ancestral area reconstruction and diversification rate analyses. All three Musaceae genera - Ensete, Musa and Musella - originated in northern Indo-Burma during the early Eocene. Musa species dispersed from 'northwest to southeast' into Southeast Asia with only few back-dispersals towards northern Indo-Burma. Musaceae colonization events of the Malayan Archipelago subcontinent are clearly linked to the geological and climatic history of the region. Musa species were only able to colonize the region east of Wallace's line after the availability of emergent land from the late Miocene onwards.

  15. Fruit Classification by Wavelet-Entropy and Feedforward Neural Network Trained by Fitness-Scaled Chaotic ABC and Biogeography-Based Optimization

    Directory of Open Access Journals (Sweden)

    Shuihua Wang

    2015-08-01

    Full Text Available Fruit classification is quite difficult because of the various categories and similar shapes and features of fruit. In this work, we proposed two novel machine-learning based classification methods. The developed system consists of wavelet entropy (WE, principal component analysis (PCA, feedforward neural network (FNN trained by fitness-scaled chaotic artificial bee colony (FSCABC and biogeography-based optimization (BBO, respectively. The K-fold stratified cross validation (SCV was utilized for statistical analysis. The classification performance for 1653 fruit images from 18 categories showed that the proposed “WE + PCA + FSCABC-FNN” and “WE + PCA + BBO-FNN” methods achieve the same accuracy of 89.5%, higher than state-of-the-art approaches: “(CH + MP + US + PCA + GA-FNN ” of 84.8%, “(CH + MP + US + PCA + PSO-FNN” of 87.9%, “(CH + MP + US + PCA + ABC-FNN” of 85.4%, “(CH + MP + US + PCA + kSVM” of 88.2%, and “(CH + MP + US + PCA + FSCABC-FNN” of 89.1%. Besides, our methods used only 12 features, less than the number of features used by other methods. Therefore, the proposed methods are effective for fruit classification.

  16. The New World Gibbobruchus Pic (Coleoptera, Chrysomelidae, Bruchinae): description of a new species and phylogenetic insights into the evolution of host associations and biogeography.

    Science.gov (United States)

    Manfio, Daiara; Jorge, Isaac R; Morse, Geoffrey E; Ribeiro-Costa, Cibele S

    2016-04-18

    The seed beetle Gibbobruchus tridentatus Manfio, Jorge & Ribeiro-Costa sp. nov. is described from the Amazon basin in Brazil (Acre) and Ecuador (Napo), and is included in an updated key to the species of Gibbobruchus Pic. This new species and the recently described G. bergamini Manfio & Ribeiro-Costa are incorporated into a phylogenetic reanalysis of the genus and into a comparative analysis of host plant use and biogeography. Species groups previously proposed were supported and the evolutionary history in host plant-use shows Gibbobruchus conserved at tribe level, Cercideae (Caesalpinioideae), with coordination between biogeographic expansion and host genus shifts. Both species, Gibbobruchus tridentatus Manfio, Jorge & Ribeiro-Costa sp. nov. and G. bergamini, were placed within the group scurra (G. tridentatus (G. scurra (G. cavillator+G. bolivianus+G. bergamini))) and supported by one synapomorphy. Additionally, we update geographic distributions and host plant records. Two hosts, Bauhinia argentinensis Burkart and B. tarapotensis Benth. are recorded for the first time as hosts for the genus and for the subfamily.

  17. Adaptive morpho-traits, taxonomy and biogeography of Metania Gray, 1867 (Porifera: Spongillina: Metaniidae) with the description of a new species from Madagascar.

    Science.gov (United States)

    Manconi, Renata; Cadeddu, Barbara; Pronzato, Roberto

    2015-01-10

    A comparative analysis of gemmular architecture adaptive morpho-traits at family level is reported for Metaniidae together with the discovery and description of a new species from the River Mangoky (High Plateau), Madagascar. The new Malagasy species, ascribed to Metania for diagnostic traits of the skeleton and the gemmular architecture, differs from all the other known species of the genus in its unique combination of diagnostic traits. Metania madagascariensis sp. nov. is characterised by encrusting growth form, conulose surface, specialized ectosomal skeleton, alveolate-reticulate choanosomal skeleton, two types of megascleres as smooth oxeas (α) and acanthoxeas (β) ornamented with spines and/or tubercles, one type of microsclere as acanthoxeas with dense spines/tubercles bearing rosettes of microspines at tips; gemmules with or without cage of megascleres and frequently surrounded by microscleres; gemmular theca trilayered with pneumatic layer of fibrous spongin, boletiform (trumpet-like) gemmuloscleres with proximal true rotule large, smooth and with irregular blunt margins, and distal knob-like pseudorotule notably smaller, with a few hooks at the margins. M. madagascariensis belongs to the Afrotropical species group of Metania. Identification keys and an annotated checklist at global level are also provided together with a species-level discussion of Metania focusing on morphology, taxonomy, nomenclature and biogeography.

  18. Nutrients, heavy metals and phthalate acid esters in solar greenhouse soils in Round-Bohai Bay-Region, China: impacts of cultivation year and biogeography.

    Science.gov (United States)

    Chen, Zhiqun; Tian, Tian; Gao, Lihong; Tian, Yongqiang

    2016-07-01

    Solar greenhouse is a common facility type used for horticultural crop production in China. However, most solar greenhouse fields have been degraded due to continuous cropping and excessive fertilizer use. Therefore, we investigated solar greenhouse soils covering a wide range of cultivation years and environmental conditions in Round-Bohai Bay-Region to test the effects of cultivation year and biogeography on nutrients, heavy metals, and phthalate acid esters (PAEs). In general, soil pH decreased while soil electrical conductivity (EC), organic matter (OM), total nitrogen (TN), NO3 (-)-N, NH4 (+)-N, mineral nitrogen (MN), Olsen-P, and NH4OAc-K contents increased as time of cultivation increased. However, this trend was influenced by sampling sites. Among sampling sites, Jiangsu showed a relatively low soil pH and high Olsen-P content, while Hebei showed a relatively high soil EC value, NO3 (-)-N, NH4 (+)-N, MN, and NH4OAc-K contents. Liaoning was characterized by relatively high soil OM and TN contents. The nutrient level indexes in evaluation of soil quality on Olsen-P and NH4OAc-K exceeded the standard seriously. The maximum values of the heavy metals Cd, Cu, and Zn were 4.87, 2.78, and 1.15 times higher than the threshold values, respectively. There was a rising trend on the heavy metal contents with the increasing cultivation years, and this trend was significantly influenced by sampling sites. Both Cu and Zn had relative high heavy metal indexes in evaluation of soil pollution. The PAEs were not detected in almost all sampling soils. Overall, the excessive fertilizer application was an important cause of nutrient accumulation and heavy metal pollution, resulting in soil degradation in solar greenhouses.

  19. A molecular phylogeny for yponomeutoidea (insecta, Lepidoptera, ditrysia and its implications for classification, biogeography and the evolution of host plant use.

    Directory of Open Access Journals (Sweden)

    Jae-Cheon Sohn

    suggesting parallel phylogenesis. Our analyses suggest that previous characterizations of yponomeutoids as predominantly Holarctic were based on insufficient sampling. CONCLUSIONS/SIGNIFICANCE: We provide the first robust molecular phylogeny for Yponomeutoidea, together with a revised classification and new insights into their life history evolution and biogeography.

  20. Inflation of Molecular Clock Rates and Dates: Molecular Phylogenetics, Biogeography, and Diversification of a Global Cicada Radiation from Australasia (Hemiptera: Cicadidae: Cicadettini).

    Science.gov (United States)

    Marshall, David C; Hill, Kathy B R; Moulds, Max; Vanderpool, Dan; Cooley, John R; Mohagan, Alma B; Simon, Chris

    2016-01-01

    Dated phylogenetic trees are important for studying mechanisms of diversification, and molecular clocks are important tools for studies of organisms lacking good fossil records. However, studies have begun to identify problems in molecular clock dates caused by uncertainty of the modeled molecular substitution process. Here we explore Bayesian relaxed-clock molecular dating while studying the biogeography of ca. 200 species from the global cicada tribe Cicadettini. Because the available fossils are few and uninformative, we calibrate our trees in part with a cytochrome oxidase I (COI) clock prior encompassing a range of literature estimates for arthropods. We show that tribe-level analyses calibrated solely with the COI clock recover extremely old dates that conflict with published estimates for two well-studied New Zealand subclades within Cicadettini. Additional subclade analyses suggest that COI relaxed-clock rates and maximum-likelihood branch lengths become inflated relative to EF-1[Formula: see text] intron and exon rates and branch lengths as clade age increases. We present corrected estimates derived from: (i) an extrapolated EF-1[Formula: see text] exon clock derived from COI-calibrated analysis within the largest New Zealand subclade; (ii) post hoc scaling of the tribe-level chronogram using results from subclade analyses; and (iii) exploitation of a geological calibration point associated with New Caledonia. We caution that considerable uncertainty is generated due to dependence of substitution estimates on both the taxon sample and the choice of model, including gamma category number and the choice of empirical versus estimated base frequencies. Our results suggest that diversification of the tribe Cicadettini commenced in the early- to mid-Cenozoic and continued with the development of open, arid habitats in Australia and worldwide. We find that Cicadettini is a rare example of a global terrestrial animal group with an Australasian origin, with all non

  1. Aplicaciones de la biogeografía histórica a la distribución de las plantas mexicanas Historical biogeography applied to the distribution of Mexican plants

    Directory of Open Access Journals (Sweden)

    Isolda Luna-Vega

    2008-06-01

    is located in the transition zone between the Nearctic and Neotropical regions, which along the autochthonous ones form a complex mixture of species with different origins, both spatial and temporal, 2 vicariant theory, that proposes a close relationship between the earth's history and the history of the biota, so that the number of species and their distribution may be explained by the complex geologic history of Mexico, and 3 pleistocenic glaciations, which explain the recent distributional patterns of plants based on ecological and historical arguments, based on paleoclimatic changes of the recent past. A continuous debate within historical biogeography has high lighted the importance of biogeography as source of evidence for taxonomy and vice versa. Historical biogeography has a close relationship with systematics, but is an independent discipline within comparative biology. Biogeography is undergoing a conceptual revolution that is causing a revision of its fundamentals and methods. The utilization of different methods in an integrative manner in the same analysis may maximize the advantages of each one.

  2. BIOGÉOGRAPHIE DU SILURE GLANE (SILURUS GLANIS : CAUSES HYDROGRAPHIQUES, CLIMATIQUES ET ANTHROPIQUES. BIOGEOGRAPHY OF THE SHEATFISH (SILURUS GLANIS : HYDROGRAPHICAL, CLIMATIC AND ANTHROPIC CAUSES.

    Directory of Open Access Journals (Sweden)

    SCHLUMBERGER O.

    2008-05-01

    Full Text Available La répartition actuelle du silure glane (Silurus glanis en France et en Europe résulte de la combinaison de facteurs à la fois hydrographiques, climatiques et anthropiques. Des données paléontologiques montrent que l'espèce faisait partie de l'ichtyofaune française (bassin du Rhône avant d'être éliminée par les glaciations. Le réchauffement climatique qui a suivi (10 000 av. JC et l'existence d'interconnexions entre, d'une part, des tributaires de la mer Noire et de la mer Caspienne et d'autre part ceux de la mer Baltique et de la mer du Nord lui ont permis de rapidement coloniser le Nord de l'Europe occidentale. Deux périodes de transplantations-introductions de l'espèce, à but économique, sont identifiées. Une première vague d'introductions hors du bassin danubien semble avoir eu lieu dès le Moyen-Age (lacs de Suisse, suivie par une deuxième période débutant vers 1800, et se poursuivant actuellement. Les effets combinés de ces introductions et des dégradations du milieu d'origine anthropique ont induit un décalage de l'aire de distribution vers le Sud et le Sud-Est de l'Europe (Italie, Espagne, tandis que ne subsistent en Suède, Carélie, Russie et Estonie que des populations relictuelles. Les résultats présentés ici, pourraient aussi concerner d'autres espèces de poissons (Percidés, Cyprinidés, qui, après avoir bénéficié pendant les glaciations des refuges constitués par les bassins de la mer Noire et de la mer Caspienne, ont pu (re- colonisé l'Europe continentale, de manière « naturelle » et avec l'aide de l'Homme. The biogeography of the sheatfish (Silurus glanis results from the combined impacts of hydrogeography, climate and man. Paleontological evidences prove that the species was present in France (Rhône river before the glaciations. The improvement of the climatic conditions (from 10 000 JC and hydrographical interconnexions between tributaries of the Black and Caspian Sea basins, and between

  3. The functional biogeography of species

    DEFF Research Database (Denmark)

    Carstensen, D.W.; Dalsgaard, B.; Svenning, J.-C.

    2013-01-01

    Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship betw...

  4. 基于生物地理学优化算法的输电网络规划%Application of Biogeography-Based Optimization in Transmission Network Planning

    Institute of Scientific and Technical Information of China (English)

    李翔硕; 王淳

    2013-01-01

    随着栖息地居住条件的变化,生物物种在各个栖息地之间不断迁移.将根据自然界物种迁移规律构造的生物地理学优化算法(biogeography-based optimization,BBO)应用于求解输电网络规划问题.针对BBO算法开采能力较强而搜索能力偏弱的特点,采用排重操作对其进行改进.以18节点系统为算例,对各种机制作用下的BBO算法的寻优能力以及与遗传算法的性能差别进行了对比分析.结果显示包含排重操作的BBO算法为兼顾了开发能力和搜索能力、可与遗传算法比拟的寻优方法.%Along with the variation of living environment decided by rainfall, geological condition, climate and so on, biological species migrate among different habitats continually. The biogeography-based optimization (BBO) algorithm that is constructed according to the law of species migration is applied in the solution of transmission network planning. In view of the features of BBO that it possesses strong exploitation ability and weak exploration ability, the BBO algorithm is improved through the operation of seeking and removing repetitive suitability vectors. Taking an 18-bus power system as the case, the performance differences between searching ability of BBO algorithm and genetic algorithm under various mechanisms are compared and analyzed. Results of comparative analysis show that the BBO algorithm, to which the operation of seeking and removing repetitive suitability vectors is applied, can considers both exploitation ability and exploration ability simultaneously, and its optimization ability is comparable to genetic algorithm.

  5. Solving flexible Job-Shop scheduling problem based on biogeography-based optimization algorithm%生物地理学算法求解柔性作业车间调度问题

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo-hui; NIE Li; MAO Xue-gang

    2014-01-01

    For the flexible Job-Shop scheduling problem (FJSP), this paper proposed the improved biogeography-based optimization algorithm (BBO), modified the migration operator and mutation operator. In the initial stage of the algorithm, it adopted hybrid initiali%针对柔性作业车间调度问题,对生物地理学优化算法中的迁移操作和突变操作进行改进,提出一种改进的生物地理学优化算法。在算法初始阶段采用混合初始化的方法,提高初始种群质量;对迁移操作和突变操作采用不同选择方法,提高算法全局搜索能力,加快收敛速度。通过编程仿真对柔性作业车间调度问题标准测试算例进行运算,并与其他文献中的计算结果进行比较,验证了该算法是可行和有效的,也可用于其他车间调度问题中。

  6. 基于改进生物地理学优化算法的SVC次同步阻尼控制器设计%Design of SVC Subsynchronous Damping Controller Based on Improved Biogeography Based Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    董飞飞; 刘涤尘; 吴军; 岑炳成; 宋春丽; 马文媛

    2014-01-01

    针对常用的次同步振荡控制器不能较好地适应电力系统时变非线性的特点,提出了一种引入余弦迁移模型、早熟判断机制、变尺度混沌变异策略及排重操作的改进生物地理学优化算法。基于该算法结合静止无功补偿器(SVC)抑制次同步振荡的机理,对次同步阻尼控制器进行优化设计,并采用特征值分析和时域仿真验证了控制系统的有效性。锦界电厂算例分析表明:经改进生物地理学算法优化的SVC次同步阻尼控制器能较好地提高机组扭振的模态阻尼,可有效抑制次同步振荡,进而保证机组和电网的安全稳定运行;与传统的生物地理学优化算法、粒子群算法及遗传算法相比,改进生物地理学优化算法在搜索最优控制参数时具有较快的搜索速度和较高的搜索精度。%In view of the common subsynchronous oscillation (SSO) controller incapability of suiting the time-varying and nonlinear characteristics of power system,the cosine migration model,the premature judging mechanism,the mutative scale of chaos mutation strategy, and re-scheduling operations are introduced into the improved biogeography-based optimization (IBBO) algorithm to design subsynchronous damping controller(SSDC)optimally based on the mechanism of suppressing SSO by static var compensator (SVC).Finally,eigenvalue analysis and electromagnetic simulation are conducted to verify the effectiveness of the controller developed.The simulation analysis of Jinjie Plant indicates that SVC-SSDC optimized by the IBBO algorithm can greatly improve the damping of the three torsional modes and thus effectively depress the multimodal SSO, ensuring stability of the system and safety of the generator shafts.Moreover,The IBBO algorithm has a faster search speed and higher search accuracy in searching for the optimal control parameters compared with the traditional biogeography-based optimization (BBO) algorithm

  7. Revision and biogeography of the Neotropical dung beetle genus Scybalophagus (Coleoptera: Scarabaeidae Revisión y Biogeografía del género neotropical de escarabajos estercoleros Scybalophagus (Coleoptera: Scarabaeidae

    Directory of Open Access Journals (Sweden)

    Federico Carlos Ocampo

    2011-12-01

    Full Text Available The South American genus Scybalophagus Martínez is comprehensively revised. The genus now includes five species, distributed in Argentina, Chile, Bolivia and Peru. All species are redescribed and diagnostic characters are provided along with illustrations of each species. Lectotypes are designated for Canthon lacordairei Laporte, 1840 (now Scybalophagus lacordairei and Canthon rugosus Blanchard, 1845 (now Scybalophagus rugosus. Scybalophagus zumpti (Frey, 1963 (=Epirinus zumpti Frey is now considered a junior synonym of S. rugosus (Blanchard. The biogeography of the genus and of each species is discussed and predictive distributions, based on environmental niche modeling, are provided for all species. Information on the biology and natural history of Scybalophagus species is discussed.El género suramericano Scybalophagus Martínez es revisado exhaustivamente. El género ahora incluye cinco especies distribuidas en Argentina, Chile, Bolivia y Perú. Se redescriben todas las especies y se proveen caracteres diagnósticos junto con ilustraciones para cada especie. Se designan lectotipos para Canthon lacordairei Laporte, 1840 (ahora Scybalophagus lacordairei y Canthon rugosus Blanchard, 1845 (ahora S. rugosus. Scybalophagus zumpti (Frey 1963 (=Epirinus zumpti Frey es ahora considerado un sinónimo junior de S. rugosus (Blanchard. La Biogeografía del género y cada especie es discutida y se presentan distribuciones potenciales, basadas en modelos de nicho ecológico, para todas las especies. Se discute la información sobre la biología e historia natural de las especies de Scybalophagus.

  8. Historical biogeography of the Fanniidae (Insecta, Diptera: A commentary on the age of the family Biogeografia histórica de Fanniidae (Insecta, Diptera: Un comentario sobre la edad de la familia

    Directory of Open Access Journals (Sweden)

    PETER LOWENBERG-NETO

    2012-09-01

    Full Text Available In a study on Fanniidae biogeography, Dominguez & Roig-Juñent (2011 argued that the family had a Pangeic origin, Late Jurassic/early Cretaceous (~146 Ma. However, recent literature on Diptera supports that Schizophora radiation occurred during Cenozoic. Fanniidae is a widespread taxon and it was interpreted under the maximum vicariance paradigm; the consequence was an analysis with no alternative hypothesis, but Pangeic origin. We verified that Fanniidae historical narrative was incongruent with the Gondwana sequential break-up. A second analysis, assuming the Fanniidae origin during early Paleocene (65 Ma, showed congruence with recent geological events and with the Muscidae diversification, a closely related Muscoidea family. Our hypothesis suggests that the Fanniidae originated in Paleogene and they were affected by few events of vicariance and several expansions during Cenozoic.En un estudio sobre biogeografía de Fanniidae, Domínguez & Roig-Juñent (2011 argumentaron que la familia era de origen Pangeico, Jurásico superior/Cretáceo inferior (~146 Ma. Sin embargo, literatura reciente sobre Diptera, confirma que la radiación de Schizophora ocurrió durante el Cenozoico. Fanniidae es un taxón ampliamente distribuido y fue interpretado bajo el paradigma de máxima vicarianza; la consecuencia, fue un análisis sin hipótesis alternativas, pero de origen pangeico. Nosotros verificamos que la narrativa histórica de Fanniidae es incongruente con la quiebra secuencial de Gondwana. Un segundo análisis, asumiendo el origen de Fanniidae durante el Paleoceno inferior (65 Ma, mostró congruencia con eventos geológicos recientes y con la diversificación de Muscidae, una familia de Muscoidea próximamente relacionada. Nuestra hipótesis sugiere que Fanniidae se originó en el Paleógeno y fueron afectados por pocos eventos de vicarianza y muchas expansiones durante el Cenozoico.

  9. Global biogeography of human infectious diseases.

    Science.gov (United States)

    Murray, Kris A; Preston, Nicholas; Allen, Toph; Zambrana-Torrelio, Carlos; Hosseini, Parviez R; Daszak, Peter

    2015-10-13

    The distributions of most infectious agents causing disease in humans are poorly resolved or unknown. However, poorly known and unknown agents contribute to the global burden of disease and will underlie many future disease risks. Existing patterns of infectious disease co-occurrence could thus play a critical role in resolving or anticipating current and future disease threats. We analyzed the global occurrence patterns of 187 human infectious diseases across 225 countries and seven epidemiological classes (human-specific, zoonotic, vector-borne, non-vector-borne, bacterial, viral, and parasitic) to show that human infectious diseases exhibit distinct spatial grouping patterns at a global scale. We demonstrate, using outbreaks of Ebola virus as a test case, that this spatial structuring provides an untapped source of prior information that could be used to tighten the focus of a range of health-related research and management activities at early stages or in data-poor settings, including disease surveillance, outbreak responses, or optimizing pathogen discovery. In examining the correlates of these spatial patterns, among a range of geographic, epidemiological, environmental, and social factors, mammalian biodiversity was the strongest predictor of infectious disease co-occurrence overall and for six of the seven disease classes examined, giving rise to a striking congruence between global pathogeographic and "Wallacean" zoogeographic patterns. This clear biogeographic signal suggests that infectious disease assemblages remain fundamentally constrained in their distributions by ecological barriers to dispersal or establishment, despite the homogenizing forces of globalization. Pathogeography thus provides an overarching context in which other factors promoting infectious disease emergence and spread are set.

  10. Microbial biogeography of public restroom surfaces.

    Directory of Open Access Journals (Sweden)

    Gilberto E Flores

    Full Text Available We spend the majority of our lives indoors where we are constantly exposed to bacteria residing on surfaces. However, the diversity of these surface-associated communities is largely unknown. We explored the biogeographical patterns exhibited by bacteria across ten surfaces within each of twelve public restrooms. Using high-throughput barcoded pyrosequencing of the 16 S rRNA gene, we identified 19 bacterial phyla across all surfaces. Most sequences belonged to four phyla: Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria. The communities clustered into three general categories: those found on surfaces associated with toilets, those on the restroom floor, and those found on surfaces routinely touched with hands. On toilet surfaces, gut-associated taxa were more prevalent, suggesting fecal contamination of these surfaces. Floor surfaces were the most diverse of all communities and contained several taxa commonly found in soils. Skin-associated bacteria, especially the Propionibacteriaceae, dominated surfaces routinely touched with our hands. Certain taxa were more common in female than in male restrooms as vagina-associated Lactobacillaceae were widely distributed in female restrooms, likely from urine contamination. Use of the SourceTracker algorithm confirmed many of our taxonomic observations as human skin was the primary source of bacteria on restroom surfaces. Overall, these results demonstrate that restroom surfaces host relatively diverse microbial communities dominated by human-associated bacteria with clear linkages between communities on or in different body sites and those communities found on restroom surfaces. More generally, this work is relevant to the public health field as we show that human-associated microbes are commonly found on restroom surfaces suggesting that bacterial pathogens could readily be transmitted between individuals by the touching of surfaces. Furthermore, we demonstrate that we can use high-throughput analyses of bacterial communities to determine sources of bacteria on indoor surfaces, an approach which could be used to track pathogen transmission and test the efficacy of hygiene practices.

  11. Floristics and Plant Biogeography in China

    Institute of Scientific and Technical Information of China (English)

    De-Zhu Li

    2008-01-01

    In 1998, a revolutionary system of angiosperm classification, the Angiosperm Phylogeny Group system was published.Meanwhile, another new system of classification of angiosperms, the eight-class system was proposed by C.Y. Wu and colleagues based on long term work on the flora of China. The Flora Reipublicae Popularis Sinicae project was initiated in 1959 and completed by 2004. It is the largest Flora so far completed in the world, including 31 228 species of vascular plants,or one-eighth of the global plant diversity. The English-language and updated Flora of China (FOC) is an international joint effort initiated in 1988 and accelerated in 1998. Up to now, 15 of the 24 volumes of the FOC have been published. Based on the fioristic data, the composition, characteristics, floristic divisions and affinities of the flora of China have been studied by Wu and colleagues since 1965. In the past 10years, analyses of the available floristic data have been very productive.The East Asiatic Floristic Kingdom was proposed in 1998. All 346 families of angiosperms in China, according to the eightclass system of classification, were comprehensively discussed by using knowledge of current and historical distribution of seed plants in the world, together with some morphological and molecular data. A scheme of distribution patterns or areal-types of families and genera of seed plants in China was modified and elucidated, together with a proposed scheme of areal-types of the world. Molecular phylogenetic and biogeographical studies of angiosperms in China in the past 10 yearsalso witnessed a progressive development. Integration of morphological and molecular data and fossil evidence revealed some significant results. Eastern Asia, which used to be regarded as an important center of survival during the ice age, is likely an important center of diversification of angiosperms.

  12. Global Biogeography and Diversification History of Palms

    DEFF Research Database (Denmark)

    Baker, William J.; Eiserhardt, Wolf L.; Kissling, W. Daniel

    and habitat heterogeneity variables. Incorporation of phylogenetic evidence reveals strong imprints of in situ diversification in the Neotropics and on islands, of biotic interchange, and of forest loss in Africa. We inferred an origin for palms in the mid-Cretaceous of Laurasia, which is significant for our...

  13. Component-compatibility in historical biogeography

    NARCIS (Netherlands)

    Zandee, M.; Roos, M.C.

    1985-01-01

    -The problems of reconstructing historical relationships for areas of endemism from distributional data for groups of taxa and the cladistic relationships among the members of those groups can be solved by applying the two principles of parsimony and mutual inclusion or exclusion (compatibility) of

  14. Biogeography of circum-Antarctic springtails.

    Science.gov (United States)

    McGaughran, Angela; Stevens, Mark I; Holland, Barbara R

    2010-10-01

    We examine the effects of isolation over both ancient and contemporary timescales on evolutionary diversification and speciation patterns of springtail species in circum-Antarctica, with special focus on members of the genus Cryptopygus (Collembola, Isotomidae). We employ phylogenetic analysis of mitochondrial DNA (cox1), and ribosomal DNA (18S and 28S) genes in the programmes MrBayes and RAxML. Our aims are twofold: (1) we evaluate existing taxonomy in light of previous work which found dubious taxonomic classification in several taxa based on cox1 analysis; (2) we evaluate the biogeographic origin of our chosen suite of springtail species based on dispersal/vicariance scenarios, the magnitude of genetic divergence among lineages and the age and accessibility of potential habitat. The dubious taxonomic characterisation of Cryptopygus species highlighted previously is confirmed by our multi-gene phylogenetic analyses. Specifically, according to the current taxonomy, Cryptopygus antarcticus subspecies are not completely monophyletic and neither are Cryptopygus species in general. We show that distribution patterns among species/lineages are both dispersal- and vicariance-driven. Episodes of colonisation appear to have occurred frequently, the routes of which may have followed currents in the Southern Ocean. In several cases, the estimated divergence dates among species correspond well with the timing of terrestrial habitat availability. We conclude that these isotomid springtails have a varied and diverse evolutionary history in the circum-Antarctic that consists of both ancient and recent elements and is reflected in a dynamic contemporary fauna.

  15. Phylogeny and biogeography of Spathelioideae (Rutaceae)

    NARCIS (Netherlands)

    Appelhans, Marc Sebastian

    2011-01-01

    This thesis presents a detailed molecular phylogenetic and biogeographic study of the Spathelioideae clade, a group of seven small Sapindalean genera with remarkable morphological diversity. The systematic placement of these genera has always been in dispute and the results of this thesis show that

  16. Historical biogeography of the Isthmus of Panama.

    Science.gov (United States)

    Leigh, Egbert G; O'Dea, Aaron; Vermeij, Geerat J

    2014-02-01

    About 3 million years ago (Ma), the Isthmus of Panama joined the Americas, forming a land bridge over which inhabitants of each America invaded the other-the Great American Biotic Interchange. These invasions transformed land ecosystems in South and Middle America. Humans invading from Asia over 12000 years ago killed most mammals over 44 kg, again transforming tropical American ecosystems. As a sea barrier, the isthmus induced divergent environmental change off its two coasts-creating contrasting ecosystems through differential extinction and diversification. Approximately 65 Ma invading marsupials and ungulates of North American ancestry, and xenarthrans of uncertain provenance replaced nearly all South America's non-volant mammals. There is no geological evidence for a land bridge at that time. Together with rodents and primates crossing from Africa 42 to 30 Ma, South America's mammals evolved in isolation until the interchange's first heralds less than 10 Ma. Its carnivores were ineffective marsupials. Meanwhile, North America was invaded by more competitive Eurasian mammals. The Americas had comparable expanses of tropical forest 55 Ma; later, climate change confined North American tropical forest to a far smaller area. When the isthmus formed, North American carnivores replaced their marsupial counterparts. Although invaders crossed in both directions, North American mammals spread widely, diversified greatly, and steadily replaced South American open-country counterparts, unused to effective predators. Invading South American mammals were less successful. South America's birds, bats, and smaller rainforest mammals, equally isolated, mostly survived invasion. Its vegetation, enriched by many overseas invaders, remained intact. This vegetation resists herbivory effectively. When climate permitted, South America's rainforest, with its bats, birds and mammals, spread to Mexico. Present-day tropical American vegetation is largely zoned by trade-offs between exploiting well-watered settings versus surviving droughts, exploiting fertile versus coping with poor soil, and exploiting lowland warmth versus coping with cooler altitudes. At the start of the Miocene, a common marine biota extended from Trinidad to Ecuador and western Mexico, which evolved in isolation from the Indo-Pacific until the Pleistocene. The seaway between the Americas began shoaling over 12 Ma. About 10 Ma the land bridge was briefly near-complete, allowing some interchange of land mammals between the continents. By 7 Ma, the rising sill had split deeper-water populations. Sea temperature, salinity and sedimentary carbon content had begun to increase in the Southern Caribbean, but not the Pacific. By 4 Ma, the seaway's narrowing began to extinguish Caribbean upwellings. By 2 Ma, upwellings remained only along Venezuela; Caribbean plankton, suspension-feeding molluscs and their predators had declined sharply, largely replaced by bottom-dwelling corals and calcareous algae and magnificent coral reefs. Closing the seaway extinguished the Eastern Pacific's reef corals (successors recolonized from the Indo-Pacific 6000 years ago), whereas many molluscs of productive waters that once thrived in the Caribbean now survive only in the Eastern Pacific. The present-day productive Eastern Pacific, with few, small coral reefs and a plankton-based ecosystem contrasts with the Caribbean, whose clear water favours expansive coral reefs and bottom-dwelling primary producers. These ecosystems reflect the trade-off between fast growth and effective defence with attendant longevity. Overfishing with new technologies during the last few centuries, however, has caused population crashes of ever-smaller marine animals, devastating Caribbean ecosystems.

  17. Biogeography of marine podocopid ostracodes in Micronesia

    Science.gov (United States)

    Weissleader, L.S.; Gilinsky, N.L.; Ross, R.M.; Cronin, T. M.

    1989-01-01

    Bottom lagoonal sediment samples from 12 islands and atolls yielded >70 species representing >32 ostracode genera. All or most samples from a particular lagoon generally form distinct subgroups (Jaccard =0.45-0.50). At lower levels, 5 groups delineate faunal regions within Micronesia: the Gilbert Islands (Onotoa) in the SE part of the region, the N Marshall Islands (Enewetak, Rongelap, Bikini), the SE Marshall Islands (Kwajalein, Jaluit, Majuro, Arno), the Marianas and Caroline Islands (Guam, Truk, Pohnpei) and Pingelap. Pingelap, Kwajalein and Onotoa have the highest species richness (S=32-42) and Shannon-Wiener diversity values (H(S)=2.62-3.02) in the study area. Enewetak, Jaluit, Majuro and Arno show lower values (S=23-27, H(S)=2.29-2.70). Of the ostracode species living in Micronesia, 64.3% have Indo-West Pacific affinities, 7.1% are circumtropical, 5.7% have East Pacific-Caribbean affinities, 11.4% are endemic to Micronesia, and 11.4% have unknown affinities. If the SE Asian region is a primary species-source, results show that each Micronesian lagoon is equally likely to be colonized by dispersal from the source region, despite differences in distance from a hypothetical source. However, each lagoon has a distinct ostracode assemblage, probably the result of unique history of random colonization events, local extinctions and environmental disturbances. -from Authors

  18. Microbial biogeography of San Francisco Bay sediments

    Science.gov (United States)

    Lee, J. A.; Francis, C. A.

    2014-12-01

    The largest estuary on the west coast of North America, San Francisco Bay is an ecosystem of enormous biodiversity, and also enormous human impact. The benthos has experienced dredging, occupation by invasive species, and over a century of sediment input as a result of hydraulic mining. Although the Bay's great cultural and ecological importance has inspired numerous surveys of the benthic macrofauna, to date there has been almost no investigation of the microbial communities on the Bay floor. An understanding of those microbial communities would contribute significantly to our understanding of both the biogeochemical processes (which are driven by the microbiota) and the physical processes (which contribute to microbial distributions) in the Bay. Here, we present the first broad survey of bacterial and archaeal taxa in the sediments of the San Francisco Bay. We conducted 16S rRNA community sequencing of bacteria and archaea in sediment samples taken bimonthly for one year, from five sites spanning the salinity gradient between Suisun and Central Bay, in order to capture the effect of both spatial and temporal environmental variation on microbial diversity. From the same samples we also conducted deep sequencing of a nitrogen-cycling functional gene, nirS, allowing an assessment of evolutionary diversity at a much finer taxonomic scale within an important and widespread functional group of bacteria. We paired these sequencing projects with extensive geochemical metadata as well as information about macrofaunal distribution. Our data reveal a diversity of distinct biogeographical patterns among different taxa: clades ubiquitous across sites; clades that respond to measurable environmental drivers; and clades that show geographical site-specificity. These community datasets allow us to test the hypothesis that salinity is a major driver of both overall microbial community structure and community structure of the denitrifying bacteria specifically; and to assess whether patterns of diversity observed at the broadest of taxonomic scales also apply to patterns observed within a single extremely diverse gene (nirS). In sum, this project provides a first look at the forces driving the migration and selection of microbial communities in San Francisco Bay.

  19. Global biogeography and evolution of Cuvierina pteropods

    NARCIS (Netherlands)

    Burridge, A.K.; Goetze, E.; Raes, N.; Huisman, J.; Peijnenburg, K.T.C.A.

    2015-01-01

    Background: helled pteropods are planktonic gastropods that are potentially good indicators of the effects of ocean acidification. They also have high potential for the study of zooplankton evolution because they are metazoan plankton with a good fossil record. We investigated phenotypic and genetic

  20. PYCNOIB: biodiversity and biogeography of Iberian pycnogonids.

    Directory of Open Access Journals (Sweden)

    Anna Soler-Membrives

    Full Text Available Biodiversity and biogeographic studies comparing the distribution patterns of benthic marine organisms across the Iberian Atlantic and Mediterranean waters are scarce. The Pycnogonida (sea spiders are a clear example of both endemicity and diversity, and are considered a key taxon to study and monitor biogeographic and biodiversity patterns. This is the first review that compiles data about abundance and diversity of Iberian pycnogonids and examines their biogeographic patterns and bathymetric constraints using GIS tools. A total of 17,762 pycnogonid records from 343 localities were analyzed and were found to contain 65 species, 21 genera and 12 families. Achelia echinata and Ammothella longipes (family Acheliidae were the most abundant comprising ~80% of the total records. The Acheliidae is also the most speciose in Iberian waters with 15 species. In contrast, the family Nymphonidae has 7 species but is significantly less abundant (<1% of the total records than Acheliidae. Species accumulation curves indicate that further sampling would increase the number of Iberian species records. Current sampling effort suggests that the pycnogonid fauna of the Mediterranean region may be richer than that of the Atlantic. The Strait of Gibraltar and the Alboran Sea are recognized as species-rich areas that act as buffer zones between the Atlantic and Mediterranean boundaries. The deep waters surrounding the Iberian Peninsula are poorly surveyed, with only 15% of the sampling sites located below 1000 m. Further deep-water sampling is needed mainly on the Iberian Mediterranean side.

  1. Modelling chestnut biogeography for American chestnut restoration

    DEFF Research Database (Denmark)

    Fei, Songlin; Liang, Liang; Paillet, Frederick L.

    2012-01-01

    Aim Chestnuts (Castanea spp.) are ecologically and economically important species. We studied the general biology, distribution and climatic limits of seven chestnut species from around the world. We provided climatic matching of Asiatic species to North America to assist the range-wide restoration...... of American chestnut [C. dentata (Marsh.) Borkh.] by incorporating blight-resistant genes from Asiatic species. Location North America, Europe and East Asia. Methods General chestnut biology was reviewed on the basis of published literature and field observations. Chestnut distributions were established using...... Maxent modelling to predict corresponding suitable climate zones for those species in North America. Results Chestnuts are primarily distributed in the warm-temperate and subtropical zones in the northern hemisphere. PCA results revealed that thermal gradient was the primary control of chestnut...

  2. Historical biogeography of the isthmus of panama

    OpenAIRE

    2014-01-01

    About 3million years ago (Ma), the Isthmus of Panama joined the Americas, forming a land bridge over which inhabitants of each America invaded the other-the Great American Biotic Interchange. These invasions transformed land ecosystems in South and Middle America. Humans invading from Asia over 12000years ago killed most mammals over 44kg, again transforming tropical American ecosystems. As a sea barrier, the isthmus induced divergent environmental change off its two coasts-creating contrasti...

  3. Atlantic reef fish biogeography and evolution

    Science.gov (United States)

    Floeter, S.R.; Rocha, L.A.; Robertson, D.R.; Joyeux, J.C.; Smith-Vaniz, W.F.; Wirtz, P.; Edwards, A.J.; Barreiros, J.P.; Ferreira, C.E.L.; Gasparini, J.L.; Brito, A.; Falcon, J.M.; Bowen, B.W.; Bernardi, G.

    2008-01-01

    Aim: To understand why and when areas of endemism (provinces) of the tropical Atlantic Ocean were formed, how they relate to each other, and what processes have contributed to faunal enrichment. Location: Atlantic Ocean. Methods: The distributions of 2605 species of reef fishes were compiled for 25 areas of the Atlantic and southern Africa. Maximum-parsimony and distance analyses were employed to investigate biogeographical relationships among those areas. A collection of 26 phylogenies of various Atlantic reef fish taxa was used to assess patterns of origin and diversification relative to evolutionary scenarios based on spatio-temporal sequences of species splitting produced by geological and palaeoceanographic events. We present data on faunal (species and genera) richness, endemism patterns, diversity buildup (i.e. speciation processes), and evaluate the operation of the main biogeographical barriers and/or filters. Results: Phylogenetic (proportion of sister species) and distributional (number of shared species) patterns are generally concordant with recognized biogeographical provinces in the Atlantic. The highly uneven distribution of species in certain genera appears to be related to their origin, with highest species richness in areas with the greatest phylogenetic depth. Diversity buildup in Atlantic reef fishes involved (1) diversification within each province, (2) isolation as a result of biogeographical barriers, and (3) stochastic accretion by means of dispersal between provinces. The timing of divergence events is not concordant among taxonomic groups. The three soft (non-terrestrial) inter-regional barriers (mid-Atlantic, Amazon, and Benguela) clearly act as 'filters' by restricting dispersal but at the same time allowing occasional crossings that apparently lead to the establishment of new populations and species. Fluctuations in the effectiveness of the filters, combined with ecological differences among provinces, apparently provide a mechanism for much of the recent diversification of reef fishes in the Atlantic. Main conclusions: Our data set indicates that both historical events (e.g. Tethys closure) and relatively recent dispersal (with or without further speciation) have had a strong influence on Atlantic tropical marine biodiversity and have contributed to the biogeographical patterns we observe today; however, examples of the latter process outnumber those of the former. ?? 2007 The Authors.

  4. Floristics and plant biogeography in China.

    Science.gov (United States)

    Li, De-Zhu

    2008-07-01

    In 1998, a revolutionary system of angiosperm classification, the Angiosperm Phylogeny Group system was published. Meanwhile, another new system of classification of angiosperms, the eight-class system was proposed by C. Y. Wu and colleagues based on long term work on the flora of China. The Flora Reipublicae Popularis Sinicae project was initiated in 1959 and completed by 2004. It is the largest Flora so far completed in the world, including 31 228 species of vascular plants, or one-eighth of the global plant diversity. The English-language and updated Flora of China (FOC) is an international joint effort initiated in 1988 and accelerated in 1998. Up to now, 15 of the 24 volumes of the FOC have been published. Based on the floristic data, the composition, characteristics, floristic divisions and affinities of the flora of China have been studied by Wu and colleagues since 1965. In the past 10 years, analyses of the available floristic data have been very productive. The East Asiatic Floristic Kingdom was proposed in 1998. All 346 families of angiosperms in China, according to the eight-class system of classification, were comprehensively discussed by using knowledge of current and historical distribution of seed plants in the world, together with some morphological and molecular data. A scheme of distribution patterns or areal-types of families and genera of seed plants in China was modified and elucidated, together with a proposed scheme of areal-types of the world. Molecular phylogenetic and biogeographical studies of angiosperms in China in the past 10 years also witnessed a progressive development. Integration of morphological and molecular data and fossil evidence revealed some significant results. Eastern Asia, which used to be regarded as an important center of survival during the ice age, is likely an important center of diversification of angiosperms.

  5. 中国松材线虫的生物地理学与经济地理学%The biogeography and economic geography of the pine wood nematode in China

    Institute of Scientific and Technical Information of China (English)

    王宏毅

    2011-01-01

    继1982年在江苏省发现松材线虫后,中国大陆、台湾及香港12个省的113个城市中相继发现松材线虫,松材线虫对于林业的危害已迫在眉睫.从松材线虫侵入中国以来的历史分析,它主要发生在中国海拔1000 m以下的地区,而且在低海拔地区危害严重.危害最为严重的是长江中下游地区、珠江三角洲,并且在前一地区较后者更为严重;危害中等严重的地区包括长江中游、珠江中游及中国中部高海拔及丘陵地区;在海拔大约1000 m的地方,如云贵高原,松材线虫仅为局部发生,且危害较轻.松材线虫在中国主要发生在沿江河流域特别是长江流域,说明了其在中国扩散的另一生物地理学特征是从东到西及从沿海到内陆的扩散.与其他强势入侵物种相似,松材线虫的扩散是与人类活动密切相关的.20世纪80年代开始中国经济对外开放,松材线虫开始入侵,而且入侵地点发生在中国经济对外开放的前沿.松材线虫沿着长江流域扩散也与长江流域是中国经济大动脉,同时中国经济也是从沿海到内地的发展相关.因此,中国的地理地形特征、中国经济发展的地域情况及二者的互动决定了松材线虫在中国的发生、发展及扩散情况.%Following its discovery in Jiangsu Province in 1982 the pine wood nematode (PWN) has been found in 113 counties (or cities) in twelve provinces in mainland China, in addition in Taiwan and Hong Kong. As such China has been confronted with an enormous threat to its pine forests. The work reported here retraces the historical progress of the nematode's occurrence and the associated pine wilt epidemic in China based on the principles of biogeography and economic geography. The elevation-distribution areas for the PWN in China mostly occur below 1 000 m altitude and damage is most severe in the low altitude regions. That is the same situation as has occurred in Japan and other countries and it

  6. Biogeography of the leafhopper subfamily Stegelytrinae (Hemiptera: Cicadellidae), based on a cluster analysis of geographical distribution in areas of endemism combined with phylogeny of the subfamily%世界秀头叶蝉亚科生物地理学

    Institute of Scientific and Technical Information of China (English)

    魏琮; 程若琳; 张雅林

    2012-01-01

    Biogeography of the leafhopper subfamily Stegelytrinae Baker is studied based on an analysis of geographical distribution of this subfamily worldwide using a cluster analysis of the zoological distribution of areas of endemism as well as the phylogeny of representatives of this subfamily.Results show that the Stegelytrinae mainly occur in the Oriental Region and in the Mediterranean area of the Palaearctic Region,and this extends to the east side of both Wallace's and Weber's lines.Eleven areas of endemism of this subfamily are recognized.The proportions of endemic taxa in different areas of endemism are generally very high in comparison with other leafhopper groups,but distinct differences could be found among the different areas of endemism of Stegelytrinae.This subfamily is most intensively diversified in the Indochina Peninsula (INCN).This is the stegelytrine distribution center,having the highest biodiversity at both generic and species levels.The dendrogram of endemic areas of Stegelytrinae constructed using cluster analysis of the zoological distribution of Stegelytrinae at generic level shows the endemic areas of Stegelytrinae can be divided into 4 large groups.Relationships among different endemic areas of Stegelytrinae correspond largely to the geologic history of related areas,which indicates that the evolution and vicariance of this subfamily have been closely related to the history of continental drift and climate changes.It is deduced that the presumed monophyletic Stegelytrinae originated in the Oriental Region after North America had separated from Eurasia; this is the case in the monophyletic genera group which is supported by the lateral frontal sutures extending dorsally well beyond the corresponding ocellus.In addition,two expanding traces of the Stegelytrinae are presumed,which remain plausible explanations for the dispersal of Stegelytrinae:(1) New Guinea (and probably (+ Australia)) -Kalimantan-Sumatra-Malay Peninsula-Indochina Peninsula

  7. 亚洲早古近纪哺乳动物生物年代学与生物地理学的新认识%AN UPDATED MAMMALIAN BIOCHRONOLOGY AND BIOGEOGRAPHY FOR THE EARLY PALEOGENE OF ASIA

    Institute of Scientific and Technical Information of China (English)

    Pieter MISSIAEN

    2011-01-01

    近期的研究极大地丰富了亚洲古新世和早始新世哺乳动物群信息,因此有必要对现存亚洲生物年代学和生物地理学框架做出调整.在定量和定性分析的基础上,将生物年代界线与主要的动物群更替事件对应起来,改进了古新世和早始新世亚洲陆相哺乳动物分期年代对比及生物地理学的认识.以往知之甚少的上湖期以原始啮形类和钝脚类为主,其后的浓山期则呈现出亚洲哺乳动物的地方性分异.随着新的基干啮形类以及真正的啮型类的出现,啮形类开始辐射.上湖期一浓山期的界线与北美Torrejonian-Tiffanian界线相当,并且动物群更替很可能是由全球变冷阶段的开始引发的.格沙头期哺乳动物进一步分化,亚洲土著类群急剧减少,以多瘤齿兽类、夜鼩类(nyctitheriids)、克莫土兽类(cimolestids)和食果猴为代表的北美迁入物种开始出现.而在北美,亚洲哺乳动物(包括北柱兽类和原恐角兽类)的第一次入侵发生于Tiffanian-5a期初期,第二次入侵发生于Clarkforkian初期,包含了啮齿类、裂齿类及冠齿兽类.因此格沙头期的开始可与北美Tiffanian-5a的开始相对比.伯姆巴期的开始以偶蹄类、奇蹄类和真灵长类的首次出现为标志,与古新世一始新世界线相当.这些类群在亚洲的出现与它们在北美和欧洲出现于始新世之初的情况类似.与格沙头期初期的动物群扩散不同,伯姆巴期的动物群扩散似乎持续了更长时间,并且也有可能直接发生在亚洲和欧洲之间.%Recent research has greatly increased the information available on Asian Paleocene and early Eocene mammal faunas, creating the need to update the existing Asian biochronological and biogeographical framework. Based on a quantitative and qualitative analysis, biochronological boundaries are refined to correspond to major faunal turnovers, and an improved age correlation and biogeography of the

  8. Revisão sistemática, análise cladística e biogeografia dos gêneros Tribotropis e Hypselotropis (Coleoptera, Anthribidae, Anthribinae, Ptychoderini Systematic revision, cladistic analysis and biogeography of the genera Tribotropis and Hypselotropis (Coleoptera, Anthribidae, Anthribinae, Ptychoderini

    Directory of Open Access Journals (Sweden)

    José Ricardo M. Mermudes

    2005-12-01

    comb. nov.; e H. vittata (Kirsch, 1889 comb. nov.. A key to species, illustrations and maps of distribution are provided. The biogeography based on patterns of distribution of the species are discussed.

  9. The paleobotanical record of Colombia: Implications for biogeography and biodiversity

    NARCIS (Netherlands)

    Hooghiemstra, H.; Wijninga, V.M.; Cleef, A.M.

    2006-01-01

    Plant microfossil and macrofossil associations obtained from six dated sections from the area of the basin of Bogota¿ (2550 m, Eastern Cordillera, Colombia) show the evolution of the late Neogene Andean montane forest, triggered by the Andean orogeny. Progressive adaptation of warm tropical taxa to

  10. Systematics and biogeography of the jellyfish Aurelia labiata (Cnidaria: Scyphozoa).

    Science.gov (United States)

    Gershwin, L A

    2001-08-01

    The hypothesis that the common eastern North Pacific Aurelia is A. aurita is falsified with morphological analysis. The name Aurelia labiata is resurrected, and the species is redescribed, to refer to medusae differing from A. aurita by a suite of characters related to a broad and elongated manubrium. Specifically, the oral arms are short, separated by and arising from the base of the fleshy manubrium, and the planulae are brooded upon the manubrium itself, rather than on the oral arms. Aurelia aurita possesses no corresponding enlarged structure. Furthermore, the number of radial canals is typically much greater in A. labiata, and thus the canals often appear more anastomosed than in A. aurita. Finally, most A. labiata medusae possess a 16-scalloped bell margin, whereas the margin is 8-scalloped in most A. aurita. Separation of the two forms has previously been noted on the basis of allozyme and isozyme analyses and on the histology of the neuromuscular system. Partial 18S rDNA sequencing corroborates these findings. Three distinct morphotypes of A. labiata, corresponding to separate marine bioprovinces, have been identified among 17 populations from San Diego, California, to Prince William Sound, Alaska. The long-undisputed species A. limbata may be simply a color morph of A. labiata, or a species within a yet-unelaborated A. labiata species complex. The first known introduction of Aurelia cf. aurita into southern California waters is documented. Although traditional jellyfish taxonomy tends to recognize many species as cosmopolitan or nearly so, these results indicate that coastal species, such as A. labiata, may experience rapid divergence among isolated populations, and that the taxonomy of such species should therefore be scrutinized with special care.

  11. Biogeography of Sinorhizobium meliloti nodulating alfalfa in different Croatian regions.

    Science.gov (United States)

    Donnarumma, Francesca; Bazzicalupo, Marco; Blažinkov, Mihaela; Mengoni, Alessio; Sikora, Sanjia; Babić, Katarina Huić

    2014-09-01

    Sinorhizobium meliloti is a nitrogen-fixing rhizobium symbiont of legumes, widespread in many temperate environments the high genetic diversity of which enables it to thrive as a symbiont of host legumes and free-living in soil. Soil type, together with geographic differences and host plant genotype, seem to be prominent factors in shaping rhizobial genetic diversity. While a large body of research supports the idea that the genetic structure of free-living microbial taxa exhibits a clear biogeographic pattern, few investigations have been performed on the biogeographic pattern of S. meliloti genotypes in a restricted geographic range. In the present study, a collection of 128 S. meliloti isolates from three different regions in Croatia was investigated to analyze the relationship between genetic diversity, geographic distribution, soil features and isolate phenotypes by using amplified fragment length polymorphism (AFLP) as a genome-wide scanning method. Results obtained led to the conclusion that the genotypes of isolates cluster according to the region of origin and that the differentiation of S. meliloti populations can be mainly ascribed to geographic isolation following an isolation-by-distance model, with a strong distance-decay relationship of genetic similarity with distance, in which local soil conditions are not the major component influencing the isolate phenotypes or their genomic differentiation.

  12. Lepidopetalum Blume (Sapindaceae): taxonomy, phylogeny, and historical biogeography

    NARCIS (Netherlands)

    Welzen, van P.C.; Piskaut, P.; Windadri, F.I.

    1922-01-01

    The genus Lepidopetalum Blume (Sapindaceae) contains 6 species, of which one, L. fructoglabrum, is newly described. Four species are found on New Guinea of which one also occurs in Australia, one on the Nicobar Islands and Sumatra and one on the Philippines. Specimens from Java, Sulawesi, the Molucc

  13. Late Quaternary environments and biogeography in the Great Basin

    Science.gov (United States)

    Thompson, R. S.; Mead, J. I.

    1982-01-01

    Plant and animal remains found in packrat ( Neotoma spp.) middens and cave fill from the eastern and southern Great Basin region reveal the presence of subalpine conifers and boreal mammals at relatively low elevations during the Late Wisconsin. Limber pine ( Pinus flexilis) and bristlecone pine ( P. longaeva) were important in the late Pleistocene plant communities throughout this region. Spruce ( Picea cf. engelmannii) and common juniper ( Juniperus communis) were present in some of the more northerly localities, and Douglas fir ( Pseudotsuga menziesii) and white fir ( Abies concolor) were present in southern and eastern localities. Single needle pinyon pine ( Pinus monophylla), common across this region today, was apparently not present north of the Sheep Range of southern Nevada during the Late Wisconsin. Pikas ( Ochotona cf. princeps), small boreal mammals present in only a few Great Basin mountain ranges today, were common throughout the region. Heather voles ( Phenacomys cf. intermedius) have been found in two cave fill deposits in Nevada, though they are unknown in the Great Basin today. Limber and bristlecone pines are generally restricted to rocky substrates in modern subalpine habitats in the Great Basin, and this may also have been the case when these plants grew at lower elevations during the Late Wisconsin. Subalpine conifers were present on the rock outcrops sampled by the packrat middens, but shrub communities, perhaps dominated by sagebrush ( Artemisia spp.), may have been present on alluvial valley-bottom substrates. Forested habitats would thus have been isolated habitat islands, as they are today. Boreal small mammals, including pikas and heather voles, were able to colonize the Great Basin mountain ranges during the late Pleistocene. We suggest that these mammals were able to survive in the intervening valley-bottoms under a cool-summer climatic regime, and that continuous forest or woodland corridors were not necessary for migration.

  14. Fungal biogeography. Global diversity and geography of soil fungi.

    Science.gov (United States)

    Tedersoo, Leho; Bahram, Mohammad; Põlme, Sergei; Kõljalg, Urmas; Yorou, Nourou S; Wijesundera, Ravi; Villarreal Ruiz, Luis; Vasco-Palacios, Aída M; Thu, Pham Quang; Suija, Ave; Smith, Matthew E; Sharp, Cathy; Saluveer, Erki; Saitta, Alessandro; Rosas, Miguel; Riit, Taavi; Ratkowsky, David; Pritsch, Karin; Põldmaa, Kadri; Piepenbring, Meike; Phosri, Cherdchai; Peterson, Marko; Parts, Kaarin; Pärtel, Kadri; Otsing, Eveli; Nouhra, Eduardo; Njouonkou, André L; Nilsson, R Henrik; Morgado, Luis N; Mayor, Jordan; May, Tom W; Majuakim, Luiza; Lodge, D Jean; Lee, Su See; Larsson, Karl-Henrik; Kohout, Petr; Hosaka, Kentaro; Hiiesalu, Indrek; Henkel, Terry W; Harend, Helery; Guo, Liang-dong; Greslebin, Alina; Grelet, Gwen; Geml, Jozsef; Gates, Genevieve; Dunstan, William; Dunk, Chris; Drenkhan, Rein; Dearnaley, John; De Kesel, André; Dang, Tan; Chen, Xin; Buegger, Franz; Brearley, Francis Q; Bonito, Gregory; Anslan, Sten; Abell, Sandra; Abarenkov, Kessy

    2014-11-28

    Fungi play major roles in ecosystem processes, but the determinants of fungal diversity and biogeographic patterns remain poorly understood. Using DNA metabarcoding data from hundreds of globally distributed soil samples, we demonstrate that fungal richness is decoupled from plant diversity. The plant-to-fungus richness ratio declines exponentially toward the poles. Climatic factors, followed by edaphic and spatial variables, constitute the best predictors of fungal richness and community composition at the global scale. Fungi show similar latitudinal diversity gradients to other organisms, with several notable exceptions. These findings advance our understanding of global fungal diversity patterns and permit integration of fungi into a general macroecological framework.

  15. On the morphology, biometry and biogeography of Lamtopyxiscallistoma (Amoebozoa: Arcellinida).

    Science.gov (United States)

    Todorov, Milcho

    2015-01-01

    The ultra-structure of the shell and the morphometric variability of soil inhabiting testate amoeba Lamtopyxiscallistoma from Madagascar were studied by using light- and scanning electron microscopy. The biometrical characteristic of the species was made on the basis of 75 specimens measured. In addition to the diameter of the shell, six other shell characters were described biometrically for the first time. The analysis of the variation coefficients shows that the studied population of L.callistoma is comparatively homogeneous and almost all measured characters are weakly to moderate variable (CV less than 10%). Scanning electron microscopy (SEM) studies on the shell ultra-morphology show that it has a smooth apertural surface with a thick layer of porous and fibrous organic cement and a rough dorsal surface composed of bigger and angular pieces of quartz. The shell wall has a thickness of about 5-6 µm and is composed of three layers. Unlike the previously accepted opinion that species is characterized by the presence of four teeth, this study shows that population of L.callistoma from Madagascar is comprised of both, specimens with four teeth and specimens with three teeth, in ratio of about 60% to 40%. Taking into account the restricted geographical distribution, large sizes and characteristic apertural morphology of L.callistoma it is assumed that this species, like some bryophilic 'Nebelas' with circumaustral distribution (e.g. Apoderavas, Alocoderacockayni, Certesellacertesi, Certesellamartiali, etc.), can be used as an example that in free-living microbial eukaryotes 'not everything is everywhere'.

  16. Mitogenomic phylogeny, diversification, and biogeography of South American spiny rats

    DEFF Research Database (Denmark)

    Fabre, Pierre-Henri; Upham, Nathan S.; Emmons, Louise H.

    2017-01-01

    Echimyidae is one of the most speciose and ecologically diverse rodent families in the world, occupying a wide range of habitats in the Neotropics. However, a resolved phylogeny at the genus-level is still lacking for these 22 genera of South American spiny rats, including the coypu (Myocastorinae...

  17. Rethinking dog domestication by integrating genetics, archeology, and biogeography.

    Science.gov (United States)

    Larson, Greger; Karlsson, Elinor K; Perri, Angela; Webster, Matthew T; Ho, Simon Y W; Peters, Joris; Stahl, Peter W; Piper, Philip J; Lingaas, Frode; Fredholm, Merete; Comstock, Kenine E; Modiano, Jaime F; Schelling, Claude; Agoulnik, Alexander I; Leegwater, Peter A; Dobney, Keith; Vigne, Jean-Denis; Vilà, Carles; Andersson, Leif; Lindblad-Toh, Kerstin

    2012-06-05

    The dog was the first domesticated animal but it remains uncertain when the domestication process began and whether it occurred just once or multiple times across the Northern Hemisphere. To ascertain the value of modern genetic data to elucidate the origins of dog domestication, we analyzed 49,024 autosomal SNPs in 1,375 dogs (representing 35 breeds) and 19 wolves. After combining our data with previously published data, we contrasted the genetic signatures of 121 breeds with a worldwide archeological assessment of the earliest dog remains. Correlating the earliest archeological dogs with the geographic locations of 14 so-called "ancient" breeds (defined by their genetic differentiation) resulted in a counterintuitive pattern. First, none of the ancient breeds derive from regions where the oldest archeological remains have been found. Second, three of the ancient breeds (Basenjis, Dingoes, and New Guinea Singing Dogs) come from regions outside the natural range of Canis lupus (the dog's wild ancestor) and where dogs were introduced more than 10,000 y after domestication. These results demonstrate that the unifying characteristic among all genetically distinct so-called ancient breeds is a lack of recent admixture with other breeds likely facilitated by geographic and cultural isolation. Furthermore, these genetically distinct ancient breeds only appear so because of their relative isolation, suggesting that studies of modern breeds have yet to shed light on dog origins. We conclude by assessing the limitations of past studies and how next-generation sequencing of modern and ancient individuals may unravel the history of dog domestication.

  18. Phylogeny and biogeography of Tynanthus Miers (Bignonieae, Bignoniaceae).

    Science.gov (United States)

    M P de Medeiros, Maria Cláudia; Lohmann, Lúcia G

    2015-04-01

    The origin of Neotropical biodiversity represents a key question in evolutionary biology. Despite the attempts to decipher the role of ecological and historical factors to present-day distribution patterns, robust phylogenetic studies of Neotropical clades are still needed before a comprehensive picture of the origin of Neotropical biodiversity can be achieved. Tynanthus Miers (Bignonieae, Bignoniaceae) is a well-circumscribed genus of Neotropical lianas with species that are narrowly distributed, except from a few taxa. The genus is characterized by a clove odor, small bilabiate flowers with the two upper lobes almost fused, and fruits with raised margins, all of which represent morphological synapomorphies for this clade. Other distinctive characters are the thecae reflexed forward, the densely pubescent ovaries and the poorly-developed nectariferous disk. The circumscription of the genus has remained constant over the years, despite the problematic limits of most genera of tribe Bignonieae. In this study, we reconstruct the phylogeny of Tynanthus based on two plastid (ndhF and rpl32-trnL) and one nuclear (pepC) markers and use this phylogenetic framework to investigate the biogeographical history of the genus. Our phylogenetic hypothesis provides further support for the monophyly of Tynanthus, and strongly supports a series of infra-generic clades. Most species are reconstructed as monophyletic, while T. cognatus and T. polyanthus are paraphyletic. Biogeographic reconstructions suggest that Tynanthus originated between 9.4 and 21.5Mya, most likely at approximately 15.3Mya. The MRCA of the genus was likely broadly distributed through lowland Amazonia, Western South America and Central America and diversified in the Neotropics during the Miocene. Closely related species are generally distributed within the same biogeographic area, suggesting that niche conservatism has played an important role in the diversification history of the group.

  19. Coastal Staphylinidae (Coleoptera: A worldwide checklist, biogeography and natural history

    Directory of Open Access Journals (Sweden)

    Kee-Jeong Ahn

    2011-06-01

    Full Text Available We provide a list of the 392 described species of Staphylinidae confined to coastal habitats worldwide. The list is in taxonomic sequence by subfamily, tribe, and genus and includes 91 genera. We provide the page reference of the original description of every species and genus listed and of many synonyms. We note the existence of recent reviews, phylogenies and keys of each of the tribes and genera included. Coastal Staphylinidae contain eight subfamilies: Microsilphinae, Omaliinae, Pselaphinae, Aleocharinae, Oxytelinae, Scydmaeninae, Paederinae, and Staphylininae. By ‘coastal habitats’ we mean habitats existing on the sea coast and subject to inundation or at least splashing by the very highest tides. This includes rocky, boulder, coral, sandy, and muddy seashores, and at least portions of salt-marshes, estuaries, and mangrove swamps. We exclude the sand dune habitat and higher parts of sea-cliffs. The list notes distribution of all the species, first according to the ocean or sea on whose shores it has been recorded, and second by country (and for the larger countries by province or state. Although this distribution is undoubtedly incomplete, it provides a basis for future development of a dedicated database. The ‘Habitats, Habits, and Classificatory Notes’ section is designed to provide ecologists with further taxonomic and ecological information. It includes references to descriptions of the immature stages, behavior of adults and immatures, their food, natural enemies, and habitat. We would have preferred to separate these entities, but current knowledge of ecology is developed in few instances beyond natural history. The Pacific Ocean basin was the origin and contributed to the dispersal of the majority of specialist coastal Staphylinidae at the level of genus. However, at the level of species, species belonging to non-coastal-specialist genera are about as likely to occur on the shores of other oceans as on the shores of the Pacific. This difference is a reflection of the antiquity of coastal genera and species. A complete bibliography, and habitat and habitus photographs of some representative coastal Staphylinidae species are provided.  

  20. Analyses towards determining Madagascar’s place in global biogeography

    Directory of Open Access Journals (Sweden)

    Şerban PROCHEŞ, Syd RAMDHANI

    2012-06-01

    Full Text Available The relationships of Madagascan plant and animal taxa have been the object of much fascination, Madagascar sharing numerous lineages with Africa, others with Asia, Australia, or the Americas, and many others being of uncertain relationships. In commonly accepted global regionalization schemata, Madagascar is treated together with Africa for animals, and with Africa, tropical Asia and the Pacific islands in the case of plants. Here we examine the similarities between the biotic assemblages of (i tropical Africa, (ii Madagascar, and (iii the rest of the world, on a basic taxonomic level, considering the families of vascular plants and vertebrates as analysis units. The percentages of endemic families, families shared pair-wise between regions, or present in all three, are roughly similar between the two broad groups, though plant families with ranges limited to one region are proportionally fewer. In dendrograms and multidimensional scaling plots for different groups, Madagascar clusters together with Africa, Asia or both, and sometimes with smaller Indian Ocean Islands, but quite often (though not in plants as a convincingly separate cluster. Our results for vertebrates justify the status of full zoogeographic region for Madagascar, though an equally high rank in geobotanical regionalization would mean also treating Africa and Tropical Asia as separate units, which would be debata­ble given the overall greater uniformity of plant assemblages. Beyond the Madagascan focus of this paper, the differences between plant and vertebrate clusters shown here suggest different levels of ecological plasticity at the same taxonomic level, with plant families being much more environmentally-bound, and thus clustering along biome lines rather than regional lines [Current Zoology 58 (3: 363-374, 2012].

  1. Quaternary biogeography of the Mustelidae family on the Mediterranean islands

    Directory of Open Access Journals (Sweden)

    Marco Masseti

    1995-12-01

    Full Text Available Abstract Five taxa of the Mustelidae family now occur on the Mediterranean islands: the pine marten, Martes martes L., 1758, distributed on some of the Balearic and Tyrrhenian islands, the stone marten, M. foina Erxleben, 1777, which occurs on many islands of the basin, the badger, Meles meles Brisson, 1762, that has been only reported from some Greek islands, the weasel, Musteln nivalis L., 1766, common to many of the islands, and the otter, Lutra lutra L., 1758, recorded from the Greek islands. During Late Pleistocene times, only few carnivores seem to have occurred, however, on these islands and none is referable to the species that are present today. Paleontological evidence attests only to the occurrence of endemic elements, most of which were related to the Lutrinae subfamily. Apart from L. lutra, the absence during Late Pleistocene and Early Holocene of the continental species present today suggests that these carnivores are allochthonous. They were imported by man, for various purposes, probably since prehistorical and/or early historical times. Riassunto Biogeografia quaternaria della famiglia Mustelidae nelle isole del Mediterraneo - La distribuzione attuale dei rappresentanti della famiglia Mustelidae nelle isole mediterranee interessa esclusivamente cinque specie: la martora, Martes martes L., 1758, presente su alcune isole baleariche e tirreniche, la faina, M. foina Erxleben, 1777, diffusa in varie isole del Mediterraneo, il tasso, Meles meles Brisson, 1762, che viene solo segnalato per alcune isole greche, la donnola, Mustela nivalis L., 1766, che interessa molte isole del bacino e la lontra, Lutra lutra L., 1758, nota solamente per alcune isole greche. Nel corso del Pleistocene altre forme di mustelidi hanno comunque interessato queste isole e nessuna di esse può essere riferita tassonomicamente a quelle oggi presenti. Il Quaternario delle isole mediterranee è infatti esclusivamente caratterizzato dalla presenza di mustelidi endemici, appartenenti per la maggior parte alla sottofamiglia Lutrinae. Fatta eccezione per L. lutra, l'assenza durante il tardo Pleistocene e l'Olocene antico dei mustelidi continentali, oggi presenti sulle isole, suggerisce un'origine antropocora della loro diffusione. Essi devono essere stati infatti introdotti dall'uomo, per ragioni diverse, fino dalle epoche preistoriche e/o protostoriche.

  2. [Zooplankton of the Costa Rica Dome: taxonomy and biogeography].

    Science.gov (United States)

    Vicencio Aguilar, M E; Fernández Alamo, M A

    1996-08-01

    A list of the species and taxa of some pelagic animals from a tropical upwelling region, based on collections made off the coast of Costa Rica is presented. The list includes a total of 224 species, 53 genera and 11 subspecific forms in Cnidaria, Annelida, Mollusca, Artropoda (Crustacea), Chaetognatha and Pisces.

  3. Lessons in Biogeography: Simulating Evolution Using Playing Cards.

    Science.gov (United States)

    Knapp, Paul A.; Thompson, James M.

    1994-01-01

    States that teaching the concepts of evolution to secondary school and college students is difficult. Presents a playing card game-based simulation that teaches the complex idea of natural selection in a simple, nonthreatening way. Includes three figures, one table, and step-by-step instructional procedures. (CFR)

  4. The last diadectomorph sheds light on Late Palaeozoic tetrapod biogeography.

    Science.gov (United States)

    Liu, Jun; Bever, G S

    2015-05-01

    Diadectomorpha is a clade of Late Palaeozoic vertebrates widely recognized as the sister group of crown-group Amniota and the first tetrapod lineage to evolve high-fibre herbivory. Despite their evolutionary importance, diadectomorphs are restricted stratigraphically and geographically, with all records being from the Upper Carboniferous and Lower Permian of North America and Germany. We describe a new diadectomorph, Alveusdectes fenestralis, based on a partial skull from the Upper Permian of China. The new species exhibits the derived mechanism for herbivory and is recovered phylogenetically as a deeply nested diadectid. Approximately 16 Myr younger than any other diadectomorph, Alveusdectes is the product of at least a 46 Myr ghost lineage. How much of this time was probably spent in Russia and/or central Asia will remain unclear until a specimen is described that subdivides this cryptic history, but the lineage assuredly crossed this region before entering the relatively isolated continent of North China. The discovery of Alveusdectes raises important questions regarding diadectomorph extinction dynamics including what, if any, ecological factors limited the diversity of this group in eastern Pangea. It also suggests that increased sampling in Asia will likely significantly affect our views of clade and faunal insularity leading up to the Permo-Triassic extinction.

  5. TEMPERATURE REQUIREMENTS AND BIOGEOGRAPHY OF ANTARCTIC, ARCTIC AND AMPHIEQUATORIAL SEAWEEDS

    NARCIS (Netherlands)

    WIENCKE, C; BARTSCH, [No Value; BISCHOFF, B; PETERS, AF; BREEMAN, AM

    1994-01-01

    The temperature requirements for growth and survival of cold water seaweeds from both Hemispheres are compared and discussed in relation to the climatic history of the various regions and in relation to the origin of amphiequatorial distribution patterns. Endemic Antarctic species are most strongly

  6. Global diversity and biogeography of deep-sea pelagic prokaryotes

    Science.gov (United States)

    Salazar, Guillem; Cornejo-Castillo, Francisco M; Benítez-Barrios, Verónica; Fraile-Nuez, Eugenio; Álvarez-Salgado, X Antón; Duarte, Carlos M; Gasol, Josep M; Acinas, Silvia G

    2016-01-01

    The deep-sea is the largest biome of the biosphere, and contains more than half of the whole ocean's microbes. Uncovering their general patterns of diversity and community structure at a global scale remains a great challenge, as only fragmentary information of deep-sea microbial diversity exists based on regional-scale studies. Here we report the first globally comprehensive survey of the prokaryotic communities inhabiting the bathypelagic ocean using high-throughput sequencing of the 16S rRNA gene. This work identifies the dominant prokaryotes in the pelagic deep ocean and reveals that 50% of the operational taxonomic units (OTUs) belong to previously unknown prokaryotic taxa, most of which are rare and appear in just a few samples. We show that whereas the local richness of communities is comparable to that observed in previous regional studies, the global pool of prokaryotic taxa detected is modest (~3600 OTUs), as a high proportion of OTUs are shared among samples. The water masses appear to act as clear drivers of the geographical distribution of both particle-attached and free-living prokaryotes. In addition, we show that the deep-oceanic basins in which the bathypelagic realm is divided contain different particle-attached (but not free-living) microbial communities. The combination of the aging of the water masses and a lack of complete dispersal are identified as the main drivers for this biogeographical pattern. All together, we identify the potential of the deep ocean as a reservoir of still unknown biological diversity with a higher degree of spatial complexity than hitherto considered. PMID:26251871

  7. Biogeography of Radiolaria Polycystina (Protista) in the World Ocean

    Science.gov (United States)

    Boltovskoy, Demetrio; Correa, Nancy

    2016-12-01

    Analysis of 307 species of Radiolaria Polycystina in a worldwide dataset of 4774 plankton, sediment trap, and surface sediment samples allows recognizing six major biogeographic Domains. Five of them are circumglobal (Polar North, Polar South, Bi-Subpolar, Transitional and Tropical-Subtropical), and one is restricted to the Eastern Equatorial Pacific. Each Domain is characterized by a particular suite of species, all of which, however, occur widely, albeit sparsely, in one or more other Domains. Of the eight environmental variables evaluated, temperature correlates best with the partitions established. Species distributions in the water column and in the sediments are generally in agreement, but in the sediments cold water forms extend farther towards the equator than do warm water radiolarians towards the poles. In the Recent sedimentary record of planktonic Foraminifera the same phenomenon is magnified by the higher dissolution rates of warm water species, as compared with the cold water ones. Of the three major oceans, the Pacific was the most speciose, but estimates based on data corrected for sample-size show much smaller inter-oceanic differences, with ∼10 radiolarians probably being absent from either basin. The radiolarian biogeographic pattern is generally similar to those based on other planktonic and nektonic open-ocean organisms, but the degree of uniqueness of the Domains, as well as the position of the intervening boundaries, are variable, which reflects methodological differences, as well as taxon-specific traits. Partitions of the World Ocean defined on the basis of species ranges resemble the major divisions (presumably functionally homogeneous units) established on the basis of physical traits and chlorophyll fields, but secondary divisions nested within the latter are not reflected by any of the biogeographic schemes based on species distribution ranges. This conflict raises questions about the importance of several physical mechanisms for structuring pelagic communities, and/or on the coupling of structure and function in the pelagic realm.

  8. Biodiversity and biogeography of Antarctic and sub-Antarctic mollusca

    Science.gov (United States)

    Linse, Katrin; Griffiths, Huw J.; Barnes, David K. A.; Clarke, Andrew

    2006-04-01

    For many decades molluscan data have been critical to the establishment of the concept of a global-scale increase in species richness from the poles to the equator. Low polar diversity is key to this latitudinal cline in diversity. Here we investigate richness patterns in the two largest classes of molluscs at both local and regional scales throughout the Southern Ocean. We show that biodiversity is very patchy in the Southern Ocean (at the 1000-km scale) and test the validity of historical biogeographic sub-regions and provinces. We used multivariate analysis of biodiversity patterns at species, genus and family levels to define richness hotspots within the Southern Ocean and transition areas. This process identified the following distinct sub-regions in the Southern Ocean: Antarctic Peninsula, Weddell Sea, East Antarctic—Dronning Maud Land, East Antarctic—Enderby Land, East Antarctic—Wilkes Land, Ross Sea, and the independent Scotia arc and sub Antarctic islands. Patterns of endemism were very different between the bivalves and gastropods. On the basis of distributional ranges and radiation centres of evolutionarily successful families and genera we define three biogeographic provinces in the Southern Ocean: (1) the continental high Antarctic province excluding the Antarctic Peninsula, (2) the Scotia Sea province including the Antarctic Peninsula, and (3) the sub Antarctic province comprising the islands in the vicinity of the Antarctic Circumpolar Current.

  9. The biogeography and extinction of megapodes in Oceania

    NARCIS (Netherlands)

    Steadman, D.W.

    1999-01-01

    The arrival of prehistoric peoples in Oceania over the past several millennia resulted in the extinction of many species and populations of megapodes. Before these anthropogenic losses, species of megapodes ranged across Melanesia, Western Polynesia, and much of Micronesia. Island groups that lack m

  10. Integrating agricultural expansion into conservation biogeography: conflicts and priorities

    Directory of Open Access Journals (Sweden)

    Ricardo Dobrovolski

    2014-06-01

    Full Text Available Increasing food production without compromising biodiversity is one of the great challenges for humanity. The aims of my thesis were to define spatial priorities for biodiversity conservation and to evaluate conservation conflicts considering agricultural expansion in the 21st century. I also tested the effect of globalizing conservation efforts on both food production and biodiversity conservation. I found spatial conflicts between biodiversity conservation and agricultural expansion. However, incorporating agricultural expansion data into the spatial prioritization process can significantly alleviate conservation conflicts, by reducing spatial correlation between the areas under high impact of agriculture and the priority areas for conservation. Moreover, developing conservation blueprints at the global scale, instead of the usual approach based on national boundaries, can benefit both food production and biodiversity. Based on these findings I conclude that the incorporation of agricultural expansion as a key component for defining global conservation strategies should be added to the list of solutions for our cultivated planet.

  11. Phylogeny and historical biogeography of the lastreopsid ferns (Dryopteridaceae).

    Science.gov (United States)

    Labiak, Paulo H; Sundue, Michael; Rouhan, Germinal; Hanks, Judith G; Mickel, John T; Moran, Robbin C

    2014-07-01

    • Premise of the study: As currently circumscribed, Lastreopsis has about 45 species and occurs in Australia, southern Asia, Africa, Madagascar, and the neotropics. Previous molecular phylogenetic studies suggested that Lastreopsis is paraphyletic. Our study focuses on resolving relationships among the lastreopsid ferns (Lastreopsis, Megalastrum, and Rumohra), the evolution of morphological characters, and an understanding of the temporal and spatial patterns that have led to the current diversity and geographical distribution of its extant species.• Methods: Phylogenetic relationships were recovered under Bayesian, maximum likelihood, and maximum parsimony methods, using a data set of four plastid markers. Divergence time estimates were made using BEAST, and the biogeographic hypotheses were tested under the DEC model and the RASP/S-DIVA methods.• Key results: Lastreopsis was recovered as paraphyletic, and at least one of its clades should be recognized as a distinct genus, Parapolystichum. Coveniella poecilophlebia and Oenotrichia tripinnata were nested within Lastreopsis s.s., Megalastrum and Rumohra as sister to the Lastreopsis s.s., and the Lastreopsis amplissima clades. The initial diversification of the lastreopsids took place at about 56.55 Ma, from a neotropical ancestor.• Conclusions: Taxonomic recognition of Parapolystichum is warranted to preserve the monophyly of Lastreopsis. Diversification among the main clades of the lastreopsid ferns was influenced by climatic and geological changes in the southern hemisphere. The biogeographic history of the group is intimately related to the trans-Antarctic corridor between Australia and South America, with evidence for multiple lineage interchanges between Australia and South America during the Oligocene and the Eocene epochs.

  12. Dispersal and biogeography of silica-scaled chrysophytes

    DEFF Research Database (Denmark)

    Kristiansen, Jørgen

    2008-01-01

    . The distribution of a species at a given time depends on several factors: dispersal capacity—available vectors—suitable available habitats—and most important: sufficient time for dispersal. It is remarkable that the chrysophytes—in spite of their fragile cell construction and apparently low dispersal capacity......The silica-scaled chrysophytes—here mainly represented by the freshwater genera Mallomonas and Synura—have special problems in dispersal from one habitat to another because they cannot tolerate desiccation. Their dispersal is limited by the fragile construction and aquatic habit. Dispersal from one...

  13. Phylogeny and biogeography of the fruit doves (Aves: Columbidae).

    Science.gov (United States)

    Cibois, Alice; Thibault, Jean-Claude; Bonillo, Céline; Filardi, Christopher E; Watling, Dick; Pasquet, Eric

    2014-01-01

    We reconstruct the phylogeny of fruit doves (genus Ptilinopus) and allies with a dense sampling that includes almost all species, based on mitochondrial and nuclear sequence data. We evaluate the most likely biogeographic scenario for the evolution of this group that colonized many islands of the Pacific Ocean. We also investigate the evolution of one of the main plumage character of fruit doves (the color of the crown), and we propose several revisions of the group's systematics. All Ptilinopus taxa formed a monophyletic group that includes two morphologically distinct genera, Alectroenas and Drepanoptila, confirming a previous result found with less species and genes. The divergence time analysis suggests that the basal divergences within Ptilinopus dated to the Early Oligocene, and the biogeographic analysis indicates that fruit doves originated most probably from the proto New Guinea region. The earliest dispersals from the New Guinea region to Oceania occurred with the colonization of New Caledonia and Fiji. A large group of Polynesian species (Central and Eastern), as well as the three taxa found in Micronesia and four species from the Guinean-Moluccan region, form the "purpuratus" clade, the largest diversification of fruit doves within Oceania, which also has a New Guinean origin. However, the eastbound colonization of fruit doves was not associated with a significant increase of their diversification rate. Overall, the Melanesian region did not act as a cradle for fruit doves, in contrast to the New Guinea region which is found as the ancestral area for several nodes within the phylogeny.

  14. Pollination, biogeography and phylogeny of oceanic island bellflowers (Campanulaceae)

    DEFF Research Database (Denmark)

    Olesen, Jens Mogens; Alarcón, M.; Ehlers, Bodil

    2012-01-01

    of these species and their relatives were gathered from atpB, matK, rbcL and trnL-F regions, building the most complete phylogeny of Campanulaceae to date. Six of the island bellflower species were bird-pollinated and two (A. vidalii and M. aurea) were lizard-pollinated. Insects also visited some of the species...

  15. The biogeography of Mid-Atlantic CEAP wetlands

    Science.gov (United States)

    Background/Question/Methods: The national U.S.D.A. Conservation Effects Assessment Project (CEAP) is a multi-agency effort to quantify the environmental benefits of conservation practices. The goal of CEAP is to determine the effectiveness of wetland conservation practices and programs, including im...

  16. The historical biogeography of groupers: Clade diversification patterns and processes.

    Science.gov (United States)

    Ma, Ka Yan; Craig, Matthew Thomas; Choat, John Howard; van Herwerden, Lynne

    2016-07-01

    Groupers (family Epinephelidae) are a clade of species-rich, biologically diverse reef fishes. Given their ecological variability and widespread distribution across ocean basins, it is important to scrutinize their evolutionary history that underlies present day distributions. This study investigated the patterns and processes by which grouper biodiversity has been generated and what factors have influenced their present day distributions. We reconstructed a robust, time-calibrated molecular phylogeny of Epinephelidae with comprehensive (∼87%) species sampling, whereby diversification rates were estimated and ancestral ranges were reconstructed. Our results indicate that groupers originated in what is now the East Atlantic during the mid-Eocene and diverged successively to form six strongly supported main clades. These clades differ in age (late Oligocene to mid-Miocene), geographic origin (West Atlantic to West Indo-Pacific) and temporal-spatial diversification pattern, ranging from constant rates of diversification to episodes of rapid radiation. Overall, divergence within certain biogeographic regions was most prevalent in groupers, while vicariant divergences were more common in Tropical Atlantic and East Pacific groupers. Our findings reveal that both biological and geographical factors have driven grouper diversification. They also underscore the importance of scrutinizing group-specific patterns to better understand reef fish evolution.

  17. Algal biogeography: metagenomics shows distribution of a picoplanktonic pelagophyte.

    Science.gov (United States)

    Raven, John A

    2012-09-11

    How can we determine the distribution of uncultured marine microorganisms? Targeted metagenomics has provided the complete chloroplast genome sequence, and the distribution, for a picoplanktonic pelagophyte alga.

  18. The biogeography of trophic cascades on US oyster reefs.

    Science.gov (United States)

    Kimbro, David L; Byers, James E; Grabowski, Jonathan H; Hughes, A Randall; Piehler, Michael F

    2014-07-01

    Predators can indirectly benefit prey populations by suppressing mid-trophic level consumers, but often the strength and outcome of trophic cascades are uncertain. We manipulated oyster reef communities to test the generality of potential causal factors across a 1000-km region. Densities of oyster consumers were weakly influenced by predators at all sites. In contrast, consumer foraging behaviour in the presence of predators varied considerably, and these behavioural effects altered the trophic cascade across space. Variability in the behavioural cascade was linked to regional gradients in oyster recruitment to and sediment accumulation on reefs. Specifically, asynchronous gradients in these factors influenced whether the benefits of suppressed consumer foraging on oyster recruits exceeded costs of sediment accumulation resulting from decreased consumer activity. Thus, although predation on consumers remains consistent, predator influences on behaviour do not; rather, they interact with environmental gradients to cause biogeographic variability in the net strength of trophic cascades.

  19. The Aplacophora: History, Taxonomy, Phylogeny, Biogeography, and Ecology

    Science.gov (United States)

    1992-02-01

    871-882. Field, K. G., G. J. Olsen, D. J. Lane, S. J. Giovannoni, M. T. Ghiselin, E. C. Raff, N. R. Pace and R. A. Raff. 1988. Molecular phylogeny of...Laboratory, Beaufort, North Carolina. 9. Harbor Branch Laboratory, FL Pierce, Florida. 10. Dives 492. 563, 752-754, 849, 1072. 11. Intituto de Biologia ...University (1965) Stns 351, 2361, 2732. and 3417 (14 specimens): and from the Inslituto de Biologia . Universidade Federal do Rio de Janeiro (9 specimens). 52

  20. Biogeography and diversification of Brassicales: A 103million year tale.

    Science.gov (United States)

    Cardinal-McTeague, Warren M; Sytsma, Kenneth J; Hall, Jocelyn C

    2016-06-01

    Brassicales is a diverse order perhaps most famous because it houses Brassicaceae and, its premier member, Arabidopsis thaliana. This widely distributed and species-rich lineage has been overlooked as a promising system to investigate patterns of disjunct distributions and diversification rates. We analyzed plastid and mitochondrial sequence data from five gene regions (>8000bp) across 151 taxa to: (1) produce a chronogram for major lineages in Brassicales, including Brassicaceae and Arabidopsis, based on greater taxon sampling across the order and previously overlooked fossil evidence, (2) examine biogeographical ancestral range estimations and disjunct distributions in BioGeoBEARS, and (3) determine where shifts in species diversification occur using BAMM. The evolution and radiation of the Brassicales began 103Mya and was linked to a series of inter-continental vicariant, long-distance dispersal, and land bridge migration events. North America appears to be a significant area for early stem lineages in the order. Shifts to Australia then African are evident at nodes near the core Brassicales, which diverged 68.5Mya (HPD=75.6-62.0). This estimated age combined with fossil evidence, indicates that some New World clades embedded amongst Old World relatives (e.g., New World capparoids) are the result of different long distance dispersal events, whereas others may be best explained by land bridge migration (e.g., Forchhammeria). Based on these analyses, the Brassicaceae crown group diverged in Europe/Northern Africa in the Eocene, circa 43.4Mya (HPD=46.6-40.3) and Arabidopsis separated from close congeners circa 10.4Mya. These ages fall between divergent dates that were previously published, suggesting we are slowly converging on a robust age estimate for the family. Three significant shifts in species diversification are observed in the order: (1) 58Mya at the crown of Capparaceae, Cleomaceae and Brassicaceae, (2) 38Mya at the crown of Resedaceae+Stixis clade, and (3) 21Mya at the crown of the tribes Brassiceae and Sisymbrieae within Brassicaceae.

  1. Biogeography of cedrela (meliaceae, sapindales) in central and South america.

    Science.gov (United States)

    Muellner, Alexandra N; Pennington, Terence D; Koecke, A Valerie; Renner, Susanne S

    2010-03-01

    Dated phylogenies have helped clarify the complex history of many plant families that today are restricted to the world's tropical forests, but that have Eocene, Oligocene, and Miocene fossils from the northern hemisphere. One such family is the Meliaceae. Here we infer the history of the neotropical Meliaceae genus Cedrela (17 species), the sister clade of which today is restricted to tropical Asia. Sequences from the nuclear ribosomal spacer region and five plastid loci obtained for all ingroup species and relevant outgroups were used to infer species relationships and for molecular-clock dating under two Bayesian relaxed clock models. The clock models differed in their handling of rate autocorrelation and sets of fossil constraints. Results suggest that (1) crown group diversification in Cedrela started in the Oligocene/Early Miocene and intensified in the Late Miocene and Early Pliocene, and (2) Central American Cedrela species do not form a clade, implying reentry into Central America after the closure of the Panamanian Isthmus. At present, Cedrela is distributed in both dry and humid habitats, but morphological features suggest an origin in dry forest under seasonal climates, fitting with Miocene and Pliocene Cedrela fossils from deciduous forests.

  2. Biodiversity, biogeography and phylogeography of Ordovician rhynchonelliform brachiopods

    DEFF Research Database (Denmark)

    Harper, David A T; Rasmussen, Christian M Ø; Liljeroth, Maria

    2013-01-01

    began to radiate in low-latitude faunas, anticipating their dominance in Silurian faunas. The Hirnantian was marked by severe extinctions particularly across orthidestrophomenide clades within the context of few, but well-defined, climatically controlled provincial belts. © The Geological Society...... was particularly well explored and utilized by the strophomenides, especially the Plectambonitoidea, which radiated rapidly during this interval. The porambonitoids, on the other hand, were still in recovery following the early Darriwilian extinctions. Orthides remained dominant, particularly at high latitudes...

  3. Global biogeography of Prochlorococcus genome diversity in the surface ocean.

    Science.gov (United States)

    Kent, Alyssa G; Dupont, Chris L; Yooseph, Shibu; Martiny, Adam C

    2016-08-01

    Prochlorococcus, the smallest known photosynthetic bacterium, is abundant in the ocean's surface layer despite large variation in environmental conditions. There are several genetically divergent lineages within Prochlorococcus and superimposed on this phylogenetic diversity is extensive gene gain and loss. The environmental role in shaping the global ocean distribution of genome diversity in Prochlorococcus is largely unknown, particularly in a framework that considers the vertical and lateral mechanisms of evolution. Here we show that Prochlorococcus field populations from a global circumnavigation harbor extensive genome diversity across the surface ocean, but this diversity is not randomly distributed. We observed a significant correspondence between phylogenetic and gene content diversity, including regional differences in both phylogenetic composition and gene content that were related to environmental factors. Several gene families were strongly associated with specific regions and environmental factors, including the identification of a set of genes related to lower nutrient and temperature regions. Metagenomic assemblies of natural Prochlorococcus genomes reinforced this association by providing linkage of genes across genomic backbones. Overall, our results show that the phylogeography in Prochlorococcus taxonomy is echoed in its genome content. Thus environmental variation shapes the functional capabilities and associated ecosystem role of the globally abundant Prochlorococcus.

  4. Brains, tools, innovation and biogeography in crows and ravens

    DEFF Research Database (Denmark)

    Jønsson, Knud Andreas; Fabre, Pierre-Henri Fréderic; Irestedt, Martin

    2012-01-01

    Corvus. We date the phylogeny and determine ancestral areas to investigate historical biogeographical patterns of the crows. Additionally, we use data on brain size and a large database on innovative behaviour and tool use to test whether brain size (i) explains innovative behaviour and success....... The Caribbean was probably colonized from North America, although some North American ancestor may have gone extinct, and the Pacific was colonized multiple times from Asia and Australia. We did not find a correlation between relative brain size, tool use, innovative feeding strategies and dispersal success...

  5. Mexican ceratopsids: Considerations on their diversity and biogeography

    Science.gov (United States)

    Rivera-Sylva, Héctor E.; Frey, Eberhard; Stinnesbeck, Wolfgang; Guzmán-Gutiérrez, José Rubén; González-González, Arturo H.

    2017-04-01

    During the past decade, three taxa of ceratopsid ornithischians have been described from Mexico. Apparently, this group experienced a regional diversification in this area. To date Mexican Ceratopsia are represented by three species, one of which is a centrosaurine and two are chasmosaurines. Here we provide a critical review on Mexican ceratopsians and formally name a new centrosaurine ceratopsid species from the Campanian Aguja Formation as Yehuecauhceratops mudei. We also discuss possible causes for the rapid endemic diversification of Mexican ceratopsians.

  6. Historical biogeography of the strepsirhine primates of Madagascar.

    Science.gov (United States)

    Tattersall, Ian

    2006-01-01

    Lying some 400 km off the coast of southeastern Africa, Madagascar is the world's largest oceanic island. It has been in roughly the same position relative to its parent continent for 120 million years, and as a consequence its mammal fauna is unusual in composition, with a low number of major taxa but a high diversity at lower taxonomic levels. Among Madagascar's native terrestrial mammals, only the orders Primates, Rodentia, Carnivora and Insectivora are represented (plus, until recently, the enigmatic and endemic Bibymalagasia, and Artiodactyla in the form of semiaquatic pygmy hippopotamuses). This reflects the fact that terrestrial mammals are notoriously poor over-water dispersers; yet at the same time the ancestors of all of Madagascar's mammals had to have crossed a wide oceanic barrier to get to the island at various points during the Tertiary. Here I examine the palaeogeographic evidence for potential land bridge or 'stepping-stone' connections with adjacent continents from the Mesozoic through the Cenozoic, and review the fossil records and phylogenies of each of Madagascar's mammalian groups in an attempt to estimate the minimum number of crossings necessary to produce the island's current faunal composition. Probable monophyletic origins for each major group, and thus a smaller rather than a larger number of crossings of the Mozambique Channel, imply that this water barrier has acted as a powerful filter; so powerful that it is unclear whether any crossings would have been possible without some form of subaerial connection, however ephemeral, at least from time to time during the Tertiary. Clarification of how Madagascar's terrestrial mammal fauna may have originated is thus as likely to emerge from the geology of the seafloor surrounding the island as it is to come from the fossil record or from the internal and external relationships of its various components.

  7. Analyses towards determining Madagascar's place in global biogeography

    Institute of Scientific and Technical Information of China (English)

    (S)erban PROCHE(S); Syd RAMDHANI

    2012-01-01

    The relationships of Madagascan plant and animal taxa have been the object of much fascination,Madagascar sharing numerous lineages with Africa,others with Asia,Australia,or the Americas,and many others being of uncertain relationships.In commonly accepted global regionalization schemata,Madagascar is treated together with Africa for animals,and with Africa,tropical Asia and the Pacific islands in the case of plants.Here we examine the similarities between the biotic assemblages of (ⅰ)tropical Africa,(ⅱ) Madagascar,and (ⅲ) the rest of the world,on a basic taxonomic level,considering the families of vascular plants and vertebrates as analysis units.The percentages of endemic families,families shared pair-wise between regions,or present in all three,are roughly similar between the two broad groups,though plant famlies with ranges limited to one region are proportionally fewer.In dendrograms and multidimensional scaling plots for different groups,Madagascar clusters together with Africa,Asia or both,and sometimes with smaller Indian Ocean Islands,but quite often (though not in plants) as a convincingly separate cluster.Our results for vertebrates justify the status of full zoogeographic region for Madagascar,though an equally high rank in geobotanical regionaliration would mean also treating Africa and Tropical Asia as separate units,which would be debatable given the overall greater uniformity of plant assemblages.Beyond the Madagascan focus of this paper,the differences between plant and vertebrate clusters shown here suggest different levels of ecological plasticity at the same taxonomic level,with plant families being much more environmentally-bound,and thus clustering along biome lines rather than regional lines.

  8. The West Indies as a laboratory of biogeography and evolution.

    Science.gov (United States)

    Ricklefs, Robert; Bermingham, Eldredge

    2008-07-27

    Islands have long provided material and inspiration for the study of evolution and ecology. The West Indies are complex historically and geographically, providing a rich backdrop for the analysis of colonization, diversification and extinction of species. They are sufficiently isolated to sustain endemic forms and close enough to sources of colonists to develop a dynamic interaction with surrounding continental regions. The Greater Antilles comprise old fragments of continental crust, some very large; the Lesser Antilles are a more recent volcanic island arc, and the low-lying Bahama Islands are scattered on a shallow oceanic platform. Dating of island lineages using molecular methods indicates over-water dispersal of most inhabitants of the West Indies, although direct connections with what is now southern Mexico in the Early Tertiary, and subsequent land bridges or stepping stone islands linking to Central and South America might also have facilitated colonization. Species-area relationships within the West Indies suggest a strong role for endemic radiations and extinction in shaping patterns of diversity. Diversification is promoted by opportunities for allopatric divergence between islands, or within the large islands of the Greater Antilles, with a classic example provided by the Anolis lizards. The timing of colonization events using molecular clocks permits analysis of colonization-extinction dynamics by means of species accumulation curves. These indicate low rates of colonization and extinction for reptiles and amphibians in the Greater Antilles, with estimated average persistence times of lineages in the West Indies exceeding 30Myr. Even though individual island populations of birds might persist an average of 2Myr on larger islands in the Lesser Antilles, recolonization from within the archipelago appears to maintain avian lineages within the island chain indefinitely. Birds of the Lesser Antilles also provide evidence of a mass extinction event within the past million years, emphasizing the time-heterogeneity of historical processes. Geographical dynamics are matched by ecological changes in the distribution of species within islands over time resulting from adaptive radiation and shifts in habitat, often following repeatable patterns. Although extinction is relatively infrequent under natural conditions, changes in island environments as a result of human activities have exterminated many populations and others--especially old, endemic species--remain vulnerable. Conservation efforts are strengthened by recognition of aesthetic, cultural and scientific values of the unique flora and fauna of the West Indies.

  9. Global diversity and biogeography of deep-sea pelagic prokaryotes

    KAUST Repository

    Salazar, Guillem

    2015-08-07

    The deep-sea is the largest biome of the biosphere, and contains more than half of the whole ocean\\'s microbes. Uncovering their general patterns of diversity and community structure at a global scale remains a great challenge, as only fragmentary information of deep-sea microbial diversity exists based on regional-scale studies. Here we report the first globally comprehensive survey of the prokaryotic communities inhabiting the bathypelagic ocean using high-throughput sequencing of the 16S rRNA gene. This work identifies the dominant prokaryotes in the pelagic deep ocean and reveals that 50% of the operational taxonomic units (OTUs) belong to previously unknown prokaryotic taxa, most of which are rare and appear in just a few samples. We show that whereas the local richness of communities is comparable to that observed in previous regional studies, the global pool of prokaryotic taxa detected is modest (∼3600 OTUs), as a high proportion of OTUs are shared among samples. The water masses appear to act as clear drivers of the geographical distribution of both particle-attached and free-living prokaryotes. In addition, we show that the deep-oceanic basins in which the bathypelagic realm is divided contain different particle-attached (but not free-living) microbial communities. The combination of the aging of the water masses and a lack of complete dispersal are identified as the main drivers for this biogeographical pattern. All together, we identify the potential of the deep ocean as a reservoir of still unknown biological diversity with a higher degree of spatial complexity than hitherto considered.

  10. Biogeography of Drosophila (Diptera: Drosophilidae) in East and Southeast Asia.

    Science.gov (United States)

    Liu, Fu-Guo Robert; Tsaur, Shun-Chern; Huang, Hsiao-Ting

    2015-01-01

    The causes of high biological diversity in biodiversity hotspots have long been a major subject of study in conservation biology. To investigate this matter, we conducted a phylogeographic study of five Drosophila (Diptera: Drosophilidae) species from East and Southeast Asia: Drosophila albomicans Duda, D. formosana Duda, D. immigrans Sturtevant, D. melanogaster Meigen, and D. simulans Sturtevant. We collected 185 samples from 28 localities in eight countries. From each collected individual, we sequenced the autosomal extra sex comb gene (esc) and seven mitochondrial genes, including nicotinamide adenine dinucleotide hydrate-reductase dehydrogenase subunit 4 (ND4), ND4L, tRNA-His, tRNA-Pro, tRNA-Thr, partial ND5, and partial ND6. Phylogenetic analyses using maximum- likelihood and Bayesian methods revealed interesting population structure and identified the existence of two distinct D. formosana lineages (Southeast Asian and Taiwanese populations). Genetic differentiation among groups of D. immigrans suggests the possibility of endemic speciation in Taiwan. In contrast, D. melanogaster remained one extensively large population throughout East and Southeast Asia, including nearby islets. A molecular clock was used to estimate divergence times, which were compared with past geographical events to infer evolutionary scenarios. Our findings suggest that interglacial periods may have caused population isolation, thus enhancing population differentiation more strongly for some of the Drosophila species. The population structure of each Drosophila species in East and Southeast Asia has been influenced by past geographic events.

  11. Rethinking dog domestication by integrating genetics, archeology, and biogeography

    DEFF Research Database (Denmark)

    Larson, Greger; Karlsson, Elinor K.; Perri, Angela

    2012-01-01

    , and New Guinea Singing Dogs) come from regions outside the natural range of Canis lupus (the dog's wild ancestor) and where dogs were introduced more than 10,000 y after domestication. These results demonstrate that the unifying characteristic among all genetically distinct so-called ancient breeds......The dog was the first domesticated animal but it remains uncertain when the domestication process began and whether it occurred just once or multiple times across the Northern Hemisphere. To ascertain the value of modern genetic data to elucidate the origins of dog domestication, we analyzed 49......,024 autosomal SNPs in 1,375 dogs (representing 35 breeds) and 19 wolves. After combining our data with previously published data, we contrasted the genetic signatures of 121 breeds with a worldwide archeological assessment of the earliest dog remains. Correlating the earliest archeological dogs...

  12. Rethinking dog domestication by integrating genetics, archeology, and biogeography

    OpenAIRE

    Larson, G.; Karlsson, E. K.; Perri, A.; Webster, M. T.; Ho, S Y W; Peters, J; Stahl, P.W.; Piper, P J; Lingaas, F.; Fredholm, M.; Comstock, K. E.; Modiano, J. F.; Schelling, C.; Agoulnik, A.I.; Leegwater, P A

    2012-01-01

    The dog was the first domesticated animal but it remains uncertain when the domestication process began and whether it occurred just once or multiple times across the Northern Hemisphere. To ascertain the value of modern genetic data to elucidate the origins of dog domestication, we analyzed 49,024 autosomal SNPs in 1,375 dogs (representing 35 breeds) and 19 wolves. After combining our data with previously published data, we contrasted the genetic signatures of 121 breeds with a worldwide arc...

  13. Rethinking dog domestication by integrating genetics, archeology, and biogeography

    Science.gov (United States)

    Larson, Greger; Karlsson, Elinor K.; Perri, Angela; Webster, Matthew T.; Ho, Simon Y. W.; Peters, Joris; Stahl, Peter W.; Piper, Philip J.; Lingaas, Frode; Fredholm, Merete; Comstock, Kenine E.; Modiano, Jaime F.; Schelling, Claude; Agoulnik, Alexander I.; Leegwater, Peter A.; Dobney, Keith; Vigne, Jean-Denis; Vilà, Carles; Andersson, Leif; Lindblad-Toh, Kerstin

    2012-01-01

    The dog was the first domesticated animal but it remains uncertain when the domestication process began and whether it occurred just once or multiple times across the Northern Hemisphere. To ascertain the value of modern genetic data to elucidate the origins of dog domestication, we analyzed 49,024 autosomal SNPs in 1,375 dogs (representing 35 breeds) and 19 wolves. After combining our data with previously published data, we contrasted the genetic signatures of 121 breeds with a worldwide archeological assessment of the earliest dog remains. Correlating the earliest archeological dogs with the geographic locations of 14 so-called “ancient” breeds (defined by their genetic differentiation) resulted in a counterintuitive pattern. First, none of the ancient breeds derive from regions where the oldest archeological remains have been found. Second, three of the ancient breeds (Basenjis, Dingoes, and New Guinea Singing Dogs) come from regions outside the natural range of Canis lupus (the dog’s wild ancestor) and where dogs were introduced more than 10,000 y after domestication. These results demonstrate that the unifying characteristic among all genetically distinct so-called ancient breeds is a lack of recent admixture with other breeds likely facilitated by geographic and cultural isolation. Furthermore, these genetically distinct ancient breeds only appear so because of their relative isolation, suggesting that studies of modern breeds have yet to shed light on dog origins. We conclude by assessing the limitations of past studies and how next-generation sequencing of modern and ancient individuals may unravel the history of dog domestication. PMID:22615366

  14. Taxonomy, Phylogeny, and Biogeography of Baccaurea, Distichirhops, and Nothobaccaurea (Euphorbiaceae)

    NARCIS (Netherlands)

    Haegens, Raoul Martin Anne Peter

    2000-01-01

    This study comprises a taxonomic revision and phylogenetic and biogeographic analyses of the genera Baccaurea, Distichirhops, and Nothobaccaurea (Euphorbiaceae). Baccaurea was chosen as a model genus for study in the framework of the research program ‘Pathways from Asia to new Guinea’ of the Dutch S

  15. Diversity, dynamics and biogeography of Chilean benthic nearshore ecosystems: an overview and guidelines for conservation Diversidad, dinámica y biogeografía del ecosistema costero bentónico de Chile: revisión y bases para conservación marina

    Directory of Open Access Journals (Sweden)

    MIRIAM FERNANDEZ

    2000-12-01

    Full Text Available Despite Chile has been one of the pioneering countries in studies of human impact on marine communities, and despite the enormous economic and social significance that the marine environment has for the country, the development of marine conservation programs and the scientific basis for sustainability has not kept pace, with the exploitation rate of marine fisheries and the increasing use of the coast for other purposes. Although we think that the establishment of any conservation policies along the vast coastline of Chile must be based on a multitude of approaches and considerations, scientific, biological, and ecological principles should guide much of these efforts. In this paper, we attempt to present a general overview of the current knowledge about the ecology and biogeography of nearshore systems in Chile. Based on the most relevant existing information, our goals are to: 1 Identify major biogeographic and ecological features of nearshore ecosystems, and the obvious gaps in information, 2 identify the most harmful human activities impacting the structure and dynamics of these systems, and 3 suggest the possible use of indicators to assess the conservational status of different environments along the coast. This overview shows, on one side, the geographic areas of deficitary knowledge on nearshore environments that are critical for future marine conservation and management plans, and on the other, the availability of high quality information for other geographic areas along the coast. Regarding the taxonomy and large-scale patterns of species distribution, important gaps in information were detected, however no big changes in the total number of species are expected in the future. There are few large-scale patterns of species distribution are reported in the literature, and in this contribution, but more work needs to be done, particularly for some taxa, to identify areas of high species diversity as well as areas which possess unique

  16. 内蒙古西部额济纳旗晚奥陶世生物地理和奥陶-志留系分界%LATE ORDOVICIAN BIOGEOGRAPHY AND ORDOVICIAN-SILURIAN BOUNDARY IN THE ZHUSILENHAIERHAN AREA, EJIN, WESTERN INNER MONGOLIA

    Institute of Scientific and Technical Information of China (English)

    戎嘉余; 陈旭; 詹仁斌; 周志强; 郑昭昌; 王怿

    2003-01-01

    Upper Ordovician-lowest Silurian strata crop out near Danmianshan, about 10 km west of Zhusilenghaierhan Mt., about 55 km south of Yagan, 135 km east of Ejin Banner town, western Inner Mongolia (Alxa block). The strata along with their related major fossil groups (such as graptolites, corals and trilobites) have been studied by Zheng et al. (1982), Zhu et al. (1987), and Ge et al. (1990). Recent field examination in this area was carried out by the authors in the summer of 2002. Our subsequent investigation on collections has led to the discovery Holorhynchus (virgianids, Brachiopoda) from the Late Ordovician rocks, to make sure that there occur no latest Ordovician Hirnantia fauna, and to define the Ordovician-Silurian boundary on the basis of the occurrence of Normalograptus lubricus. The Ashgill brachiopod biogeography is discussed.Holorhynchus giganteus Kiaer, 1902 has been found from the Badanjilin Fomation (mid Ashgill) at the No. 3 section of Zheng et al. (1987) in this area for the first time. This is also the first record of the genus Holorhynchus in Late Ordovician of China. Holorhynchus has been known to be characterized by the total absence of a ventral median septum, together with smooth shell exterior and short, separated outer brachial plates (e.g. St. Joseph, 1938; Cocks, 1982). Through sectioning, however, the discovery of an apical median setum in ventral valve of immature specimens (less than 8mm wide) of H. giganteus led to a revised generic diagnosis for the genus (see Rong et al. in preparation). Actually, this structure is also known from an internal mold material and a transverse section of the identical species in South Norway (Cocks, 1982) and Zeravshano-Gissar Mountains, Tadzhikistan (Nikiforova and Sapel'nikov, 1973) respectively. Holorhynchus from the Badanjilin Formation at the No.3 section of Zheng et al. (1987) is associated with the brachiopods Altaethyrella, Ovalospira, Leptellina, Sowerbyella, Pectenospira, and the Agetolites

  17. Morphology, Ecology and Biogeography of the South American Caecilian Chthonerpeton Indistinctum (Amphibia: Gymnophiona: Typhlonectidae)

    NARCIS (Netherlands)

    Gudynas, E.; Williams, J.D.; Mercedes Azpelicueta, de las M.

    1988-01-01

    This study of Chthonerpeton indistinctum (Reinhardt & Lütken, 1861) considers 25 morphometric characters, teeth-counts and sex, based on 96 specimens. A multivariate analysis of characters and comparisons of geographically arranged samples is carried out by graphic and statistical methods. No trends

  18. The lizard fauna of Guam's fringing islets: Island biogeography, phylogenetic history, and conservation implications

    Science.gov (United States)

    Perry, G.; Rodda, G.H.; Fritts, T.H.; Sharp, T.R.

    1998-01-01

    We sampled the lizard fauna of twenty-two small islets fringing the Pacific island of Guam and used these data to shed light on the processes responsible for present-day diversity. Habitat diversity, measured by islet area and vegetation complexity, was significantly correlated with the number of species found on an islet. However, islet distance and elevation were not significant predictors of diversity. Distribution patterns were slightly different for the two major families in our sample, Scincidae and Gekkonidae: skinks needed larger islets to maintain a population than did geckos. Presence/absence patterns were highly and significantly nested, and population density was correlated with the number of islets on which a species was found. An area cladogram was poorly supported and showed no faunal similarity between nearby islands. These patterns indicate that extinctions on most islets were due mostly to non-catastrophic, long-acting biological causes. The presence on the islets of species extirpated on Guam and the lack of significant nestedness on islands with greater maximum elevation highlight the impact that predators (primarily brown treesnakes) can have. Our findings also show that small reserves will not suffice to protect endangered lizard faunas, and that the islets may serve as a short-term repository of such species until snake-free areas can be established on Guam.

  19. Biogeography of Anurans from the Poorly Known and Threatened Coastal Sandplains of Eastern Brazil

    Science.gov (United States)

    Xavier, Ariane Lima; Guedes, Thaís Barreto; Napoli, Marcelo Felgueiras

    2015-01-01

    The east coast of Brazil comprises an extensive area inserted in the Tropical Atlantic Domain and is represented by sandy plains of beach ridges commonly known as Restingas. The coastal environments are unique and house a rich amphibian fauna, the geographical distribution patterns of which are incipient. Biogeographical studies can explain the current distributional patterns and provide the identification of natural biogeographical units. These areas are important in elucidating the evolutionary history of the taxa and the areas where they occur. The aim of this study was to seek natural biogeographical units in the Brazilian sandy plains of beach ridges by means of distribution data of amphibians and to test the main predictions of the vicariance model to explain the patterns found. We revised and georeferenced data on the geographical distribution of 63 anuran species. We performed a search for latitudinal distribution patterns along the sandy coastal plains of Brazil using the non-metric multidimensional scaling method (NMDS) and the biotic element analysis to identify natural biogeographical units. The results showed a monotonic variation in anuran species composition along the latitudinal gradient with a break in the clinal pattern from 23°S to 25°S latitude (states of Rio de Janeiro to São Paulo). The major predictions of the vicariance model were corroborated by the detection of four biotic elements with significantly clustered distribution and by the presence of congeneric species distributed in distinct biotic elements. The results support the hypothesis that vicariance could be one of the factors responsible for the distribution patterns of the anuran communities along the sandy coastal plains of eastern Brazil. The results of the clusters are also congruent with the predictions of paleoclimatic models made for the Last Glacial Maximum of the Pleistocene, such as the presence of historical forest refugia and biogeographical patterns already detected for amphibians in the Atlantic Rainforest. PMID:26047484

  20. Biogeography and evolution of the Carassius auratus-complex in East Asia

    Directory of Open Access Journals (Sweden)

    Iguchi Kei'ichiro

    2010-01-01

    Full Text Available Abstract Background Carassius auratus is a primary freshwater fish with bisexual diploid and unisexual gynogenetic triploid lineages. It is distributed widely in Eurasia and is especially common in East Asia. Although several genetic studies have been conducted on C. auratus, they have not provided clear phylogenetic and evolutionary descriptions of this fish, probably due to selection bias in sampling sites and the DNA regions analysed. As the first step in clarifying the evolutionary entity of the world's Carassius fishes, we attempted to clarify the phylogeny of C. auratus populations distributed in East Asia. Results We conducted a detailed analysis of a large dataset of mitochondrial gene sequences [CR, 323 bp, 672 sequences (528 sequenced + 144 downloaded; CR + ND4 + ND5 + cyt b, 4669 bp in total, 53 sequences] obtained from C. auratus in East Asia. Our phylogeographic analysis revealed two superlineages, one distributed mainly among the Japanese main islands and the other in various regions in and around the Eurasian continent, including the Ryukyus and Taiwan. The two superlineages include seven lineages with high regional specificity that are composed of endemic populations indigenous to each region. The divergence time of the seven lineages was estimated to be 0.2 million years ago (Mya by a fossil-based method and 1.0-1.9 Mya by the molecular clock method. The antiquity and endemism of these lineages suggest that they are native to their respective regions, although some seem to have been affected by the artificial introduction of C. auratus belonging to other lineages. Triploids of C. auratus did not form a monophyletic lineage but were clustered mostly with sympatric diploids. Conclusions The results of the present study revealed the existence of two superlineages of C. auratus in East Asia that include seven lineages endemic to each of the seven regions examined. The lack of substantial genetic separation between triploids and diploids indicates that triploids are not composed of a single independent lineage. The ancient origins and evolutionary uniqueness of the seven lineages warrant their conservation. An overall phylogenetic framework obtained from the present study will be of use for estimating the phylogenetic relationships of Carassius fishes on the Eurasian continent.

  1. Biogeography and landscape-scale diversity of the dominant Crenarchaeota of soil.

    Science.gov (United States)

    Oline, David K; Schmidt, Steven K; Grant, Michael C

    2006-10-01

    We surveyed the diversity of soil Archaea across a large scale elevational gradient of ecosystem types, from foothills forest to alpine tundra in the Front Range of the Rocky Mountains. We used a dilution technique to sequence the single most abundant archaeal 16S rDNA sequence in each of the 40 soil cores distributed across the gradient to compare our results to those of typical 16S clone library studies. We found a greater diversity of sequences than has typically been found in clone library studies from a single site or core, identifying sequences both from the Terrestrial Group and the FFSB Group at several sites. We did not observe any significant environmental correlates with the dominant sequence type, nor was there any relationship between the spatial distance between samples and the phylogenetic similarity of the dominant sequence types. Despite using a very different methodology, our collective results are in remarkably good agreement with other studies of soil Crenarchaeota in terms of the diversity and relative abundance of sequence types identified. We are able to identify two instances of very tightly clustered sequences which we suggest are the results of global selective sweeps-one closely related to SCA1145, an abundant globally distributed group within the Terrestrial Group of Crenarchaeota, and another nested within the more basal FFSB group of sequences. We replicated our sequence results at two levels: first, by repeating the dilution and PCR processes from the same soil core DNA extraction, and second, by performing a replicate DNA extraction from the same homogenized soil core sample. Pairs of sequences produced by the dilution replicates were significantly more similar than the pairs of sequences produced by the extraction replicates, suggesting that soil Crenarchaeota exists in highly localized and discrete clonal populations.

  2. The black widow spider genus Latrodectus (Araneae: Theridiidae): phylogeny, biogeography, and invasion history.

    Science.gov (United States)

    Garb, Jessica E; González, Alda; Gillespie, Rosemary G

    2004-06-01

    The spider genus Latrodectus includes the widely known black widows, notorious because of the extreme potency of their neurotoxic venom. The genus has a worldwide distribution and comprises 30 currently recognized species, the phylogenetic relationships of which were previously unknown. Several members of the genus are synanthropic, and are increasingly being detected in new localities, an occurrence attributed to human mediated movement. In particular, the nearly cosmopolitan range of the brown widow, Latrodectus geometricus, is a suspected consequence of human transport. Although the taxonomy of the genus has been examined repeatedly, the recognition of taxa within Latrodectus has long been considered problematic due to the difficulty associated with identifying morphological features exhibiting discrete geographic boundaries. This paper presents, to our knowledge, the first phylogenetic hypothesis for the Latrodectus genus and is generated from DNA sequences of the mitochondrial gene cytochrome c oxidase subunit I. We recover two well-supported reciprocally monophyletic clades within the genus: (1) the geometricus clade, consisting of Latrodectus rhodesiensis from Africa, and its is sister species, the cosmopolitan L. geometricus, and (2) the mactans clade containing all other Latrodectus species sampled, including taxa occurring in Africa, the Middle East, Iberian Peninsula, Australia, New Zealand, and North and South America. Recovery of the geometricus and mactans clades is consistent with previous designations of species groups within the genus based on female genitalic morphology. All L. geometricus sampled, consisting of specimens from Africa, Argentina, North America, and Hawaii, were recovered as a strongly supported monophyletic group with minimal amounts of genetic divergence, corroborating the hypothesis that human transport has recently expanded the range of this species.

  3. Conquering the Sahara and Arabian deserts: systematics and biogeography of Stenodactylus geckos (Reptilia: Gekkonidae

    Directory of Open Access Journals (Sweden)

    Metallinou Margarita

    2012-12-01

    Full Text Available Abstract Background The evolutionary history of the biota of North Africa and Arabia is inextricably tied to the complex geological and climatic evolution that gave rise to the prevalent deserts of these areas. Reptiles constitute an exemplary group in the study of the arid environments with numerous well-adapted members, while recent studies using reptiles as models have unveiled interesting biogeographical and diversification patterns. In this study, we include 207 specimens belonging to all 12 recognized species of the genus Stenodactylus. Molecular phylogenies inferred using two mitochondrial (12S rRNA and 16S rRNA and two nuclear (c-mos and RAG-2 markers are employed to obtain a robust time-calibrated phylogeny, as the base to investigate the inter- and intraspecific relationships and to elucidate the biogeographical history of Stenodactylus, a genus with a large distribution range including the arid and hyper-arid areas of North Africa and Arabia. Results The phylogenetic analyses of molecular data reveal the existence of three major clades within the genus Stenodactylus, which is supported by previous studies based on morphology. Estimated divergence times between clades and sub-clades are shown to correlate with major geological events of the region, the most important of which is the opening of the Red Sea, while climatic instability in the Miocene is hypothesized to have triggered diversification. High genetic variability is observed in some species, suggesting the existence of some undescribed species. The S. petrii - S. stenurus species complex is in need of a thorough taxonomic revision. New data is presented on the distribution of the sister species S. sthenodactylus and S. mauritanicus. Conclusions The phylogenetic hypothesis for the genus Stenodactylus presented in this work permits the reconstruction of the biogeographical history of these common desert dwellers and confirms the importance of the opening of the Red Sea and the climatic oscillations of the Miocene as major factors in the diversification of the biota of North Africa and Arabia. Moreover, this study traces the evolution of this widely distributed and highly specialized group, investigates the patterns of its high intraspecific diversity and elucidates its systematics.

  4. Microbial Biogeography along an Estuarine Salinity Gradient: Combined Influences of Bacterial Growth and Residence Time

    OpenAIRE

    Crump, Byron C.; Hopkinson, Charles S.; Sogin, Mitchell L.; Hobbie, John E

    2004-01-01

    Shifts in bacterioplankton community composition along the salinity gradient of the Parker River estuary and Plum Island Sound, in northeastern Massachusetts, were related to residence time and bacterial community doubling time in spring, summer, and fall seasons. Bacterial community composition was characterized with denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA. Average community doubling time was calculated from bacterial production ([14C]leucine incorpo...

  5. Arthropod gut symbionts from the Balearic Islands: Majorca and Cabrera. Diversity and biogeography

    Directory of Open Access Journals (Sweden)

    Guàrdia Valle, Laia

    2009-12-01

    Full Text Available This study includes a catalogue with all the current data concerning the presence of trichomycetes (sensu lato in Majorca and Cabrera, as well as information on the biology, ecology and biogeographic implications of the insularity for each taxon of these arthropod-gut symbionts. Of the 13 species here reported, 10 are new for the Balearic Islands, including 4 Mesomycetozoan, of which 3 Eccrinales (Astreptonema gammari, Eccrinidus flexilis, Parataeniella dilatata, 1 Amoebidiales (Paramoebidium curvum and 6 kixckellomycotina Harpellales (Genistellospora homothallica, Harpella melusinae, Smittium culisetae, S. simulii, Stachylina grandispora and St. nana; the additional 3 were previously reported elsewhere: Asellaria ligiae (Aslleariales, Legeriomyces rarus and Stipella vigilans (Harpellales, but are here included as indissoluble part of the present Balearic catalogue. All taxa are commented, illustrated and their biogeographic implications are discussed.

    El presente estudio incluye una recopilación de todos los datos concernientes al conocimiento de los tricomicetos (sensu lato en las islas Baleares de Mallorca y Cabrera, incluyendo un catálogo de especies y notas sobre la biología, ecología e implicaciones biogeográficas de su insularidad. De las 13 especies citadas, 10 son nuevas para las Baleares, incluyendo 4 Mesomycetozoos, de los cuales 3 Eccrinales (Astreptonema gammari, Eccrinidus flexilis, Parataeniella dilatata, 1 Amoebidiales (Paramoebidium curvum y 6 Harpellales (kixckellomycotina (Genistellospora homothallica, Harpella melusinae, Smittium culisetae, S. simulii, Stachylina grandispora y St. nana; aunque las 3 especies restantes: Asellaria ligiae (Aslleariales, Legeriomyces rarus y Stipella vigilans (Harpellales fueron citadas anteriormente, se incluyen aquí brevemente como parte del catálogo.

  6. The biogeography of threatened insular iguanas and opportunities for invasive vertebrate management

    Science.gov (United States)

    Tershy, Bernie R.; Newton, Kelly M.; Spatz, Dena R.; Swinnerton, Kirsty; Iverson, John B.; Fisher, Robert N.; Harlow, Peter S.; Holmes, Nick D.; Croll, Donald A.; Iverson, J.B.; Grant, T. D.; Knapp, C. R.; Pasachnik, S. A.

    2016-01-01

    Iguanas are a particularly threatened group of reptiles, with 61% of species at risk of extinction. Primary threats to iguanas include habitat loss, direct and indirect impacts by invasive vertebrates, overexploitation, and human disturbance. As conspicuous, charismatic vertebrates, iguanas also represent excellent flagships for biodiversity conservation. To assist planning for invasive vertebrate management and thus benefit threatened iguana recovery, we identified all islands with known extant or extirpated populations of Critically Endangered and Endangered insular iguana taxa as recognized by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. For each island, we determined total area, sovereignty, the presence of invasive alien vertebrates, and human population. For the 23 taxa of threatened insular iguanas we identified 230 populations, of which iguanas were extant on 185 islands and extirpated from 45 islands. Twenty-one iguana taxa (91% of all threatened insular iguana taxa) occurred on at least one island with invasive vertebrates present; 16 taxa had 100% of their population(s) on islands with invasive vertebrates present. Rodents, cats, ungulates, and dogs were the most common invasive vertebrates. We discuss biosecurity, eradication, and control of invasive vertebrates to benefit iguana recovery: (1) on islands already free of invasive vertebrates; (2) on islands with high iguana endemicity; and (3) for species and subspecies with small total populations occurring across multiple small islands. Our analyses provide an important first step toward understanding how invasive vertebrate management can be planned effectively to benefit threatened insular iguanas.

  7. Systematics, evolution and historical biogeography of the family Ochnaceae with emphasis on the genus Campylospermum

    NARCIS (Netherlands)

    Bissiengou, P.

    2014-01-01

    Abstract Ochnaceae s.l. is a family of trees, shrubs or rarely herbs widely distributed in tropical and subtropical forests and savannas of the Old and New World, and has about 500 species in 32 genera. The family is divided into three subfamilies: Medusagynoideae, Quiinoideae and Ochnoideae. We hav

  8. Systematics, evolution and historical biogeography of the family Ochnaceae with emphasis on the genus Campylospermum

    OpenAIRE

    Bissiengou, P.

    2014-01-01

    Abstract Ochnaceae s.l. is a family of trees, shrubs or rarely herbs widely distributed in tropical and subtropical forests and savannas of the Old and New World, and has about 500 species in 32 genera. The family is divided into three subfamilies: Medusagynoideae, Quiinoideae and Ochnoideae. We have provided, for the first time, a nearly complete molecular phylogenetic analysis of Ochnaceae s.l. resolving most of the phylogeny backbone of the family using five DNA regions. Based on this, dat...

  9. Ecological niche models reveal the importance of climate variability for the biogeography of protosteloid amoebae.

    Science.gov (United States)

    Aguilar, María; Lado, Carlos

    2012-08-01

    Habitat availability and environmental preferences of species are among the most important factors in determining the success of dispersal processes and therefore in shaping the distribution of protists. We explored the differences in fundamental niches and potential distributions of an ecological guild of slime moulds-protosteloid amoebae-in the Iberian Peninsula. A large set of samples collected in a north-east to south-west transect of approximately 1000 km along the peninsula was used to test the hypothesis that, together with the existence of suitable microhabitats, climate conditions may determine the probability of survival of species. Although protosteloid amoebae share similar morphologies and life history strategies, canonical correspondence analyses showed that they have varied ecological optima, and that climate conditions have an important effect in niche differentiation. Maxent environmental niche models provided consistent predictions of the probability of presence of the species based on climate data, and they were used to generate maps of potential distribution in an 'everything is everywhere' scenario. The most important climatic factors were, in both analyses, variables that measure changes in conditions throughout the year, confirming that the alternation of fruiting bodies, cysts and amoeboid stages in the life cycles of protosteloid amoebae constitutes an advantage for surviving in a changing environment. Microhabitat affinity seems to be influenced by climatic conditions, which suggests that the micro-environment may vary at a local scale and change together with the external climate at a larger scale.

  10. Biogeography of the ubiquitous marine bacterium Alteromonas macleodii determined by multilocus sequence analysis.

    Science.gov (United States)

    Ivars-Martínez, Elena; D'Auria, Giuseppe; Rodríguez-Valera, Francisco; Sânchez-Porro, Cristina; Ventosa, Antonio; Joint, Ian; Mühling, Martin

    2008-09-01

    Twenty-three isolates of the widely distributed marine bacteria Alteromonas macleodii have been analysed by multilocus sequence analysis combined with phylogenetic and multivariate statistical analyses. The strains originated from the Pacific Ocean, Mediterranean Sea, English Channel, Black Sea and Thailand. Using the nucleotide sequences of nine loci for each of the 23 isolates, a robust identification was achieved of different clades within the single species. Strains generally clustered with the depth in the water column from which the isolate originated. Strains also showed more recombination with isolates from the same vicinity, suggesting that genetic exchange plays a role in diversification of planktonic marine prokaryotes. This study thus shows for the first time for a large set of isolates of a species of planktonic marine prokaryotes that multilocus sequence analysis overcomes the problems associated with the analysis of individual marker genes or presence of extensive recombination events. It can thus achieve intraspecific identification to the level of genotypes and, by comparison with relevant environmental data, ecotypes.

  11. Biogeography in deep time - What do phylogenetics, geology, and paleoclimate tell us about early platyrrhine evolution?

    Science.gov (United States)

    Kay, Richard F

    2015-01-01

    Molecular data have converged on a consensus about the genus-level phylogeny of extant platyrrhine monkeys, but for most extinct taxa and certainly for those older than the Pleistocene we must rely upon morphological evidence from fossils. This raises the question as to how well anatomical data mirror molecular phylogenies and how best to deal with discrepancies between the molecular and morphological data as we seek to extend our phylogenies to the placement of fossil taxa. Here I present parsimony-based phylogenetic analyses of extant and fossil platyrrhines based on an anatomical dataset of 399 dental characters and osteological features of the cranium and postcranium. I sample 16 extant taxa (one from each platyrrhine genus) and 20 extinct taxa of platyrrhines. The tree structure is constrained with a "molecular scaffold" of extant species as implemented in maximum parsimony using PAUP with the molecular-based 'backbone' approach. The data set encompasses most of the known extinct species of platyrrhines, ranging in age from latest Oligocene (∼26 Ma) to the Recent. The tree is rooted with extant catarrhines, and Late Eocene and Early Oligocene African anthropoids. Among the more interesting patterns to emerge are: (1) known early platyrrhines from the Late Oligocene through Early Miocene (26-16.5Ma) represent only stem platyrrhine taxa; (2) representatives of the three living platyrrhine families first occur between 15.7 Ma and 13.5 Ma; and (3) recently extinct primates from the Greater Antilles (Cuba, Jamaica, Hispaniola) are sister to the clade of extant platyrrhines and may have diverged in the Early Miocene. It is probable that the crown platyrrhine clade did not originate before about 20-24 Ma, a conclusion consistent with the phylogenetic analysis of fossil taxa presented here and with recent molecular clock estimates. The following biogeographic scenario is consistent with the phylogenetic findings and climatic and geologic evidence: Tropical South America has been a center for platyrrhine diversification since platyrrhines arrived on the continent in the middle Cenozoic. Platyrrhines dispersed from tropical South America to Patagonia at ∼25-24 Ma via a "Paraná Portal" through eastern South America across a retreating Paranense Sea. Phylogenetic bracketing suggests Antillean primates arrived via a sweepstakes route or island chain from northern South America in the Early Miocene, not via a proposed land bridge or island chain (GAARlandia) in the Early Oligocene (∼34 Ma). Patagonian and Antillean platyrrhines went extinct without leaving living descendants, the former at the end of the Early Miocene and the latter within the past six thousand years. Molecular evidence suggests crown platyrrhines arrived in Central America by crossing an intermittent connection through the Isthmus of Panama at or after 3.5Ma. Any more ancient Central American primates, should they be discovered, are unlikely to have given rise to the extant Central American taxa in situ.

  12. The Southern Ocean deep sea: first insights into biodiversity and biogeography

    DEFF Research Database (Denmark)

    Brandt, A.; Brix, S.; Brökeland, W.;

    2007-01-01

    environmental features, including a very deep continental shelf2 and a weakly stratified water column, and are the source for much of the deep water in the world ocean. These features suggest that deep-sea faunas around the Antarctic may be related both to adjacent shelf communities and to those in other oceans....... Unlike shallow-water Antarctic benthic communities, however, little is known about life in this vast deep-sea region2,3. Here, we report new data from recent sampling expeditions in the deep Weddell Sea and adjacent areas (748–6,348 m water depth) that reveal high levels of new biodiversity; for example......, 674 isopods species, of which 585 were new to science. Bathymetric and biogeographic trends varied between taxa. In groups such as the isopods and polychaetes, slope assemblages included species that have invaded from the shelf. In other taxa, the shelf and slope assemblages were more distinct...

  13. The avian fossil record in Insular Southeast Asia and its implications for avian biogeography and palaeoecology.

    Science.gov (United States)

    Meijer, Hanneke J M

    2014-01-01

    Excavations and studies of existing collections during the last decades have significantly increased the abundance as well as the diversity of the avian fossil record for Insular Southeast Asia. The avian fossil record covers the Eocene through the Holocene, with the majority of bird fossils Pleistocene in age. Fossil bird skeletal remains represent at least 63 species in 54 genera and 27 families, and two ichnospecies are represented by fossil footprints. Birds of prey, owls and swiftlets are common elements. Extinctions seem to have been few, suggesting continuity of avian lineages since at least the Late Pleistocene, although some shifts in species ranges have occurred in response to climatic change. Similarities between the Late Pleistocene avifaunas of Flores and Java suggest a dispersal route across southern Sundaland. Late Pleistocene assemblages of Niah Cave (Borneo) and Liang Bua (Flores) support the rainforest refugium hypothesis in Southeast Asia as they indicate the persistence of forest cover, at least locally, throughout the Late Pleistocene and Holocene.

  14. The avian fossil record in Insular Southeast Asia and its implications for avian biogeography and palaeoecology

    Directory of Open Access Journals (Sweden)

    Hanneke J.M. Meijer

    2014-03-01

    Full Text Available Excavations and studies of existing collections during the last decades have significantly increased the abundance as well as the diversity of the avian fossil record for Insular Southeast Asia. The avian fossil record covers the Eocene through the Holocene, with the majority of bird fossils Pleistocene in age. Fossil bird skeletal remains represent at least 63 species in 54 genera and 27 families, and two ichnospecies are represented by fossil footprints. Birds of prey, owls and swiftlets are common elements. Extinctions seem to have been few, suggesting continuity of avian lineages since at least the Late Pleistocene, although some shifts in species ranges have occurred in response to climatic change. Similarities between the Late Pleistocene avifaunas of Flores and Java suggest a dispersal route across southern Sundaland. Late Pleistocene assemblages of Niah Cave (Borneo and Liang Bua (Flores support the rainforest refugium hypothesis in Southeast Asia as they indicate the persistence of forest cover, at least locally, throughout the Late Pleistocene and Holocene.

  15. The Crotonia fauna of New Zealand revisited (Acari: Oribatida): taxonomy, phylogeny, ecological distribution and biogeography.

    Science.gov (United States)

    Colloff, Matthew J

    2015-04-14

    New Zealand contains 13 of the 69 species of Crotonia described globally and is the only place where all three genera of the Crotoniinae-Crotonia, Austronothrus and Holonothrus-have been recorded. Due to the pioneering work of Hammer (1966) and Luxton (1982) it also has the highest number of distribution records of Crotonia spp. anywhere. In the present study I build upon previous work to re-examine the Crotonia fauna of New Zealand in the light of recent taxonomic and biogeographical research. A new species is described, C. ramsayi sp. nov., a member of the Unguifera species group, and supplementary descriptions are provided for C. brachyrostrum (Hammer 1966), C. caudalis (Hammer, 1966), C. cophinaria (Michael, 1908), and C. unguifera (Michael 1908), as well as a key to species. Crotonia spp. from New Zealand occur predominantly in localities with relatively low mean annual temperature and high water balance, reflecting a requirement for cool, moist conditions. In New Zealand Crotonia spp. occur in an extremely wide variety of vegetation communities compared with other regions in its range (Australia, Africa and South America), and this is indicative that water balance requirements are met, regardless of vegetation type. Some elements of the New Zealand Crotonia fauna, notably the Cophinaria species group, are common to Australia, Africa and South America, indicating a shared evolutionary history pre-dating the separation of Africa from Gondwana 110 mya. The high proportion of species that occur west of the Alpine Fault is consistent with a relictual distribution of Gondwanan elements on the Australian Plate. However, it is unclear whether uplift of the Southern Alps formed a barrier to dispersal. A high representation of the morphologically closely-related Obtecta, Flagellata and Unguifera groups, shared only with South America (and, for Unguifera, with Oceania) represents a dramatically different faunal composition compared with other former Gondwanan landmasses and is consistent with submergence of most of New Zealand during the Oligocene (ca. 25 mya). All of these characteristics indicate a distinctive evolutionary pathway for the Crotonia fauna since New Zealand separated from the rest of Gondwana 80 mya.

  16. Complete mitochondrial genome sequence of the Eastern gorilla (Gorilla beringei) and implications for african ape biogeography.

    Science.gov (United States)

    Das, Ranajit; Hergenrother, Scott D; Soto-Calderón, Iván D; Dew, J Larry; Anthony, Nicola M; Jensen-Seaman, Michael I

    2014-01-01

    The Western and Eastern species of gorillas (Gorilla gorilla and Gorilla beringei) began diverging in the mid-Pleistocene, but in a complex pattern with ongoing gene flow following their initial split. We sequenced the complete mitochondrial genomes of 1 Eastern and 1 Western gorilla to provide the most accurate date for their mitochondrial divergence, and to analyze patterns of nucleotide substitutions. The most recent common ancestor of these genomes existed about 1.9 million years ago, slightly more recent than that of chimpanzee and bonobo. We in turn use this date as a calibration to reanalyze sequences from the Eastern lowland and mountain gorilla subspecies to estimate their mitochondrial divergence at approximately 380000 years ago. These dates help frame a hypothesis whereby populations became isolated nearly 2 million years ago with restricted maternal gene flow, followed by ongoing male migration until the recent past. This process of divergence with prolonged hybridization occurred against the backdrop of the African Pleistocene, characterized by intense fluctuations in temperature and aridity, while at the same time experiencing tectonic uplifting and consequent shifts in the drainage of major river systems. Interestingly, this same pattern of introgression following divergence and discrepancies between mitochondrial and nuclear loci is seen in fossil hominins from Eurasia, suggesting that such processes may be common in hominids and that living gorillas may provide a useful model for understanding isolation and migration in our extinct relatives.

  17. Biogeography and speciation patterns of the golden orb spider genus Nephila (Araneae: Nephilidae) in Asia.

    Science.gov (United States)

    Su, Yong-Chao; Chang, Yung-Hau; Smith, Deborah; Zhu, Ming-Sheng; Kuntner, Matjaž; Tso, I-Min

    2011-01-01

    The molecular phylogeny of the globally distributed golden orb spider genus Nephila (Nephilidae) was reconstructed to infer its speciation history, with a focus on SE Asian/W Pacific species. Five Asian, two Australian, four African, and one American species were included in the phylogenetic analyses. Other species in Nephilidae, Araneidae, and Tetragnathidae were included to assess their relationships with the genus Nephila, and one species from Uloboridae was used as the outgroup. Phylogenetic trees were reconstructed from one nuclear (18S) and two mitochondrial (COI and 16S) markers. Our molecular phylogeny shows that the widely distributed Asian/Australian species, N. pilipes, and an African species, N. constricta, form a clade that is sister to all other Nephila species. Nested in this Nephila clade are one clade with tropical and subtropical/temperate Asian/Australian species, and the other containing African and American species. The estimated divergence times suggest that diversification events within Nephila occurred during mid-Miocene to Pliocene (16 Mya-2 Mya), and these time periods were characterized by cyclic global warming/cooling events. According to Dispersal and Vicariance Analysis (DIVA), the ancestral range of the Asian/Australian clade was tropical Asia, and the ancestral range of the genus Nephila was either tropical Asia or Africa. We conclude that the speciation of the Asian/Australian Nephila species was driven by Neogene global cyclic climate changes. However, further population level studies comparing diversification patterns of sister species are needed to determine the mode of speciation of these species.

  18. Taxonomy and biogeography of African fruit bats (Mammalia, Megachiroptera). 4. The genus Rousettus Gray, 1821

    NARCIS (Netherlands)

    Bergmans, Wim

    1994-01-01

    The concept of the genus Rousettus Gray, 1821 as established by Andersen (1912) is revised to accommodate R. madagascariensis Grandidier, 1929, R. obliviosus Kock, 1978 and R. spinalatus Bergmans & Hill, 1980, and to reflect the following mutations. Following Bergmans et al. (1988), the genus Boneia

  19. ABOUT ORIGIN AND BIOGEOGRAPHY OF PANTEPUI BIRD FAUNA OR CROIZAT VERSUS MAYR: A CRITICAL REVISION

    Directory of Open Access Journals (Sweden)

    Marín, G.

    2010-01-01

    Full Text Available The highland sandstones of southeastern Venezuela, termed collectivelly Pantepui, are one of the most wonderful landscapes of the planet because their biogeographical conditions have concentred hot spots of high endemicity, importantly birds. Analysis of some theories about the origins of endemics Pantepui bird fauna, would invoke an “andean origin” via Llanos; nevertheless, such theories revealed serious discordances: a if the south american migrating land birds movements seem to have had a directional pattern northern-southern: how well can we to explain a “pantepuian colonization” western-eastern? b if, geologically, orogenesis of Guayana Shield is much more ancient to Andes, some “chance colonization” could have enterprised from a vice versa route: Pantepui-Andes. c if, ecologically and phytophysiographically, both the tropical and subtropical conditions of northern and northeastern venezuelan cordilleras are highly similar to guianan highlands than Andes ones (e.g., “messenerhebung” effect and formerly both formations was nearest, logically, I would suggest a new route through those cordilleras, to avoiding the enormous llanean hopping (1000 km and their antagonistic ecological features. On the grounds, it would allow to explain, partially: 1 Occurrence of guianian species, e.g., Nannopsittaca panychlora, relict on peninsula of Paria 2 That pantepuian species are nearest allied, numerically, with northern and eastern cordilleras species than such as andean ones. It seems likely that cordillerean route, ecologically more accesible only having two barriers, depresion of Unare and Pantano Oriental, on the one hand, and the conspicuous amount of paleoendemic elements, on the other hand, it allow me to infer that the Pantepui region resulted an important diversification center instead colonization center bird fauna in ancient times. Such assumption should empathize, partially, with the controvertible croizatian school, which have inquired since long ago with the mayrian viewpoints about pantepuian bird fauna origin. In light the everincreasing effects of new empirical and theorical findings, I argue contribution, consistence and current of the theories so far postulated, by using the latest scientific conceptual achievements. Nevertheless, my interpretations should be considered merely a working model based on a number of inferences to it may serve for testing the biogeographical pattern of several lineages of tepuian bird fauna.

  20. Is invasion success of Australian trees mediated by their native biogeography, phylogenetic history, or both?

    Science.gov (United States)

    Miller, Joseph T; Hui, Cang; Thornhill, Andrew; Gallien, Laure; Le Roux, Johannes J; Richardson, David M

    2016-12-30

    For a plant species to become invasive it has to progress along the introduction-naturalization-invasion (INI) continuum which reflects the joint direction of niche breadth. Identification of traits that correlate with and drive species invasiveness along the continuum is a major focus of invasion biology. If invasiveness is underlain by heritable traits, and if such traits are phylogenetically conserved, then we would expect non-native species with different introduction status (i.e. position along the INI continuum) to show phylogenetic signal. This study uses two clades that contain a large number of invasive tree species from the genera Acacia and Eucalyptus to test whether geographic distribution and a novel phylogenetic conservation method can predict which species have been introduced, became naturalized, and invasive. Our results suggest that no underlying phylogenetic signal underlie the introduction status for both groups of trees, except for introduced acacias. The more invasive acacia clade contains invasive species that have smoother geographic distributions and are more marginal in the phylogenetic network. The less invasive eucalyptus group contains invasive species that are more clustered geographically, more centrally located in the phylogenetic network and have phylogenetic distances between invasive and non-invasive species that are trending toward the mean pairwise distance. This suggests that highly invasive groups may be identified because they have invasive species with smoother and faster expanding native distributions and are located more to the edges of phylogenetic networks than less invasive groups.

  1. Diversity and biogeography of neotropical bamboos (Poaceae: Bambusoideae Diversidade e biogeografia de bambus (Poaceae: Bambusoideae

    Directory of Open Access Journals (Sweden)

    Lynn G Clark

    1990-07-01

    Full Text Available The present paper analyses the distribution of bamboos in New World. For convenience, bamboos are divided into two broad groups, the woody bamboos and the herbaceous bamboos. These categories do not necessarily reflect phylogenetic relationships among bamboo groups. The Bambuseae includes all of the woody bamboos and is probably monophyletic, whereas the herbaceous bamboos are classified into eight tribes. In the New World (including underscribed taxa, 45-46 genera and approximately 515 species are represented; only two genera: Arundinaria and Streptogyna are not exclusively neotropical. The area of greatest endemism and diversity is the humid coastal forests of Bahia, Brazil. 22 genera have been found in this relatively small area, representing 48% of all New World genera. Five of the 22 genera are endemic to the Bahia coastal forests.O presente trabalho analisa a distribuição geográfica dos bambus do Novo Mundo. Por questões práticas, os bambus foram divididos em dois grupos: os bambus lenhosos e os herbáceos, essas categorias entretanto, nem sempre refletem relacionamentos filogenéticos, pois embora as Bambuseae incluam todos os bambus lenhosos, sendo portanto provavelmetne monofiléticos, os bambus herbáceos são classificados em oito tribos. No Novo Mundo, (incluindo os taxa ainda não descritos existem cerca de 45-46 gêneros e aproximadamente 515 espécies. Desses gêneros, apenas dois: Arundinaria e Streptogyna não são exclusivamente neotropicais. A área de maior endemismo e diversidade do grupo, está nas florestas costeiras da Bahia, Brasil. Nesta região são encontrados 22 gêneros, representando 48% de todos os gêneros neotropicais e desses, 5 são exclusivos desta região da Bahia.

  2. Deconstructing environmental predictability: seasonality, environmental colour and the biogeography of marine life histories.

    Science.gov (United States)

    Marshall, Dustin J; Burgess, Scott C

    2015-02-01

    Environmental predictability is predicted to shape the evolution of life histories. Two key types of environmental predictability, seasonality and environmental colour, may influence life-history evolution independently but formal considerations of both and how they relate to life history are exceedingly rare. Here, in a global biogeographical analysis of over 800 marine invertebrates, we explore the relationships between both forms of environmental predictability and three fundamental life-history traits: location of larval development (aplanktonic vs. planktonic), larval developmental mode (feeding vs. non-feeding) and offspring size. We found that both dispersal potential and offspring size related to environmental predictability, but the relationships depended on both the environmental factor as well as the type of predictability. Environments that were more seasonal in food availability had a higher prevalence of species with a planktonic larval stage. Future studies should consider both types of environmental predictability as each can strongly affect life-history evolution.

  3. Biogeography of Mediterranean Hotspot Biodiversity: Re-Evaluating the 'Tertiary Relict' Hypothesis of Macaronesian Laurel Forests.

    Directory of Open Access Journals (Sweden)

    Paulina Kondraskov

    Full Text Available The Macaronesian laurel forests (MLF are dominated by trees with a laurophyll habit comparable to evergreen humid forests which were scattered across Europe and the Mediterranean in the Paleogene and Neogene. Therefore, MLF are traditionally regarded as an old, 'Tertiary relict' vegetation type. Here we address the question if key taxa of the MLF are relictual. We evaluated the relict hypothesis consulting fossil data and analyses based on molecular phylogenies of 18 representative species. For molecular dating we used the program BEAST, for ancestral trait reconstructions BayesTraits and Lagrange to infer ancestral areas. Our molecular dating showed that the origins of four species date back to the Upper Miocene while 14 originated in the Plio-Pleistocene. This coincides with the decline of fossil laurophyllous elements in Europe since the middle Miocene. Ancestral trait and area reconstructions indicate that MLF evolved partly from pre-adapted taxa from the Mediterranean, Macaronesia and the tropics. According to the fossil record laurophyllous taxa existed in Macaronesia since the Plio- and Pleistocene. MLF are composed of species with a heterogeneous origin. The taxa dated to the Pleistocene are likely not 'Tertiary relicts'. Some species may be interpreted as relictual. In this case, the establishment of most species in the Plio-Pleistocene suggests that there was a massive species turnover before this time. Alternatively, MLF were largely newly assembled through global recruitment rather than surviving as relicts of a once more widespread vegetation. This process may have possibly been triggered by the intensification of the trade winds at the end of the Pliocene as indicated by proxy data.

  4. Biogeography of Persephonella in deep-sea hydrothermal vents of the Western Pacific.

    Directory of Open Access Journals (Sweden)

    Sayaka eMino

    2013-04-01

    Full Text Available Deep-sea hydrothermal vent fields are areas on the seafloor with high biological productivity fueled by microbial chemosynthesis. Members of the Aquificales genus Persephonella are obligately chemosynthetic bacteria, and appear to be key players in carbon, sulfur, and nitrogen cycles in high temperature habitats at deep-sea vents. Although this group of bacteria has cosmopolitan distribution in deep-sea hydrothermal ecosystem around the world, little is known about their population structure such as intraspecific genomic diversity, distribution pattern, and phenotypic diversity. We developed the multi-locus sequence analysis (MLSA scheme for their genomic characterization. Sequence variation was determined in five housekeeping genes and one functional gene of 36 P. hydrogeniphila strains originated from the Okinawa Trough and the South Mariana Trough. Although the strains share > 98.7% similarities in 16S rRNA gene sequences, MLSA revealed 35 different sequence types, indicating their extensive genomic diversity. A phylogenetic tree inferred from all concatenated gene sequences revealed the clustering of isolates according to the geographic origin. In addition, the phenotypic clustering pattern inferred from whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS analysis can be correlated to their MLSA clustering pattern. This study represents the first MLSA combined with phenotypic analysis indicative of allopatric speciation of deep-sea hydrothermal vent bacteria.

  5. Crocodyliform biogeography during the Cretaceous: evidence of Gondwanan vicariance from biogeographical analysis.

    Science.gov (United States)

    Turner, Alan H.

    2004-01-01

    Explanations of the distributions of terrestrial vertebrates during the Mesozoic are currently vigorously contested and debated in palaeobiogeography. Recent studies focusing on dinosaurs yield conflicting hypotheses. Dispersal, coupled with regional extinction or vicariance driven by continental break-up, have been cited as the main causal factors behind dinosaur distributions in the Mesozoic. To expand the scope of the debate and test for vicariance within another terrestrial group, I herein apply a cladistic biogeographical method to a large sample of Cretaceous crocodyliform taxa. A time-slicing methodology is employed and a refinement made to account for the divergence times of the analysed clades. The results provide statistically significant evidence that Gondwana fragmentation affected crocodyliform diversification during the Mid-Late Cretaceous. Detection of a vicariant pattern within crocodyliforms is important as it helps corroborate vicariance hypotheses in other fossil and extant groups as well as furthers the move towards more taxonomically diverse approaches to palaeobiogeographical research. PMID:15451689

  6. Plate tectonics, seaways and climate in the historical biogeography of mammals.

    Science.gov (United States)

    Cox, C B

    2000-01-01

    The marsupial and placental mammals originated at a time when the pattern of geographical barriers (oceans, shallow seas and mountains) was very different from that of today, and climates were warmer. The sequence of changes in these barriers, and their effects on the dispersal of the mammal families and on the faunas of mammals in the different continents, are reviewed. The mammal fauna of South America changed greatly in the Pliocene/Pleistocene, when the newly-complete Panama Isthmus allowed the North American fauna to enter the continent and replace most of the former South American mammal families. Marsupial, but not placental, mammals reached Australia via Antarctica before Australia became isolated, while rats and bats are the only placentals that dispersed naturally from Asia to Australia in the late Cenozoic. Little is known of the early history of the mammal fauna of India. A few mammal families reached Madagascar from Africa in the early Cenozoic over a chain of islands. Africa was isolated for much of the early Cenozoic, though some groups did succeed in entering from Europe. Before the climate cooled in the mid-Cenozoic, the mammal faunas of the Northern Hemisphere were much richer than those of today.

  7. Biogeography of free-living soil nematodes from the perspective of plate tectonics.

    Science.gov (United States)

    Ferris, V R; Goseco, C G; Ferris, J M

    1976-08-01

    In this first biogeographical synthesis based on the morphology and known distribution of a group of free-living soil nematodes, data indicate a pre-Jurassic origin followed by West Gondwanaland radiation for some genera and Laurasian radiation for others.

  8. Morphological homoplasy, life history evolution, and historical biogeography of plethodontid salamanders inferred from complete mitochondrial genomes

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Rachel Lockridge; Macey, J. Robert; Jaekel, Martin; Wake, David B.; Boore, Jeffrey L.

    2004-08-01

    The evolutionary history of the largest salamander family (Plethodontidae) is characterized by extreme morphological homoplasy. Analysis of the mechanisms generating such homoplasy requires an independent, molecular phylogeny. To this end, we sequenced 24 complete mitochondrial genomes (22 plethodontids and two outgroup taxa), added data for three species from GenBank, and performed partitioned and unpartitioned Bayesian, ML, and MP phylogenetic analyses. We explored four dataset partitioning strategies to account for evolutionary process heterogeneity among genes and codon positions, all of which yielded increased model likelihoods and decreased numbers of supported nodes in the topologies (PP > 0.95) relative to the unpartitioned analysis. Our phylogenetic analyses yielded congruent trees that contrast with the traditional morphology-based taxonomy; the monophyly of three out of four major groups is rejected. Reanalysis of current hypotheses in light of these new evolutionary relationships suggests that (1) a larval life history stage re-evolved from a direct-developing ancestor multiple times, (2) there is no phylogenetic support for the ''Out of Appalachia'' hypothesis of plethodontid origins, and (3) novel scenarios must be reconstructed for the convergent evolution of projectile tongues, reduction in toe number, and specialization for defensive tail loss. Some of these novel scenarios imply morphological transformation series that proceed in the opposite direction than was previously thought. In addition, they suggest surprising evolutionary lability in traits previously interpreted to be conservative.

  9. Biogeography and taxonomic status of Myotis keaysi pilosatibialis LaVal 1973 (Chiroptera: Vespertilionidae) .

    Science.gov (United States)

    Mantilla-Meluk, Hugo; Muñoz-Garay, Javier

    2014-04-28

    We document the first confirmed Colombian records of Myotis keaysi pilosatibialis LaVal, 1973 from various localities on the Colombian Caribbean and the Eastern Cordillera of the Colombian Andes. These records confirm geographic overlap between M. k. pilosatibialis and the nominate subspecies M. k. keaysi J. A. Allen, 1914, in northeastern Colombia, questioning the subspecific status of M. k. pilosatibialis. Models of potential distribution, produced for the two taxa by the application of the Maxent algorithm, show a potential geographic overlap in the northeastern portion of the Andes of Colombia and Venezuela. In order to clarify the taxonomic status of putative M. keaysi variants, we analyzed the variation of Colombian representatives of M. keaysi through a Principal Components Analysis (PCA), and a Discriminant Function Analysis (DFA) performed on 18 cranio-dental measurements, as well as the analysis of discrete characters. The morphological independence between M. k. keaysi and M. k. pilosatibialis was supported statistically in our PCA and DFA, as well as by the presence of unique discrete characters, lending support to the recognition of M. k. pilosatibialis as full species. Herein, we include new discrete characters setting apart M. pilosatibialis from the morphologically similar species M. keaysi. 

  10. Cophylogenetics and biogeography reveal a coevolved relationship between sloths and their symbiont algae.

    Science.gov (United States)

    Fountain, Emily D; Pauli, Jonathan N; Mendoza, Jorge E; Carlson, Jenna; Peery, M Zachariah

    2017-05-01

    Specialized species, like arboreal folivores, often develop beneficial relationships with symbionts to exploit ecologically constrained lifestyles. Although coevolution can drive speciation by specialization of a symbiont to a host, a symbiotic relationship is not indicative of coevolution between host and symbiont. We tested for coevolved relationships between highly specialized two- and three-toed sloths (Choloepus spp. and Bradypus spp., respectively) and their symbiotic algae using cophylogenies and phylogeography. Our phylogeographic analysis showed a biogeographic pattern for the sloth distribution that was not found in the algal phylogeny. We found support for congruence between the sloth and algae phylogenies, implying cospeciation, only in the Bradypus lineage. Algae host-switching occurred from Bradypus spp. to Choloepus spp. Our results support a previously hypothesized symbiotic relationship between sloths and the algae in their fur and indicate that coevolution may have played a role in algae diversification. More broadly, convergent evolution may facilitate host switching between deeply diverged host lineages.

  11. Molecular phylogeny and historical biogeography of the Anatolian lizard Apathya (Squamata, Lacertidae).

    Science.gov (United States)

    Kapli, Paschalia; Botoni, Dimitra; Ilgaz, Cetin; Kumlutaş, Yusuf; Avcı, Aziz; Rastegar-Pouyani, Nasrullah; Fathinia, Behzad; Lymberakis, Petros; Ahmadzadeh, Faraham; Poulakakis, Nikos

    2013-03-01

    Apathya is a lacertid genus occurring mainly in south-east Turkey and its adjacent regions (part of Iran and Iraq). So far two morphological species have been attributed to the genus; A. cappadocica (with five subspecies, A. c.cappadocica, A. c.muhtari, A. c.schmidtlerorum, A. c. urmiana and A. c.wolteri) and A.yassujica. The first species occupies most of the genus' distribution range, while A. yassujica is endemic of the Zagros Mountains. Here, we explored Apathya's taxonomy and investigated the evolutionary history of the species by employing phylogenetic and phylogeographic approaches and using both mitochondrial (mtDNA) and nuclear markers. The phylogenetic relationships and the genetic distances retrieved, revealed that Apathya is a highly variable genus, which parallels its high morphological variation. Such levels of morphological and genetic differentiation often exceed those between species of other Lacertini genera that are already treated as full species, suggesting the necessity for a taxonomic revision of Apathya. The phylogeographical scenario emerging from the genetic data suggests that the present distribution of the genus was determined by a combination of dispersal and vicariance events between Anatolia and Southwest Asia dating back to the Miocene and continuing up to the Pleistocene. Key geological events for the understanding of the phylogeography of the genus are the movement of the Arabian plate that led to the configuration of Middle East (orogenesis of the mountain ranges of Turkey and Iran) and the formation of Anatolian Diagonal.

  12. Mitochondrial cytochrome B phylogeny and historical biogeography of the Tohoku salamander, Hynobius lichenatus (Amphibia, Caudata).

    Science.gov (United States)

    Aoki, Gen; Matsui, Masafumi; Nishikawa, Kanto

    2013-03-01

    The Tohoku salamander, Hynobius lichenatus Boulenger, 1883, is a lentic breeding species widespread throughout montane regions of northeastern Japan. To explore intraspecific genetic variation and infer evolutionary history of H. lichenatus, we performed mitochondrial DNA analysis (complete 1141 bp sequences of the mitochondrial cytochrome b gene) using 215 adult and larval individuals collected from 75 localities, encompassing known distributional range of the species. Hynobius lichenatus proved to be monophyletic, including three well-supported and geographically structured clades (Clade I from northern Kanto, Clade II from southern Tohoku, and Clade III from northern Tohoku). These clades, respectively, comprise several subclades, and show genetic distances as large as those seen between different species of Hynobius. Results of population statistic analyses indicate that all clades and most subclades have maintained high genetic diversity and demographic stability over long periods. Molecular dating indicates divergence in H. lichenatus concords with topographic evolution of northeastern Japan from late Miocene to early Pleistocene, suggesting that paleogeographic events in this region, such as orogenesis, sea level change, and volcanic activity, have been crucial for shaping genetic patterns and diversity in this species. Hynobius lichenatus greatly differs from many other animal species from northeastern Japan in its much older periods and the pattern of genetic differentiation, and is suggested as an old faunal element in this region.

  13. Diversity-dependent cladogenesis throughout western Mexico: Evolutionary biogeography of rattlesnakes (Viperidae: Crotalinae: Crotalus and Sistrurus).

    Science.gov (United States)

    Blair, Christopher; Sánchez-Ramírez, Santiago

    2016-04-01

    Rattlesnakes (Crotalus and Sistrurus) represent a radiation of approximately 42 species distributed throughout the New World from southern Canada to Argentina. Interest in this enigmatic group of snakes continues to accrue due, in part, to their ecomorphological diversity, contributions to global envenomations, and potential medicinal importance. Although the group has garnered substantial attention from systematists and evolutionary biologists for decades, little is still known regarding patterns of lineage diversification. In addition, few studies have statistically quantified broad-scale biogeographic patterns in rattlesnakes to ascertain how dispersal occurred throughout the New World, particularly among the different major biomes of the Americas. To examine diversification and biogeographic patterns in this group of snakes we assemble a multilocus data set consisting of over 6700bp encompassing three nuclear loci (NT-3, RAG-1, C-mos) and seven mitochondrial genes (12S, 16S, ATPase6, ATPase8, ND4, ND5, cytb). Fossil-calibrated phylogenetic and subsequent diversification rate analyses are implemented using maximum likelihood and Bayesian inference, to examine their evolutionary history and temporal dynamics of diversity. Based on ancestral area reconstructions we explore dispersal patterns throughout the New World. Cladogenesis occurred predominantly during the Miocene and Pliocene with only two divergences during the Pleistocene. Two different diversification rate models, advocating diversity-dependence, are strongly supported. These models indicate an early rapid radiation followed by a recent speciation rate decline. Biogeographic analyses suggest that the high elevation pine-oak forests of western Mexico served as a major speciation pump for the majority of lineages, with the desert biome of western North America colonized independently at least twice. All together, these results provide evidence for rapid diversification of rattlesnakes throughout the Mexican highlands during the Neogene, likely in response to continual orogenesis of Mexico's major mountain systems, followed by more recent dispersal into desert and tropical biomes.

  14. Phylogeny and biogeography of hawkmoths (Lepidoptera: Sphingidae: evidence from five nuclear genes.

    Directory of Open Access Journals (Sweden)

    Akito Y Kawahara

    Full Text Available BACKGROUND: The 1400 species of hawkmoths (Lepidoptera: Sphingidae comprise one of most conspicuous and well-studied groups of insects, and provide model systems for diverse biological disciplines. However, a robust phylogenetic framework for the family is currently lacking. Morphology is unable to confidently determine relationships among most groups. As a major step toward understanding relationships of this model group, we have undertaken the first large-scale molecular phylogenetic analysis of hawkmoths representing all subfamilies, tribes and subtribes. METHODOLOGY/PRINCIPAL FINDINGS: The data set consisted of 131 sphingid species and 6793 bp of sequence from five protein-coding nuclear genes. Maximum likelihood and parsimony analyses provided strong support for more than two-thirds of all nodes, including strong signal for or against nearly all of the fifteen current subfamily, tribal and sub-tribal groupings. Monophyly was strongly supported for some of these, including Macroglossinae, Sphinginae, Acherontiini, Ambulycini, Philampelini, Choerocampina, and Hemarina. Other groupings proved para- or polyphyletic, and will need significant redefinition; these include Smerinthinae, Smerinthini, Sphingini, Sphingulini, Dilophonotini, Dilophonotina, Macroglossini, and Macroglossina. The basal divergence, strongly supported, is between Macroglossinae and Smerinthinae+Sphinginae. All genes contribute significantly to the signal from the combined data set, and there is little conflict between genes. Ancestral state reconstruction reveals multiple separate origins of New World and Old World radiations. CONCLUSIONS/SIGNIFICANCE: Our study provides the first comprehensive phylogeny of one of the most conspicuous and well-studied insects. The molecular phylogeny challenges current concepts of Sphingidae based on morphology, and provides a foundation for a new classification. While there are multiple independent origins of New World and Old World radiations, we conclude that broad-scale geographic distribution in hawkmoths is more phylogenetically conserved than previously postulated.

  15. Phylogeny, systematics and biogeography of the genus panolis (lepidoptera: noctuidae based on morphological and molecular evidence.

    Directory of Open Access Journals (Sweden)

    Houshuai Wang

    Full Text Available The genus Panolis is a small group of noctuid moths with six recognized species distributed from Europe to East Asia, and best known for containing the widespread Palearctic pest species P. flammea, the pine beauty moth. However, a reliable classification and robust phylogenetic framework for this group of potentially economic importance are currently lacking. Here, we use morphological and molecular data (mitochondrial genes cytochrome c oxidase subunit I and 16S ribosomal RNA, nuclear gene elongation factor-1 alpha to reconstruct the phylogeny of this genus, with a comprehensive systematic revision of all recognized species and a new one, P. ningshan sp. nov. The analysis results of maximum parsimony, maximum likelihood and Bayesian inferring methods for the combined morphological and molecular data sets are highly congruent, resulting in a robust phylogeny and identification of two clear species groups, i.e., the P. flammea species group and the P. exquisita species group. We also estimate the divergence times of Panolis moths using two conventional mutation rates for the arthropod mitochondrial COI gene with a comparison of two molecular clock models, as well as reconstruct their ancestral areas. Our results suggest that 1 Panolis is a young clade, originating from the Oriental region in China in the Late Miocene (6-10Mya, with an ancestral species in the P. flammea group extending northward to the Palearctic region some 3-6 Mya; 2 there is a clear possibility for a representative of the Palearctic clade to become established as an invasive species in the Nearctic taiga.

  16. Biogeography, Cultivation and Genomic Characterization of Prochlorococcus in the Red Sea

    KAUST Repository

    Shibl, Ahmed A.

    2015-12-16

    Aquatic primary productivity mainly depends on pelagic phytoplankton. The globally abundant marine picocyanobacteria Prochlorococcus comprises a significant fraction of the photosynthetic biomass in most tropical, oligotrophic oceans. The Red Sea is an enclosed narrow body of water characterized by continuous solar irradiance, and negligible annual rainfall, in addition to elevated temperatures and salinity levels, which mimics a global warming scenario. Analysis of 16S rRNA sequences of bacterioplankton communities indicated the predominance of a high-light adapted ecotype (HL II) of Prochlorococcus at the surface of the Northern and Central Red Sea. To this end, we analyzed the distribution of Prochlorococcus at multiple depths within and below the euphotic zone in different regions of the Red Sea, using clone libraries of the 16S–23S rRNA internal transcribed spacer (ITS) region. Results indicated a high diversity of Prochlorococcus ecotypes at the 100 m depth in the water column and an unusual dominance of HL II-related sequences in deeper waters of the Red Sea. To further investigate the microdiversity of Prochlorococcus over a wider biogeographical scope, we used a 454-pyrosequencing approach to analyze rpoC1 gene pyrotags. Samples were collected from the surface of the water column to up to 500 m at 45 stations that span the Red Sea’s main basin from 4 north to south. Phylogenetic analysis of abundant rpoC1 OTUs revealed genotypes of recently discovered strains that belong to the high-light and lowlight clades. In addition, we used a rapid community-profiling tool (GraftM) and quantitatively analyzed rpoC1 gene abundance from 45 metagenomes to assess the Prochlorococcus community structure across vertical and horizontal physicochemical gradients. Results revealed the clustering of samples according to their depth and a strong influence on ecotypic distribution by temperature and oxygen levels. In efforts to better understand how the cells survive the unusual features of the Red Sea, a Prochlorococcus strain of the HL II adapted clade from the euphotic zone was cultured, enabling morphological analyses and growth rates measurements for the strain. In addition, we successfully sequenced and annotated the genome of the strain, which was then used for genomic comparison with other ecotypes. Interestingly, the set of unique genes identified in the draft genome included genes encoding proteins involved in salt tolerance mechanisms. The expression level and pattern of these genes in the Red Sea water column was explored through metatranscriptomic mapping and revealed their occurrence throughout, independent of the diel cycle. This led to the hypothesis that Prochlorococcus populations in the highly saline Red Sea are able to biosynthesize additional compatible solutes via several pathways to counterbalance the effects of salt stress. The results presented in this dissertation provide the first glimpse on how the environmental parameters of the Red Sea can affect the evolution, diversity and distribution patterns of Prochlorococcus ecotypes.

  17. Evolution of the platycodonoid group with particular references to biogeography and character evolution

    Institute of Scientific and Technical Information of China (English)

    Qiang Wang; Xiao-Quan Wang; Hang Sun; Yan Yu; Xing-Jin He; De-Yuan Hong

    2014-01-01

    The Qinghai-Tibet Plateau (QTP) is an important center of origin and diversification for many northern temperate plants. The hypothesis“out-of-QTP”suggests that the majority of northern temperate plants have originated and dispersed from the QTP and adjacent regions. An interesting question is whether the biogeographic history of the platycodonoids (Campanulaceae), a group mainly distributed in the QTP and adjacent regions, coincides with the hypothesis“out-of-QTP”? Furthermore, how have the diagnostic charac-ters of the platycodonoids evolved? In the present study, al 10 genera of the platycodonoids were sampled for molecular phylogeny and dating analyses, and ancestral states of distribution and characters were reconstructed. The results do not support the platycodonoids as an“out-of-QTP”group, but instead they might have descended from Tethyan ancestors. The dispersal and diversification of the platycodo-noids in Asia might have been driven by the uplift of the QTP. The present study highlights the importance of the Tethyan Tertiary flora for the origin of the Sino-Himalayan flora and the influence of the uplift of QTP on diversification of northern temperate plants. In addition, character state reconstruction reveals that the inferior ovary, capsule, long-colpate pol en, and chromosome number 2n ¼ 14 are probably ancestral states.

  18. NOAA ESRI Grid - depth predictions bathymetry model in New York offshore planning area from Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents depth predictions from a bathymetric model developed for the New York offshore spatial planning area. The model also includes...

  19. Long distance kelp rafting impacts seaweed biogeography in the Northeast Pacific: the kelp conveyor hypothesis.

    Science.gov (United States)

    Saunders, Gary W

    2014-12-01

    Routine DNA barcoding of the Haida Gwaii seaweed flora revealed "endemic species" attributed initially to this region's past as a glacial refugium. However, subsequent barcode records from central California rapidly eroded this list leaving species characterized by disjunct distributions (DD) between California and Haida Gwaii. This observation prompted a more detailed look at species for California and British Columbia and revealed that 33 of 180 DNA-barcoded genetic groups in common between these regions (~18%) predominantly displayed DD between California and northern British Columbia. A previous discovery that a red abalone shell found in Haida Gwaii (far north of its range) had a float-bearing kelp (Nereocystis luetkeana) holdfast attached to it prompted a closer consideration of the COI-5P barcode data in support of a "kelp conveyor hypothesis." The hypothesis posits that there has been a net migration of Californian species to northern British Columbia the vector being species growing on substrata carried along with kelp rafts on the winter Davidson Current.

  20. Historical Biogeography of the Southeast Asian genus Spatholobus (Legum.-Papilionoideae) and its allies

    NARCIS (Netherlands)

    Ridder-Numan, Jeannette W.A.

    1996-01-01

    The genera Butea, Meizotropis and Spatholobus (Leguminosae—Papilionoideae), occurring in continental Southeast Asia and the West Malesian Archipelago, are treated phylogenetically with Kunstleria as an outgroup. The genera Spatholobus (29 species), Butea and Meizotropis (each 2 species) are usually

  1. Revision and biogeography of the Neotropical dung beetle genus Scybalophagus (Coleoptera: Scarabaeidae

    Directory of Open Access Journals (Sweden)

    Federico Carlos OCAMPO

    2011-01-01

    Full Text Available El género suramericano Scybalophagus Martínez es revisado exhaustivamente. El género ahora incluye cinco especies distribuidas en Argentina, Chile, Bolivia y Perú. Se redescriben todas las especies y se proveen caracteres diagnósticos junto con ilustraciones para cada especie. Se designan lectotipos para Canthon lacordairei Laporte, 1840 (ahora Scybalophagus lacordairei y Canthon rugosus Blanchard, 1845 (ahora S. rugosus. Scybalophagus zumpti (Frey 1963 (=Epirinus zumpti Frey es ahora considerado un sinónimo junior de S. rugosus (Blanchard. La Biogeografía del género y cada especie es discutida y se presentan distribuciones potenciales, basadas en modelos de nicho ecológico, para todas las especies. Se discute la información sobre la biología e historia natural de las especies de Scybalophagus.

  2. Phylogeny and biogeography of the Canarian Solanum vespertilio and S. lidii (Solanaceae

    Directory of Open Access Journals (Sweden)

    Anderson, Gregory J.

    2006-12-01

    Full Text Available The endemic and rare Solanum vespertilio and S. lidii from the Canary Islands are notable in being andromonoecious, self compatible, highly heterandrous (with short >reward= anthers and one very long >pollination= anther, and bearing strongly zygomorphic corollas. Solanum vespertilio flowers are also tetramerous, and some display enantiostyly. Given their island distribution, uncommon for solanums, and many distinctive reproductive features, the phylogenetic position is of interest. With new molecular data from the chloroplast trnT-F region and the nuclear granule-bound starch synthase gene (GBSSI or waxy, we confirm the hypothesis that these two species are phylogenetically associated with Solanum lineages from Africa, rather than with previously suggested Mexican species. The phylogeny facilitates understanding the evolution of the unique suite of reproductive characteristics in these island endemics.Las endémicas y raras especies Solanum vespertilio y S. lidii de las Islas Canarias son notables por ser andromonoicas, autocompatibles, altamente heterándricas (con anteras cortas para recompensa y una muy larga para polinización y por tener corolas fuertemente zigomórficas. Las flores de Solanum vespertilio son, además, tetrámeras y muestran enantiostilia. Dada su distribución insular, poco común para Solanum, y sus distintivas características reproductivas, su posición filogenética es de interés. Con nuevos datos moleculares de la región trnT-F del ADN del cloroplasto y del gen nuclear de la enzima almidón sintasa unida al gránulo (GBSSI o waxy, confirmamos la hipótesis de que estas dos especies están filogenéticamente asociadas con los linajes geográficamente próximos de Solanum africanos, más que con especies mexicanas previamente sugeridas. La filogenia facilita la comprensión de la evolución del conjunto singular de características reproductivas de estas especies endémicas de islas.

  3. A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America, and the Biogeography of Neoceratopsia.

    Directory of Open Access Journals (Sweden)

    Andrew A Farke

    Full Text Available The fossil record for neoceratopsian (horned dinosaurs in the Lower Cretaceous of North America primarily comprises isolated teeth and postcrania of limited taxonomic resolution, hampering previous efforts to reconstruct the early evolution of this group in North America. An associated cranium and lower jaw from the Cloverly Formation (?middle-late Albian, between 104 and 109 million years old of southern Montana is designated as the holotype for Aquilops americanus gen. et sp. nov. Aquilops americanus is distinguished by several autapomorphies, including a strongly hooked rostral bone with a midline boss and an elongate and sharply pointed antorbital fossa. The skull in the only known specimen is comparatively small, measuring 84 mm between the tips of the rostral and jugal. The taxon is interpreted as a basal neoceratopsian closely related to Early Cretaceous Asian taxa, such as Liaoceratops and Auroraceratops. Biogeographically, A. americanus probably originated via a dispersal from Asia into North America; the exact route of this dispersal is ambiguous, although a Beringian rather than European route seems more likely in light of the absence of ceratopsians in the Early Cretaceous of Europe. Other amniote clades show similar biogeographic patterns, supporting an intercontinental migratory event between Asia and North America during the late Early Cretaceous. The temporal and geographic distribution of Upper Cretaceous neoceratopsians (leptoceratopsids and ceratopsoids suggests at least intermittent connections between North America and Asia through the early Late Cretaceous, likely followed by an interval of isolation and finally reconnection during the latest Cretaceous.

  4. Molecular phylogenetics of the Brazilian giant bromeliads (Alcantarea, Bromeliaceae): implications for morphological evolution and biogeography.

    Science.gov (United States)

    Versieux, Leonardo M; Barbará, Thelma; Wanderley, Maria das Graças Lapa; Calvente, Alice; Fay, Michael F; Lexer, Christian

    2012-07-01

    The genus Alcantarea comprises near 30 species endemic to rocky outcrops from eastern Brazil. Most species are ornamental and several are threatened due to habitat loss and over collection. In this paper we examine the phylogenetics of Alcantarea and its relationship with the Brazilian members of Vriesea, a genus of which Alcantarea has been treated as a subgenus. We discuss the morphological evolution of the stamen position and its implication for pollination and the occurrence of Alcantarea in the Espinhaço mountain range rocky savanna-like habitat vegetation. DNA sequence data derived from two plastid markers (trnK-rps16, trnC-petN) and from a low copy nuclear gene (Floricaula/Leafy) together with 20 nuclear microsatellite loci were the data source to perform analyses and construct phylogenetic and Neighbor Joining trees for the genus. Alcantarea is well supported as monophyletic in both Bayesian and parsimony analyses, but sections of Vriesea, represented by the eastern Brazilian species, appear paraphyletic. Microsatellites delimit geographically isolated species groups. Nevertheless individuals belonging to a single species may appear related to distinct clusters of species, suggesting that hybridization and/or homoplasy and/or incomplete lineage sorting are also influencing the analysis based on such markers and may be the reasons for some unexpected results. Alcantarea brasiliana is hypothesized as putative hybrid between A. imperialis and A. geniculata. Spreading stamens, a morphological floral characteristic assumed to be related to Chiropterophily, apparently evolved multiple times within the genus, and invasion of rocky savanna-like habitat vegetation by Atlantic rainforest ancestors seems to have occurred multiple times as well.

  5. Limit theorems for splitting trees with structured immigration and applications to biogeography

    CERN Document Server

    Richard, Mathieu

    2010-01-01

    We consider a branching process with Poissonian immigration where individuals have inheritable types. At rate $\\theta$, new individuals singly enter the total population and start a new population which evolves like a supercritical, homogeneous, binary Crump-Mode-Jagers process: individuals have i.i.d. lifetimes durations (non necessarily exponential) during which they give birth independently at constant rate b. First, using spine decomposition, we relax previously known assumptions required for a.s. convergence of total population size. Then, we consider three models of structured populations: either all immigrants have a different type, or types are drawn in a discrete spectrum or in a continuous spectrum. In each model, the vector (P_1,P_2,...) of relative abundances of surviving families converges a.s. In the first model, the limit is the GEM distribution with parameter $\\theta/b$.

  6. NOAA ESRI Shapefile - sediment composition class predictions in New York offshore planning area from Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents sediment composition class predictions from a sediment spatial model developed for the New York offshore spatial planning area. The...

  7. First insights into the biodiversity and biogeography of the Southern Ocean deep sea.

    Science.gov (United States)

    Brandt, Angelika; Gooday, Andrew J; Brandão, Simone N; Brix, Saskia; Brökeland, Wiebke; Cedhagen, Tomas; Choudhury, Madhumita; Cornelius, Nils; Danis, Bruno; De Mesel, Ilse; Diaz, Robert J; Gillan, David C; Ebbe, Brigitte; Howe, John A; Janussen, Dorte; Kaiser, Stefanie; Linse, Katrin; Malyutina, Marina; Pawlowski, Jan; Raupach, Michael; Vanreusel, Ann

    2007-05-17

    Shallow marine benthic communities around Antarctica show high levels of endemism, gigantism, slow growth, longevity and late maturity, as well as adaptive radiations that have generated considerable biodiversity in some taxa. The deeper parts of the Southern Ocean exhibit some unique environmental features, including a very deep continental shelf and a weakly stratified water column, and are the source for much of the deep water in the world ocean. These features suggest that deep-sea faunas around the Antarctic may be related both to adjacent shelf communities and to those in other oceans. Unlike shallow-water Antarctic benthic communities, however, little is known about life in this vast deep-sea region. Here, we report new data from recent sampling expeditions in the deep Weddell Sea and adjacent areas (748-6,348 m water depth) that reveal high levels of new biodiversity; for example, 674 isopods species, of which 585 were new to science. Bathymetric and biogeographic trends varied between taxa. In groups such as the isopods and polychaetes, slope assemblages included species that have invaded from the shelf. In other taxa, the shelf and slope assemblages were more distinct. Abyssal faunas tended to have stronger links to other oceans, particularly the Atlantic, but mainly in taxa with good dispersal capabilities, such as the Foraminifera. The isopods, ostracods and nematodes, which are poor dispersers, include many species currently known only from the Southern Ocean. Our findings challenge suggestions that deep-sea diversity is depressed in the Southern Ocean and provide a basis for exploring the evolutionary significance of the varied biogeographic patterns observed in this remote environment.

  8. First insights into the biodiversity and biogeography of the Southern Ocean deep sea

    NARCIS (Netherlands)

    Brandt, A.; Gooday, A.J.; Brandao, S.N.; Mesel, de I.G.

    2007-01-01

    Shallow marine benthic communities around Antarctica show high levels of endemism, gigantism, slow growth, longevity and late maturity, as well as adaptive radiations that have generated considerable biodiversity in some taxa. The deeper parts of the Southern Ocean exhibit some unique environmental

  9. First insights into the biodiversity and biogeography of the Southern Ocean deep sea

    OpenAIRE

    Brandt, A.; Gooday, A. J.; Brandão, S.N.; Brix, S.; Brökeland, W.; Cedhagen, T.; Choudhury, M.; Cornelius, N.; Danis, B; Mesel, I. de; Diaz, R. J.; Gillan, D.C.; Ebbe, B.; Howe, J.A.; Janussen, D.

    2007-01-01

    Shallow marine benthic communities around Antarctica show high levels of endemism, gigantism, slow growth, longevity and late maturity, as well as adaptive radiations that have generated considerable biodiversity in some taxa1. The deeper parts of the Southern Ocean exhibit some unique environmental features, including a very deep continental shelf2 and a weakly stratified water column, and are the source for much of the deep water in the world ocean. These features suggest that deep-sea faun...

  10. Phylogenetics, biogeography and population genetics of the ascidian Botryllus schlosseri in the Mediterranean Sea and beyond.

    Science.gov (United States)

    Reem, Eitan; Douek, Jacob; Paz, Guy; Katzir, Gadi; Rinkevich, Baruch

    2017-02-01

    The wide distribution of the ascidian Botryllus schlosseri along the Mediterranean coasts has been documented since the eighteenth century. However, despite copious documentation, analyses of dispersal modes and genetic profiles were limited to local populations or restricted regions. In order to get a pan-Mediterranean overview, 288 specimens from 11 populations of B. schlosseri from the western and eastern Mediterranean basins were sampled and analyzed using five microsatellite loci and COI sequences. Both molecular markers revealed high polymorphisms, with 182 microsatellites alleles and 54 COI haplotypes. Overall, Fst, Dest, and COI Фpt values were 0.146, 0.635 and 0.322, respectively, reflecting a high genetic diversity and a significant genetic structure as compared to other B. schlosseri populations worldwide, reflected by substantially higher values for effective number of alleles (Ne) in the Mediterranean. A phylogenetic analysis of the COI sequences resulted in four distinct clades and two molecular operational taxonomic units (OTUs). We recorded a stronger genetic structure among the populations of the eastern basin compared to the western basin (microsatellites Fst=0.217 versus 0.082; COI Фpt=0.416 versus 0.171), suggesting either a restricted connectivity between the basins or a stronger genetic drift in each basin. The occurrence of two OTUs and different ecological conditions may also contribute to this finding. Mean Nei's genetic distance in the eastern Mediterranean populations was more than three times higher compared to the western basin. No correlation was observed between geographic and genetic distances (Mantel test), suggesting that maritime transport is the main dispersal vector of B. schlosseri colonies. The possibility that the Mediterranean is a center of diversity for B. schlosseri, and probably its site of origin, is further discussed.

  11. Phylogenetics and biogeography of the dung beetle genus Onthophagus inferred from mitochondrial genomes.

    Science.gov (United States)

    Breeschoten, Thijmen; Doorenweerd, Camiel; Tarasov, Sergei; Vogler, Alfried P

    2016-12-01

    Phylogenetic relationships of dung beetles in the tribe Onthophagini, including the species-rich, cosmopolitan genus Onthophagus, were inferred using whole mitochondrial genomes. Data were generated by shotgun sequencing of mixed genomic DNA from >100 individuals on 50% of an Illumina MiSeq flow cell. Genome assembly of the mixed reads produced contigs of 74 (nearly) complete mitogenomes. The final dataset included representatives of Onthophagus from all biogeographic regions, closely related genera of Onthophagini, and the related tribes Onitini and Oniticellini. The analysis defined four major clades of Onthophagini, which was paraphyletic for Oniticellini, with Onitini as sister group to all others. Several (sub)genera considered as members of Onthophagus in the older literature formed separate deep lineages. All New World species of Onthophagus formed a monophyletic group, and the Australian taxa are confined to a single or two closely related clades, one of which forms the sister group of the New World species. Dating the tree by constraining the basal splits with existing calibrations of Scarabaeoidea suggests an origin of Onthophagini sensu lato in the Eocene and a rapid spread from an African ancestral stock into the Oriental region, and secondarily to Australia and the Americas at about 20-24 Mya. The successful assembly of mitogenomes and the well-supported tree obtained from these sequences demonstrates the power of shotgun sequencing from total genomic DNA of species pools as an efficient tool in genus-level phylogenetics.

  12. Climate change and temperature-dependent biogeography: oxygen limitation of thermal tolerance in animals

    Science.gov (United States)

    Pörtner, H. O.

    2001-03-01

    Recent years have shown a rise in mean global temperatures and a shift in the geographical distribution of ectothermic animals. For a cause and effect analysis the present paper discusses those physiological processes limiting thermal tolerance. The lower heat tolerance in metazoa compared with unicellular eukaryotes and bacteria suggests that a complex systemic rather than molecular process is limiting in metazoa. Whole-animal aerobic scope appears as the first process limited at low and high temperatures, linked to the progressively insufficient capacity of circulation and ventilation. Oxygen levels in body fluids may decrease, reflecting excessive oxygen demand at high temperatures or insufficient aerobic capacity of mitochondria at low temperatures. Aerobic scope falls at temperatures beyond the thermal optimum and vanishes at low or high critical temperatures when transition to an anaerobic mitochondrial metabolism occurs. The adjustment of mitochondrial densities on top of parallel molecular or membrane adjustments appears crucial for maintaining aerobic scope and for shifting thermal tolerance. In conclusion, the capacity of oxygen delivery matches full aerobic scope only within the thermal optimum. At temperatures outside this range, only time-limited survival is supported by residual aerobic scope, then anaerobic metabolism and finally molecular protection by heat shock proteins and antioxidative defence. In a cause and effect hierarchy, the progressive increase in oxygen limitation at extreme temperatures may even enhance oxidative and denaturation stress. As a corollary, capacity limitations at a complex level of organisation, the oxygen delivery system, define thermal tolerance limits before molecular functions become disturbed.

  13. The diversity and biogeography of Western Indian Ocean reef-building corals.

    Science.gov (United States)

    Obura, David

    2012-01-01

    This study assesses the biogeographic classification of the Western Indian Ocean (WIO) on the basis of the species diversity and distribution of reef-building corals. Twenty one locations were sampled between 2002 and 2011. Presence/absence of scleractinian corals was noted on SCUBA, with the aid of underwater digital photographs and reference publications for species identification. Sampling effort varied from 7 to 37 samples per location, with 15 to 45 minutes per dive allocated to species observations, depending on the logistics on each trip. Species presence/absence was analyzed using the Bray-Curtis similarity coefficient, followed by cluster analysis and multi-dimensional scaling. Total (asymptotic) species number per location was estimated using the Michaelis-Menten equation. Three hundred and sixty nine coral species were named with stable identifications and used for analysis. At the location level, estimated maximum species richness ranged from 297 (Nacala, Mozambique) to 174 (Farquhar, Seychelles). Locations in the northern Mozambique Channel had the highest diversity and similarity, forming a core region defined by its unique oceanography of variable meso-scale eddies that confer high connectivity within this region. A distinction between mainland and island fauna was not found; instead, diversity decreased radially from the northern Mozambique Channel. The Chagos archipelago was closely related to the northern Mozambique Channel region, and analysis of hard coral data in the IUCN Red List found Chagos to be more closely related to the WIO than to the Maldives, India and Sri Lanka. Diversity patterns were consistent with primary oceanographic drivers in the WIO, reflecting inflow of the South Equatorial Current, maintenance of high diversity in the northern Mozambique Channel, and export from this central region to the north and south, and to the Seychelles and Mascarene islands.

  14. The diversity and biogeography of Western Indian Ocean reef-building corals.

    Directory of Open Access Journals (Sweden)

    David Obura

    Full Text Available This study assesses the biogeographic classification of the Western Indian Ocean (WIO on the basis of the species diversity and distribution of reef-building corals. Twenty one locations were sampled between 2002 and 2011. Presence/absence of scleractinian corals was noted on SCUBA, with the aid of underwater digital photographs and reference publications for species identification. Sampling effort varied from 7 to 37 samples per location, with 15 to 45 minutes per dive allocated to species observations, depending on the logistics on each trip. Species presence/absence was analyzed using the Bray-Curtis similarity coefficient, followed by cluster analysis and multi-dimensional scaling. Total (asymptotic species number per location was estimated using the Michaelis-Menten equation. Three hundred and sixty nine coral species were named with stable identifications and used for analysis. At the location level, estimated maximum species richness ranged from 297 (Nacala, Mozambique to 174 (Farquhar, Seychelles. Locations in the northern Mozambique Channel had the highest diversity and similarity, forming a core region defined by its unique oceanography of variable meso-scale eddies that confer high connectivity within this region. A distinction between mainland and island fauna was not found; instead, diversity decreased radially from the northern Mozambique Channel. The Chagos archipelago was closely related to the northern Mozambique Channel region, and analysis of hard coral data in the IUCN Red List found Chagos to be more closely related to the WIO than to the Maldives, India and Sri Lanka. Diversity patterns were consistent with primary oceanographic drivers in the WIO, reflecting inflow of the South Equatorial Current, maintenance of high diversity in the northern Mozambique Channel, and export from this central region to the north and south, and to the Seychelles and Mascarene islands.

  15. Biogeography and Phylogeny of Wood-feeding Cockroaches in the Genus Cryptocercus

    Directory of Open Access Journals (Sweden)

    Kiyoto Maekawa

    2011-07-01

    Full Text Available Subsocial, xylophagous cockroaches of the genus Cryptocercus exhibit a disjunct distribution, with representatives in mature montane forests of North America, China, Korea and the Russian Far East. All described species are wingless and dependent on rotting wood for food and shelter at all stages of their life cycle; consequently, their distribution is tied to that of forests and strongly influenced by palaeogeographical events. Asian and American lineages form distinct monophyletic groups, comprised of populations with complex geographic substructuring. We review the phylogeny and distribution of Cryptocercus, and discuss splitting events inferred from molecular data.

  16. Phylogenetic Systematics, Biogeography, and Ecology of the Electric Fish Genus Brachyhypopomus (Ostariophysi: Gymnotiformes)

    Science.gov (United States)

    de Santana, Carlos David; Waddell, Joseph C.; Lovejoy, Nathan R.

    2016-01-01

    A species-level phylogenetic reconstruction of the Neotropical bluntnose knifefish genus Brachyhypopomus (Gymnotiformes, Hypopomidae) is presented, based on 60 morphological characters, approximately 1100 base pairs of the mitochondrial cytb gene, and approximately 1000 base pairs of the nuclear rag2 gene. The phylogeny includes 28 species of Brachyhypopomus and nine outgroup species from nine other gymnotiform genera, including seven in the superfamily Rhamphichthyoidea (Hypopomidae and Rhamphichthyidae). Parsimony and Bayesian total evidence phylogenetic analyses confirm the monophyly of the genus, and identify nine robust species groups. Homoplastic osteological characters associated with diminutive body size and occurrence in small stream habitats, including loss of squamation and simplifications of the skeleton, appear to mislead a phylogenetic analysis based on morphological characters alone–resulting in the incorrect placing of Microsternarchus + Racenisia in a position deeply nested within Brachyhypopomus. Consideration of geographical distribution in light of the total evidence phylogeny indicates an origin for Brachyhypopomus in Greater Amazonia (the superbasin comprising the Amazon, Orinoco and major Guiana drainages), with subsequent dispersal and vicariance in peripheral basins, including the La Plata, the São Francisco, and trans-Andean basins of northwest South America and Central America. The ancestral habitat of Brachyhypopomus likely resembled the normoxic, low-conductivity terra firme stream system occupied by many extant species, and the genus has subsequently occupied a wide range of terra firme and floodplain habitats including low- and high-conductivity systems, and normoxic and hypoxic systems. Adaptations for impedance matching to high conductivity, and/or for air breathing in hypoxic systems have attended these habitat transitions. Several species of Brachyhypopomus are eurytopic with respect to habitat occupancy and these generally exhibit wider geographical ranges than stenotopic species. PMID:27736882

  17. Spatial modelling of Calanus finmarchicus and Calanus helgolandicus: parameter differences explain differences in biogeography

    Directory of Open Access Journals (Sweden)

    Robert John Wilson

    2016-09-01

    Full Text Available The North Atlantic copepods Calanus finmarchicus and C. helgolandicus are moving north in response to rising temperatures. Understanding the drivers of their relative geographic distributions is required in order to anticipate future changes. To explore this, we created a new spatially explicit stage-structured model of their populations throughout the North Atlantic. Recent advances in understanding Calanus biology, including U-shaped relationships between growth and fecundity and temperature, and a new model of diapause duration are incorporated in the model. Equations were identical for both species, but some parameters were species-specific. The model was parameterized using Continuous Plankton Recorder Survey data and tested using time series of abundance and fecundity. The geographic distributions of both species were reproduced by assuming that only known interspecific differences and a difference in the temperature influence on mortality exist. We show that differences in diapause capability are not necessary to explain why C. helgolandicus is restricted to the continental shelf. Smaller body size and higher overwinter temperatures likely make true diapause implausible for C. helgolandicus. Known differences were incapable of explaining why only C. helgolandicus exists southwest of the British Isles. Further, the fecundity of C. helgolandicus in the English Channel is much lower than we predict. We hypothesize that food quality is a key influence on the population dynamics of these species. The modelling framework presented can potentially be extended to further Calanus species.

  18. Remarks on the biogeography of land invasions Consideraciones biogeográficas sobre las invasiones terrestres

    Directory of Open Access Journals (Sweden)

    EDUARDO H. RAPOPORT

    2000-06-01

    Full Text Available The percentage of exotic plant species (PES at large geographic scales is presented in form of political maps (Texas and North America and of isoline maps (Great Britain. In the latter case it is possible to visualize that higher proportions of alien invaders are present in urban and industrial areas as well as in maritime ports rather than in agricultural lands. Consequently, it is possible to predict that the ratio of urban to agricultural species will continue to increase in the future. Based on a survey of 200 world floras, a multiple regression analysis is presented in order to determine the importance of different factors in the yield of PES values. The contribution to the total variance was: disturbance degree 55 %; total species richness 14%; insularity 9%, and latitude 2%. Neither the mean annual precipitation nor the mean annual temperature showed a significant contribution to the total variance. The predominance of Europe as the main deliverer of weeds to other temperate regions in the world has been attributed to the aggressive or imperialistic geopolitics of this region, and to the construction of the first international oceanic fleet. There are reasons to believe, however, that the great size of Eurasia also played a role in the success of its weedy invasive flora. Since several authors found a weak positive correlation between the radial rate of dispersal and the invading success in plants, a table collecting 153 data allowed a first, tentative comparison among different taxa. The mean dispersal rates were 64.2 for microorganisms; 48.5 for invertebrates, 17.2 for vertebrates, 6.9 for plants, and 0.19 km/yr for palynological registers. A discussion about the significance of these results is included. An alternative way to compare invasive ability, especially among agricultural pests, is by means of an index of cosmopolitanism (C* which varied as follows: 0.642 for phytopathogens, 0.439 for insects and 0.259 for weeds. Weeds are 15 times, agricultural insects 26 times and phytopathogens 37 times more cosmopolitan than, say, common mammals, taken as an example for comparison. Finally, although animals (invertebrates plus vertebrates show a higher mean dispersal rate than plants (field observations plus ancient pollen registers, it seems that animals are better colonizers of pristine or scarcely disturbed communities, while plants are more successful in anthropic habitatsSe analiza el porcentaje de especies de plantas exóticas (PES a escala macrogeográfica en forma de mapas políticos (Texas y América del Norte y mapas de isolíneas (Gran Bretaña. En estos últimos se observa mayor concentración del PES en puertos y áreas urbanas e industriales más que en áreas agrícolas. En consecuencia, es predecible que la razón entre ruderales y arvenses siga aumentando en el futuro. Sobre la base de un censo de 200 floras del mundo se hace un análisis de regresión múltiple para determinar la importancia de factores que contribuyen a la variación en el PES (disturbios 55 %, riqueza de especies 14%, insularidad 9% y latitud 2%. Precipitación y temperatura media anual no contribuyen significativamente en la varianza. La predominancia de Europa como principal distribuidora mundial de malezas ha sido atribuida a su geopolítica imperialista y construcción de la primera flota marina internacional. A ello, sin embargo, debió contribuir también el tamaño de Eurasia. Ya que varios autores hallaron una débil correlación positiva entre la tasa de dispersión y el éxito invasor en plantas, se hizo una comparación entre taxones mediante 153 datos colectados. Las tasas lineales de dispersión, en km/año, fueron 64,2 en microorganismos, 48,5 en invertebrados, 17,2 en vertebrados, 6,9 en plantas y 0,19 en registros palinológicos. Otra manera de comparar la capacidad invasora, especialmente, en plagas agrícolas, es a través del índice de cosmopolitismo (C*, que resultó ser 0,642 para fitopatógenos, 0,439 para insectos y 0,259 para malezas. Las malezas son 15, los insectos agrícolas 26 veces y los fitopatógenos 37 veces más cosmopolitas que los mamíferos, tomados como ejemplo comparativo. Finalmente, aunque los animales (invertebrados y vertebrados muestran mayor tasa media de dispersión que las plantas, y son mejores colonizadores de comunidades prístinas o poco disturbadas, las plantas son más exitosas en ambientes antrópicos

  19. Faunal Biogeography Community Structure and Genetic Connectivity of North Atlantic Seamounts

    Science.gov (United States)

    2008-09-01

    haplotype with many closely associated rare haplotypes, which is indicative of rapid population expansion (Slatkin and Hudson 1991; Teske et al. 2005...populations 156 are thought to be older than those characterized by a star phylogeny (Slatkin and Hudson 1991; Teske et al. 2005). Variation was also seen...1465. TESKE , P. R. and others 2005. Molecular evidence for long-distance colonization in an Indo-Pacific seahorse lineage. Marine Ecology Progress

  20. [The use of cladistic principles in the phylogeny and biogeography of the Lacerta].

    Science.gov (United States)

    Renous, S

    1979-01-01

    The methodology used in Phylogenetics remains one of the more interesting problems in comparative biology. Among the methods used, the cladistic is the most accurate. In the present case, among the Saurians, the characters chosen appeared early and cannot be referred to any adaptation bound to an evolutive progress. We have successively considered their distribution in the classification, their polarity and one phylogenetic hypothesis based on the Hennig's concepts. Such a work leads necessarily to systematical conclusions. For instance, we note the heterogeneity of some families. Among the Iguania, the Iguanidea are polyphyletics, the north-american forms breaking up from the other very early. Among the Scincomorpha, the Lacertilia result from two parts of different origins. This research verifies some systematic cuttings in the modern classification: among the Anguimorpha, the separation between Helodermatidea and the group, Varanidea-Lanthanotidea. The characters studied show a non-random distribution in the classification and show also some consistency with the geographical distribution of the extant Saurians. Therefore, it is important to search for the most parsimonious geographical hypothesis, which is in concern with the present data on the continental drift and generally on the history of the Earth, and which strengthens the cladograms posed from the selected characters.

  1. Benthic foraminiferal biogeography in NW European fjords: A baseline for assessing future change

    Science.gov (United States)

    Murray, John W.; Alve, Elisabeth

    2016-11-01

    The seaboard extending from northern Svalbard to Scotland is the only region of the world where fjords have been comprehensively studied for their live (stained) benthic foraminiferal faunas. These modern faunas provide essential baseline data for the interpretation of the postglacial and continuing environmental changes in those fjords and this is the first biogeographic synthesis. The data come from the surface sediment assemblages (mainly sampled in the 1990's) from all the available literature. Due to limited information of shallow water assemblages in the north, only the species occurrences in deeper water from below the halocline are considered. Amongst these, only "common species" species occurring in more than one fjord are included. There is a clear pattern of distribution with five groups of taxa: 5 widespread species found throughout the region; 53 species reaching their northern limit; 13 species reaching their southern limit; 11 deep-sea species; 1 recently introduced species. Although there is an abrupt change in temperature from Tanafjorden in northern Norway to Hornsund in southern Svalbard, the faunal change from N to S is progressive throughout the investigated region. The area of overlap of the northern and southern species corresponds with the previously recognised boundary between the Barents Sea Province and the Norwegian Coast Province based on shelf and upper slope invertebrate macrofaunal benthos and plankton. Temperature is the main abiotic control on the distributions. For the fjords which have shallow sills separating them from the open shelf it is likely that most of the foraminiferal colonisers of the deeper fjord basins are sourced from the shelf or slope via propagules. One species has recently been introduced from further south into the southern region probably through the discharge of ballast water from ships. The biodiversity of the pristine Svalbard fjords extends below what is considered to reflect acceptable ecological status for mainland Norway, illustrating the need to introduce new methods to determine possible deviations from the reference conditions as defined in the EU's Water Framework Directive (WFD; 2000/60/EC). Altogether 347 species have so far been recorded in Norwegian waters: 214 in fjords (60 above and 180 below the halocline of which 26 occur both above and below the halocline) and 266 on the shelf and slope (133 of which also occur in fjords).

  2. Biogeography of bacterial communities in hot springs: a focus on the actinobacteria.

    Science.gov (United States)

    Valverde, Angel; Tuffin, Marla; Cowan, Don A

    2012-07-01

    Actinobacteria are ubiquitous in soil, freshwater and marine ecosystems. Although various studies have focused on the microbial ecology of this phylum, data are scant on the ecology of actinobacteria endemic to hot springs. Here, we have investigated the molecular diversity of eubacteria, with specific focus on the actinobacteria in hot springs in Zambia, China, New Zealand and Kenya. Temperature and pH values at sampling sites ranged between 44.5 and 86.5 °C and 5-10, respectively. Non-metric multidimensional scaling analysis of 16S rRNA gene T-RFLP patterns showed that samples could be separated by geographical location. Multivariate analysis showed that actinobacterial community composition was best predicted by changes in pH and temperature, whereas temperature alone was the most important variable explaining differences in bacterial community structure. Using 16S rRNA gene libraries, 28 major actinobacterial OTUs were found. Both molecular techniques indicated that many of the actinobacterial phylotypes were unique and exclusive to the respective sample. Collectively, these results support the view that both actinobacterial diversity and endemism are high in hot spring ecosystems.

  3. Biogeography of key mesozooplankton species in the North Atlantic and egg production of Calanus finmarchicus

    Science.gov (United States)

    Melle, W.; Runge, J. A.; Head, E.; Plourde, S.; Castellani, C.; Licandro, P.; Pierson, J.; Jónasdóttir, S. H.; Johnson, C.; Broms, C.; Debes, H.; Falkenhaug, T.; Gaard, E.; Gislason, A.; Heath, M. R.; Niehoff, B.; Nielsen, T. G.; Pepin, P.; Stenevik, E. K.; Chust, G.

    2015-08-01

    Here we present a new, pan-North-Atlantic compilation of data on key mesozooplankton species, including the most important copepod, Calanus finmarchicus. Distributional data of eight representative zooplankton taxa, from recent (2000-2009) Continuous Plankton Recorder data, are presented, along with basin-scale data of the phytoplankton colour index. Then we present a compilation of data on C. finmarchicus, including observations of abundance, demography, egg production and female size, with accompanying data on temperature and chlorophyll. This is a contribution by Canadian, European and US scientists and their institutions: http://doi.pangaea.de/10.1594/PANGAEA.820732, http://doi.pangaea.de/10.1594/PANGAEA.824423, http://doi.pangaea.de/10.1594/PANGAEA.828393 (please also see Melle et al., 2013; Castellani and Licandro, 2013; Jónasdóttir et al., 2014).

  4. Late Paleozoic fusulinids from Sonora, Mexcio: importance for interpretation of depositional settings, biogeography, and paleotectonics

    Science.gov (United States)

    Stevens, Calvin H.; Poole, Forrest G.; Amaya-Martínez, Ricardo

    2014-01-01

    Three sets of fusulinid faunas in Sonora, Mexico, discussed herein, record different depositional and paleotectonic settings along the southwestern margin of Laurentia (North America) during Pennsylvanian and Permian time. The settings include: offshelf continental rise and ocean basin (Rancho Nuevo Formation in the Sonora allochthon), shallow continental shelf (La Cueva Limestone), and foredeep basin on the continental shelf (Mina México Formation). Our data represent 41 fusulinid collections from 23 localities with each locality providing one to eight collections. Reworked fusulinids in the Middle and Upper Pennsylvanian part of the Rancho Nuevo Formation range in age from Desmoinesian into Virgilian (Moscovian-Gzhelian). Indigenous Permian fusulinids in the La Cueva Limestone range in age from middle or late Wolfcampian to middle Leonardian (late Sakmarian-late Artinskian), and reworked Permian fusulinids in the Mina México Formation range in age from early to middle Leonardian (middle-late Artinskian). Conodonts of Guadalupian age occur in some turbidites in the Mina México Formation, indicating the youngest foredeep deposit is at least Middle Permian in age. Our fusulinid collections indicate a hiatus of at least 10 m.y. between the youngest Pennsylvanian (Virgilian) rocks in the Sonora allochthon and the oldest Permian (middle Wolfcampian) rocks in the region. Most fusulinid faunas in Sonora show affinities to those of West Texas, New Mexico, and Arizona; however, some genera and species are similar to those in southeastern California. As most species are similar to those east of the southwest-trending Transcontinental arch in New Mexico and Arizona, this arch may have formed a barrier preventing large-scale migration and mixing of faunas between the southern shelf of Laurentia in northwestern Mexico and the western shelf in the southwestern United States. The Sonora allochthon, consisting of pre-Permian (Lower Ordovician to Upper Pennsylvanian) deep-water continental-rise and ocean-basin rocks, was thrust northward 50–200 km over Permian and older shallow-water carbonate-shelf rocks and Permian deep-water foredeep rocks of southern Laurentia. As Triassic rocks unconformably overlie the Sonora allochthon, we conclude that terminal movement of the allochthon was in Late Permian time.

  5. Cleaning up the biogeography of Labroides dimidiatus using phylogenetics and morphometrics

    Science.gov (United States)

    Sims, C. A.; Riginos, C.; Blomberg, S. P.; Huelsken, T.; Drew, J.; Grutter, A. S.

    2014-03-01

    Cleaner fishes are some of the most conspicuous organisms on coral reefs due to their behaviour and prominent body pattern, consisting of a lateral stripe and blue/yellow colouration. All obligate cleaner fishes share this body stripe pattern, which is an important signal for attracting client fishes. However, variability in the cleaning signal of the cleaner fish Labroides dimidiatus has been documented across its range. Here, we investigate the geographic distribution of cleaner signal polymorphisms in L. dimidiatus and contrast this to phylogeographic variation in mitochondrial (mt) DNA. We used samples from 12 sites for genetic analyses, encompassing much of L. dimidiatus' range from the Red Sea to Fiji. We obtained morphometric measures of the cleaner signal body stripe width from individuals among six of the sites and qualitatively grouped tail stripe shape. mtDNA control region sequences were used for phylogenetic and population genetic analyses. We found that body stripe width was significantly correlated with tail stripe shape and geographical location, with Indian Ocean populations differing in morphology from western Pacific populations. L. dimidiatus haplotypes formed two reciprocally monophyletic clades, although in contrast to morphology, Japanese cleaner fish fell within the same clade as Indian Ocean cleaner fish and both clade types were sympatric in Papua New Guinea. An additional novel finding of our research was that the inclusion of two closely related cleaner fish species, Labroides pectoralis and Labroides bicolor, in the phylogenetic analysis rendered L. dimidiatus polyphyletic. Overall, the findings suggest the diversity within L. dimidiatus is underestimated.

  6. Biogeography and spatio-temporal diversification of Selenidera and Andigena toucans (Aves: Ramphastidae).

    Science.gov (United States)

    Lutz, Holly L; Weckstein, Jason D; Patané, José S L; Bates, John M; Aleixo, Alexandre

    2013-12-01

    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.

  7. On the nature of systematics and biogeography : I. The Willis-Curve

    NARCIS (Netherlands)

    Wittenrood, H.G.; Blöte, H.C.

    1934-01-01

    Since the appearance of ,,Age and Area" by Dr. J. C.Willis in 1922 the progress in this matter has not been so great as before. From the contribution of a few chapters by some well-known biologists, and from many approving remarks by others quoted throughout the book one might derive that the theory

  8. Middle Pleistocene vertebrate fossils from the Nefud Desert, Saudi Arabia: Implications for biogeography and palaeoecology

    Science.gov (United States)

    Stimpson, Christopher M.; Lister, Adrian; Parton, Ash; Clark-Balzan, Laine; Breeze, Paul S.; Drake, Nick A.; Groucutt, Huw S.; Jennings, Richard; Scerri, Eleanor M. L.; White, Tom S.; Zahir, Muhammad; Duval, Mathieu; Grün, Rainer; Al-Omari, Abdulaziz; Al Murayyi, Khalid Sultan M.; Zalmout, Iyaed S.; Mufarreh, Yahya A.; Memesh, Abdullah M.; Petraglia, Michael D.

    2016-07-01

    The current paucity of Pleistocene vertebrate records from the Arabian Peninsula - a landmass of over 3 million km2 - is a significant gap in our knowledge of the Quaternary. Such data are critical lines of contextual evidence for considering animal and hominin dispersals between Africa and Eurasia generally, and hominin palaeoecology in the Pleistocene landscapes of the Arabian interior specifically. Here, we describe an important contribution to the record and report stratigraphically-constrained fossils of mammals, birds and reptiles from recent excavations at Ti's al Ghadah in the southwestern Nefud Desert. Combined U-series and ESR analyses of Oryx sp. teeth indicate that the assemblage is Middle Pleistocene in age and dates to ca. 500 ka. The identified fauna is a biogeographical admixture that consists of likely endemics and taxa of African and Eurasian affinity and includes extinct and extant (or related Pleistocene forms of) mammals (Palaeoloxodon cf. recki, Panthera cf. gombaszogenis, Equus hemionus, cf. Crocuta crocuta, Vulpes sp., Canis anthus, Oryx sp.), the first Pleistocene records of birds from the Arabian Peninsula (Struthio sp., Neophron percnopterus, Milvus cf. migrans, Tachybaptus sp. Anas sp., Pterocles orientalis, Motacilla cf. alba) and reptiles (Varanidae/Uromastyx sp.). We infer that the assemblage reflects mortality in populations of herbivorous animals and their predators and scavengers that were attracted to freshwater and plant resources in the inter-dune basin. At present, there is no evidence to suggest hominin agency in the accumulation of the bone assemblages. The inferred ecological characteristics of the taxa recovered indicate the presence, at least periodically, of substantial water-bodies and open grassland habitats.

  9. Canary grasses (Phalaris, Poaceae): biogeography, molecular dating and the role of floret structure in dispersal.

    Science.gov (United States)

    Voshell, Stephanie M; Hilu, Khidir W

    2014-01-01

    Canary grasses (Phalaris, Poaceae) include 21 species, widely spread throughout the temperate and subtropical regions of the world with two centres of diversity: the Mediterranean Basin and western North America. The genus contains annual and perennial, endemic, cosmopolitan, wild, and invasive species with diploid, tetraploid and hexaploid cytotypes. As such, Phalaris presents an ideal platform to study diversification via historic hybridization and polyploidy events, and geographical dispersal in grasses. We present the first empirical phylogeographic study for Phalaris testing current, intuitive hypotheses on the centres of origin, historic dispersal events and diversification within a geological timeframe. Bayesian methods (beast, version 1.6.2) were used to establish divergence dates, and dispersal-vicariance analyses (rasp, version 2.1b) were implemented for ancestral node reconstructions. Our phylogeographic results indicate that the genus emerged during the Miocene epoch [20.6-8.4 Ma (million years ago)] in the Mediterranean basin followed by dispersal and vicariance events to Africa, Asia and the Americas. We propose that a diploid ancestor of P. arundinacea migrated to western North America via the Bering Strait, where further diversification emerged in the New World. It appears that polyploidy played a major role in the evolution of the genus in the Old World, while diversification in the New World followed a primarily diploid pathway. Dispersal to various parts of the Americas followed different routes. Fertile florets with hairy protruding sterile lemmas showed significant correlation with wider geographical distribution.

  10. Dated historical biogeography of the temperate Loliinae (Poaceae, Pooideae) grasses in the northern and southern hemispheres.

    Science.gov (United States)

    Inda, Luis A; Segarra-Moragues, José Gabriel; Müller, Jochen; Peterson, Paul M; Catalán, Pilar

    2008-03-01

    Divergence times and biogeographical analyses have been conducted within the Loliinae, one of the largest subtribes of temperate grasses. New sequence data from representatives of the almost unexplored New World, New Zealand, and Eastern Asian centres were added to those of the panMediterranean region and used to reconstruct the phylogeny of the group and to calculate the times of lineage-splitting using Bayesian approaches. The traditional separation between broad-leaved and fine-leaved Festuca species was still maintained, though several new broad-leaved lineages fell within the fine-leaved clade or were placed in an unsupported intermediate position. A strong biogeographical signal was detected for several Asian-American, American, Neozeylandic, and Macaronesian clades with different affinities to both the broad and the fine-leaved Festuca. Bayesian estimates of divergence and dispersal-vicariance analyses indicate that the broad-leaved and fine-leaved Loliinae likely originated in the Miocene (13My) in the panMediterranean-SW Asian region and then expanded towards C and E Asia from where they colonized the New World. Further expansions in America (10-3.8My) showed a predominant migratory route from North to South (N Americathe AndesPatagonia). This late Tertiary scenario of successive colonizations and secondary polyploid radiations in the southern hemisphere from the northern hemisphere was accompanied by occasional transcontinental long-distance dispersal events between South America and New Zealand. Multiple Pliocene dispersal events (3.6-2.5My) from the near SW European and NW African continents gave rise to the Macaronesian Loliinae flora, while a more recent Pleistocene origin (2-1My) is hypothesized for the high polyploid lineages that successfully colonized newly deglaciated areas in both hemispheres.

  11. New geological framework for Western Amazonia (Brazil) and implications for biogeography and evolution

    Science.gov (United States)

    de Fátima Rossetti, Dilce; Mann de Toledo, Peter; Góes, Ana Maria

    2005-01-01

    Although many of the current hypotheses to explain the origin and distribution of the Amazon biodiversity has been based directly or indirectly on geological data, the reconstruction of the geological history of the Amazon region is still inadequate to analyze its relationship with the biodiversity. This work has the main goal to characterize the sedimentary successions formed in the Brazilian Amazon in the Neogene-Quaternary discussing the evolution of the depositional systems through time and analyzing their main controlling mechanisms in order to fill up this gap. Radar image interpretation, sedimentological studies, and radiocarbon dating allowed the mapping of Plio-Pleistocene to Holocene units along the Solimões-Amazonas River, Brazil. This integrated work led to the characterization of five sedimentary successions overlying Miocene deposits of the Solimões/Pebas Formation, which include the following: Içá Formation (Plio-Pleistocene), deposits Q1 (37,400-43,700 14C yr B.P.), deposits Q2 (27,200 14C yr B.P.), deposits Q3 (6730-2480 14C yr B.P.), and deposits Q4 (280-130 14C yr B.P.). These deposits occur mostly to the west of Manaus, forming NW-SE elongated belts that are progressively younger from SW to NE, indicating a subsiding basin with a depocenter that migrated to the NE. The reconstruction of the depositional history is consistent with significant changes in the landscapes. Hence, the closure of a large lake system at the end of the Miocene gave rise to the development of a Plio-Pleistocene fluvial system. This was yet very distinct from the modern drainage, with shallow, energetic, highly migrating, braided to anastomosed channels having an overall northeast outlet. This fluvial system formed probably under climatic conditions relatively drier than today's. During the early Pleistocene, there was pronounced erosion, followed by a renewed depositional phase ca. 40,000 14C yr B.P., with the development of prograding lobes and/or crevasse splays associated with a lake system (i.e., fan-delta) and/or fluvial flood plain areas. After a period of erosion, a fluvial system with eastward draining channels started to develop at around 27,000 14C yr B.P. The fluvial channels were overflooded in mid-Holocene time. This flooding is attributed to an increased period of humidity, with a peak between 5000 and 2500 14C yr B.P. The data presented herein support that, rather than being a monotonous area, the Amazonia was a place with frequent changes in landscape throughout the Neogene-Quaternary, probably as a result of climatic and tectonic factors. We hypothesize that these changes in the physical environment stressed the biota, resulting in speciation and thus had a great impact on modern biodiversity.

  12. Avian gene trees, landscape evolution, and geology: towards a modern synthesis of Amazonian historical biogeography?

    OpenAIRE

    Aleixo, Alexandre Luis Padovan; Rossetti, Dilce de Fátima

    2007-01-01

    Recent studies have improved our understanding of Amazonian geological history during the late Tertiary and Quaternary, two periods regarded as critical for the recent diversification of the Amazonian avifauna. The notion that geologically older and more stable areas of Amazonia (such as the Brazilian and Guianan shields) functioned as ‘‘species-pumps’’, whereas geologically more dynamic areas (such as the western Amazonian lowlands) mostly ‘‘captured’’ part of the div...

  13. Multi Objective Optimization Using Biogeography Based Optimization and Differentional Evolution Algorithm

    Directory of Open Access Journals (Sweden)

    Samira Abdi

    2012-11-01

    The proposed algorithm (MOBBO/DE makes the use of nondominated sorting approach improve the convergence ability efficiently and hence it can generate the promising candidate solutions. It also combines crowding distance to guarantee the diversity of Pareto optimal solutions. The proposed approach is validated using several test functions and some metrics taken from the standard literature on evolutionary multi-objective optimization. Results indicate that the approach is highly competitive and that can be considered a viable alternative to solve multi-objective optimization problems.

  14. On the morphology, biometry and biogeography of Lamtopyxis callistoma (Amoebozoa: Arcellinida

    Directory of Open Access Journals (Sweden)

    Milcho Todorov

    2015-01-01

    Full Text Available The ultra-structure of the shell and the morphometric variability of soil inhabiting testate amoeba Lamtopyxis callistoma from Madagascar were studied by using light- and scanning electron microscopy. The biometrical characteristic of the species was made on the basis of 75 specimens measured. In addition to the diameter of the shell, six other shell characters were described biometrically for the first time. The analysis of the variation coefficients shows that the studied population of L. callistoma is comparatively homogeneous and almost all measured characters are weakly to moderate variable (CV less than 10%. Scanning electron microscopy (SEM studies on the shell ultra-morphology show that it has a smooth apertural surface with a thick layer of porous and fibrous organic cement and a rough dorsal surface composed of bigger and angular pieces of quartz. The shell wall has a thickness of about 5-6 µm and is composed of three layers. Unlike the previously accepted opinion that species is characterized by the presence of four teeth, this study shows that population of L. callistoma from Madagascar is comprised of both, specimens with four teeth and specimens with three teeth, in ratio of about 60% to 40%. Taking into account the restricted geographical distribution, large sizes and characteristic apertural morphology of L. callistoma it is assumed that this species, like some bryophilic ‘Nebelas’ with circumaustral distribution (e.g. Apodera vas, Alocodera cockayni, Certesella certesi, Certesella martiali, etc., can be used as an example that in free-living microbial eukaryotes ‘not everything is everywhere’.

  15. Functional biogeography of oceanic islands and the scaling of functional diversity in the Azores.

    Science.gov (United States)

    Whittaker, Robert J; Rigal, François; Borges, Paulo A V; Cardoso, Pedro; Terzopoulou, Sofia; Casanoves, Fernando; Pla, Laura; Guilhaumon, François; Ladle, Richard J; Triantis, Kostas A

    2014-09-23

    Analyses of species-diversity patterns of remote islands have been crucial to the development of biogeographic theory, yet little is known about corresponding patterns in functional traits on islands and how, for example, they may be affected by the introduction of exotic species. We collated trait data for spiders and beetles and used a functional diversity index (FRic) to test for nonrandomness in the contribution of endemic, other native (also combined as indigenous), and exotic species to functional-trait space across the nine islands of the Azores. In general, for both taxa and for each distributional category, functional diversity increases with species richness, which, in turn scales with island area. Null simulations support the hypothesis that each distributional group contributes to functional diversity in proportion to their species richness. Exotic spiders have added novel trait space to a greater degree than have exotic beetles, likely indicating greater impact of the reduction of immigration filters and/or differential historical losses of indigenous species. Analyses of species occurring in native-forest remnants provide limited indications of the operation of habitat filtering of exotics for three islands, but only for beetles. Although the general linear (not saturating) pattern of trait-space increase with richness of exotics suggests an ongoing process of functional enrichment and accommodation, further work is urgently needed to determine how estimates of extinction debt of indigenous species should be adjusted in the light of these findings.

  16. Conserving Biogeography: Habitat Loss and Vicariant Patterns in Endemic Squamates of the Cerrado Hotspot.

    Science.gov (United States)

    de Mello, Pietro L H; Machado, Ricardo B; Nogueira, Cristiano de C

    2015-01-01

    Little is known about the threat levels and impacts of habitat loss over the Cerrado Squamate fauna. The region is under severe habitat loss due to mechanized agriculture, accelerated by changes in the Brazilian National Forest Code. The Squamate fauna of the Cerrado is rich in endemics and is intrinsically associated with its surrounding microhabitats, which make up a mosaic of phitophysiognomies throughout the region. Herein we evaluate current conservation status of Squamate biogeographic patterns in the Brazilian Cerrado, the single savanna among global biodiversity hotspots. To do so, we first updated point locality data on 49 endemic Squamates pertaining to seven non-random clusters of species ranges in the Cerrado. Each cluster was assumed to be representative of different biogeographic regions, holding its own set of species, herein mapped according to their extent of occurrence (EOO). We then contrasted these data in four different scenarios, according to the presence or absence of habitat loss and the presence or absence of the current protected area (PA) cover. We searched for non-random patterns of habitat loss and PA coverage among these biogeographic regions throughout the Cerrado. Finally, with the species EOO as biodiversity layers, we used Zonation to discuss contemporary PA distribution, as well as to highlight current priority areas for conservation within the Cerrado. We ran Zonation under all four conservation scenarios mentioned above. We observed that habitat loss and PA coverage significantly differed between biogeographic regions. The southernmost biogeographic region is the least protected and the most impacted, with priority areas highly scattered in small, disjunct fragments. The northernmost biogeographic region (Tocantins-Serra Geral) is the most protected and least impacted, showing extensive priority areas in all Zonation scenarios. Therefore, current and past deforestation trends are severely threatening biogeographic patterns in the Cerrado. Moreover, PA distribution is spatially biased, and does not represent biogeographic divisions of the Cerrado. Consequently, we show that biogeographic patterns and processes are being erased at an accelerated pace, reinforcing the urgent need to create new reserves and to avoid the loss of the last remaining fragments of once continuous biogeographic regions. These actions are fundamental and urgent for conserving biogeographic and evolutionary information in this highly imperiled savanna hotspot.

  17. Phylogeny and biogeography of Triportheidae (Teleostei: Characiformes) based on molecular data.

    Science.gov (United States)

    Mariguela, T C; Roxo, F F; Foresti, F; Oliveira, C

    2016-03-01

    Triportheidae represents a relatively small family of characiform fishes with highly modified morphology. The relationship among characiform families is still unclear, and a phylogenetic analysis for the family including a representative number of Triportheus species has never been performed. Here, we inferred a phylogeny for 19 of the 22 species recognized for this family and two possible new Triportheus species using two mitochondrial and three nuclear genes. Our results show that (1) Triportheidae is monophyletic and a sister group of the clade consisting of the families Bryconidae and Gasteropelecidae; (2) Triportheus is monophyletic, but some species need to be reviewed and described; (3) all genera in Triportheidae, except for Agoniates originated in the period between Early Oligocene and Early Miocene; and (4) speciation in Triportheidae coincides with important geological events in South America, reinforcing the importance of time-calibrated trees to study fish evolution.

  18. Biogeography of Triatominae (Hemiptera: Reduviidae in Ecuador: implications for the design of control strategies

    Directory of Open Access Journals (Sweden)

    Fernando Abad-Franch

    2001-07-01

    Full Text Available Chagas disease control strategies strongly depend on the triatomine vector species involved in Trypanosoma cruzi transmission within each area. Here we report the results of the identification of specimens belonging to various species of Triatominae captured in Ecuador (15 species from 17 provinces and deposited in the entomological collections of the Catholic University of Ecuador (Quito, Instituto Oswaldo Cruz (Brazil, the Natural History Museum London (UK, the London School of Hygiene and Tropical Medicine (UK, the National Institute of Hygiene (Quito, and the Vozandes Hospital (Quito. A critical review of published information and new field records are presented. We analysed these data in relation to the life zones where triatomines occur (11 life zones, excluding those over 2,200 m altitude, and provide biogeographical maps for each species. These records are discussed in terms of epidemiological significance and design of control strategies. Findings relevant to the control of the main vector species are emphasised. Different lines of evidence suggest that Triatoma dimidiata is not native to Ecuador-Peru, and that synanthropic populations of Rhodnius ecuadoriensis in southern Ecuador-northern Peru might be isolated from their sylvatic conspecifics. Local eradication of T. dimidiata and these R. ecuadoriensis populations might therefore be attainable. However, the presence of a wide variety of native species indicates the necessity for a strong longitudinal surveillance system.

  19. Modelling the future biogeography of North Atlantic zooplankton communities in response to climate change

    KAUST Repository

    Villarino, E

    2015-07-02

    Advances in habitat and climate modelling allow us to reduce uncertainties of climate change impacts on species distribution. We evaluated the impacts of future climate change on community structure, diversity, distribution and phenology of 14 copepod species in the North Atlantic. We developed and validated habitat models for key zooplankton species using continuous plankton recorder (CPR) survey data collected at mid latitudes of the North Atlantic. Generalized additive models (GAMs) were applied to relate the occurrence of species to environmental variables. Models were projected to future (2080–2099) environmental conditions using coupled hydroclimatix–biogeochemical models under the Intergovernmental Panel on Climate Change (IPCC) A1B climate scenario, and compared to present (2001–2020) conditions. Our projections indicated that the copepod community is expected to respond substantially to climate change: a mean poleward latitudinal shift of 8.7 km per decade for the overall community with an important species range variation (–15 to 18 km per decade); the species seasonal peak is expected to occur 12–13 d earlier for Calanus finmarchicus and C. hyperboreus; and important changes in community structure are also expected (high species turnover of 43–79% south of the Oceanic Polar Front). The impacts of the change expected by the end of the century under IPCC global warming scenarios on copepods highlight poleward shifts, earlier seasonal peak and changes in biodiversity spatial patterns that might lead to alterations of the future North Atlantic pelagic ecosystem. Our model and projections are supported by a temporal validation undertaken using the North Atlantic climate regime shift that occurred in the 1980s: the habitat model built in the cold period (1970–1986) has been validated in the warm period (1987–2004).

  20. Biogeography of jellyfish in the North Atlantic, by traditional and genomic methods

    NARCIS (Netherlands)

    Licandro, P.; Blackett, M.; Fischer, A.; Hosia, A.; Kennedy, J.; Kirby, R.R.; Raab, K.; Stern, R.; Tranter, P.

    2015-01-01

    Scientific debate on whether or not the recent increase in reports of jellyfish outbreaks represents a true rise in their abundance has outlined a lack of reliable records of Cnidaria and Ctenophora. Here we describe different jellyfish data sets produced within the EU programme EURO-BASIN. These

  1. A necessarily complex model to explain the biogeography of the amphibians and reptiles of Madagascar.

    Science.gov (United States)

    Brown, Jason L; Cameron, Alison; Yoder, Anne D; Vences, Miguel

    2014-10-09

    Pattern and process are inextricably linked in biogeographic analyses, though we can observe pattern, we must infer process. Inferences of process are often based on ad hoc comparisons using a single spatial predictor. Here, we present an alternative approach that uses mixed-spatial models to measure the predictive potential of combinations of hypotheses. Biodiversity patterns are estimated from 8,362 occurrence records from 745 species of Malagasy amphibians and reptiles. By incorporating 18 spatially explicit predictions of 12 major biogeographic hypotheses, we show that mixed models greatly improve our ability to explain the observed biodiversity patterns. We conclude that patterns are influenced by a combination of diversification processes rather than by a single predominant mechanism. A 'one-size-fits-all' model does not exist. By developing a novel method for examining and synthesizing spatial parameters such as species richness, endemism and community similarity, we demonstrate the potential of these analyses for understanding the diversification history of Madagascar's biota.

  2. Insights into Himalayan biogeography from geckos: a molecular phylogeny of Cyrtodactylus (Squamata: Gekkonidae).

    Science.gov (United States)

    Agarwal, Ishan; Bauer, Aaron M; Jackman, Todd R; Karanth, K Praveen

    2014-11-01

    The India-Asia collision profoundly influenced the climate, topography and biodiversity of Asia, causing the formation of the biodiverse Himalayas. The species-rich gekkonid genus Cyrtodactylus is an ideal clade for exploring the biological impacts of the India-Asia collision, as previous phylogenetic hypotheses suggest basal divergences occurred within the Himalayas and Indo-Burma during the Eocene. To this end, we sampled for Cyrtodactylus across Indian areas of the Himalayas and Indo-Burma Hotspots and used three genes to reconstruct relationships and estimate divergence times. Basal divergences in Cyrtodactylus, Hemidactylus and the Palaearctic naked-toed geckos were simultaneous with or just preceded the start of the India-Asia collision. Diversification within Cyrtodactylus tracks the India-Asia collision and subsequent geological events. A number of geographically concordant clades are resolved within Indo-Burmese Cyrtodactylus. Our study reveals 17 divergent lineages that may represent undescribed species, underscoring the previously undocumented diversity of the region. The importance of rocky habitats for Cyrtodactylus indicates the Indo-Gangetic flood plains and the Garo-Rajmahal Gap are likely to have been important historical barriers for this group.

  3. Ancient watercourses and biogeography of the Sahara explain the peopling of the desert.

    Science.gov (United States)

    Drake, Nick A; Blench, Roger M; Armitage, Simon J; Bristow, Charlie S; White, Kevin H

    2011-01-11

    Evidence increasingly suggests that sub-Saharan Africa is at the center of human evolution and understanding routes of dispersal "out of Africa" is thus becoming increasingly important. The Sahara Desert is considered by many to be an obstacle to these dispersals and a Nile corridor route has been proposed to cross it. Here we provide evidence that the Sahara was not an effective barrier and indicate how both animals and humans populated it during past humid phases. Analysis of the zoogeography of the Sahara shows that more animals crossed via this route than used the Nile corridor. Furthermore, many of these species are aquatic. This dispersal was possible because during the Holocene humid period the region contained a series of linked lakes, rivers, and inland deltas comprising a large interlinked waterway, channeling water and animals into and across the Sahara, thus facilitating these dispersals. This system was last active in the early Holocene when many species appear to have occupied the entire Sahara. However, species that require deep water did not reach northern regions because of weak hydrological connections. Human dispersals were influenced by this distribution; Nilo-Saharan speakers hunting aquatic fauna with barbed bone points occupied the southern Sahara, while people hunting Savannah fauna with the bow and arrow spread southward. The dating of lacustrine sediments show that the "green Sahara" also existed during the last interglacial (∼125 ka) and provided green corridors that could have formed dispersal routes at a likely time for the migration of modern humans out of Africa.

  4. Systematics and biogeography of Sternarchellini (Gymnotiformes: Apteronotidae: Diversification of electric fishes in large Amazonian rivers

    Directory of Open Access Journals (Sweden)

    Stephen J. Ivanyisky III

    Full Text Available The Sternarchellini (Gymnotiformes, Apteronotidae is a clade of 10 electric fish species that inhabit deep river channels of the Amazon and Orinoco basins, attain moderate adult body sizes (15-50 cm TL, and have a predatory life style. Here we trace the evolutionary origin and diversification of Sternarchellini using standard phylogenetic and biogeographic procedures and a dataset of 70 morphological characters. The main results are: 1 the genus Sternarchellaincludes both species currently assigned to the genus Magosternarchus; and 2 neither of the multi-species assemblages of Sternarchellini in the Amazon and Orinoco basins are monophyletic. Historical biogeographic analysis suggests that sternarchelline evolution was linked to the large-scale river capture event that formed the modern Amazon and Orinoco basins, i.e. the Late Miocene rise of the Vaupes structural arch and concomitant breaching of the Purus structural arch. This event is hypothesized to have contributed to formation of the modern sternarchelline species, and to the formation of the modern basin-wide sternarchelline species assemblages. The results indicate that cladogenesis (speciation and anagenesis (adaptive evolution were decoupled processes in the evolution of Sternarchellini.

  5. Phylogeny and biogeography of the Poecilia sphenops species complex (Actinopterygii, Poeciliidae) in Central America.

    Science.gov (United States)

    Alda, Fernando; Reina, Ruth G; Doadrio, Ignacio; Bermingham, Eldredge

    2013-03-01

    We inferred the phylogenetic relationships among members of the Poecilia sphenops species complex to resolve the colonization process and radiation of this group in Central America. We analyzed 2550 base pairs (bp) of mitochondrial DNA (mtDNA), including ATP synthase 6 and 8, cytochrome oxidase subunit I and NADH dehydrogenase subunit 2 genes, and 906bp of the nuclear S7 ribosomal protein of 86 ingroup individuals from 61 localities spanning most of its distribution from Mexico to Panama. Our mitochondrial data rendered a well-supported phylogeny for the P. sphenops complex that differed with the nuclear data set topology, which did not recover the monophyly of the P. mexicana mitochondrial lineage. Coalescent-based simulations tests indicated that, although hybridization cannot be completely ruled out, this incongruence is most likely due to incomplete lineage sorting in this group, which also showed the widest geographic distribution. A single colonization event of Central America from South America was estimated to have occurred between the early Paleocene and Oligocene (53-22millionyears ago). Subsequently, two largely differentiated evolutionary lineages diverged around the Early Oligocene-Miocene (38-13million years ago), which are considered two separate species complexes: P. sphenops and P. mexicana, which can also be distinguished by their tricuspid and unicuspid inner jaw teeth, respectively. Ultimately, within lineage diversification occurred mainly during the Miocene (22-5million years ago). All major cladogenetic events predated the final closure of the Isthmus of Panama. The allopatric distribution of lineages together with the long basal internodes suggest that vicariance and long term isolations could be the main evolutionary forces promoting radiation in this group, although dispersal through water barriers might also have occurred. Lastly, our results suggest the need to review the current species distribution and taxonomy of the P. sphenops complex sensu lato.

  6. Biogeography and evolution of Thermococcus isolates from hydrothermal vent systems of the Pacific

    Directory of Open Access Journals (Sweden)

    Mark Thomas Price

    2015-09-01

    Full Text Available Thermococcus is a genus of hyperthermophilic archaea that is ubiquitous in marine hydrothermal environments growing in anaerobic subsurface habitats but able to survive in cold oxygenated seawater. DNA analyses of Thermococcus isolates were applied to determine the relationship between geographic distribution and relatedness focusing primarily on isolates from the Juan de Fuca Ridge and South East Pacific Rise. Amplified fragment length polymorphism (AFLP analysis and multilocus sequence typing (MLST were used to resolve genomic differences in 90 isolates of Thermococcus, making biogeographic patterns and evolutionary relationships apparent. Isolates were differentiated into regionally endemic populations however there was also evidence in some lineages of cosmopolitan distribution. The biodiversity identified in Thermococcus isolates and presence of distinct lineages within the same vent site suggests the utilization of varying ecological niches in this genus. In addition to resolving biogeographic patterns in Thermococcus, this study has raised new questions about the closely related Pyrococcus genus. The phylogenetic placement of Pyrococcus type strains shows the close relationship between Thermococcus and Pyrococcus and the unresolved divergence of these two genera.

  7. Distribution, autecology and biogeography of Dryopidae and Elmidae (Coleoptera, Dryopoidea in the Balearic Islands

    Directory of Open Access Journals (Sweden)

    Rico, E.

    1998-12-01

    Full Text Available The distribution of the Dryopidae and Elmidae in the Balearic Islands was studied. Three species of Dryopidae —Dryops algiricus (Lucas, 1949, D. gracilis (Karsch, 1881 and D. sulcipennis (Costa, 1883— and one of Elmidae —Oulimnius echinatus Berthélemy, 1979— were found. Bibliographical data of other three species of Dryopidae exist, but their presence is either refuted —Dryops lutulentus (Erichson, 1847— or requires confirmation —Dryops luridus (Erichson, 1847 and D. rufipes (Krynicki, 1832—. Dryops gracilis and D. sulcipennis are recorded for first time in the archipelago. The first autecological data of the different species in the archipelago and a biogeographical analysis are provided.

    Se realiza un estudio sobre la distribución de los Dryopidae y Elmidae en las islas Baleares. Tres especies de Dryopidae —Dryops algiricus (Lucas, 1949, D. gracilis (Karsch, 1881 y D. sulcipennis (Costa, 1883— y una de Elmidae —Oulimnius echinatus Berthélemy, 1979— han sido halladas. Existen datos bibliográficos de otras tres especies de Dryopidae, pero su presencia es excluida —Dryops lutulentus (Erichson, 1847— o se considera que debe ser confirmada —Dryops luridus (Erichson, 1847 y D. rufipes (Krynicki, 1832—. Dryops gracilis y D. sulcipennis se citan por primera vez en el archipiélago. Se aportan los primeros datos sobre la autoecología de las diferentes especies en las islas y se realiza un análisis biogeográfico.

  8. Ciliate biogeography in Antarctic and Arctic freshwater ecosystems: endemism or global distribution of species?

    Science.gov (United States)

    Petz, Wolfgang; Valbonesi, Alessandro; Schiftner, Uwe; Quesada, Antonio; Cynan Ellis-Evans, J

    2007-02-01

    Ciliate diversity was investigated in situ in freshwater ecosystems of the maritime (South Shetland Islands, mainly Livingston Island, 63 degrees S) and continental Antarctic (Victoria Land, 75 degrees S), and the High Arctic (Svalbard, 79 degrees N). In total, 334 species from 117 genera were identified in both polar regions, i.e. 210 spp. (98 genera) in the Arctic, 120 spp. (73 genera) in the maritime and 59 spp. (41 genera) in the continental Antarctic. Forty-four species (13% of all species) were common to both Arctic and Antarctic freshwater bodies and 19 spp. to both Antarctic areas (12% of all species). Many taxa are cosmopolitans but some, e.g. Stentor and Metopus spp., are not, and over 20% of the taxa found in any one of the three areas are new to science. Cluster analysis revealed that species similarity between different biotopes (soil, moss) within a study area was higher than between similar biotopes in different regions. Distinct differences in the species composition of freshwater and terrestrial communities indicate that most limnetic ciliates are not ubiquitously distributed. These observations and the low congruence in species composition between both polar areas, within Antarctica and between high- and temperate-latitude water bodies, respectively, suggest that long-distance dispersal of limnetic ciliates is restricted and that some species have a limited geographical distribution.

  9. Phylogenetic position and biogeography of Hillebrandia sandwicensis (Begoniaceae): a rare Hawaiian relict.

    Science.gov (United States)

    Clement, Wendy L; Tebbitt, Mark C; Forrest, Laura L; Blair, Jaime E; Brouillet, Luc; Eriksson, Torsten; Swensen, Susan M

    2004-06-01

    The Begoniaceae consist of two genera, Begonia, with approximately 1400 species that are widely distributed in the tropics, and Hillebrandia, with one species that is endemic to the Hawaiian Islands and the only member of the family native to those islands. To help explain the history of Hillebrandia on the Hawaiian Archipelago, phylogenetic relationships of the Begoniaceae and the Cucurbitales were inferred using sequence data from 18S, rbcL, and ITS, and the minimal age of both Begonia and the Begoniaceae were indirectly estimated. The analyses strongly support the placement of Hillebrandia as the sister group to the rest of the Begoniaceae and indicate that the Hillebrandia lineage is at least 51-65 million years old, an age that predates the current Hawaiian Islands by about 20 million years. Evidence that Hillebrandia sandwicensis has survived on the Hawaiian Archipelago by island hopping from older, now denuded islands to younger, more mountainous islands is presented. Various scenarios for the origin of ancestor to Hillebrandia are considered. The geographic origin of source populations unfortunately remains obscure; however, we suggest a boreotropic or a Malesian-Pacific origin is most likely. Hillebrandia represents the first example in the well-studied Hawaiian flora of a relict genus.

  10. Biogeography of jellyfish in the North Atlantic, by traditional and genomic methods

    Science.gov (United States)

    Licandro, P.; Blackett, M.; Fischer, A.; Hosia, A.; Kennedy, J.; Kirby, R. R.; Raab, K.; Stern, R.; Tranter, P.

    2015-07-01

    Scientific debate on whether or not the recent increase in reports of jellyfish outbreaks represents a true rise in their abundance has outlined a lack of reliable records of Cnidaria and Ctenophora. Here we describe different jellyfish data sets produced within the EU programme EURO-BASIN. These data were assembled with the aim of creating an improved baseline and providing new data that can be used to evaluate the current diversity and standing stocks of jellyfish in the North Atlantic region. Using a net adapted to sample gelatinous zooplankton quantitatively, cnidarians and ctenophores were collected from the epipelagic layer during spring-summer 2010-2013, in inshore and offshore waters between lat 59 and 68° N and long 62° W and 5° E. Jellyfish were also identified and counted in samples opportunistically collected by other sampling equipment in the same region and at two coastal stations in the Bay of Biscay and in the Gulf of Cadiz. Continuous Plankton Recorder (CPR) samples collected in 2009-2012 were re-analysed with the aim of identifying the time and location of cnidarian blooms across the North Atlantic Basin. Overall the data show high variability in jellyfish abundance and diversity, mainly in relation to different water masses and bathymetry. Higher densities were generally recorded on the shelves, where the communities tend to be more diverse due to the presence of meropelagic medusae. Comparison of net records from the G.O. Sars transatlantic cruise shows that information on jellyfish diversity differs significantly depending on the sampling gear utilised. Indeed, the big trawls mostly collect relatively large scyphozoan and hydrozoan species, while small hydrozoans and early stages of Ctenophora are only caught by smaller nets. Based on CPR data from 2009 to 2012, blooms of cnidarians occurred in all seasons across the whole North Atlantic Basin. Molecular analysis revealed that, contrary to previous hypotheses, the CPR is able to detect blooms of meroplanktonic and holoplanktonic hydrozoans and scyphozoans. Through combination of different types of data, key jellyfish taxa for the spring-summer period were identified in the northern North Atlantic regions. Key species for the central and southern North Atlantic could be inferred based on the blooms identified by the CPR survey, although this should be confirmed further by comparison with quantitative data. The identification by DNA barcoding of 23 jellyfish specimens collected during the EURO-BASIN cruises contributes to increasing the still very limited number of jellyfish sequences available on GenBank. All observations presented here can be downloaded from PANGAEA (http://doi.pangaea.de/10.1594/PANGAEA.835732).

  11. Cladistics and biogeography of the assassin bug genus Rasahus Amyot & Serville (Heteroptera: Reduviidae: Peiratinae)

    NARCIS (Netherlands)

    Morrone, J.J.; Coscarón, M. del C.

    1998-01-01

    The assassin bug genus Rasahus Amyot & Serville (Heteroptera: Reduviidae: Peiratinae) comprises 26 Neotropical species. A cladistic analysis of the genus was carried out using 63 characters from external morphology, body vestiture, and male and female genitalia, with the species considered as termin

  12. Scaling up from epidemiology to biogeography: local infection patterns predict geographical distribution in fish parasites

    NARCIS (Netherlands)

    Poulin, R.; Blanar, C.A.; Thieltges, D.W.; Marcogliese, D.J.

    2012-01-01

    Aim We investigated how the spatial distribution of parasites, measured as either their geographical range size or their frequency of occurrence among localities, relates to either their average local abundance or the variance in their abundance among localities where they occur. Location We used da

  13. Molecular Taxonomy, Phylogeny and Biogeography of nematodes belonging to the Trichinella genus

    Science.gov (United States)

    Studying parasites of the genus Trichinella provides scientists of today many advantages. This is a group of zoonotic nematodes that circulate freely among wildlife hosts with one in particular, Trichinella spiralis that is particularly well adapted to domestic swine. Indeed, recent reports suggest ...

  14. Plate tectonics, seaways and climate in the historical biogeography of mammals

    Directory of Open Access Journals (Sweden)

    Cox C Barry

    2000-01-01

    Full Text Available The marsupial and placental mammals originated at a time when the pattern of geographical barriers (oceans, shallow seas and mountains was very different from that of today, and climates were warmer. The sequence of changes in these barriers, and their effects on the dispersal of the mammal families and on the faunas of mammals in the different continents, are reviewed. The mammal fauna of South America changed greatly in the Pliocene/Pleistocene, when the newly-complete Panama Isthmus allowed the North American fauna to enter the continent and replace most of the former South American mammal families. Marsupial, but not placental, mammals reached Australia via Antarctica before Australia became isolated, while rats and bats are the only placentals that dispersed naturally from Asia to Australia in the late Cenozoic. Little is known of the early history of the mammal fauna of India. A few mammal families reached Madagascar from Africa in the early Cenozoic over a chain of islands. Africa was isolated for much of the early Cenozoic, though some groups did succeed in entering from Europe. Before the climate cooled in the mid-Cenozoic, the mammal faunas of the Northern Hemisphere were much richer than those of today.

  15. Molecular Phylogeny and Biogeography of the Amphidromous Fish Genus Dormitator Gill 1861 (Teleostei: Eleotridae).

    Science.gov (United States)

    Galván-Quesada, Sesángari; Doadrio, Ignacio; Alda, Fernando; Perdices, Anabel; Reina, Ruth Gisela; García Varela, Martín; Hernández, Natividad; Campos Mendoza, Antonio; Bermingham, Eldredge; Domínguez-Domínguez, Omar

    2016-01-01

    Species of the genus Dormitator, also known as sleepers, are representatives of the amphidromous freshwater fish fauna that inhabit the tropical and subtropical coastal environments of the Americas and Western Africa. Because of the distribution of this genus, it could be hypothesized that the evolutionary patterns in this genus, including a pair of geminate species across the Central American Isthmus, could be explained by vicariance following the break-up of Gondwana. However, the evolutionary history of this group has not been evaluated. We constructed a time-scaled molecular phylogeny of Dormitator using mitochondrial (Cytochrome b) and nuclear (Rhodopsin and β-actin) DNA sequence data to infer and date the cladogenetic events that drove the diversification of the genus and to relate them to the biogeographical history of Central America. Two divergent lineages of Dormitator were recovered: one that included all of the Pacific samples and another that included all of the eastern and western Atlantic samples. In contrast to the Pacific lineage, which showed no phylogeographic structure, the Atlantic lineage was geographically structured into four clades: Cameroon, Gulf of Mexico, West Cuba and Caribbean, showing evidence of potential cryptic species. The separation of the Pacific and Atlantic lineages was estimated to have occurred ~1 million years ago (Mya), whereas the four Atlantic clades showed mean times of divergence between 0.2 and 0.4 Mya. The splitting times of Dormitator between ocean basins are similar to those estimated for other geminate species pairs with shoreline estuarine preferences, which may indicate that the common evolutionary histories of the different clades are the result of isolation events associated with the closure of the Central American Isthmus and the subsequent climatic and oceanographic changes.

  16. Genomes of three facultatively symbiotic Frankia sp. strainsreflect host plant biogeography

    Energy Technology Data Exchange (ETDEWEB)

    Normand, Philippe; Lapierre, Pascal; Tisa, Louis S.; Gogarten, J.Peter; Alloisio, Nicole; Bagnarol, Emilie; Bassi, Carla A.; Berry,Alison; Bickhart, Derek M.; Choisne, Nathalie; Couloux, Arnaud; Cournoyer, Benoit; Cruveiller, Stephane; Daubin, Vincent; Demange, Nadia; Francino, M. Pilar; Ggoltsman, Eugene; Huang, Ying; Kopp, Olga; Labarre,Laurent; Lapidus, Alla; Lavire, Celine; Marechal, Joelle; Martinez,Michele; Mastronunzio, Juliana E.; Mullin, Beth; Niemann, James; Pujic,Pierre; Rawnsley, Tania; Rouy, Zoe; Schenowitz, Chantal; Sellstedt,Anita; Tavares, Fernando; Tomkins, Jeffrey P.; Vallenet, David; Valverde,Claudio; Wall, Luis; Wang, Ying; Medigue, Claudine; Benson, David R.

    2006-02-01

    Filamentous actinobacteria from the genus Frankia anddiverse woody trees and shrubs together form N2-fixing actinorhizal rootnodule symbioses that are a major source of new soil nitrogen in widelydiverse biomes 1. Three major clades of Frankia sp. strains are defined;each clade is associated with a defined subset of plants from among theeight actinorhizal plant families 2,3. The evolution arytrajectoriesfollowed by the ancestors of both symbionts leading to current patternsof symbiont compatibility are unknown. Here we show that the competingprocesses of genome expansion and contraction have operated in differentgroups of Frankia strains in a manner that can be related to thespeciation of the plant hosts and their geographic distribution. Wesequenced and compared the genomes from three Frankia sp. strains havingdifferent host plant specificities. The sizes of their genomes variedfrom 5.38 Mbp for a narrow host range strain (HFPCcI3) to 7.50Mbp for amedium host range strain (ACN14a) to 9.08 Mbp for a broad host rangestrain (EAN1pec.) This size divergence is the largest yet reported forsuch closely related bacteria. Since the order of divergence of thestrains is known, the extent of gene deletion, duplication andacquisition could be estimated and was found to be inconcert with thebiogeographic history of the symbioses. Host plant isolation favoredgenome contraction, whereas host plant diversification favored genomeexpansion. The results support the idea that major genome reductions aswell as expansions can occur in facultatively symbiotic soil bacteria asthey respond to new environments in the context of theirsymbioses.

  17. Lessons from parasitic flatworms about evolution and historical biogeography of their vertebrate hosts.

    Science.gov (United States)

    Verneau, Olivier; Du Preez, Louis; Badets, Mathieu

    2009-01-01

    Cophylogenetic studies investigate the evolutionary trends within host-parasite associations. Examination of the different levels of fidelity between host and parasite phylogenies provides a powerful tool to inspect patterns and processes of parasite diversification over host evolution and geological times. Within the phylum Platyhelminthes, the monogeneans are mainly fish parasites. The Polystomatidae, however, are known from the sarcopterygian Australian lungfish and tetrapods such as amphibians, freshwater turtles, and the African hippopotamus. Cophylogenetic and biogeographic vicariance analyses, supplemented by molecular calibrations, showed that the Polystomatidae may track the evolutionary history of the first aquatic tetrapods in the Palaeozoic age. Evolutionary lines of the major polystome lineages would also be intimately related to the evolution of their hosts over hundreds of millions years. Since the Mesozoic, evolution of polystomes would have been shaped mainly by plate tectonics during the break-up of Gondwanaland and subsequent dispersal of ancestral neobatrachian host lineages. Therefore the Polystomatidae could serve as a novel model to improve cophylogenetic tools and to inspect a suite of questions about the evolution of vertebrate hosts.

  18. The 'Expansion-Contraction' model of Pleistocene biogeography: rocky shores suffer a sea change?

    Science.gov (United States)

    Marko, Peter B; Hoffman, Jessica M; Emme, Sandra A; Mcgovern, Tamara M; Keever, Carson C; Cox, L Nicole

    2010-01-01

    Approximately 20,000 years ago the last glacial maximum (LGM) radically altered the distributions of many Northern Hemisphere terrestrial organisms. Fewer studies describing the biogeographic responses of marine species to the LGM have been conducted, but existing genetic data from coastal marine species indicate that fewer taxa show clear signatures of post-LGM recolonization. We have assembled a mitochondrial DNA (mtDNA) data set for 14 co-distributed northeastern Pacific rocky-shore species from four phyla by combining new sequences from ten species with previously published sequences from eight species. Nuclear sequences from four species were retrieved from GenBank, plus we gathered new elongation factor 1-alpha sequences from the barnacle Balanus glandula. Results from demographic analyses of mtDNA for five (36%) species (Evasterias troschelii, Pisaster ochraceus, Littorina sitkana, L. scutulata, Xiphister mucosus) were consistent with large population expansions occurring near the LGM, a pattern expected if these species recently recolonized the region. However, seven (50%) species (Mytilus trossulus, M. californianus, B. glandula, S. cariosus, Patiria miniata, Katharina tunicata, X. atropurpureus) exhibited histories consistent with long-term stability in effective population size, a pattern indicative of regional persistence during the LGM. Two species of Nucella with significant mtDNA genetic structure showed spatially variable demographic histories. Multilocus analyses for five species were largely consistent with mtDNA: the majority of multilocus interpopulation divergence times significantly exceeded the LGM. Our results indicate that the LGM did not extirpate the majority of species in the northeastern Pacific; instead, regional persistence during the LGM appears a common biogeographic history for rocky-shore organisms in this region.

  19. The Pleistocene biogeography of eastern North America: A nonmigration scenario for deciduous forest

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C. [Argonne National Lab., IL (United States). Environmental Research Div.; Iltis, H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Botany

    1998-12-31

    The current reconstruction of the vegetation of eastern North America at the last glacial maximum postulates a very wide zone of tundra and boreal forest south of the ice. This reconstruction requires that the deciduous forest retreated far to the south. The authors believe that this reconstruction is seriously in error. Geologic evidence for glacial activity or tundra is absent from the southern Appalachians. Positive evidence for boreal forest is based on pollen identifications for Picea, Betula, and Pinus, when in reality southern members of these genera have pollen that cannot be distinguished from that of northern members. Further, pollen of typical southern species such as oaks and hickories occurs throughout profiles that past authors had labeled boreal. Pollen evidence for a far southern deciduous forest refuge is lacking. Data on endemics are particularly challenging for the scenario in which deciduous forest migrated to the south and back. The southern Appalachian region is rife with endemics that are often extreme-habitat specialists unable to migrate. The previously glaciated zone is almost completely lacking in endemics. Outlier populations, range boundaries, and absence of certain hybrids all argue against a large boreal zone. The new reconstruction postulates a cold zone no more than 75--100 miles wide south of the ice in the East.

  20. Field theory for biogeography: a spatially explicit model for predicting patterns of biodiversity.

    Science.gov (United States)

    O'Dwyer, James P; Green, Jessica L

    2010-01-01

    Predicting the variation of biodiversity across the surface of the Earth is a fundamental issue in ecology, and in this article we focus on one of the most widely studied spatial biodiversity patterns: the species-area relationship (SAR). The SAR is a central tool in conservation, being used to predict species loss following global climate change, and is striking in its universality throughout different geographical regions and across the tree of life. In this article we draw upon the methods of quantum field theory and the foundation of neutral community ecology to derive the first spatially explicit neutral prediction for the SAR. We find that the SAR has three phases, with a power law increase at intermediate scales, consistent with decades of documented empirical patterns. Our model also provides a building block for incorporating non-neutral biological variation, with the potential to bridge the gap between neutral and niche-based approaches to community assembly.

  1. Climate change alters plant biogeography in Mediterranean prairies along the West Coast, USA.

    Science.gov (United States)

    Pfeifer-Meister, Laurel; Bridgham, Scott D; Reynolds, Lorien L; Goklany, Maya E; Wilson, Hannah E; Little, Chelsea J; Ferguson, Aryana; Johnson, Bart R

    2016-02-01

    Projected changes in climate are expected to have widespread effects on plant community composition and diversity in coming decades. However, multisite, multifactor climate manipulation studies that have examined whether observed responses are regionally consistent and whether multiple climate perturbations are interdependent are rare. Using such an experiment, we quantified how warming and increased precipitation intensity affect the relative dominance of plant functional groups and diversity across a broad climate gradient of Mediterranean prairies. We implemented a fully factorial climate manipulation of warming (+2.5-3.0 °C) and increased wet-season precipitation (+20%) at three sites across a 520-km latitudinal gradient in the Pacific Northwest, USA. After seeding with a nearly identical mix of native species at all sites, we measured plant community composition (i.e., cover, richness, and diversity), temperature, and soil moisture for 3 years. Warming and the resultant drying of soils altered plant community composition, decreased native diversity, and increased total cover, with warmed northern communities becoming more similar to communities further south. In particular, after two full years of warming, annual cover increased and forb cover decreased at all sites mirroring the natural biogeographic pattern. This suggests that the extant climate gradient of increasing heat and drought severity is responsible for a large part of the observed biogeographic pattern of increasing annual invasion in US West Coast prairies as one moves further south. Additional precipitation during the rainy season did little to relieve drought stress and had minimal effects on plant community composition. Our results suggest that the projected increase in drought severity (i.e., hotter, drier summers) in Pacific Northwest prairies may lead to increased invasion by annuals and a loss of forbs, similar to what has been observed in central and southern California, resulting in novel species assemblages and shifts in functional composition, which in turn may alter ecosystem functions.

  2. Biodiversity, community structural shifts, and biogeography of prokaryotes within Antarctic continental shelf sediment.

    Science.gov (United States)

    Bowman, John P; McCuaig, Robert D

    2003-05-01

    16S ribosomal DNA (rDNA) clone library analysis was conducted to assess prokaryotic diversity and community structural changes within a surficial sediment core obtained from an Antarctic continental shelf area (depth, 761 m) within the Mertz Glacier Polynya (MGP) region. Libraries were created from three separate horizons of the core (0- to 0.4-cm, 1.5- to 2.5-cm, and 20- to 21-cm depth positions). The results indicated that at the oxic sediment surface (depth, 0 to 0.4 cm) the microbial community appeared to be dominated by a small subset of potentially r-strategist (fast-growing, opportunistic) species, resulting in a lower-than-expected species richness of 442 operational taxonomic units (OTUs). At a depth of 1.5 to 2.5 cm, the species richness (1,128 OTUs) was much higher, with the community dominated by numerous gamma and delta proteobacterial phylotypes. At a depth of 20 to 21 cm, a clear decline in species richness (541 OTUs) occurred, accompanied by a larger number of more phylogenetically divergent phylotypes and a decline in the predominance of Proteobacteria. Based on rRNA and clonal abundance as well as sequence comparisons, syntrophic cycling of oxidized and reduced sulfur compounds appeared to be the dominant process in surficial MGP sediment, as phylotype groups putatively linked to these processes made up a large proportion of clones throughout the core. Between 18 and 65% of 16S rDNA phylotypes detected in a wide range of coastal and open ocean sediments possessed high levels of sequence similarity (>95%) with the MGP sediment phylotypes, indicating that many sediment prokaryote phylotype groups defined in this study are ubiquitous in marine sediment.

  3. Microbial biogeography of drinking water: patterns in phylogenetic diversity across space and time.

    Science.gov (United States)

    Roeselers, Guus; Coolen, Jordy; van der Wielen, Paul W J J; Jaspers, Marco C; Atsma, Adrie; de Graaf, Bendert; Schuren, Frank

    2015-07-01

    In this study, we collected water from different locations in 32 drinking water distribution networks in the Netherlands and analysed the spatial and temporal variation in microbial community composition by high-throughput sequencing of 16S rRNA gene amplicons. We observed that microbial community compositions of raw source and processed water were very different for each distribution network sampled. In each network, major differences in community compositions were observed between raw and processed water, although community structures of processed water did not differ substantially from end-point tap water. End-point water samples within the same distribution network revealed very similar community structures. Network-specific communities were shown to be surprisingly stable in time. Biofilm communities sampled from domestic water metres varied distinctly between households and showed no resemblance to planktonic communities within the same distribution networks. Our findings demonstrate that high-throughput sequencing provides a powerful and sensitive tool to probe microbial community composition in drinking water distribution systems. Furthermore, this approach can be used to quantitatively compare the microbial communities to match end-point water samples to specific distribution networks. Insight in the ecology of drinking water distribution systems will facilitate the development of effective control strategies that will ensure safe and high-quality drinking water.

  4. Biogeographical consequences of Cenozoic tectonic events within East Asian margins: a case study of Hynobius biogeography.

    Directory of Open Access Journals (Sweden)

    Jun Li

    Full Text Available Few studies have explored the role of Cenozoic tectonic evolution in shaping patterns and processes of extant animal distributions within East Asian margins. We select Hynobius salamanders (Amphibia: Hynobiidae as a model to examine biogeographical consequences of Cenozoic tectonic events within East Asian margins. First, we use GenBank molecular data to reconstruct phylogenetic interrelationships of Hynobius by bayesian and maximum likelihood analyses. Second, we estimate the divergence time using the bayesian relaxed clock approach and infer dispersal/vicariance histories under the 'dispersal-extinction-cladogenesis' model. Finally, we test whether evolutionary history and biogeographical processes of Hynobius should coincide with the predictions of two major hypotheses (the 'vicariance'/'out of southwestern Japan' hypothesis. The resulting phylogeny confirmed Hynobius as a monophyletic group, which could be divided into nine major clades associated with six geographical areas. Our results show that: (1 the most recent common ancestor of Hynobius was distributed in southwestern Japan and Hokkaido Island, (2 a sister taxon relationship between Hynobius retardatus and all remaining species was the results of a vicariance event between Hokkaido Island and southwestern Japan in the Middle Eocene, (3 ancestral Hynobius in southwestern Japan dispersed into the Taiwan Island, central China, 'Korean Peninsula and northeastern China' as well as northeastern Honshu during the Late Eocene-Late Miocene. Our findings suggest that Cenozoic tectonic evolution plays an important role in shaping disjunctive distributions of extant Hynobius within East Asian margins.

  5. Demise and rise : the biogeography and taxonomy of the Odonata of tropical Africa

    NARCIS (Netherlands)

    Dijkstra, Klaas-Douwe Benediktus

    2007-01-01

    Africa has a large and almost uninterrupted land surface that is isolated from surrounding continents. In the last 20 million years Africa had a variable and increasingly dry climate. As a result the Afrotropics have only half as many odonate species as tropical America or Asia. ‘Relict’ families ar

  6. Phylogeny, Historical Biogeography and the Evolution of Migration in Accipitrid Birds of Prey (Aves: Accipitriformes

    Directory of Open Access Journals (Sweden)

    Nagy Jenő

    2014-06-01

    Full Text Available A legtöbb mérsékelt övi madárfaj életciklusában alapvető szerepet tölt be a vonulás. A rendszeres, nagy kiterjedésű mozgások, melyek a mérsékelt övi vonulási rendszereket jellemzik, egyes feltételezések szerint a trópusi fajok poszt-glaciális, északi irányú terjeszkedésével párhuzamosan jelentek meg. Ezen felül a vonulás előfordulását számos ökológiai tényező is befolyásolhatja, mint például a környezet szezonalitásának mértéke vagy a téli túlélést befolyásoló tényezők. A vonulás eredete és evolúciója ezért csak úgy érthető meg, ha a madarak biogeográfiai történetiségét és ökológiáját filogenetikai kontextusban tanulmányozzuk. Jelen vizsgálatban a vágómadár-alakúak (Accipitriformes vonulásának evolúcióját elemeztük komparatív módszerekkel. Első lépésben létrehoztunk egy fosszilis adatok alapján datált molekuláris törzsfát, amelyen jellegrekonstrukciót végeztünk és rekonstruáltuk a fajok ősi elterjedési területét. Az elemzéseink alapján a vonulás többször alakult ki a ragadozók esetében, legkorábban a héjaformákon (Accipitrinae belül, vélhetően a Miocén közepén. A legtöbb esetben a vonuló leszármazási vonalak nem vonuló őseinél trópusi elterjedésre következtethetünk. A direkcionális evolúciós teszt alapján a vonulás a trópusokon jelent meg és megnövelte a mérsékelt égöv kolonizációjának rátáját. Eszerint tehát a mérsékelt övi ragadozómadár fajok vonuló trópusi fajok leszármazottainak tekinthetők, melyek az erősen szezonális, északi élőhelyek irányába terjeszkedtek. Végezetül negatív kapcsolatot találtunk a vonulás megjelenése és a táplálékspecializáció mértéke között.

  7. Genetic diversity and biogeography of red turpentine beetle Dendroctonus valens in its native and invasive regions

    Institute of Scientific and Technical Information of China (English)

    Yan-Wen Cai; Xin-Yue Cheng; Ru-Mei Xu; Dong-Hong Duan; Lawrence R. Kirkendall

    2008-01-01

    Sequences of 479 bp region of the mitochondrial COI gene were applied to detect population genetic diversity and structure of Dendroctonus valens populations. By comparing the genetic diversity between native and invasive populations, it was shown that the genetic diversity of Chinese populations was obviously lower than that of native populations with both indices of haplotype diversity and Nei's genetic diversity, suggesting genetic bottleneck occurred in the invasive process of D. valens, and was then followed by a relatively quick population buildup. According to phylogenetic analyses of haplotypes, we suggested that the origin of the Chinese population was from California, USA. Phylogenetic and network analysis of native populations of D. valens revealed strong genetic structure at two distinct spatial and temporal scales in North America. The main cause resulting in current biogeographic pattern was supposedly due to recycled glacial events. Meanwhile, a cryptic species might exist in the Mexican and Guatemalan populations.

  8. The biogeography of red snow microbiomes and their role in melting arctic glaciers

    Science.gov (United States)

    Lutz, Stefanie; Anesio, Alexandre M.; Raiswell, Rob; Edwards, Arwyn; Newton, Rob J.; Gill, Fiona; Benning, Liane G.

    2016-06-01

    The Arctic is melting at an unprecedented rate and key drivers are changes in snow and ice albedo. Here we show that red snow, a common algal habitat blooming after the onset of melting, plays a crucial role in decreasing albedo. Our data reveal that red pigmented snow algae are cosmopolitan as well as independent of location-specific geochemical and mineralogical factors. The patterns for snow algal diversity, pigmentation and, consequently albedo, are ubiquitous across the Arctic and the reduction in albedo accelerates snow melt and increases the time and area of exposed bare ice. We estimated that the overall decrease in snow albedo by red pigmented snow algal blooms over the course of one melt season can be 13%. This will invariably result in higher melt rates. We argue that such a `bio-albedo' effect has to be considered in climate models.

  9. A recent shark radiation: molecular phylogeny, biogeography and speciation of wobbegong sharks (family: Orectolobidae).

    Science.gov (United States)

    Corrigan, Shannon; Beheregaray, Luciano B

    2009-07-01

    The elasmobranch fish are an ancient, evolutionarily successful, but under-researched vertebrate group, particularly in regard to their recent evolutionary history. Their lineage has survived four mass extinction events and most present day taxa are thought to be derived from Mesozoic forms. Here we present a molecular phylogenetic analysis of the family Orectolobidae that provides evidence for recent events of diversification in this shark group. Species interrelationships in Orectolobidae were reconstructed based on four mitochondrial and nuclear genes. In line with previous morphological work, our results do not support current taxonomic arrangements in Orectolobidae and indicate that a taxonomic revision of the family is warranted. We propose that the onset of diversification of orectolobid sharks is of Miocene age and occurred within the Indo-Australian region. Surprisingly, we also find evidence for a recent ( approximately last 2 million years) and rapid radiation of wobbegong sharks. Allopatric speciation followed by range expansion seems like the general most likely explanation to account for wobbegong relationships and distributions. We suggest that the evolution of this shark group was mostly influenced by two temporal scenarios of diversification. The oldest relates to major geological changes in the Indo-West Pacific associated with the Miocene collision of the Indo-Australian and Eurasian plates. The most recent scenario was influenced by changes in oceanography and the emergence of biogeographic barriers related to Pleistocene glacial cycles in Australian waters.

  10. Biogeography and floral evolution of baobabs (Adansonia, Bombacaceae) as inferred from multiple data sets.

    Science.gov (United States)

    Baum, D A; Small, R L; Wendel, J F

    1998-06-01

    The phylogeny of baobab trees was analyzed using four data sets: chloroplast DNA restriction sites, sequences of the chloroplast rpl16 intron, sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA, and morphology. We sampled each of the eight species of Adansonia plus three outgroup taxa from tribe Adansonieae. These data were analyzed singly and in combination using parsimony. ITS and morphology provided the greatest resolution and were largely concordant. The two chloroplast data sets showed concordance with one another but showed significant conflict with ITS and morphology. A possible explanation for the conflict is genealogical discordance within the Malagasy Longitubae, perhaps due to introgression events. A maximum-likelihood analysis of branching times shows that the dispersal between Africa and Australia occurred well after the fragmentation of Gondwana and therefore involved overwater dispersal. The phylogeny does not permit unambiguous reconstruction of floral evolution but suggests the plausible hypothesis that hawkmoth pollination was ancestral in Adansonia and that there were two parallel switches to pollination by mammals in the genus.

  11. Historical biogeography of Western Palaearctic pelobatid and pelodytid frogs: a molecular phylogenetic perspective

    NARCIS (Netherlands)

    Veith, M.; Fromhage, L.; Kosuch, J.; Vences, M.

    2006-01-01

    Spadefoot toads (Pelobates) and Parsley frogs (Pelodytes) are an enigmatic group of Western Palaearctic anurans. In the genus Pelobates, a fossorial lifestyle has enforced a conserved bauplan that masks their intraspecific evolutionary history. We used partial sequences of the mitochondrial 16S and

  12. Historical Biogeography of Five Characidium Fish Species: Dispersal from the Amazon Paleobasin to Southeastern South America

    Science.gov (United States)

    Sosa, Chrystian C.; Chacón-Vargas, Katherine; García-Merchán, Víctor Hugo

    2016-01-01

    Characidium is a Neotropical fish genus. Its distribution ranges from eastern Panama to northern Argentina, and it is an important component of the Neotropical ichthyofauna present in the major rivers of South America. We here provide an approximation to the dispersal and historical distributions of Characidium. The biogeographic history of five species of the genus was analyzed through nuclear RAG-2 and mitochondrial 16S genes and a time-calibrated phylogenetic analysis using three outgroup species. A biogeographical reconstruction was performed to estimate ancestral geographic ranges and infer the historical events that impacted the geographic distributions of Characidium species. Our results showed Characidium as a monophyletic group. The molecular clock suggests that the most recent common ancestor of Characidium originated during the Eocene, about 50.2 Mya. In addition, different dispersion and vicariance events could be inferred, which possibly gave rise to the present geographical distribution of the genus. Our results point to the rise of the Andean mountains and sea fluctuations as being important events in the formations and delimitation of different rivers, which influenced the distribution of South American ichthyofauna. PMID:27741308

  13. Mitogenomic evaluation of the historical biogeography of cichlids toward reliable dating of teleostean divergences

    Directory of Open Access Journals (Sweden)

    Miya Masaki

    2008-07-01

    Full Text Available Abstract Background Recent advances in DNA sequencing and computation offer the opportunity for reliable estimates of divergence times between organisms based on molecular data. Bayesian estimations of divergence times that do not assume the molecular clock use time constraints at multiple nodes, usually based on the fossil records, as major boundary conditions. However, the fossil records of bony fishes may not adequately provide effective time constraints at multiple nodes. We explored an alternative source of time constraints in teleostean phylogeny by evaluating a biogeographic hypothesis concerning freshwater fishes from the family Cichlidae (Perciformes: Labroidei. Results We added new mitogenomic sequence data from six cichlid species and conducted phylogenetic analyses using a large mitogenomic data set. We found a reciprocal monophyly of African and Neotropical cichlids and their sister group relationship to some Malagasy taxa (Ptychochrominae sensu Sparks and Smith. All of these taxa clustered with a Malagasy + Indo/Sri Lankan clade (Etroplinae sensu Sparks and Smith. The results of the phylogenetic analyses and divergence time estimations between continental cichlid clades were much more congruent with Gondwanaland origin and Cretaceous vicariant divergences than with Cenozoic transmarine dispersal between major continents. Conclusion We propose to add the biogeographic assumption of cichlid divergences by continental fragmentation as effective time constraints in dating teleostean divergence times. We conducted divergence time estimations among teleosts by incorporating these additional time constraints and achieved a considerable reduction in credibility intervals in the estimated divergence times.

  14. Global population genetic structure and biogeography of the oceanic copepods Eucalanus hyalinus and E. spinifer

    DEFF Research Database (Denmark)

    Goetze, Erica

    2005-01-01

    Although theory dictates that limited gene flow between populations is a necessary precursor to speciation under allopatric and parapatric models, it is currently unclear how genetic differentiation between conspecific populations can arise in open-ocean plankton species. I examined two recently ...... is an important factor determining the historical and contemporary patterns of dispersal of the two species. I suggest that species-specific ecological differences are likely to be a primary determinant of population genetic structure of open-ocean plankton......Although theory dictates that limited gene flow between populations is a necessary precursor to speciation under allopatric and parapatric models, it is currently unclear how genetic differentiation between conspecific populations can arise in open-ocean plankton species. I examined two recently...... experiencing extensive gene flow within features of the large-scale ocean circulation. Mitochondrial DNA analyses of 450 and 383 individuals of E. hyalinus and E. spinifer, respectively, revealed that habitat discontinuities at the boundaries of subtropical gyres in the North and South Pacific, as well...

  15. Planktonic foraminiferal biogeography in the Indian sector of the Southern Ocean: Contribution from CPR data

    Science.gov (United States)

    Meilland, Julie; Fabri-Ruiz, Salomé; Koubbi, Philippe; Monaco, Claire Lo; Cotte, Cédric; Hosie, Graham W.; Sanchez, Sophie; Howa, Hélène

    2016-04-01

    Within the framework of the Scientific Committee on Antarctic Research (SCAR) Southern Ocean-Continuous Plankton Recorder (SO-CPR) Survey, the oceanic regions around Crozet and Kerguelen Islands were investigated in February-March 2013. Living planktonic Foraminifera (LPF) were collected in the upper mixed layer with a CPR along a 2160 nautical mile sea transect that crossed main hydrological fronts in the Indian sector of the Southern Ocean. In the SO-CPR database, mean total abundances of Foraminifera occurring during late austral summer are highly variable at an inter-annual scale, from 10 to 250 ind.m-3, representing 10-40% of the total zooplankton abundance, respectively. In the Southern Ocean, major inter-annual changes in zooplankton community structure were already reported. In this study, we describe the large scale distributional pattern of individual planktonic foraminiferal species living in near-surface waters of the Indian sector of the Southern Ocean, and we attempt to explain why major spatial variability in relative species abundances occurs during a late austral summer. In February-March 2013, LPF total abundances recorded between 42.86°S and 56.42°S ranged from 0 to a maximum of 258 ind.m-3. In the Open Ocean Zone, the LPF community was composed of four major species (Globigerinita uvula, Neogloboquadrina pachyderma, Neogloboquadrina incompta, Globigerina bulloides). Generally, LPF total abundances are supposed to mirror primary production induced by hydrological fronts or induced by topography near Crozet and Kerguelen Islands. However, during late austral summer 2013, high foraminiferal abundances in the upper mixed layer did not always match the pattern of near-surface primary production (high Chl-a concentration areas delineated from satellite imagery). Low LPF standing stocks in late austral summer in the Southern Ocean contrasted with the presence of high densities of heavily silicified diatoms. This suggests that the late bloom production is not a suitable resource for planktonic Foraminifera. Consequently, LPF regional distribution in the upper mixed layer cannot be directly reconstructed from Chl-a concentration maps derived from satellite imagery. Knowledge of phytoplankton community composition is needed to understand the impact of primary production on foraminiferal population dynamics. Our results also emphasize that the polar/subpolar foraminiferal assemblages are characterized by high abundances of G. uvula in the iron-enriched waters surrounding the French Sub-Antarctic Islands. This species might react either to coastal or late summer production in high latitudes.

  16. Assessing the limits of random amplified polymorphic DNAs (RAPDs) in seaweed biogeography

    NARCIS (Netherlands)

    vanOppen, MJH; Klerk, H; deGraaf, M; Stam, WT; Olsen, JL

    1996-01-01

    As judged by comparison with other molecular data sets, random amplified polymorphic DNA (RAPD) data are robust in identifying large-scale biogeographic populations that range from hundreds to thousands of kilometers apart. As the geographical scale is shifted downward, however, RAPD data often fail

  17. NOAA ESRI Grid - sediment size predictions model in New York offshore planning area from Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents sediment size predictions from a sediment spatial model developed for the New York offshore spatial planning area. The model also includes...

  18. Multilocus sequence analysis for the assessment of phylogenetic diversity and biogeography in hyphomonas bacteria from diverse marine environments.

    Science.gov (United States)

    Li, Chongping; Lai, Qiliang; Li, Guizhen; Liu, Yang; Sun, Fengqin; Shao, Zongze

    2014-01-01

    Hyphomonas, a genus of budding, prosthecate bacteria, are primarily found in the marine environment. Seven type strains, and 35 strains from our collections of Hyphomonas, isolated from the Pacific Ocean, Atlantic Ocean, Arctic Ocean, South China Sea and the Baltic Sea, were investigated in this study using multilocus sequence analysis (MLSA). The phylogenetic structure of these bacteria was evaluated using the 16S rRNA gene, and five housekeeping genes (leuA, clpA, pyrH, gatA and rpoD) as well as their concatenated sequences. Our results showed that each housekeeping gene and the concatenated gene sequence all yield a higher taxonomic resolution than the 16S rRNA gene. The 42 strains assorted into 12 groups. Each group represents an independent species, which was confirmed by virtual DNA-DNA hybridization (DDH) estimated from draft genome sequences. Hyphomonas MLSA interspecies and intraspecies boundaries ranged from 93.3% to 96.3%, similarity calculated using a combined DDH and MLSA approach. Furthermore, six novel species (groups I, II, III, IV, V and XII) of the genus Hyphomonas exist, based on sequence similarities of the MLSA and DDH values. Additionally, we propose that the leuA gene (93.0% sequence similarity across our dataset) alone could be used as a fast and practical means for identifying species within Hyphomonas. Finally, Hyphomonas' geographic distribution shows that strains from the same area tend to cluster together as discrete species. This study provides a framework for the discrimination and phylogenetic analysis of the genus Hyphomonas for the first time, and will contribute to a more thorough understanding of the biological and ecological roles of this genus.

  19. Phylogenetic analysis of Attalea (Arecaceae) : insights into the historical biogeography of a recently diversified Neotropical plant group

    OpenAIRE

    Freitas,C.; Meerow, A. W.; Pintaud, Jean-Christophe; Henderson, A.; Noblick, L.; COSTA, F. R. C.; Barbosa, C. E.; Barrington, D.

    2016-01-01

    We present a dated phylogenetic tree for the Neotropical genus Attalea (Arecaceae). We used six orthologues from the nuclear WRKY gene family across 98 accessions to address relationships among species and biogeographical hypotheses. We found that the formerly recognized groups within Attalea are not monophyletic and therefore there is no support for multiple genera as previously thought. Species of Attalea-like palms from the Atlantic forest form a well-supported clade sister to the Attalea ...

  20. Molecular phylogeny and biogeography of the Cuban genus Girardinus Poey, 1854 and relationships within the tribe Girardinini (Actinopterygii, Poeciliidae).

    Science.gov (United States)

    Doadrio, Ignacio; Perea, Silvia; Alcaraz, Lourdes; Hernandez, Natividad

    2009-01-01

    Phylogenetic relationships among members of the freshwater fish tribe Girardinini were inferred to test existing colonization and diversification hypotheses for this group in the Caribbean. The genetic material examined was mitochondrial (cytochrome b, 1140 bp) and nuclear (RAG-1 and beta-actin, 2450 bp) DNA from 161 specimens representing 44 ingroup and three outgroup taxa. Our mtDNA and combined data matrix (mtDNA+nuclear DNA) results rendered a well-supported phylogeny for the tribe Girardinini and suggest the need to review the group's current taxonomy. From the data presented here, it may be inferred that the Girardinini diverged from other poeciliid fishes approximately 62 Mya ago in the Palaeocene period. This estimate, however, conflicts with the hypothesis that today's vertebrate fauna is the result of the more recent colonization of the Antillean islands during the Early Oligocene (35-33 Mya ago). The isolation of western, central and eastern Cuba during the Miocene and that of the Juventud Island and Guanahacabibes Peninsula during the Pliocene, are the main geologic events that could have promoted speciation in this group.

  1. Biogeography and conservation of viperids from North-West Africa : an application of ecological niche-based models and GIS

    OpenAIRE

    J. C. Brito; Fahd, S.; Geniez, P.; Martinez-Freiria, F.; Pleguezuelos, J. M.; Trape, Jean-François

    2011-01-01

    North-West Africa is an outstanding region to study biogeographic patterns in biodiversity distribution. This study identifies biogeographic affinities and areas of probable occurrence for seven viperid snakes through the combination of high resolution presence data and environmental factors. Vipers exhibited distinct biogeographical affinities: Bitis arietans was mostly found along savannahs, Echis leucogaster along the Sahel/savannahs, Cerastes cerastes and C vipera throughout most desertic...

  2. ENVIRONMENTAL-REGULATION OF DEVELOPMENT, LIFE-HISTORY AND BIOGEOGRAPHY OF HELMINTHORA-STACKHOUSEI (RHODOPHYTA) BY DAYLENGTH AND TEMPERATURE

    NARCIS (Netherlands)

    CUNNINGHAM, EM; GUIRY, MD; BREEMAN, AM

    1993-01-01

    The marine red alga Helminthora stackhousei (Clemente) Cremades et Perez-Cirera [ = H. divaricata (C. Agardh) J. Agardh] from the west coast of Ireland has a heteromorphic life history in culture. Tetrasporangia are formed on uniseriate, filamentous tetrasporophytes, mainly under short-day condition

  3. Biogeography of heterotrophic flagellate populations indicates the presence of generalist and specialist taxa in the Arctic Ocean.

    Science.gov (United States)

    Thaler, Mary; Lovejoy, Connie

    2015-03-01

    Heterotrophic marine flagellates (HF) are ubiquitous in the world's oceans and represented in nearly all branches of the domain Eukaryota. However, the factors determining distributions of major taxonomic groups are poorly known. The Arctic Ocean is a good model environment for examining the distribution of functionally similar but phylogenetically diverse HF because the physical oceanography and annual ice cycles result in distinct environments that could select for microbial communities or favor specific taxa. We reanalyzed new and previously published high-throughput sequencing data from multiple studies in the Arctic Ocean to identify broad patterns in the distribution of individual taxa. HF accounted for fewer than 2% to over one-half of the reads from the water column and for up to 60% of reads from ice, which was dominated by Cryothecomonas. In the water column, many HF phylotypes belonging to Telonemia and Picozoa, uncultured marine stramenopiles (MAST), and choanoflagellates were geographically widely distributed. However, for two groups in particular, Telonemia and Cryothecomonas, some species level taxa showed more restricted distributions. For example, several phylotypes of Telonemia favored open waters with lower nutrients such as the Canada Basin and offshore of the Mackenzie Shelf. In summary, we found that while some Arctic HF were successful over a range of conditions, others could be specialists that occur under particular conditions. We conclude that tracking species level diversity in HF not only is feasible but also provides a potential tool for understanding the responses of marine microbial ecosystems to rapidly changing ice regimes.

  4. Historical biogeography of the catfish genus Hypostomus (Siluriformes: Loricariidae), with implications on the diversification of Neotropical ichthyofauna.

    Science.gov (United States)

    Montoya-Burgos, J I

    2003-07-01

    Tropical South America possesses the largest ichthyofauna of any continental region. To test whether palaeohydrological changes may have been the causes of such diversification, the 'hydrogeological' hypothesis, the phylogenetic relationships of 51 representatives of the catfish genus Hypostomus (Siluriformes: Loricariidae) were inferred using mitochondrial D-loop haplotype sequences. Specimens were collected in all main tropical South American rivers systems east to the Andes. The major interrelationships found with the D-loop data were confirmed with a subset of 21 species using complete internal transcribed spacer (ITS) region sequences. The phylogenetic analysis indicate that the genus Hypostomus can be divided into four monophyletic clades. The historical biogeographical analysis of each of these clades allows the identification of seven major cladogenetic events. Using calibrated D-loop and ITS molecular clocks, date estimations were attributed to each of these cladogenetic events allowing a linkage between four of them with documented hydrogeological changes. Comparisons with published distribution patterns of unrelated fish groups indicate that several of the reconstructed and dated hydrogeological-cladogenetic events may have acted at a large scale on the diversification of Neotropical freshwater fish fauna during late Tertiary.

  5. Phylogenetic relationships and historical biogeography of neotropical parrots (Psittaciformes: Psittacidae: Arini) inferred from mitochondrial and nuclear DNA sequences.

    Science.gov (United States)

    Tavares, Erika Sendra; Baker, Allan J; Pereira, Sérgio Luiz; Miyaki, Cristina Yumi

    2006-06-01

    Previous hypotheses of phylogenetic relationships among Neotropical parrots were based on limited taxon sampling and lacked support for most internal nodes. In this study we increased the number of taxa (29 species belonging to 25 of the 30 genera) and gene sequences (6388 base pairs of RAG-1, cyt b, NADH2, ATPase 6, ATPase 8, COIII, 12S rDNA, and 16S rDNA) to obtain a stronger molecular phylogenetic hypothesis for this group of birds. Analyses of the combined gene sequences using maximum likelihood and Bayesian methods resulted in a well-supported phylogeny and indicated that amazons and allies are a sister clade to macaws, conures, and relatives, and these two clades are in turn a sister group to parrotlets. Key morphological and behavioral characters used in previous classifications were mapped on the molecular tree and were phylogenetically uninformative. We estimated divergence times of taxa using the molecular tree and Bayesian and penalized likelihood methods that allow for rate variation in DNA substitutions among sites and taxa. Our estimates suggest that the Neotropical parrots shared a common ancestor with Australian parrots 59 Mya (million of years ago; 95% credibility interval (CrI) 66, 51 Mya), well before Australia separated from Antarctica and South America, implying that ancestral parrots were widespread in Gondwanaland. Thus, the divergence of Australian and Neotropical parrots could be attributed to vicariance. The three major clades of Neotropical parrots originated about 50 Mya (95% CrI 57, 41 Mya), coinciding with periods of higher sea level when both Antarctica and South America were fragmented with transcontinental seaways, and likely isolated the ancestors of modern Neotropical parrots in different regions in these continents. The correspondence between major paleoenvironmental changes in South America and the diversification of genera in the clade of amazons and allies between 46 and 16 Mya suggests they diversified exclusively in South America. Conversely, ancestors of parrotlets and of macaws, conures, and allies may have been isolated in Antarctica and/or the southern cone of South America, and only dispersed out of these southern regions when climate cooled and Antarctica became ice-encrusted about 35 Mya. The subsequent radiation of macaws and their allies in South America beginning about 28 Mya (95% CrI 22, 35 Mya) coincides with the uplift of the Andes and the subsequent formation of dry, open grassland habitats that would have facilitated ecological speciation via niche expansion from forested habitats.

  6. Phylogenetics and biogeography of a spectacular Old World radiation of butterflies: the subtribe Mycalesina (Lepidoptera: Nymphalidae: Satyrini

    Directory of Open Access Journals (Sweden)

    Torres Elizabeth

    2010-06-01

    Full Text Available Abstract Background Butterflies of the subtribe Mycalesina (Nymphalidae: Satyrinae are important model organisms in ecology and evolution. This group has radiated spectacularly in the Old World tropics and presents an exciting opportunity to better understand processes of invertebrate rapid radiations. However, the generic-level taxonomy of the subtribe has been in a constant state of flux, and relationships among genera are unknown. There are six currently recognized genera in the group. Mycalesis, Lohora and Nirvanopsis are found in the Oriental region, the first of which is the most speciose genus among mycalesines, and extends into the Australasian region. Hallelesis and Bicyclus are found in mainland Africa, while Heteropsis is primarily Madagascan, with a few species in Africa. We infer the phylogeny of the group with data from three genes (total of 3139 bp and use these data to reconstruct events in the biogeographic history of the group. Results The results indicate that the group Mycalesina radiated rapidly around the Oligocene-Miocene boundary. Basal relationships are unresolved, but we recover six well-supported clades. Some species of Mycalesis are nested within a primarily Madagascan clade of Heteropsis, while Nirvanopsis is nested within Lohora. The phylogeny suggests that the group had its origin either in Asia or Africa, and diversified through dispersals between the two regions, during the late Oligocene and early Miocene. The current dataset tentatively suggests that the Madagascan fauna comprises two independent radiations. The Australasian radiation shares a common ancestor derived from Asia. We discuss factors that are likely to have played a key role in the diversification of the group. Conclusions We propose a significantly revised classification scheme for Mycalesina. We conclude that the group originated and radiated from an ancestor that was found either in Asia or Africa, with dispersals between the two regions and to Australasia. Our phylogeny paves the way for further comparative studies on this group that will help us understand the processes underlying diversification in rapid radiations of invertebrates.

  7. Escape from the Ponto-Caspian: evolution and biogeography of an endemic goby species flock (Benthophilinae: Gobiidae: Teleostei).

    Science.gov (United States)

    Neilson, Matthew E; Stepien, Carol A

    2009-07-01

    Endemic Ponto-Caspian gobies include a flock of 24 "neogobiin" species (containing the nominal genera and subgenera Apollonia, Babka, Neogobius, Mesogobius, Ponticola, and Proterorhinus; Teleostei: Gobiidae), of which a large proportion (5 species; 21%) recently escaped to invade other freshwater Eurasian systems and the North American Great Lakes. We provide its first comprehensive phylogenetic and biogeographic analysis based on 4709 bp sequences from two mitochondrial and two nuclear genes with maximum parsimony, likelihood, and Bayesian approaches. We additionally compare its relationships with the tadpole gobies (Benthophilus and Caspiosoma), which comprise a related endemic Ponto-Caspian gobiid group; along with a variety of postulated relatives and outgroups. Results of all phylogenetic approaches are highly congruent and provide very strong support for recognizing the subfamily Benthophilinae; which encompasses both the "neogobiins" and tadpole gobies, and genetically diverges from other Gobiidae subfamilies-including (non-monophyletic) Gobiinae and Gobinellinae. Benthophilinae contains three tribes: Neogobiini (Neogobius, which is synonymized here with Apollonia; containing the type species N. fluviatilis, along with N. melanostomus and N. caspius), Ponticolini (containing the genera Mesogobius, Proterorhinus, Babka, and Ponticola-elevating the latter two from subgenera and removing them from the formerly paraphyletic Neogobius), and Benthophilini (tadpole gobies). Within Ponticolini, Proterorhinus and Mesogobius comprise the sister clade of the Ponticola and Babka clade. Further work is needed to clarify the interrelationships of the tadpole gobies. Invasiveness is widespread in freshwater and euryhaline taxa of Neogobius, Proterorhinus, Babka, and Ponticola; but not in marine species, Mesogobius, or tadpole gobies.

  8. Historical biogeography of Thyrsophorini psocids and description of a new neotropical species of Thyrsopsocopsis (Psocodea: Psocomorpha: Psocidae

    Directory of Open Access Journals (Sweden)

    Cristian Román-Palacios

    2016-05-01

    Full Text Available When based on phylogenetic proposals, biogeographic historic narratives have a great interest for hypothesizing paths of origin of the current biodiversity. Among the many questions that remain unsolved about psocids, the distribution of Thyrsophorini represents still a remarkable enigma. This tribe had been considered as exclusively Neotropical, until the description of Thyrsopsocopsis thorntoni Mockford, 2004, from Vietnam. Three hypotheses have been proposed to explain this atypical distribution, recurring to dispersal, vicariance and morphological parallelism between lineages, but the lack of evidence has not allowed a unique support. Here, we describe a new Neotropical species of Thyrsopsocopsis, and also attempt to test the three biogeographical hypotheses in a phylogenetic context. In our analyses, the position of Cycetes (Cycetini and Thyrsopsocopsis among Thyrsophorini psocids is well resolved, suggesting a dispersal event from the Neotropics for both genera.

  9. Historical biogeography of the land snail Cornu aspersum: a new scenario inferred from haplotype distribution in the Western Mediterranean basin

    Directory of Open Access Journals (Sweden)

    Madec Luc

    2010-01-01

    Full Text Available Abstract Background Despite its key location between the rest of the continent and Europe, research on the phylogeography of north African species remains very limited compared to European and North American taxa. The Mediterranean land mollusc Cornu aspersum (= Helix aspersa is part of the few species widely sampled in north Africa for biogeographical analysis. It then provides an excellent biological model to understand phylogeographical patterns across the Mediterranean basin, and to evaluate hypotheses of population differentiation. We investigated here the phylogeography of this land snail to reassess the evolutionary scenario we previously considered for explaining its scattered distribution in the western Mediterranean, and to help to resolve the question of the direction of its range expansion (from north Africa to Europe or vice versa. By analysing simultaneously individuals from 73 sites sampled in its putative native range, the present work provides the first broad-scale screening of mitochondrial variation (cyt b and 16S rRNA genes of C. aspersum. Results Phylogeographical structure mirrored previous patterns inferred from anatomy and nuclear data, since all haplotypes could be ascribed to a B (West or a C (East lineage. Alternative migration models tested confirmed that C. aspersum most likely spread from north Africa to Europe. In addition to Kabylia in Algeria, which would have been successively a centre of dispersal and a zone of secondary contacts, we identified an area in Galicia where genetically distinct west and east type populations would have regained contact. Conclusions Vicariant and dispersal processes are reviewed and discussed in the light of signatures left in the geographical distribution of the genetic variation. In referring to Mediterranean taxa which show similar phylogeographical patterns, we proposed a parsimonious scenario to account for the "east-west" genetic splitting and the northward expansion of the western (B clade which roughly involves (i the dispersal of ancestral (eastern types through Oligocene terranes in the Western Mediterranean (ii the Tell Atlas orogenesis as gene flow barrier between future west and east populations, (iii the impact of recurrent climatic fluctuations from mid-Pliocene to the last ice age, (iv the loss of the eastern lineage during Pleistocene northwards expansion phases.

  10. Biogeography of speciation of two sister species of neotropical amazona (Aves, Psittaciformes based on mitochondrial sequence data.

    Directory of Open Access Journals (Sweden)

    Amanda V Rocha

    Full Text Available Coalescent theory provides powerful models for population genetic inference and is now increasingly important in estimates of divergence times and speciation research. We use molecular data and methods based on coalescent theory to investigate whether genetic evidence supports the hypothesis of A. pretrei and A. tucumana as separate species and whether genetic data allow us to assess which allopatric model seems to better explain the diversification process in these taxa. We sampled 13 A. tucumana from two provinces in northern Argentina and 28 A. pretrei from nine localities of Rio Grande do Sul, Brazil. A 491 bp segment of the mitochondrial gene cytochrome c oxidase I was evaluated using the haplotype network and phylogenetic methods. The divergence time and other demographic quantities were estimated using the isolation and migration model based on coalescent theory. The network and phylogenetic reconstructions showed similar results, supporting reciprocal monophyly for these two taxa. The divergence time of lineage separation was estimated to be approximately 1.3 million years ago, which corresponds to the lower Pleistocene. Our results enforce the current taxonomic status for these two Amazon species. They also support that A. pretrei and A. tucumana diverged with little or no gene flow approximately 1.3 million years ago, most likely after the establishment of a small population in the Southern Yungas forest by dispersion of a few founders from the A. pretrei ancestral population. This process may have been favored by habitat corridors formed in hot and humid periods of the Quaternary. Considering that these two species are considered threatened, the results were evaluated for their implications for the conservation of these two species.

  11. Environmental Mapping of Paracoccidioides spp. in Brazil Reveals New Clues into Genetic Diversity, Biogeography and Wild Host Association

    Science.gov (United States)

    Arantes, Thales Domingos; Theodoro, Raquel Cordeiro; Teixeira, Marcus de Melo; Bosco, Sandra de Moraes Gimenes; Bagagli, Eduardo

    2016-01-01

    Background Paracoccidioides brasiliensis and Paracoccidioides lutzii are the etiological agents of Paracoccidioidomycosis (PCM), and are easily isolated from human patients. However, due to human migration and a long latency period, clinical isolates do not reflect the spatial distribution of these pathogens. Molecular detection of P. brasiliensis and P. lutzii from soil, as well as their isolation from wild animals such as armadillos, are important for monitoring their environmental and geographical distribution. This study aimed to detect and, for the first time, evaluate the genetic diversity of P. brasiliensis and P. lutzii for Paracoccidioidomycosis in endemic and non-endemic areas of the environment, by using Nested PCR and in situ hybridization techniques. Methods/Principal Findings Aerosol (n = 16) and soil (n = 34) samples from armadillo burrows, as well as armadillos (n = 7) were collected in endemic and non-endemic areas of PCM in the Southeastern, Midwestern and Northern regions of Brazil. Both P. brasiliensis and P. lutzii were detected in soil (67.5%) and aerosols (81%) by PCR of Internal Transcribed Spacer (ITS) region (60%), and also by in situ hybridization (83%). Fungal isolation from armadillo tissues was not possible. Sequences from both species of P. brasiliensis and P. lutzii were detected in all regions. In addition, we identified genetic Paracoccidioides variants in soil and aerosol samples which have never been reported before in clinical or armadillo samples, suggesting greater genetic variability in the environment than in vertebrate hosts. Conclusions/Significance Data may reflect the actual occurrence of Paracoccidioides species in their saprobic habitat, despite their absence/non-detection in seven armadillos evaluated in regions with high prevalence of PCM infection by P. lutzii. These results may indicate a possible ecological difference between P. brasiliensis and P. lutzii concerning their wild hosts. PMID:27045486

  12. An evaluation of the influence of environment and biogeography on community structure: the case of Holarctic mammals

    DEFF Research Database (Denmark)

    Rodríguez, J.; Hortal, Joaquín; Nieto, M.

    2006-01-01

    to Bailey's ecoregions (used as a surrogate of regional climate), and the positions of the communities in the dimensions of the CA are compared in relation to ecoregion and realm. Partial regression was used to test for the relative influence of ecoregion and realm over each dimension and to evaluate...

  13. Systematics and biogeography of the Hylarana frog (Anura: Ranidae) radiation across tropical Australasia, Southeast Asia, and Africa.

    Science.gov (United States)

    Oliver, Lauren A; Prendini, Elizabeth; Kraus, Fred; Raxworthy, Christopher J

    2015-09-01

    We present an inclusive molecular phylogeny for Hylarana across its global distribution, utilizing two mitochondrial and four nuclear gene regions for 69 of the 97 currently described species. We use phylogenetic methods to test monophyly of Hylarana, determine relationships among ten putative subgenera, identify major clades, reconstruct biogeographic history, and estimate continental dispersal dates. Results support Hylarana as a monophyletic group originating approximately 26.9MYA and comprising eight clades that partly correspond to currently described subgenera plus two new groups. The African and Australasian species each form clades embedded within a paraphyletic Southeast Asian group. We estimate that Africa and Australasia were colonized by Hylarana s.l. from SE Asia approximately 18.7 and 10.8MYA, respectively. Biogeographic reconstructions also support three separate colonization events in India from Southeast Asia. Examination of museum specimens identified morphological characters useful for delineating subgenera and species. We herein elevate all supported subgenera to genus rank and formally describe two new genera to produce a revised taxonomy congruent with our new phylogenetic and biogeographic findings.

  14. Korarchaeota diversity, biogeography, and abundance in Yellowstone and Great Basin hot springs and ecological niche modeling based on machine learning.

    Directory of Open Access Journals (Sweden)

    Robin L Miller-Coleman

    Full Text Available Over 100 hot spring sediment samples were collected from 28 sites in 12 areas/regions, while recording as many coincident geochemical properties as feasible (>60 analytes. PCR was used to screen samples for Korarchaeota 16S rRNA genes. Over 500 Korarchaeota 16S rRNA genes were screened by RFLP analysis and 90 were sequenced, resulting in identification of novel Korarchaeota phylotypes and exclusive geographical variants. Korarchaeota diversity was low, as in other terrestrial geothermal systems, suggesting a marine origin for Korarchaeota with subsequent niche-invasion into terrestrial systems. Korarchaeota endemism is consistent with endemism of other terrestrial thermophiles and supports the existence of dispersal barriers. Korarchaeota were found predominantly in >55°C springs at pH 4.7-8.5 at concentrations up to 6.6×10(6 16S rRNA gene copies g(-1 wet sediment. In Yellowstone National Park (YNP, Korarchaeota were most abundant in springs with a pH range of 5.7 to 7.0. High sulfate concentrations suggest these fluids are influenced by contributions from hydrothermal vapors that may be neutralized to some extent by mixing with water from deep geothermal sources or meteoric water. In the Great Basin (GB, Korarchaeota were most abundant at spring sources of pH<7.2 with high particulate C content and high alkalinity, which are likely to be buffered by the carbonic acid system. It is therefore likely that at least two different geological mechanisms in YNP and GB springs create the neutral to mildly acidic pH that is optimal for Korarchaeota. A classification support vector machine (C-SVM trained on single analytes, two analyte combinations, or vectors from non-metric multidimensional scaling models was able to predict springs as Korarchaeota-optimal or sub-optimal habitats with accuracies up to 95%. To our knowledge, this is the most extensive analysis of the geochemical habitat of any high-level microbial taxon and the first application of a C-SVM to microbial ecology.

  15. NOAA ESRI Grid - depth uncertainty predictions in New York offshore planning area from Biogeography Branch bathymetry model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents depth uncertainty predictions from a bathymetric model developed for the New York offshore spatial planning area. The model also includes...

  16. Phylogenetic analysis of Attalea (Arecaceae): insights on the historical biogeography of a recently diversified Neotropical plant group

    Science.gov (United States)

    Technical Abstract Here we present a dated phylogenetic tree of the neotropical palm genus Attalea (Arecaceae). We used six orthologs from the nuclear WRKY gene family across 98 accessions to address relationships among species and biogeographic hypotheses. Here we found that the formerly recognized...

  17. Phylogeny and historical biogeography of the cocosoid palms (Arecaceae, Arecoideae, Cocoseae) inferred from sequences of six WRKY gene family loci

    Science.gov (United States)

    Arecaceae tribe Cocoseae is the most economically important tribe of palms, including both coconut and African oil palm. It is mostly represented in the Neotropics, with one and two genera endemic to South Africa and Madagascar, respectively. Using primers for six single copy WRKY gene family loci...

  18. Diversity and biogeography of sooty blotch and flyspeck fungi on apple in the eastern and midwestern United States.

    Science.gov (United States)

    Díaz Arias, María M; Batzer, Jean C; Harrington, Thomas C; Wong, Amy Wang; Bost, Steven C; Cooley, Daniel R; Ellis, Michael A; Hartman, John R; Rosenberger, David A; Sundin, George W; Sutton, Turner B; Travis, James W; Wheeler, Michael J; Yoder, Keith S; Gleason, Mark L

    2010-04-01

    Sooty blotch and flyspeck (SBFS) fungi on apple fruit were sampled from nine orchards in four midwestern U.S. states during 2000 and 30 orchards in 10 eastern U.S. states during 2005 in order to estimate taxonomic diversity and discern patterns of geographic distribution. Forty apple fruit per orchard were arbitrarily sampled and colonies of each mycelial phenotype were counted on each apple. Representative colonies were isolated, cultures were purified, and DNA was extracted. For representative isolates, the internal transcribed spacer (ITS) and large subunit (LSU) regions of ribosomal DNA were amplified and sequenced. In total, 60 SBFS putative species were identified based on ITS sequences and morphological characteristics; 30 of these were discovered in the 2005 survey. Modified Koch's postulates were fulfilled for all 60 species in an Iowa orchard; colonies resulting from inoculation of apple fruit were matched to the original isolates on the basis of mycelial type and ITS sequence. Parsimony analysis for LSU sequences from both surveys revealed that 58 putative SBFS species were members of the Dothideomycetes, 52 were members of the Capnodiales, and 36 were members of the Mycosphaerellaceae. The number of SBFS species per orchard varied from 2 to 15. Number of SBFS species and values of the Margalef and Shannon indexes were significantly (P < 0.05) lower in 21 orchards that had received conventional fungicide sprays during the fruit maturation period than in 14 unsprayed orchards. Several SBFS species, including Schizothyrium pomi, Peltaster fructicola, and Pseudocercosporella sp. RH1, were nearly ubiquitous, whereas other species, such as Stomiopeltis sp. RS5.2, Phialophora sessilis, and Geastrumia polystigmatis, were found only within restricted geographic regions. The results document that the SBFS complex is far more taxonomically diverse than previously recognized and provide strong evidence that SBFS species differ in geographic distribution. To achieve more efficient management of SBFS, it may be necessary to understand the environmental biology of key SBFS species in each geographic region.

  19. Soil Heterogeneity Reflected in Biogeography of Beech Forests in the Borderland Between the Bohemian Massif and the Outer Western Carpathians

    Directory of Open Access Journals (Sweden)

    Samec Pavel

    2014-12-01

    Full Text Available Soil environment characteristics naturally affect the biogeographical classification of forests in central Europe. However, even on the same localities, different systems of vegetation classification de-scribe the forest types according to the naturally dominant tree species with different accuracy. A set of 20 representative natural beech stands in the borderland between the Bohemian Massif (Hercyni-an biogeographical subprovince and the Outer Western Carpathians (Westcarpathian subprovince was selected in order to compare textural, hydrostatic, physico-chemical and chemical properties of soils between the included geomorphological regions, bioregions and biotopes. Differences in the soils of the surveyed beech stands were mainly due to volume weight and specific weight, maximum capillary capacity (MCC, porosity, base saturation (BS, total soil nitrogen (Nt and fulvic acids. Specifics in the relations between these soil characteristics indicated that transient trans-Hercynian beech forests developed in the borderland between the two compared subprovinces. Soils of the investigated Hercynian beech forests were generally characterized by lower BS and lower Nt. Soils of the trans-Hercynian beech forests were more similar to the Carpathian beech forest soils than soils in the other Hercynian beech forests. Soils of the trans-Hercynian and Carpathian beech forests showed similarly higher BS, deeper occurrence of humic substances, lower specific weight and also higher MCC. Higher content of humic substances as well as MCC indicated an equal effect on forest ecology, which may contribute to more accurate classification of forests.

  20. The oldest ascocerid cephalopod from the Silurian of Estonia and notes on the biogeography of the order Ascocerida (class Cephalopoda

    Directory of Open Access Journals (Sweden)

    Martina Aubrechtova

    2016-05-01

    Full Text Available The early Palaeozoic order Ascocerida is a group of morphologically unique and rare cephalopods known from the Ordovician and Silurian rocks of Avalonia, Baltica, Laurentia and Perunica. The limited Estonian record of Silurian ascocerids is complemented with a specimen from the Pähkla locality (Island of Saaremaa; Paadla Regional Stage, Ludlow Series representing the stratigraphically oldest known occurrence of ascocerids in the Silurian of Estonia. The strata that were formerly exposed in Pähkla are likely correlated to the Hemse Group of the Island of Gotland (Sweden having a remarkable record of ascocerids. The appearance of Silurian ascocerids in Estonia is confined to a time interval when the group had the highest species diversity and the widest geographic dispersion, reaching also outside Baltica for the first time.

  1. Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae, in Madagascar

    Directory of Open Access Journals (Sweden)

    Raharimalala Fara

    2012-03-01

    Full Text Available Abstract Background In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML method with the gene time reversible (GTR model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p -16 and period (F = 36.22, p = 2.548 × 10-13, that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. Conclusion In Madagascar, Ae. albopictus has extended its geographical distribution whereas, Ae. aegypti has become rare, contrasting with what was previously observed. Changes are predominantly driven by human activities and the rainfall regime that provide suitable breeding sites for the highly anthropophilic mosquito Ae. albopictus. Moreover, these populations were found to be highly susceptible to chikungunya virus. In the light of this study, Ae. albopictus may have been involved in the recent outbreaks of chikungunya and dengue epidemics in Madagascar, and consequently, control measures should be promoted to limit its current expansion.

  2. Molecular phylogenetics and biogeography of the Neotropical skink genus Mabuya Fitzinger (Squamata: Scincidae) with emphasis on Colombian populations.

    Science.gov (United States)

    Pinto-Sánchez, Nelsy Rocío; Calderón-Espinosa, Martha L; Miralles, Aurélien; Crawford, Andrew J; Ramírez-Pinilla, Martha Patricia

    2015-12-01

    Understanding the phylogenetic and geographical history of Neotropical lineages requires having adequate geographic and taxonomic sampling across the region. However, Colombia has remained a geographical gap in many studies of Neotropical diversity. Here we present a study of Neotropical skinks of the genus Mabuya, reptiles that are difficult to identify or delimit due to their conservative morphology. The goal of the present study is to propose phylogenetic and biogeographic hypotheses of Mabuya including samples from the previously under-studied territory of Colombia, and address relevant biogeographic and taxonomic issues. We combined molecular and morphological data sampled densely by us within Colombia with published data representing broad sampling across the Neotropical realm, including DNA sequence data from two mitochondrial (12S rRNA and cytochrome b) and three nuclear genes (Rag2, NGFB and R35). To evaluate species boundaries we employed a general mixed Yule-coalescent (GMYC) model applied to the mitochondrial data set. Our results suggest that the diversity of Mabuya within Colombia is higher than previously recognized, and includes lineages from Central America and from eastern and southern South America. The genus appears to have originated in eastern South America in the Early Miocene, with subsequent expansions into Central America and the Caribbean in the Late Miocene, including at least six oceanic dispersal events to Caribbean Islands. We identified at least four new candidate species for Colombia and two species that were not previously reported in Colombia. The populations of northeastern Colombia can be assigned to M. zuliae, while specimens from Orinoquia and the eastern foothills of the Cordillera Oriental of Colombia correspond to M. altamazonica. The validity of seven species of Mabuya sensu lato was not supported due to a combination of three factors: (1) non-monophyly, (2) <75% likelihood bootstrap support and <0.95 Bayesian posterior probability, and (3) GMYC analysis collapsing named species. Finally, we suggest that Mabuya sensu stricto may be regarded as a diverse monophyletic genus, widely distributed throughout the Neotropics.

  3. BIODIVERSITY AND BIOGEOGRAPHY OF FRESHWATER CRUSTACEANS (DECAPODA: NATANTIA FROM VANUATU, A COMPARISON WITH FIJI AND NEW CALEDONIA.

    Directory of Open Access Journals (Sweden)

    MARQUET G.

    2002-01-01

    Full Text Available This is the first comprehensive study of freshwater decapoda crustaceans from Vanuatu. Of the nineteen species collected during this study, eighteen appear to be new records for the archipelago. However none of these species is endemic to Vanuatu, nine having a Pacific distribution and ten an Indo-Pacific distribution. Half of the species recorded were widely distributed in Vanuatu, whereas the others were more restricted. A comparison is made with the freshwater decapoda fauna of the two neighbouring archipelagoes namely, those of Fiji and New Caledonia, which have already been thoroughly surveyed.

  4. Evolutionary Relationships and Biogeography of the Ant-Epiphytic Genus Squamellaria (Rubiaceae: Psychotrieae and Their Taxonomic Implications.

    Directory of Open Access Journals (Sweden)

    Guillaume Chomicki

    Full Text Available Ecological research on ant/plant symbioses in Fiji, combined with molecular phylogenetics, has brought to light four new species of Squamellaria in the subtribe Hydnophytinae of the Rubiaceae tribe Psychotrieae and revealed that four other species, previously in Hydnophytum, need to be transferred to Squamellaria. The diagnoses of the new species are based on morphological and DNA traits, with further insights from microCT scanning of flowers and leaf δ(13C ratios (associated with Crassulacean acid metabolism. Our field and phylogenetic work results in a new circumscription of the genus Squamellaria, which now contains 12 species (to which we also provide a taxonomic key, not 3 as in the last revision. A clock-dated phylogeny and a model-testing biogeographic framework were used to infer the broader geographic history of rubiaceous ant plants in the Pacific, specifically the successive expansion of Squamellaria to Vanuatu, the Solomon Islands, and Fiji. The colonization of Vanuatu may have occurred from Fiji, when these islands were still in the same insular arc, while the colonization of the Solomon islands may have occurred after the separation of this island from the Fiji/Vanuatu arc. Some of these ant-housing epiphytes must have dispersed with their specialized ants, for instance attached to floating timber. Others acquired new ant symbionts on different islands.

  5. Historical Biogeography of the Marine Snail Littorina saxatilis Inferred from Haplotype and Shell Morphology Evolution in NW Spain.

    Science.gov (United States)

    Tirado, Terencia; Saura, María; Rolán-Alvarez, Emilio; Quesada, Humberto

    2016-01-01

    The marine snail Littorina saxatilis exhibits extreme morphological variation between and within geographical regions and represents an excellent model for assessing local adaptation. Previous studies support the hypothesis of parallel evolution in sympatry of two morphologically different ecotypes (named as RB and SU) that co-inhabit different habitats from Galician rocky shores (NW Spain), and which are interrupted by sheltered areas inhabited by a different morph never studied before (named as SRB). Here, we use morphological and mitochondrial DNA (mtDNA) sequence data to test hypotheses on the origin and diversification of SRB snails and to assess their evolutionary relationships with RB and SU ecotypes. Our results show that the SRB morph displays the largest size and shell elongation and the smallest relative shell aperture, representing an extreme type of the RB vs. SU polymorphism, which has been linked to adaptation to sheltered ecological factors. Phylogenetic analysis shows that the SRB morph shares ancestry with RB and SU ecotypes, rejecting the hypothesis that the SRB morph marks relict populations from which these ecotypes evolved in Galician coasts. Our data support that genetic differentiation among SRB, RB and SU morphs results from a general pattern of restricted gene flow and isolation by distance linked to the colonization of Galician coasts by two independent mtDNA lineages, rather than from a random fragmentation of the initial distributional range. Therefore, the confinement of distinct lineages to specific geographical areas denote evident limits to the distances these snails can disperse. Morphological analysis indicates no association between mtDNA lineage and a specific morphotype, and suggests the independent gain of convergent morphological patterns within each mtDNA lineage in populations occupying contrasting habitats following the colonization of Galician coasts.

  6. Phylogenetics of neotropical Platymiscium (Leguminosae: Dalbergieae): systematics, divergence times, and biogeography inferred from nuclear ribosomal and plastid DNA sequence data.

    Science.gov (United States)

    Saslis-Lagoudakis, Charilaos; Chase, Mark W; Robinson, Daniel N; Russell, Stephen J; Klitgaard, Bente B

    2008-10-01

    Platymiscium is a neotropical legume genus of forest trees in the Pterocarpus clade of the pantropical "dalbergioid" clade. It comprises 19 species (29 taxa), distributed from Mexico to southern Brazil. This study presents a molecular phylogenetic analysis of Platymiscium and allies inferred from nuclear ribosomal (nrITS) and plastid (trnL, trnL-F and matK) DNA sequence data using parsimony and Bayesian methods. Divergence times are estimated using a Bayesian method assuming a relaxed molecular clock (multidivtime). Within the Pterocarpus clade, new sister relationships are recovered: Pterocarpus + Etaballia, Inocarpus + Tipuana and Paramachaerium + Maraniona. Our results support monophyly of Platymiscium, which is resolved into three major clades, each with distinct geographic ranges and ecological preferences. Diversification in Platymiscium has been driven by habitat fragmentation, invasion of novel geographic regions, and ecological diversification, revealing general patterns of diversification in the neotropics. We hypothesize that Platymiscium arose in dry habitats of South America and radiated northward. The Amazon basin was invaded twice both within the last 5.6 My and Central America twice before the closure of the Isthmus of Panama. Divergence times of the P. pubescens complex, restricted to seasonally dry tropical forests of South America, support pre-Pleistocene divergence in this biome.

  7. In the Wake of Invasion: Tracing the Historical Biogeography of the South American Cricetid Radiation (Rodentia, Sigmodontinae)

    OpenAIRE

    Leite, Rafael N; Sergios-Orestis Kolokotronis; Francisca C Almeida; Werneck, Fernanda P.; Duke S Rogers; Marcelo Weksler

    2014-01-01

    The Great American Biotic Interchange (GABI) was greatly influenced by the completion of the Isthmus of Panama and impacted the composition of modern faunal assemblages in the Americas. However, the contribution of preceding events has been comparatively less explored, even though early immigrants in the fossil records are evidence for waif dispersals. The cricetid rodents of the subfamily Sigmodontinae are a classic example of a species-rich South American radiation resulting from an early e...

  8. Diversity, biogeography and biodegradation potential of actinobacteria in the deep-sea sediments along the Southwest Indian Ridge

    Directory of Open Access Journals (Sweden)

    Ping Chen

    2016-08-01

    Full Text Available The phylum Actinobacteria has been reported to be common or even abundant in deep marine sediments, however, knowledge about the diversity, distribution, and function of actinobacteria is limited. In this study, actinobacterial diversity in the deep sea along the Southwest Indian Ridge (SWIR was investigated using both 16S rRNA gene pyrosequencing and culture-based methods. The samples were collected at depths of 1662–4000 m below water surface. Actinobacterial sequences represented 1.2–9.1% of all microbial 16S rRNA gene amplicon sequences in each sample. A total of 5 actinobacterial classes, 17 orders, 28 families and 52 genera were detected by pyrosequencing, dominated by the classes Acidimicrobiia and Actinobacteria. Differences in actinobacterial community compositions were found among the samples. The community structure showed significant correlations to geochemical factors, notably pH, calcium, total organic carbon, total phosphorus, and total nitrogen, rather than to spatial distance at the scale of the investigation. In addition, 176 strains of the Actinobacteria class, belonging to 9 known orders, 18 families, and 29 genera, were isolated. Among these cultivated taxa, 8 orders, 13 families, and 15 genera were also recovered by pyrosequencing. At a 97% 16S rRNA gene sequence similarity, the pyrosequencing data encompassed 77.3% of the isolates but the isolates represented only 10.3% of the actinobacterial reads. Phylogenetic analysis of all the representative actinobacterial sequences and isolates indicated that at least four new orders within the phylum Actinobacteria were detected by pyrosequencing. More than half of the isolates spanning 23 genera and all samples demonstrated activity in the degradation of refractory organics, including polycyclic aromatic hydrocarbons and polysaccharides, suggesting their potential ecological functions and biotechnological applications for carbon recycling.

  9. Korarchaeota diversity, biogeography, and abundance in Yellowstone and Great Basin hot springs and ecological niche modeling based on machine learning.

    Science.gov (United States)

    Miller-Coleman, Robin L; Dodsworth, Jeremy A; Ross, Christian A; Shock, Everett L; Williams, Amanda J; Hartnett, Hilairy E; McDonald, Austin I; Havig, Jeff R; Hedlund, Brian P

    2012-01-01

    Over 100 hot spring sediment samples were collected from 28 sites in 12 areas/regions, while recording as many coincident geochemical properties as feasible (>60 analytes). PCR was used to screen samples for Korarchaeota 16S rRNA genes. Over 500 Korarchaeota 16S rRNA genes were screened by RFLP analysis and 90 were sequenced, resulting in identification of novel Korarchaeota phylotypes and exclusive geographical variants. Korarchaeota diversity was low, as in other terrestrial geothermal systems, suggesting a marine origin for Korarchaeota with subsequent niche-invasion into terrestrial systems. Korarchaeota endemism is consistent with endemism of other terrestrial thermophiles and supports the existence of dispersal barriers. Korarchaeota were found predominantly in >55°C springs at pH 4.7-8.5 at concentrations up to 6.6×10(6) 16S rRNA gene copies g(-1) wet sediment. In Yellowstone National Park (YNP), Korarchaeota were most abundant in springs with a pH range of 5.7 to 7.0. High sulfate concentrations suggest these fluids are influenced by contributions from hydrothermal vapors that may be neutralized to some extent by mixing with water from deep geothermal sources or meteoric water. In the Great Basin (GB), Korarchaeota were most abundant at spring sources of pH<7.2 with high particulate C content and high alkalinity, which are likely to be buffered by the carbonic acid system. It is therefore likely that at least two different geological mechanisms in YNP and GB springs create the neutral to mildly acidic pH that is optimal for Korarchaeota. A classification support vector machine (C-SVM) trained on single analytes, two analyte combinations, or vectors from non-metric multidimensional scaling models was able to predict springs as Korarchaeota-optimal or sub-optimal habitats with accuracies up to 95%. To our knowledge, this is the most extensive analysis of the geochemical habitat of any high-level microbial taxon and the first application of a C-SVM to microbial ecology.

  10. Molecular phylogeny of Nyctaginaceae: taxonomy, biogeography, and characters associated with a radiation of xerophytic genera in North America.

    Science.gov (United States)

    Douglas, Norman A; Manos, Paul S

    2007-05-01

    The four o'clock family (Nyctaginaceae) has a number of genera with unusual morphological and ecological characters, several of which appear to have a "tendency" to evolve repeatedly in Nyctaginaceae. Despite this, the Nyctaginaceae have attracted little attention from botanists. To produce a phylogeny for the Nyctaginaceae, we sampled 51 species representing 25 genera (of 28-31) for three chloroplast loci (ndhF, rps16, rpl16, and nrITS) and included all genera from North America. Parsimony, likelihood, and Bayesian methods were used to reconstruct the phylogeny for the family. The family is neotropical in origin. A radiation of woody taxa unites Pisonia and Pisoniella with the difficult tropical genera Neea and Guapira, which also form a clade, though neither appears to be monophyletic. This group is sister to a clade containing Bougainvillea, Belemia, and Phaeoptilum. A dramatic radiation of genera occurred in the deserts of North America. The tribe Nyctagineae and its subtribes are paraphyletic, due to over-reliance on a few homoplasious characters, i.e., pollen morphology and involucre presence. Two notable characters associated with the desert radiation are cleistogamy and edaphic endemism on gypsum soils. We discuss evolutionary trends in these traits in light of available data about self-incompatibility and gypsum tolerance in Nyctaginaceae.

  11. Mollusca, Hirudinea, and Amphibia biogeography and paleobiology in Tule Valley and adjacent regions of Bonneville Basin, western USA [draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Mollusk, leeches (Hirudinea), and amphibian distribution are described for Tule Valley and adjacent Snake Valley and Fish Springs Flat, Tule Valley aquatic resources...

  12. Late Cretaceous (Maestrichtian) Calcareous Nannoplankton Biogeography with Emphasis on Events Immediately Preceding the Cretaceous/Paleocene Boundary

    Science.gov (United States)

    1993-02-01

    Yucatan Peninsula ( Mexico ) was proposed as the site of the K/P boundary impact (Hildebrand et al., 1991). In contrast to extraterrestrial causes of...Paleotemperatures. Spoleto, July 26-27, 1965. Consiglio Nazionale delle Richerche, Laboratorio di Geologia Nucleare, Pisa, 1-22. 3 Crux, J. A., 1991...Jacobsen, S. B., and Boynton, W. V., 1991. Chicxulub Crater: A possible Cretaceous/Tertiary boundary impact crater on the Yucatin Peninsula, Mexico . lgl.Lvg

  13. Spatial and Temporal Shifts in Bacterial Biogeography and Gland Occupation during the Development of a Chronic Infection

    Science.gov (United States)

    Zavros, Yana; Shepherd, Benjamin; Salama, Nina R.

    2016-01-01

    ABSTRACT Gland colonization may be one crucial route for bacteria to maintain chronic gastrointestinal infection. We developed a quantitative gland isolation method to allow robust bacterial population analysis and applied it to the gastric pathobiont Helicobacter pylori. After infections in the murine model system, H. pylori populations multiply both inside and outside glands in a manner that requires the bacteria to be motile and chemotactic. H. pylori is able to achieve gland densities averaging 25 to 40 bacteria/gland after 2 to 4 weeks of infection. After 2 to 4 weeks of infection, a primary infection leads to colonization resistance for a secondary infection. Nonetheless, about ~50% of the glands remained unoccupied, suggesting there are as-yet unappreciated parameters that prevent gastric gland colonization. During chronic infections, H. pylori populations collapsed to nearly exclusive gland localization, to an average of <8 bacteria/gland, and only 10% of glands occupied. We analyzed an H. pylori chemotaxis mutant (Che−) to gain mechanistic insight into gland colonization. Che− strains had a severe inability to spread to new glands and did not protect from a secondary infection but nonetheless achieved a chronic gland colonization state numerically similar to that of the wild type. Overall, our analysis shows that bacteria undergo substantial population dynamics on the route to chronic colonization, that bacterial gland populations are maintained at a low level during chronic infection, and that established gland populations inhibit subsequent colonization. Understanding the parameters that promote chronic colonization will allow the future successful design of beneficial microbial therapeutics that are able to maintain long-term mammalian colonization. PMID:27729513

  14. Biogeography of bacteriophages at four hydrothermal vent sites in the Antarctic based on g23 sequence diversity.

    Science.gov (United States)

    Millard, Andrew D; Pearce, David; Zwirglmaier, Katrin

    2016-04-01

    In this study, which was carried out within the ChEsSO consortium project (Chemosynthetically driven ecosystems south of the Polar Front), we sampled two hydrothermal vent sites on the East Scotia Ridge, Scotia Sea, one in the Kemp Caldera, South Sandwich Arc and one in the Bransfield Strait, north-west of the Antarctic Peninsula, which exhibit strong differences in their chemical characteristics. We compared a subset of their bacteriophage population by Sanger- and 454-sequencing of g23, which codes for the major capsid protein of T4likeviruses. We found that the sites differ vastly in their bacteriophage diversity, which reflects the differences in the chemical conditions and therefore putatively the differences in microbial hosts living at these sites. Comparing phage diversity in the vent samples to other aquatic samples, the vent samples formed a distinct separate cluster, which also included the non-vent control samples that were taken several hundred meters above the vent chimneys. This indicates that the influence of the vents on the microbial population and therefore also the bacteriophage population extends much further than anticipated.

  15. Phylogenetic relationships of the species and biogeography of the characid genus Oligosarcus Günther, 1864 (Ostariophysi, Characiformes, Characidae).

    Science.gov (United States)

    Ribeiro, Alexandre Cunha; Menezes, Naércio Aquino

    2015-04-23

    The characid genus Oligosarcus consists of 20 described species distributed throughout most of South American river basins below 14º south latitude. This study focus on the phylogenetic relationships of the species of Oligosarcus based on the analysis of osteological characters to provide data to discuss the biogeographic history of the genus. The analysis resulted in a single most parsimonious tree with 152 steps (CI= 0.355 and RI= 0.600). The 18 included Oligosarcus species were hierarchically organized into 17 clades. A minimal age of 15 Ma for the genus is suggested based on the putatively cladogenetic event represented by the continued shortening of the Eastern Cordillera that established the eastern boundary of the modern central Andean plateau and was responsible for cladogenesis between the common ancestor of O. schindleri + O. bolivianus versus the remaining congeners. There is a pronounced disjunction in the upland species distribution by the lowland areas of the Chaco-Pantanal basin. This indicates that upland habitats (headwater streams) are preferential habitats for a set of species including O. argenteus, O. bolivianus, O. brevioris, O. paranensis, O. perdido, O. pintoi, O. planaltinae, O. brevioris, and O. schindleri. Fragmentation of populations of O. pintoi and O. perdido are at least 2.5 Ma old, since the origin of the upper Paraguay depression clearly promoted the present-day observed disjunction in the distribution of these species. The lowland Oligosarcus species are all included in a single clade but the obtained results suggest that fragmentation of upland versus lowland components of the genus was not causally related to a single vicariant event. The available fossil record of Oligosarcus indicates that the genus already occurred in the coastal plain at about 2.3 to 1.25 Ma. The sister-group relationship between O. hepsetus and O. longirostris provided additional evidences of the so-called historical affinities between the SE Brazilian coastal plain and the Rio Iguaçu drainage basin.

  16. Description of a new Lithoxus (Siluriformes: Loricariidae from the Guayana Highlands with a discussion of Guiana Shield biogeography

    Directory of Open Access Journals (Sweden)

    Nathan K. Lujan

    Full Text Available Lithoxus jantjae, new species, is described from above Tencua Falls in headwaters of the Ventuari River, a white- to clearwater river flowing west from the Maigualida and Parima mountains in the Guayana Highlands of southern Venezuela. Lithoxus jantjae represents a nearly 600 km westward range expansion for a genus historically known only from Guyana, Suriname, French Guiana, and Brazil. Lithoxus jantjae shares with other species of Lithoxus a dorsoventrally depressed body and a large, papilose oral disk with small toothcups and few teeth. It can be distinguished from congeners by a unique combination of characters including 12 branched caudal-fin rays, medial premaxillary tooth cusps enlarged, and a convex posterior margin of the adipose-fin membrane. With the discovery of L. jantjae, Lithoxus becomes the most recent example of a growing list of rheophilic loricariid genera with disjunct distributions on east and west sides of the Guayana Highlands. A biogeographic hypothesis relying on the existence of a proto-Berbice River uniting the southern Guayana Highlands with rivers of the central Guiana Shield is advanced to partially explain the modern distribution of these species.

  17. Novel insights into the historical biogeography of the streak-breasted scimitar babbler complex (Aves:Timaliidae:Pomatorhinus ruficollis complex)

    Institute of Scientific and Technical Information of China (English)

    Sushma REDDY; rpd S NYRI

    2015-01-01

    The Streak-breasted Scimitar Babblers of thePomatorhinus ruficollis species complex are found in most of the fo-rested habitats across southern and eastern Asia. The diversification history of this group is obscured by high plumage variation across populations and conflicting genetic signal across loci. We combined genetic and geographic data from several recent stu-dies to investigate how these species diversified across China using both phylogenetic and ecological niche modeling analyses. These two lines of evidence are consistent in showing that two well-sampled species,P. reconditus andP. nigrostellatus,in cen-tral and southern China respectively, likely experienced a history of isolation and expansion as suitable habitat contracted during the last interglacial and expanded in patchy extent during the glacial maximum. The genetic analysis showed that populations ofP. nigrostellatus on Hainan Island are very similar to the ones in nearby mainland southern China. We recovered two well-supported clades withinP. reconditus that were not geographically structured with both containing individuals from the same localities across central China. This phylogenetic result corresponded to the ecological niche models that showed expansion from refugia since the last interglacial. This study illustrates the value of using an integrative approach and detailed geographic sampling to help understand the recent diversification of birds in China [Current Zoology 61 (5): 910–921, 2015].

  18. The taxonomy and biogeography of the bloetei group of the genus Baetura Stål, 1866 (Homoptera, Tibicinidae)

    NARCIS (Netherlands)

    Boer, de A.J.

    1989-01-01

    The bloetei group is proposed for a monophyletic group of 18 species of the genus Baeturia Stål, 1866. Fifteen species are described as new ( B. bilebanarai, B. bismarckensis, B. bloetei, B. boulardi, B. brandti, B. cristovalensis, B. gressitti, B. macgillavryi, B. manusensis, B. marginata, B. menda

  19. Evolutionary Relationships and Biogeography of the Ant-Epiphytic Genus Squamellaria (Rubiaceae: Psychotrieae) and Their Taxonomic Implications

    Science.gov (United States)

    Chomicki, Guillaume; Renner, Susanne S.

    2016-01-01

    Ecological research on ant/plant symbioses in Fiji, combined with molecular phylogenetics, has brought to light four new species of Squamellaria in the subtribe Hydnophytinae of the Rubiaceae tribe Psychotrieae and revealed that four other species, previously in Hydnophytum, need to be transferred to Squamellaria. The diagnoses of the new species are based on morphological and DNA traits, with further insights from microCT scanning of flowers and leaf δ13C ratios (associated with Crassulacean acid metabolism). Our field and phylogenetic work results in a new circumscription of the genus Squamellaria, which now contains 12 species (to which we also provide a taxonomic key), not 3 as in the last revision. A clock-dated phylogeny and a model-testing biogeographic framework were used to infer the broader geographic history of rubiaceous ant plants in the Pacific, specifically the successive expansion of Squamellaria to Vanuatu, the Solomon Islands, and Fiji. The colonization of Vanuatu may have occurred from Fiji, when these islands were still in the same insular arc, while the colonization of the Solomon islands may have occurred after the separation of this island from the Fiji/Vanuatu arc. Some of these ant-housing epiphytes must have dispersed with their specialized ants, for instance attached to floating timber. Others acquired new ant symbionts on different islands. PMID:27028599

  20. Phylogeny and biogeography of 91 species of heroine cichlids (Teleostei: Cichlidae) based on sequences of the cytochrome b gene.

    Science.gov (United States)

    Pérez, Gustavo A Concheiro; Rícan, Oldrich; Ortí, Guillermo; Bermingham, Eldredge; Doadrio, Ignacio; Zardoya, Rafael

    2007-04-01

    Heroini constitute the second largest tribe of Neotropical cichlids and show their greatest diversity in Mesoamerica. Although heroine species are morphologically and ecologically very diverse, they were all historically assigned to one single genus, Cichlasoma that was never formally revised from a phylogenetic point of view. Here, we present the most comprehensive molecular phylogeny of the tribe Heroini to date, based on the complete DNA sequence of the mitochondrial gene cytochrome b, and the analysis of 204 individuals representing 91 species. Phylogenetic analyses did not support the monophyly of heroines because the genus Pterophyllum was placed as the sister group of all remaining heroines plus cichlasomatines. However, the recovered relative position of Pterophyllum was without strong statistical support. Within the remaining heroines, Hyspelecara and Hoplarchus are recovered with low support in a basal position with respect to a clade that includes Heros, Uaru, Mesonauta, and Symphysodon, and the circumamazonian (CAM) heroines. The first clade is restricted to South America. The largest clade of heroines, the CAM heroines, include more than 85% of the species within the tribe. This clade is mostly Mesoamerican, but also contains four species found in the Greater Antilles (Nandopsis), and three genera found in South America (the 'Heros' festae group, Australoheros, and Caquetaia). Up to eight major lineages can be recovered within the CAM heroines, but the phylogenetic relationships among them remain unresolved. Two large suprageneric groups can be distinguished, the amphilophines and the herichthyines. The amphilophines include Amphilophus, Archocentrus, Hypsophrys, Neetroplus, Parachromis, Petenia, and five additional unnamed genera (the 'Heros' istlanus group, the 'Amphilophus' calobrensis group, the 'Heros' urophthalmus group, the 'Heros' wesseli group, and the 'Heros' sieboldii group). The herichthyines include the crown-group herichthyines (Herichthys, Theraps, Vieja, and Paratheraps) and the genera Tomocichla, Herotilapia, and Thorichthys, together with three unnamed genera (the 'Heros' umbriferus group, the 'Heros' grammodes group, and the 'Heros' salvini group). Amphilophines are prevalent in southern Mesomerica south of the Motagua fault. Herichthyines have basal linages in Central America, whereas crown-group herichthyines and three related genera are found north from the Motagua fault. At least two independent origins are required to explain current Mesoamerican heroine distribution. Dispersal of heroines from South America into Mesoamerica was dated between 24 and 16 million years ago (MYA) based on geological calibrations and on standard fish mitochondrial cytochrome b rates, respectively. These datings cannot be reconciled with currently known geological evidence, and the existence of a connection between Central America and South America in the Miocene needs to be postulated in order to explain the origins of Mesoamerican heroine lineages. However, our datings agree with those estimated for the dispersal of other secondary freshwater fishes (Rivulidae, Synbranchus) into Mesoamerica, and predate the invasion of primary freshwater fishes by at least 10 myr.

  1. Molecular phylogeny and biogeography of the highly specialized grade schizothoracine fishes (Teleostei:Cyprinidae) inferred from cytochrome b sequences

    Institute of Scientific and Technical Information of China (English)

    HE DeKui; CHEN YiFeng

    2007-01-01

    We recovered the phylogenetic relationships among 23 species and subspecies of the highly specialized grade schizothoracine fishes distributing at 36 geographical sites in the Tibetan Plateau and its surrounding regions by analyzing sequences of cytochrome b genes. Furthermore, we estimated the possible divergent times among lineages based on a historical geological isolation event in the Tibetan Plateau. The molecular data revealed that the highly specialized grade schizothoracine fishes were not a monophyletic group, but were the same as genera Gymnocypris and Schizogypsis. Our results indicated that the molecular phylogenetic relationships apparently reflected their geographical and historical associations with drainages, namely species from the same and adjacent drainages clustered together and had close relationships. The divergence times of different lineages were well consistent with the rapid uplift phases of the Tibetan Plateau in the late Cenozoic, suggesting that the origin and evolution of schizothoracine fishes were strongly influenced by environment changes resulting from the upheaval of the Tibetan Plateau.

  2. Use of Parsimony Analysis to Identify Areas of Endemism of Chinese Birds: Implications for Conservation and Biogeography

    Directory of Open Access Journals (Sweden)

    Xiao-Lei Huang

    2010-05-01

    Full Text Available Parsimony analysis of endemicity (PAE was used to identify areas of endemism (AOEs for Chinese birds at the subregional level. Four AOEs were identified based on a distribution database of 105 endemic species and using 18 avifaunal subregions as the operating geographical units (OGUs. The four AOEs are the Qinghai-Zangnan Subregion, the Southwest Mountainous Subregion, the Hainan Subregion and the Taiwan Subregion. Cladistic analysis of subregions generally supports the division of China’s avifauna into Palaearctic and Oriental realms. Two PAE area trees were produced from two different distribution datasets (year 1976 and 2007. The 1976 topology has four distinct subregional branches; however, the 2007 topology has three distinct branches. Moreover, three Palaearctic subregions in the 1976 tree clustered together with the Oriental subregions in the 2007 tree. Such topological differences may reflect changes in the distribution of bird species through circa three decades.

  3. Biogeography of freshwater fishes from the Northeastern Mata Atlântica freshwater ecoregion: distribution, endemism, and area relationships

    Directory of Open Access Journals (Sweden)

    Priscila Camelier

    Full Text Available The Northeastern Mata Atlântica freshwater ecoregion (NMAF includes part of the eastern Brazilian coastal drainages, has high level of fish endemism and great biogeographic significance. A taxonomic inventory of freshwater fishes from 25 drainages of the NMAF ecoregion and a biogeographic analysis using the Parsimony Analysis of Endemicity (PAE method were carried out. A total of 192 native species was listed. The PAE method was applied to 24 basins and 37 species, resulting in five equally parsimonious area diagrams. The strict consensus diagram indicates the existence of two main groups of basins throughout the NMAF ecoregion. These groups were denominated: North Group and Central-South Group. The Central-South Group shows a basal polytomy composed by two Groups (Central Group and South Group plus the rio Itapemirim basin. The North Group is composed by eight drainages from the rio Sergipe to the rio Paraguaçu, the Central Group by five drainages from the rio Cachoeira to the rio Jequitinhonha, and the South Group by nine drainages from the rio Buranhém to the rio Doce. Comments about the species distribution and the fish fauna shared with adjacent ecoregions are provided. We also present a comparison of the hypothesis of river relationships proposed herein with published phylogenetic hypotheses that include taxa relevant to this study.

  4. Biogeography of the sediment bacterial community responds to a nitrogen pollution gradient in the East China Sea.

    Science.gov (United States)

    Xiong, Jinbo; Ye, Xiansen; Wang, Kai; Chen, Heping; Hu, Changju; Zhu, Jianlin; Zhang, Demin

    2014-03-01

    Patterns of microbial distribution represent the integrated effects of historical and biological processes and are thus a central issue in ecology. However, there is still active debate on whether dispersal limitation contributes to microbial diversification in strongly connected systems. In this study, sediment samples were collected along a transect representing a variety of seawater pollution levels in the East China Sea. We investigated whether changes in sediment bacterial community structures would indicate the effects of the pollution gradient and of dispersal limitation. Our results showed consistent shifts in bacterial communities in response to pollution. More geographically distant sites had more dissimilar communities (r = -0.886, P pollution gradient. This study provides direct evidence that dispersal limitation exists in a strongly connected marine sediment ecosystem and that candidate indicator taxa can be applied to evaluate coastal pollution levels.

  5. Advances in taxonomy, ecology, and biogeography of Dirivultidae (copepoda associated with chemosynthetic environments in the deep sea.

    Directory of Open Access Journals (Sweden)

    Sabine Gollner

    Full Text Available Copepoda is one of the most prominent higher taxa with almost 80 described species at deep-sea hydrothermal vents. The unique copepod family Dirivultidae with currently 50 described species is the most species rich invertebrate family at hydrothermal vents.We reviewed the literature of Dirivultidae and provide a complete key to species, and map geographical and habitat specific distribution. In addition we discuss the ecology and origin of this family.Dirivultidae are only present at deep-sea hydrothermal vents and along the axial summit trough of midocean ridges, with the exception of Dirivultus dentaneus found associated with Lamellibrachia species at 1125 m depth off southern California. To our current knowledge Dirivultidae are unknown from shallow-water vents, seeps, whale falls, and wood falls. They are a prominent part of all communities at vents and in certain habitat types (like sulfide chimneys colonized by pompei worms they are the most abundant animals. They are free-living on hard substrate, mostly found in aggregations of various foundation species (e.g. alvinellids, vestimentiferans, and bivalves. Most dirivultid species colonize more than one habitat type. Dirivultids have a world-wide distribution, but most genera and species are endemic to a single biogeographic region. Their origin is unclear yet, but immigration from other deep-sea chemosynthetic habitats (stepping stone hypothesis or from the deep-sea sediments seems unlikely, since Dirivultidae are unknown from these environments. Dirivultidae is the most species rich family and thus can be considered the most successful taxon at deep-sea vents.

  6. Morphology, ecology and biogeography of Stauroneis pachycephala P.T. Cleve (Bacillariophyta) and its transfer to the genus Envekadea

    Science.gov (United States)

    Atazadeh, Islam; Edlund, Mark B.; van de Vijver, Bart; Mills, Keely; Spaulding, Sarah A.; Gell, Peter A.; Crawford, Simon; Barton, Andrew F.; Lee, Sylvia S.; Smith, Kathryn E.L.; Newall, Peter; Potapova, Marina

    2014-01-01

    Stauroneis pachycephala was described in 1881 from the Baakens River, Port Elizabeth, South Africa. Recently, it was found during surveys of the MacKenzie River (Victoria, Australia), the Florida Everglades (USA) and coastal marshes of Louisiana (USA). The morphology, ecology and geographic distribution of this species are described in this article. This naviculoid species is characterised by lanceolate valves with a gibbous centre, a sigmoid raphe, an axial area narrowing toward the valve ends, and capitate valve apices. The central area is a distinct stauros that is slightly widened near the valve margin. The raphe is straight and filiform, and the terminal raphe fissures are strongly deflected in opposite directions. Striae are fine and radiate in the middle of the valve, becoming parallel and eventually convergent toward the valve ends. The external surface of the valves and copulae is smooth and lacks ornamentation. We also examined the type material of S. pachycephala. Our observations show this species has morphological characteristics that fit within the genus Envekadea. Therefore, the transfer of S. pachycephala to Envekadea is proposed and a lectotype is designated.

  7. Diversity and biogeography of bacterial assemblages in surface sediments across the San Pedro Basin, Southern California Borderlands.

    Science.gov (United States)

    Hewson, Ian; Jacobson Meyers, Myrna E; Fuhrman, Jed A

    2007-04-01

    Sediment bacteria play important roles in the biogeochemistry of ocean sediments; however, factors influencing assemblage composition have not been extensively studied. We examined extractable sediment bacterial abundance, the composition of bacterial assemblages using a high-throughput molecular fingerprinting approach, and several sediment biogeochemical parameters (organic matter content and alkaline phosphatase activity), along a 35 km transect from Point Fermin, Southern California, to Santa Catalina Island, across the approximately 900-m-deep San Pedro Basin. Automated rRNA intergenic spacer analysis (ARISA) demonstrated that in two spatially isolated shallow (approximately < 60 m, on opposite sides of the channel) sediment environments, assemblages were more similar to each other than to deeper communities. Distinct communities existed in deeper and shallower sediments, and stations within the deep basin over 2 km apart contained remarkably similar assemblage fingerprints. The relative contribution to total amplified DNA fluorescence of operational taxonomic units (OTUs) was significantly correlated to that of other OTUs in few comparisons (2.7% of total), i.e. few bacterial types were found together or apart consistently. The relative proportions within assemblages of only a few OTU were significantly correlated to measured physicochemical parameters (organic matter content and wet/dry weight ratio of sediments) or enzyme (alkaline phosphatase) activities. A low percentage of shared OTU between shallow and deep sediments, and the presence of similar, but spatially isolated assemblages suggests that bacterial OTU may be widely dispersed over scales of a few kilometres, but that environmental conditions select for particular assemblages.

  8. Biogeography of the ‘water flea’ Daphnia O. F. Müller (Crustacea: Branchiopoda: Anomopoda on the Indian subcontinent

    Directory of Open Access Journals (Sweden)

    Sameer M. Padhye

    2016-06-01

    Full Text Available Studies on Daphnia distribution in Indian subcontinent have been few and regionally restricted despite Daphnia being by far the most studied cladoceran. We here present a first biogeographical assessment of the genus on the Indian subcontinent (Afghanistan, Pakistan, India, Nepal, Bhutan, Bangladesh and Sri Lanka. We collected all pertinent literature and considered nineteen bioclimatic variables along with latitude, longitude, and altitude for statistical analysis of factors governing distribution in space. Significant variables (determined by Kruskal Wallis test were tested by nonparametric multivariate analysis of variance (PERMANOVA to clarify whether Daphnia species had specific environmental requirements. Canonical correspondence analysis was used to understand how environmental variables affected distribution.  Eight Daphnia (Ctenodaphnia and 4 Daphnia s.str. occurred at 100 different localities. The variables temperature, altitude and latitude differed among species and so did their bio-climatic requirements. Daphnia distribution responded positively to altitude and negatively to a decrease in latitude and temperature.

  9. Early evolution and historical biogeography of fishflies (Megaloptera: Chauliodinae: implications from a phylogeny combining fossil and extant taxa.

    Directory of Open Access Journals (Sweden)

    Xingyue Liu

    Full Text Available Fishflies (Corydalidae: Chauliodinae are one of the main groups of the basal holometabolous insect order Megaloptera, with ca. 130 species distributed worldwide. A number of genera from the Southern Hemisphere show remarkably disjunctive distributions and are considered to be the austral remnants or "living fossils" of Gondwana. Hitherto, the evolutionary history of fishflies remains largely unexplored due to limited fossil record and incomplete knowledge of phylogenetic relationships. Here we describe two significant fossil species of fishflies, namely Eochauliodes striolatus gen. et sp. nov. and Jurochauliodes ponomarenkoi Wang & Zhang, 2010 (original designation for fossil larvae only, from the Middle Jurassic of Inner Mongolia, China. These fossils represent the earliest fishfly adults. Furthermore, we reconstruct the first phylogenetic hypothesis including all fossil and extant genera worldwide. Three main clades within Chauliodinae are recognized, i.e. the Dysmicohermes clade, the Protochauliodes clade, and the Archichauliodes clade. The phylogenetic and dispersal-vicariance (DIVA analyses suggest Pangaean origin and global distribution of fishflies before the Middle Jurassic. The generic diversification of fishflies might have happened before the initial split of Pangaea, while some Gondwanan-originated clades were likely to be affected by the sequential breakup of Pangaea. The modern fauna of Asian fishflies were probably derived from their Gondwanan ancestor but not the direct descendents of the Mesozoic genera in Asia.

  10. Systematics and biogeography of the Neotropical genus Mabuya, with special emphasis on the Amazonian skink Mabuya nigropunctata (Reptilia, Scincidae).

    Science.gov (United States)

    Miralles, A; Carranza, S

    2010-03-01

    Phylogenetic analyses using up to 1532 base pairs (bp) of mitochondrial DNA from 106 specimens of Neotropical Mabuya, including 18 of the 19 recognized South American and Mesoamerican species, indicate that most species of the genus are monophyletic, including M. nigropunctata that had previously been reported to be paraphyletic. The present results shows that this species includes three highly divergent and largely allopatric lineages restricted to occidental, meridional, and oriental Amazonia. Our dataset demonstrates that previous claims regarding the paraphyletic status of M. nigropunctata and the phylogenetic relationships within this species complex based on the analysis of three mitochondrial and four nuclear genes (approx. 5000bp) were erroneous and resulted from two contaminated cytochrome b sequences. The phylogenetic results indicate that diversification in the Neotropical genus Mabuya started approximately in the Middle Miocene (15.5-13.4Ma). The divergence dates estimated for the Mabuya nigropunctata species complex suggest that the major cladogenetic events that produced the three main groups (occidental (oriental+meridional)) occurred during the Late Miocene. These estimations show that diversification within the M. nigropunctata species complex was not triggered by the climatic changes that occurred during the Pleistocene, as has been suggested by several authors. Rather, our data support the hypothesis that the late tertiary (essentially Miocene epoch) was a period that played a very important role in the generation of biological diversity in the Amazonian forests. Speciation between Mabuyacarvalhoi, endemic to the coastal mountain range of Venezuela, and M. croizati, restricted to the Guiana Shield, occurred during the Middle Miocene and may have been as the result of a vicariant event produced by the formation of the present day Orinoco river drainage basin and the consequent appearance of the Llanos del Orinoco, which acted as a barrier to dispersal between these two species. The split between M. bistriata and M. altamazonica and between the occidental and (meridional+oriental) clades of M. nigropunctata fits very well with the biogeographic split between the eastern and western Amazon basins reported for several other taxa.

  11. Phylogenetic relationships, character evolution, and biogeography of the subfamily Lygosominae (Reptilia: Scincidae) inferred from mitochondrial DNA sequences.

    Science.gov (United States)

    Honda, M; Ota, H; Kobayashi, M; Nabhitabhata, J; Yong, H S; Hikida, T

    2000-06-01

    Phylogenetic relationships among the lygosomine skinks were inferred from 1249 base positions of mitochondrial DNA sequences of 12S and 16S rRNA genes. The monophyly of this subfamily was confirmed and the presence of five distinct infrasubfamilial lineages detected. Of these, the Sphenomorphus group appears to have diverged first, followed by the Lygosoma and Egernia groups in order, leaving the Eugongylus and Mabuya groups as sister groups. Our results did not support monophyly of the Mabuya group sensu lato (i.e., an assemblage of the Lygosoma, Egernia, and Mabuya groups), for which a number of morphological and karyological studies demonstrated a considerable similarity. Our results also contradict the previous hypothesis, formulated on the basis of morphological and immunological data, which argued for the sister relationship between the Egernia and the Eugongylus groups. Morphological and karyological characters used to define the Mabuya group (sensu lato) may actually represent plesiomorphic states. The phylogenetic diversity of lygosomine skinks in the Australian region appears to have increased through multiple colonizations from Southeast Asia.

  12. Environmental Mapping of Paracoccidioides spp. in Brazil Reveals New Clues into Genetic Diversity, Biogeography and Wild Host Association.

    Directory of Open Access Journals (Sweden)

    Thales Domingos Arantes

    2016-04-01

    Full Text Available Paracoccidioides brasiliensis and Paracoccidioides lutzii are the etiological agents of Paracoccidioidomycosis (PCM, and are easily isolated from human patients. However, due to human migration and a long latency period, clinical isolates do not reflect the spatial distribution of these pathogens. Molecular detection of P. brasiliensis and P. lutzii from soil, as well as their isolation from wild animals such as armadillos, are important for monitoring their environmental and geographical distribution. This study aimed to detect and, for the first time, evaluate the genetic diversity of P. brasiliensis and P. lutzii for Paracoccidioidomycosis in endemic and non-endemic areas of the environment, by using Nested PCR and in situ hybridization techniques.Aerosol (n = 16 and soil (n = 34 samples from armadillo burrows, as well as armadillos (n = 7 were collected in endemic and non-endemic areas of PCM in the Southeastern, Midwestern and Northern regions of Brazil. Both P. brasiliensis and P. lutzii were detected in soil (67.5% and aerosols (81% by PCR of Internal Transcribed Spacer (ITS region (60%, and also by in situ hybridization (83%. Fungal isolation from armadillo tissues was not possible. Sequences from both species of P. brasiliensis and P. lutzii were detected in all regions. In addition, we identified genetic Paracoccidioides variants in soil and aerosol samples which have never been reported before in clinical or armadillo samples, suggesting greater genetic variability in the environment than in vertebrate hosts.Data may reflect the actual occurrence of Paracoccidioides species in their saprobic habitat, despite their absence/non-detection in seven armadillos evaluated in regions with high prevalence of PCM infection by P. lutzii. These results may indicate a possible ecological difference between P. brasiliensis and P. lutzii concerning their wild hosts.

  13. Magnetochronology of the LOS Colorados Formation (argentina): Late Triassic Terrestrial Biogeography and the Delayed Dispersal of Dinosaurs

    Science.gov (United States)

    Kent, D. V.; Santi Malnis, P.; Colombi, C.; Alcober, O.; Martinez, R.

    2013-12-01

    A measured magnetozone sequence defined by 24 sampling sites with normal polarity and 28 sites with reverse polarity characteristic magnetizations was established for the heretofore poorly age-constrained Los Colorados Formation and its enigmatic vertebrate fauna in the Ischigualasto-Villa Union continental rift basin of Argentina. The polarity pattern in this ~600 m-thick redbed section can be correlated to Chrons E7r to E15n of the Newark astronomical polarity time scale. This represents a time interval from 227 to 213 Ma, indicating that the Los Colorados Formation is entirely Norian in age with no Rhaetian strata and ending more than 11 Myr before the onset of the Jurassic. The magnetochronology also implies that the underlying Ischigualasto Formation and its vertebrate assemblages including the earliest known dinosaurs are confined to the Carnian, consistent with recently published radioisotopic dates. A paleogeographic reconstruction and simplified zonal climate model indicate that the Ischigualasto and Los Colorados Formations were deposited in the austral temperate humid belt that apparently allowed the incubation of a unique vertebrate fauna with early dinosaurs that only dispersed across the tropics to the Northern Hemisphere in the later Norian. The faunal dispersal across the Pangean supercontinent may have been in response to sufficiently reduced contrasts between climate zones in non-polar regions resulting from decreasing atmospheric pCO2 levels.

  14. Taxonomy, biogeography and DNA barcodes of Geodia species (Porifera, Demospongiae, Tetractinellida) in the Atlantic boreo-arctic region

    DEFF Research Database (Denmark)

    Cardenas, Paco; Rapp, Hans Tore; Klitgaard, Anne Birgitte

    2013-01-01

    Geodia species north of 60 degrees N in the Atlantic appeared in the literature for the first time when Bowerbank described Geodia barretti and G.macandrewii in 1858 from western Norway. Since then, a number of species have been based on material from various parts of the region: G.simplex, Isops......, except for G.barretti which had two haplotypes. 18S is unique for four species but cannot discriminate G.phlegraei and G.parva. Two keys to the boreo-arctic Geodia are included, one based on external morphology, the other based on spicule morphology.(c) 2013 The Linnean Society of London...

  15. Historical factors that have shaped the evolution of tropical reef fishes: A review of phylogenies, biogeography, and remaining questions.

    Directory of Open Access Journals (Sweden)

    Peter Francis Cowman

    2014-11-01

    Full Text Available Biodiversity patterns across the marine tropics have intrigued evolutionary biologists and ecologists alike. Tropical coral reefs host 1/3 of all marine species of fish on 0.1% of the ocean’s surface. Yet our understanding of how mechanistic processes have underpinned the generation of diversity is limited. However, it has become clear that the biogeographic history of the marine tropics has played an important role in shaping the diversity of tropical reef fishes we see today. In the last decade, molecular phylogenies and age estimation techniques have provided a temporal framework in which the ancestral biogeographic origins of reef fish lineages have been inferred, but few have included fully sampled phylogenies or made inferences at a global scale. We are currently at a point where new sequencing technologies are accelerating the reconstruction and the resolution of the Fish Tree of Life. How will a complete phylogeny of fishes benefit the study of biodiversity in the tropics? Here, I review the literature concerning the evolutionary history of reef-associated fishes from a biogeographic perspective. I summarize the major biogeographic and climatic events over the last 65 million years that have regionalized the tropical marine belt and what effect they have had on the molecular record of fishes and global biodiversity patterns. By examining recent phylogenetic trees of major reef associated groups, I identify gaps to be filled in order to obtain a clearer picture of the origins of coral reef fish assemblages. Finally, I discuss questions that remain to be answered and new approaches to uncover the mechanistic processes that underpin the evolution of biodiversity on coral reefs.

  16. Phylogeny and biogeography of pacific Rubus subgenus Idaeobatus (Rosaceae) species: Investigating the origin of the endemic Hawaiian raspberry R. macraei

    Science.gov (United States)

    Morden, C.W.; Gardner, D.E.; Weniger, D.A.

    2003-01-01

    The endemic Hawaiian raspberries Rubus hawaiensis and R. macraei (both subgenus Idaeobatus) had been thought to be closely related species until recent molecular studies demonstrated otherwise. These studies suggest that they are the products of separate colonizations to the Hawaiian Islands. Affinities of R. hawaiensis to R. spectabilis of western North America were clearly confirmed. However, no clear relation to R. macraei has been published. This study was initiated to examine species of subg. Idaeobatus from the surrounding Pacific region as well as species from other subgenera to better evaluate biogeographic and phylogenetic affinities of R. macraei by means of chromosome analysis and molecular data using the chloroplast gene ndbF. Results show that R. macraei clusters in a clade with species of blackberries, subg. Rubus, and of these it is most closely linked to R. ursinus. Chromosomally, R. macraei is 2n = 6x = 42, a number that would be a new report for subg. Idaeobatus. However, polyploidy is common in subg. Rubus. Analyses indicate that R. macraei and R. hawaiensis are derived from separate colonizations from North America and that similarities between them are due to convergent evolution in the Hawaiian environment.

  17. Fine-scale biogeography: tidal elevation strongly affects population genetic structure and demographic history in intertidal fishes

    Directory of Open Access Journals (Sweden)

    Sophie von der Heyden

    2013-04-01

    Full Text Available Numerous studies have demonstrated population genetic structuring in marine species, yet few have investigated the effect of vertical zonation on gene flow and population structure. Here we use three sympatric, closely related clinid species, Clinus cottoides, C. superciliosus and Muraenoclinus dorsalis, to test whether zonation on South African intertidal rocky shores affects phylogeographic patterns. We show that the high‐shore restricted species has reduced gene flow and considerably higher Fst values (Fst = 0.9 than the mid‐ and low‐shore species (Fst

  18. Hacia una síntesis biogeográfica de México Toward a synthesis of Mexican biogeography

    Directory of Open Access Journals (Sweden)

    Juan J. Morrone

    2005-12-01

    Full Text Available El reconocimiento de componentes bióticos constituye una primera etapa hacia una teoría biogeográfica sintética. En México podemos caracterizar 3 componentes bióticos principales, cada uno con una combinación diferente de elementos bióticos. El componente Neártico (región Neártica incluye las áreas áridas subtropicales del norte del país, en las provincias biogeográficas de California, Baja California, Sonora, Altiplano Mexicano y Tamaulipas. En este componente predomina el elemento original (Septentrional Antiguo o Paleoamericano, junto con otro de dispersión más reciente (Neártico y un tercero Neotropical Antiguo. Los eventos vicariantes asociados con la evolución biótica del componente Neártico se relacionan con la formación de la Sierra Madre Occidental, que aisló el desierto de Chihuahua de los desiertos de Sonora y Mohave; y la expansión del Mar de Cortés, que aisló la Península de Baja California del continente. El componente Transicional (Zona de Transición Mexicana incluye las áreas básicamente montañosas del centro del país, que se asignan a las provincias biogeográficas de la Sierra Madre Oriental, Sierra Madre Occidental, Eje Volcánico Transmexicano, Cuenca del Balsas y Sierra Madre del Sur. En este componente coexisten los elementos Paleoamericano, Neártico, Mesoamericano Tropical y Mesoamericano de Montaña. Los eventos vicariantes asociados con la evolución biótica del componente Transicional se relacionan con el desarrollo de las Sierras Madre y el vulcanismo del Eje Volcánico Transmexicano. El componente Neotropical (región Neotropical incluye áreas tropicales húmedas y subhúmedas del sur de México, asignadas a las provincias biogeográficas de la Costa Pacífica Mexicana, Golfo de México, Chiapas y Península de Yucatán. En éste predomina el elemento Mesoamericano Tropical, aunque también presenta los elementos Neártico y Antillano. Los eventos vicariantes asociados con la evolución biótica del componente Neotropical se relacionan con el desarrollo de los istmos de Tehuantepec y Panamá y la inundación de las tierras bajas de Nicaragua y de la Península de Yucatán.Recognition of biotic components constitutes the first step toward a synthetic biogeographic theory. In Mexico we can characterize three main biotic components, each one having a particular combination of different biotic elements. The Nearctic component (Nearctic region includes the arid subtropical areas in the north of the country, in the Californian, Baja Californian, Sonoran, Mexican Plateau and Tamaulipan biogeographic provinces. This component is dominated by the original element (Old Northern or Paleoamerican, together with one of more recent dispersal (Nearctic and a third of ancient Neotropical origin. Vicariant events associated with the biotic evolution of the Nearctic component are related to the uplift of the Sierra Madre Occidental, which separated the Chihuahuan desert from the Sonoran and Mojave deserts; and the expansion of the Sea of Cortes, separating the Peninsula of Baja California from the continental mainland. The Transitional component (Mexican Transition Zone includes basically montane areas in central Mexico, which are assigned to the Sierra Madre Oriental, Sierra Madre Occidental, Transmexican Volcanic Belt, Balsas basin and Sierra Madre del Sur biogeographic provinces. In this component, the Paleoamerican, Nearctic, Tropical Mesoamerican and Montane Mesoamerican elements coexist. Vicariant events associated with the biotic evolution of the Transitional component are the development of the Sierras Madre and the volcanism of the Transmexican Volcanic Belt. The Neotropical component (Neotropical region includes humid and subhumid tropical areas of southern Mexico, assigned to the Mexican Pacific Coast, Mexican Gulf, Chiapas and Yucatan Peninsula biogeographic provinces. In it the Tropical Mesoamerican element predominates, but Nearctic and Antillean elements are also present. Vicariant events associated with the biotic evolution of the Neotropical component are related to the development of the isthmuses of Tehuantepec and Panama, and the inundation of the lowlands of Nicaragua and the Yucatan Peninsula.

  19. Systematics and evolutionary history of butterflies in the "Taygetis clade" (Nymphalidae: Satyrinae: Euptychiina): towards a better understanding of Neotropical biogeography.

    Science.gov (United States)

    Matos-Maraví, Pável F; Peña, Carlos; Willmott, Keith R; Freitas, André V L; Wahlberg, Niklas

    2013-01-01

    The so-called "Taygetis clade" is a group of exclusively Neotropical butterflies classified within Euptychiina, one of the largest subtribes in the subfamily Satyrinae. Since the distribution of the ten genera belonging to this group ranges throughout the entire Neotropics, from lowlands to lower montane habitats, it offers a remarkable opportunity to study the region's biogeographic history as well as different scenarios for speciation in upland areas. We inferred a robust and well-sampled phylogeny using DNA sequences from four genes (4035 bp in total) using maximum parsimony and Bayesian inference. We estimated divergence times using the Bayesian relaxed clock method calibrated with node ages from previous studies. Ancestral ranges of distribution were estimated using the dispersal-extinction-cladogenesis (DEC) model as implemented in the program Lagrange. We propose several taxonomic changes and recognize nine well-supported natural genera within the "Taygetis clade": Forsterinaria (subsuming Guaianaza syn. nov.), Parataygetis, Posttaygetis, Harjesia (excluding Harjesia griseola and Harjesia oreba), Pseudodebis (including Taygetomorpha syn. nov.,), Taygetina (subsuming Coeruleotaygetis syn. nov., Harjesia oreba comb. nov., Taygetis weymeri comb. nov. and Taygetis kerea comb. nov.), Taygetis (excluding Taygetis ypthima, Taygetis rectifascia, Taygetis kerea and Taygetis weymeri), and two new genera, one containing Harjesia griseola, and the other Taygetis ypthima and Taygetis rectifascia. The group diversified mainly during late Miocene to Pliocene, coinciding with the period of drastic changes in landscape configuration in the Neotropics. Major dispersals inferred from the Amazon basin towards northwestern South America, the Atlantic forests and the eastern slope of the Andes have mostly shaped the evolution and diversification of the group. Furthermore, expansion of larval dietary repertoire might have aided net diversification in the two largest genera in the clade, Forsterinaria and Taygetis.

  20. Biodiversity and biogeography of hydrothermal vent species in the western Pacific: a biological perspective of TAIGA project

    Science.gov (United States)

    Seo, M.; Watanabe, H.; Nakamura, M.; Sasaki, T.; Ogura, T.; Yahagi, T.; Takahashi, Y.; Ishibashi, J.; Kojima, S.

    2012-12-01

    Deep-sea hydrothermal vents are scientifically interesting environments where strong interactions of geology, chemistry, and biology can be observed. The hydrothermal vents are geologically controlled in association with magmatic activities while diversity of chemicals (such as hydrogen sulfide) contained in hydrothermal fluid is controlled by geochemical interaction between heated seawater and surrounding rocks. In addition to those geological and chemical characters of hydrothermal vents, high biomasses of chemosynthetic community have been known around many vents since the first discovery in the 1970s. To understand the unique system and diversity of biological communities associated with vents is highly valuable in geological, chemical, and biological sciences. As an activity of the research project "TAIGA (Trans-crustal Advection & In-situ bio-geochemical processes of Global sub-seafloor Aquifer)" (Representative: Tetsuro Urabe, Department of Earth & Planetary Science, the University of Tokyo), we analyzed population structures and connectivity as well as larval ecology of various hydrothermal vent species in the Okinawa Trough and the Mariana Trough in an attempt to estimate faunal transitional history associated with hydrothermal activities. The specimens analyzed in the present study were collected by R/V Yokosuka with manned submersible Shinkai6500 and R/V Natsushima with ROV Hyper-Dolphin during YK10-11 and NT11-20 cruises, respectively. In the Mariana Trough (YK10-11), benthic and planktonic faunas were investigated by multiple sampling and use of plankton samplers in three hydrothermal vents (Snail, Archaean, and Urashima-Pika fields). Faunal compositions were then compared as well as size compositions and genetic diversities of major vent species among local populations. In the Okinawa Trough (NT11-20), multiple quantitative sampling was made with simultaneous environmental measurements at more than two sites in five hydrothermal vents (Minami-Ensei Knoll, Yoron Knoll, Izena Hole, Irabu Knoll, and Hatoma Knoll). Among the local populations, biodiversities were analyzed and compared in consideration of abiotic environmental factors including temperature and chemical compositions. Ecological aspects of larvae were examined by laboratory experiments in addition to the genetic approaches and population dynamics. Preliminary results of the ongoing studies suggested that the biodiversity of vents may be consistent with geographical history. By accumulating results of diversified approaches, we progress our study to reveal not only biological characters but also geological and chemical aspects of those hydrothermal vents.

  1. Evolution around the Red Sea: Systematics and biogeography of the agamid genus Pseudotrapelus (Squamata: Agamidae) from North Africa and Arabia.

    Science.gov (United States)

    Tamar, Karin; Scholz, Sebastian; Crochet, Pierre-André; Geniez, Philippe; Meiri, Shai; Schmitz, Andreas; Wilms, Thomas; Carranza, Salvador

    2016-04-01

    Since the Oligocene, regions adjacent to the Red Sea have experienced major environmental changes, from tectonic movements and continuous geological activity to shifting climatic conditions. The effect of these events on the distribution and diversity of the regional biota is still poorly understood. Agamid members of the genus Pseudotrapelus are diurnal, arid-adapted lizards distributed around the Red Sea from north-eastern Africa, across the mountains and rocky plateaus of the Sinai and Arabian Peninsulas northwards to Syria. Despite recent taxonomic work and the interest in the group as a model for studying biogeographic and diversity patterns of the arid areas of North Africa and Arabia, its taxonomy is poorly understood and a comprehensive phylogeny is still lacking. In this study, we analyzed 92 Pseudotrapelus specimens from across the entire distribution range of the genus. We included all known species and subspecies, and sequenced them for mitochondrial (16S, ND4 and tRNAs) and nuclear (MC1R, c-mos) markers. This enabled us to obtain the first time-calibrated molecular phylogeny of the genus, using gene trees, species trees and coalescent-based methods for species delimitation. Our results revealed Pseudotrapelus as a monophyletic genus comprised of two major clades and six independently evolving lineages. These lineages correspond to the five currently recognized species and a sixth lineage relating to the synonymized P. neumanni. The subspecific validity of P. sinaitus werneri needs further assessment as it does not form a distinct cluster relative to P. s. sinaitus. The onset of Pseudotrapelus diversification is estimated to have occurred in Arabia during the late Miocene. Radiation has likely resulted from vicariance and dispersal events due to the continued geological instability, sea level fluctuations and climatic changes within the region.

  2. Molecular Biogeography of Tribe Thermopsideae (Leguminosae: A Madrean-Tethyan Disjunction Pattern with an African Origin of Core Genistoides

    Directory of Open Access Journals (Sweden)

    Ming-Li Zhang

    2015-01-01

    Full Text Available Thermopsideae has 45 species and exhibits a series of interesting biogeographical distribution patterns, such as Madrean-Tethyan disjunction and East Asia-North America disjunction, with a center of endemism in the Qinghai-Xizang Plateau (QTP and Central Asia. Phylogenetic analysis in this paper employed maximum likelihood using ITS, rps16, psbA-trnH, and trnL-F sequence data; biogeographical approaches included BEAST molecular dating and Bayesian dispersal and vicariance analysis (S-DIVA. The results indicate that the core genistoides most likely originated in Africa during the Eocene to Oligocene, ca. 55-30 Ma, and dispersed eastward to Central Asia at ca. 33.47 Ma. The origin of Thermopsideae is inferred as Central Asian and dated to ca. 28.81 Ma. Ammopiptanthus is revealed to be a relic. Birth of the ancestor of Thermopsideae coincided with shrinkage of the Paratethys Sea at ca. 30 Ma in the Oligocene. The Himalayan motion of QTP uplift of ca. 20 Ma most likely drove the diversification between Central Asia and North America. Divergences in East Asia, Central Asia, the Mediterranean, and so forth, within Eurasia, except for Ammopiptanthus, are shown to be dispersals from the QTP. The onset of adaptive radiation at the center of the tribe, with diversification of most species in Thermopsis and Piptanthus at ca. 4-0.85 Ma in Tibet and adjacent regions, seems to have resulted from intense northern QTP uplift during the latter Miocene to Pleistocene.

  3. NOAA ESRI Grid - predictions of seabird diversity in the New York offshore planning area made by the NOAA Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents seabird diversity predictions from spatial models developed for the New York offshore spatial planning area. This raster was derived from...

  4. Multi-locus fossil-calibrated phylogeny, biogeography and a subgeneric revision of the Margaritiferidae (Mollusca: Bivalvia: Unionoida).

    Science.gov (United States)

    Bolotov, Ivan N; Vikhrev, Ilya V; Bespalaya, Yulia V; Gofarov, Mikhail Y; Kondakov, Alexander V; Konopleva, Ekaterina S; Bolotov, Nikita N; Lyubas, Artyom A

    2016-10-01

    The taxonomy and biogeographic history of the bivalve family Margaritiferidae are controversial because previous molecular studies did not provide a well-resolved phylogenetic framework for these enigmatic freshwater mussels that have extensive but disjunct distribution in North America, Eurasia and North Africa. In this study, we present a new, fossil-calibrated phylogenetic hypothesis based on five molecular markers (∼4kb of total length) for ten species. Our results indicate that all recent margaritiferids are in the single genus, Margaritifera Schumacher, 1816. Additionally, we identified three relatively well-supported phylogenetic clades that are valid subgenera, i.e., Margaritifera s. str. (Holarctic), Margaritanopsis (=Cumberlandia) (southeast North America-southeast Asia disjunct) and Pseudunio (Mediterranean). We suggest that the crown lineage of the Margaritiferidae most likely originated in the Cretaceous (mean age 93Ma, 95% CI 66-126Ma). The combined results of ancestral area reconstructions based on the three different approaches (S-DIVA, DEC and S-DEC) showed that ancient vicariance events could have played an important role in speciation within the family. The rates of mitochondrial evolution of margaritiferids are notably slow, which may be associated with their longevity, long generation time and low metabolic rates. Our findings highlight the complex biogeographic history of the Margaritiferidae as an intermixing of ancient vicariance and dispersal events, which were most likely associated with some inland barriers, continental movements and a sea level dynamic.

  5. Evolution and biogeography of the slipper orchids: Eocene vicariance of the conduplicate genera in the Old and New World Tropics.

    Directory of Open Access Journals (Sweden)

    Yan-Yan Guo

    Full Text Available Intercontinental disjunctions between tropical regions, which harbor two-thirds of the flowering plants, have drawn great interest from biologists and biogeographers. Most previous studies on these distribution patterns focused on woody plants, and paid little attention to herbs. The Orchidaceae is one of the largest families of angiosperms, with a herbaceous habit and a high species diversity in the Tropics. Here we investigate the evolutionary and biogeographical history of the slipper orchids, which represents a monophyletic subfamily (Cypripedioideae of the orchid family and comprises five genera that are disjunctly distributed in tropical to temperate regions. A relatively well-resolved and highly supported phylogeny of slipper orchids was reconstructed based on sequence analyses of six maternally inherited chloroplast and two low-copy nuclear genes (LFY and ACO. We found that the genus Cypripedium with a wide distribution in the northern temperate and subtropical zones diverged first, followed by Selenipedium endemic to South America, and finally conduplicate-leaved genera in the Tropics. Mexipedium and Phragmipedium from the neotropics are most closely related, and form a clade sister to Paphiopedilum from tropical Asia. According to molecular clock estimates, the genus Selenipedium originated in Palaeocene, while the most recent common ancestor of conduplicate-leaved slipper orchids could be dated back to the Eocene. Ancestral area reconstruction indicates that vicariance is responsible for the disjunct distribution of conduplicate slipper orchids in palaeotropical and neotropical regions. Our study sheds some light on mechanisms underlying generic and species diversification in the orchid family and tropical disjunctions of herbaceous plant groups. In addition, we suggest that the biogeographical study should sample both regional endemics and their widespread relatives.

  6. Biogeography, Host Specificity, and Molecular Phylogeny of the Basidiomycetous Yeast Phaffia rhodozyma and Its Sexual Form, Xanthophyllomyces dendrorhous▿

    OpenAIRE

    Sampaio, José Paulo; Libkind, Diego; Ruffini, Alejandra; Alves, Leonor; van Broock,Maria

    2006-01-01

    Applied and Environmental Microbiology, Vol. 73, No.4 Phaffia rhodozyma (sexual form, Xanthophyllomyces dendrorhous) is a basidiomycetous yeast that has been found in tree exudates in the Northern Hemisphere at high altitudes and latitudes. This yeast produces astaxanthin, a carotenoid pigment with biotechnological importance because it is used in aquaculture for fish pigmentation. We isolated X. dendrorhous from the Southern Hemisphere (Patagonia, Argentina), where it was associated with ...

  7. Phylogenetics and biogeography of eastern Asian-North American disjunct genus Pachysandra (Buxaceae) inferred from nucleotide sequences

    Institute of Scientific and Technical Information of China (English)

    Zhi-hua JIAO; Jian-hua LI

    2009-01-01

    Pachysandra is an eastern Asian-North American disjunct genus with three species, two in eastern Asia (Pachysandra axillaris and Pachysandra terminalis) and one in eastern North America (Pachysandra procumbens). Although morphological and cytological studies suggest a close affinity of Pprocumbens with P axillaris, molecular data from nuclear and chloroplast DNA regions have provided conflicting signals. In this study, we tested previous phylogenetic hypotheses using sequences of nuclear ribosomal DNA internal transcribed spacers and chloroplast ndhF gene from multiple individuals of each of the three species. We also estimated the time of divergence between eastern Asia and eastern North America. Our results support the morphological and cytological conclusion that P procumbens is more closely related to P axillaris than to P terminalis. The estimated time of divergence of P axillaris and P procumbens was 14.64-5.5 mya, consistent with estimates from many other eastern Asian-North American disjunct genera. The migration of Pachysandra populations from eastern Asia to North America might have occurred by way of the North Atlantic land bridge.

  8. Historical factors that have shaped the evolution of tropical reef fishes: a review of phylogenies, biogeography, and remaining questions.

    Science.gov (United States)

    Cowman, Peter F

    2014-01-01

    Biodiversity patterns across the marine tropics have intrigued evolutionary biologists and ecologists alike. Tropical coral reefs host 1/3 of all marine species of fish on 0.1% of the ocean's surface. Yet our understanding of how mechanistic processes have underpinned the generation of this diversity is limited. However, it has become clear that the biogeographic history of the marine tropics has played an important role in shaping the diversity of tropical reef fishes we see today. In the last decade, molecular phylogenies and age estimation techniques have provided a temporal framework in which the ancestral biogeographic origins of reef fish lineages have been inferred, but few have included fully sampled phylogenies or made inferences at a global scale. We are currently at a point where new sequencing technologies are accelerating the reconstruction and the resolution of the Fish Tree of Life. How will a complete phylogeny of fishes benefit the study of biodiversity in the tropics? Here, I review the literature concerning the evolutionary history of reef-associated fishes from a biogeographic perspective. I summarize the major biogeographic and climatic events over the last 65 million years that have regionalized the tropical marine belt and what effect they have had on the molecular record of fishes and global biodiversity patterns. By examining recent phylogenetic trees of major reef associated groups, I identify gaps to be filled in order to obtain a clearer picture of the origins of coral reef fish assemblages. Finally, I discuss questions that remain to be answered and new approaches to uncover the mechanistic processes that underpin the evolution of biodiversity on coral reefs.

  9. Spatially extensive microbial biogeography of the Indian Ocean provides insights into the unique community structure of a pristine coral atoll

    DEFF Research Database (Denmark)

    Jeffries, Thomas C; Ostrowski, Martin; Williams, Rohan B

    2015-01-01

    Microorganisms act both as drivers and indicators of perturbations in the marine environment. In an effort to establish baselines to predict the response of marine habitats to environmental change, here we report a broad survey of microbial diversity across the Indian Ocean, including the first...... patterns in microbial community composition across the Indian Ocean. Samples from within the Salomon Islands lagoon contained a community which was different even from adjacent samples despite constant water exchange, driven by the dominance of the photosynthetic cyanobacterium Synechococcus. In the lagoon...

  10. NOAA ESRI Grid - seafloor hardbottom occurrence predictions model in New York offshore planning area from Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents hard bottom occurrence predictions from a spatial model developed for the New York offshore spatial planning area. This model builds upon the...

  11. Listriodon guptai Pilgrim, 1926 (Mammalia, Suidae) from the early Miocene of the Bugti Hills, Balochistan, Pakistan: new insights into early Listriodontinae evolution and biogeography

    Science.gov (United States)

    Orliac, Maeva Judith; Antoine, Pierre-Olivier; Métais, Grégoire; Marivaux, Laurent; Crochet, Jean-Yves; Welcomme, Jean-Loup; Baqri, Syed Rafiqul Hassan; Roohi, Ghazala

    2009-08-01

    New dental remains of listriodont suids are described from the lower member of the early to middle Miocene Vihowa Formation of the Bugti Hills, Pakistan. The material is homogeneous in terms of morphology and dimensions and referred as a whole to Listriodon guptai Pilgrim, 1926. This species is also mentioned in coeval deposits of the Zinda Pir Dome, Pakistan, dating back to ca. 19 Ma. The early occurrence of an advanced listriodont in Pakistan constrains the age of acquisition of several characters correlated to lophodonty within Listriodontini, and raises major questions about the early history of the Old World Listriodontinae. Strong morphological similarity between Listriodon guptai and the African species Listriodon akatikubas found in the late early Miocene of Maboko (Kenya, ca. 16.5 Ma) suggests that this latter is most probably a migrant originating from Asia.

  12. Three genome-based phylogeny of Cupressaceae s.l.: further evidence for the evolution of gymnosperms and Southern Hemisphere biogeography.

    Science.gov (United States)

    Yang, Zu-Yu; Ran, Jin-Hua; Wang, Xiao-Quan

    2012-09-01

    Phylogenetic information is essential to interpret the evolution of species. While DNA sequences from different genomes have been widely utilized in phylogenetic reconstruction, it is still difficult to use nuclear genes to reconstruct phylogenies of plant groups with large genomes and complex gene families, such as gymnosperms. Here, we use two single-copy nuclear genes, together with chloroplast and mitochondrial genes, to reconstruct the phylogeny of the ecologically-important conifer family Cupressaceae s.l., based on a complete sampling of its 32 genera. The different gene trees generated are highly congruent in topology, supporting the basal position of Cunninghamia and the seven-subfamily classification, and the estimated divergence times based on different datasets correspond well with each other and with the oldest fossil record. These results imply that we have obtained the species phylogeny of Cupressaceae s.l. In addition, possible origins of all three polyploid conifers were investigated, and a hybrid origin was suggested for Cupressus, Fitzroya and Sequoia. Moreover, we found that the biogeographic history of Cupressaceae s.l. is associated with the separation between Laurasia and Gondwana and the further break-up of the latter. Our study also provides new evidence for the gymnosperm phylogeny.

  13. Refuge Begonias. Taxonomy, phylogeny and historical biogeography of Begonia sect. Loasibegonia and sect. Scutobegonia in relation to glacial rain forest refuges in Africa.

    NARCIS (Netherlands)

    Sosef, M.S.M.

    1994-01-01

    Begonia is a genus of + 1000 species and is represented in all tropical areas. In Wageningen, under the guidance of dr J.J.F.E. de Wilde, the continental African begonias are being studied. Continental Africa has some 120 species, divided over 10 sections, and compared with the amount of spe

  14. Species on the rocks: Systematics and biogeography of the rock-dwelling Ptyodactylus geckos (Squamata: Phyllodactylidae) in North Africa and Arabia.

    Science.gov (United States)

    Metallinou, Margarita; Červenka, Jan; Crochet, Pierre-André; Kratochvíl, Lukáš; Wilms, Thomas; Geniez, Philippe; Shobrak, Mohammed Y; Brito, José C; Carranza, Salvador

    2015-04-01

    The understanding of the diversity of species in the Palearctic and the processes that have generated it is still weak for large parts of the arid areas of North Africa and Arabia. Reptiles are among their most remarkable representatives, with numerous groups well adapted to the diverse environments. The Ptyodactylus geckos are a strictly rock-dwelling genus with homogeneous morphology distributed across mountain formations and rocky plateaus from the western African ranges in Mauritania and the Maghreb to the eastern tip of the Arabian Peninsula, with an isolated species in southern Pakistan. Here, we use a broad sampling of 378 specimens, two mitochondrial (12S and cytb) and four nuclear (c-mos, MC1R, ACM4, RAG2) markers in order to obtain the first time-calibrated molecular phylogeny of the genus and place its diversification in a temporal framework. The results reveal high levels of intraspecific variability, indicative of undescribed diversity, and they do not support the monophyly of one species (P. ragazzii). Ptyodactylus species are allopatric across most of their range, which may relate to their high preference for the same type of structural habitat. The onset of their diversification is estimated to have occurred in the Late Oligocene, while that of several deep clades in the phylogeny took place during the Late Miocene, a period when an increase in aridification in North Africa and Arabia initiated.

  15. From the mountains to the coast and back again: Ancient biogeography in a radiation of short-range endemic harvestmen from California.

    Science.gov (United States)

    Emata, K N; Hedin, M

    2016-05-01

    The harvestmen genus Calicina is represented by 25 short-range endemic species occurring in the western Sierra Nevada, Transverse and Coast Ranges of California. Our principal aim was to reconstruct the temporal and spatial biogeographic history of this arachnid lineage. We inferred a time-calibrated species tree for 21 of 25 described Calicina species using multiple genes and multilocus coalescent-based methods. This species tree was used as a framework for algorithmic biogeographic and divergence time analyses, and a phylogenetic canonical correlation analysis (CCA) was used to examine the relationship between morphological evolution and environmental variables. Species tree and biogeographic analyses indicate that high-elevation Sierran taxa are early-diverging in Calicina, with subsequent biogeographic "criss-crossing" of lineages from the Sierra Nevada to the Coast Ranges, back to the Sierra Nevada, then back to Coast Ranges. In both the Sierra Nevada and Coast Ranges, distantly-related parapatric lineages essentially never occur in sympatry. CCA reveals that in both the Coast Ranges and the Sierra Nevada, distant phylogenetic relatives evolve convergent morphologies. Our evidence shows that Calicina is clearly dispersal-limited, with an ancient biogeographic history that provides unique insight into the complex geologic evolution of California since the mid-Paleogene.

  16. Chloroplast phylogeny of asplenioid ferns based on rbcL and trnL-F Spacer sequences (Polypodiidae, aspleniaceae) and its implications for biogeography

    NARCIS (Netherlands)

    Schneider, H.; Russell, S.J.; Cox, C.J.; Bakker, F.T.; Henderson, S.; Rumsey, F.; Barrett, J.; Gibby, M.; Vogel, J.C.

    2004-01-01

    Molecular phylogenies have been generated to investigate relationships among species and putative segregates in Asplenium, one of the largest genera in ferns. Of the ~700 described taxa, 71 are included in a phylogenetic analysis using the chloroplast rbcL gene and trnL-F spacer. Our results support

  17. Phylogeny and Historical Biogeography of Asian Pterourus Butterflies (Lepidoptera: Papilionidae): A Case of Intercontinental Dispersal from North America to East Asia.

    Science.gov (United States)

    Wu, Li-Wei; Yen, Shen-Horn; Lees, David C; Lu, Chih-Chien; Yang, Ping-Shih; Hsu, Yu-Feng

    2015-01-01

    The phylogenetic status of the well-known Asian butterflies often known as Agehana (a species group, often treated as a genus or a subgenus, within Papilio sensu lato) has long remained unresolved. Only two species are included, and one of them especially, Papilio maraho, is not only rare but near-threatened, being monophagous on its vulnerable hostplant, Sassafras randaiense (Lauraceae). Although the natural history and population conservation of "Agehana" has received much attention, the biogeographic origin of this group still remains enigmatic. To clarify these two questions, a total of 86 species representatives within Papilionidae were sampled, and four genes (concatenated length 3842 bp) were used to reconstruct their phylogenetic relationships and historical scenarios. Surprisingly, "Agehana" fell within the American Papilio subgenus Pterourus and not as previously suggested, phylogenetically close to the Asian Papilio subgenus Chilasa. We therefore formally synonymize Agehana with Pterourus. Dating and biogeographic analysis allow us to infer an intercontinental dispersal of an American ancestor of Asian Pterourus in the early Miocene, which was coincident with historical paleo-land bridge connections, resulting in the present "East Asia-America" disjunction distribution. We emphasize that species exchange between East Asia and America seems to be a quite frequent occurrence in butterflies during the Oligocene to Miocene climatic optima.

  18. Application of Numerical Taxonomy in Biogeography in Entomology%数量分类学在昆虫学中的生物地理学研究

    Institute of Scientific and Technical Information of China (English)

    李建锋

    2011-01-01

    Numerical taxonomy converts the record of characters into digital, and then by similarity analysis expresses genetic relationship in entomology.%数量分类学(numerical taxonomy)把全部性状状态的记录都改换成数值通过相似性分析来描述昆虫学中的亲缘关系.

  19. Biogeografia do gênero Mikania Willd. (Asteraceae no Rio Grande do Sul, Brasil Biogeography of the genus Mikania Willd. (Asteraceae in Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Mara Rejane Ritter

    2004-09-01

    Full Text Available A distribuição geográfica das 39 espécies nativas de Mikania Willd. no Rio Grande do Sul foi estudada em duas escalas: uma escala regional, utilizando regiões fisiográficas como unidades, e uma escala continental, considerando regiões político-geográficas como unidades. A riqueza específica e a amplitude de distribuiçãoforam obtidas diretamente de matrizes de presença e ausência, relacionando espécies e regiões. A matriz regional foi analisada por dois métodos multivariados, uma análise de agrupamentos e uma análise de coordenadas principais, utilizando o complemento do coeficiente de Jaccard como elemento de comparação (dissimilaridade. Na escala regional as regiões mais ricas foram o Litoral e a Depressão Central, enquanto na escala continental, a maioria das espécies sul-rio-grandenses foram também encontradas no Sudeste do Brasil e no Sul da América do Sul. A análise multivariada evidenciou dois grupos principais no Estado, um oriental e outro ocidental. Em cada um desses grupos foram evidenciados dois subgrupos relacionados a características climáticas e geológicas do Estado.Os padrões de distribuição de Mikania confirmam o caráter tropical do gênero e as principais rotas de migração descritas para a flora do Sul do Brasil.The geographical distribution of the 39 species of Mikania Willd. native in Rio Grande do Sul was studied at two scales: a state-regional scale, using physiographic regions as units, and an american-continental scale, considering politic-geographic regions as units. Specific richness and distribution amplitude were obtained directly from presence and absence matrixes, relating species and regions. The state-regional matrix was also analysed by two multivariate methods, a cluster analysis and a principal coordinate analysis, using the complement of the Jaccard coefficient as a measure of dissimilarity. At the state-regional scale, the richest regions were the Coastal Plain and the Central Depression, whereas at the american-continental scale, most of the South Riograndean species were also found in Southeastern Brazil and Southern South America. The multivariate analysis evidenced two main groups in Rio Grande do Sul, one eastern and another western. Within each of these groups, two subgroups related to climatic and geological features were evidenced. The distribution patterns of Mikania confirm the tropical character of the genus, and the main migration routes described for the southern Brazilian vascular flora.

  20. Have giant lobelias evolved several times independently? Life form shifts and historical biogeography of the cosmopolitan and highly diverse subfamily Lobelioideae (Campanulaceae

    Directory of Open Access Journals (Sweden)

    Antonelli Alexandre

    2009-01-01

    Full Text Available Abstract Background The tendency of animals and plants to independently develop similar features under similar evolutionary pressures - convergence - is a widespread phenomenon in nature. In plants, convergence has been suggested to explain the striking similarity in life form between the giant lobelioids (Campanulaceae, the bellflower family of Africa and the Hawaiian Islands. Under this assumption these plants would have developed the giant habit from herbaceous ancestors independently, in much the same way as has been suggested for the giant senecios of Africa and the silversword alliance of Hawaii. Results Phylogenetic analyses based on plastid (rbcL, trnL-F and nuclear (internal transcribed spacer [ITS] DNA sequences for 101 species in subfamily Lobelioideae demonstrate that the large lobelioids from eastern Africa the Hawaiian Islands, and also South America, French Polynesia and southeast Asia, form a strongly supported monophyletic group. Ancestral state reconstructions of life form and distribution, taking into account phylogenetic uncertainty, indicate their descent from a woody ancestor that was probably confined to Africa. Molecular dating analyses using Penalized Likelihood and Bayesian relaxed clock approaches, and combining multiple calibration points, estimate their first diversification at ~25-33 million years ago (Ma, shortly followed by several long-distance dispersal events that resulted in the current pantropical distribution. Conclusion These results confidently show that lobelioid species, commonly called 'giant', are very closely related and have not developed their giant form from herbaceous ancestors independently. This study, which includes the hitherto largest taxon sampling for subfamily Lobelioideae, highlights the need for a broad phylogenetic framework for testing assumptions about morphological development in general, and convergent evolution in particular.