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Biogeographic Analysis (biogeographic + analysis)
Selected AbstractsBiogeographic analysis of endemic cacti of the Sierra Madre Oriental, MexicoBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2009HAMLET SANTA ANNA DEL CONDE JUÁREZ The distribution of cacti species that inhabit the Sierra Madre Oriental (SMO) was analysed. Grid-cells were analysed using parsimony analysis of endemicity (PAE) and endemism indices. Areas characterized by their diagnostic species were determined, aiming to propose areas for the conservation of threatened cacti. Distributional data were obtained from 1936 herbarium specimens, electronic information, and from field collections. Eight areas of endemism and three main clades were obtained from the grid-cell analysis. Areas obtained from the endemism indices are very similar to those obtained with the PAE, but differ in the association of grid-cells. PAE showed endemism patterns indicating that southern and central sections of the SMO province are the areas richest in geographically-restricted species. The results obtained with different endemism indices detected more or less the same areas, although the importance level is different. The corrected weighted endemism index can be considered as a reliable measure of endemism because it is unrelated to species richness. A regionalization of the SMO in three subprovinces is suggested, supported by characteristic cacti taxa and the existence of natural barriers. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 373,389. [source] Continental speciation in the tropics: contrasting biogeographic patterns of divergence in the Uroplatus leaf-tailed gecko radiation of MadagascarJOURNAL OF ZOOLOGY, Issue 4 2008C. J. Raxworthy Abstract A fundamental expectation of vicariance biogeography is for contemporary cladogenesis to produce spatial congruence between speciating sympatric clades. The Uroplatus leaf-tailed geckos represent one of most spectacular reptile radiations endemic to the continental island of Madagascar, and thus serve as an excellent group for examining patterns of continental speciation within this large and comparatively isolated tropical system. Here we present the first phylogeny that includes complete taxonomic sampling for the group, and is based on morphology and molecular (mitochondrial and nuclear DNA) data. This study includes all described species, and we also include data for eight new species. We find novel outgroup relationships for Uroplatus and find strongest support for Paroedura as its sister taxon. Uroplatus is estimated to have initially diverged during the mid-Tertiary in Madagascar, and includes two major speciose radiations exhibiting extensive spatial overlap and estimated contemporary periods of speciation. All sister species are either allopatric or parapatric. However, we found no evidence for biogeographic congruence between these sympatric clades, and dispersal events are prevalent in the dispersal,vicariance biogeographic analyses, which we estimate to date to the Miocene. One sister-species pair exhibits isolated distributions that we interpret as biogeographic relicts, and two sister-species pairs have parapatric distributions separated by elevation. Integrating ecological niche models with our phylogenetic results finds both conserved and divergent niches between sister species. We also found substantial intra-specific genetic variation, and for the three most widespread species, poor intra-specific predictive performance for ecological niche models across the latitudinal span of Madagascar. These latter results indicate the potential for intra-specific niche specialization along environmental gradients, and more generally, this study suggests a complex speciation history for this group in Madagascar, which appears to include multiple speciation processes. [source] The mid-latitude biodiversity ridge in terrestrial cave faunaECOGRAPHY, Issue 1 2006David C. Culver The world's obligate cave-dwelling fauna holds considerable promise for biogeographic analysis because it represents a large number of independent evolutionary experiments in isolation in caves and adaptation to subterranean life. We focus on seven north temperate regions of at least 2000 km2, utilizing more than 4300 records of obligate cave-dwelling terrestrial invertebrates. In North America, highest diversity was found in northeast Alabama while in Europe highest diversity was found in Aričge, France, and in southeast Slovenia. Based on these regions as well as more qualitative data from 16 other regions, we hypothesize that a ridge (ca 42°,46° in Europe and 34° in North America) of high biodiversity occurs in temperate areas of high productivity and cave density. This may reflect a strong dependence of cave communities on long term surface productivity (as reflected in actual evapotranspiration), because the subterranean fauna relies almost entirely on resources produced outside caves. This dependence may explain the unique biodiversity pattern of terrestrial cave invertebrates. [source] Historical biogeography of Southeast Asia and the West Pacific, or the generality of unrooted area networks as historical biogeographic hypothesesJOURNAL OF BIOGEOGRAPHY, Issue 2 2003Peter C. van Welzen Abstract Aim Unrooted area networks are perhaps a general way in which different historical biogeographical patterns may be combined. Location Southeast Asia up to the West Pacific, Australia, South America. Methods Unrooted area networks based on Primary Brooks Parsimony Analysis of different data sets of Southeast Asian,West Pacific, Australian and South American clades. Results A large Brooks Parsimony historical (cladistic) biogeographic analysis of Southeast Asia and the West Pacific gave a meaningful result when all clades (representing different historical biogeographic patterns) were united into one matrix and an unrooted area network was produced. This network showed geographically adjacent areas as neighbours, which is interpreted as clades dispersing and speciating as soon as areas rafted towards each other. This pseudo-vicariance mechanism, together with the very limited, mainly linear dispersal possibilities, a few large, widespread clades with many endemic species, and the large overlap in distributions displayed by different patterns, may explain the peculiar result. When applied to examples from other areas (bird data from Australia and South America), unrooted area networks for all data perform very poorly. Main conclusions Unrooted historical general area networks are not universally applicable. In general, it is better to split historical patterns a priori and analyse them separately. [source] A cladistic biogeographic analysis of New Zealand land mollusca: where is the evidence?JOURNAL OF BIOGEOGRAPHY, Issue 4 2001A comment on G.M. Barker, P.C. Mayhill (1999) Patterns of diversity, habitat relationships in terrestrial mollusc communities of the Pukeamaru Ecological District, northeastern New Zealand. No abstract is available for this article. [source] Estimating ancestral distributions of lineages with uncertain sister groups: a statistical approach to Dispersal,Vicariance Analysis and a case using Aesculus L. (Sapindaceae) including fossilsJOURNAL OF SYSTEMATICS EVOLUTION, Issue 5 2009A.J. HARRIS Abstract, We propose a simple statistical approach for using Dispersal,Vicariance Analysis (DIVA) software to infer biogeographic histories without fully bifurcating trees. In this approach, ancestral ranges are first optimized for a sample of Bayesian trees. The probability P of an ancestral range r at a node is then calculated as where Y is a node, and F(rY) is the frequency of range r among all the optimal solutions resulting from DIVA optimization at node Y, t is one of n topologies optimized, and Pt is the probability of topology t. Node Y is a hypothesized ancestor shared by a specific crown lineage and the sister of that lineage "x", where x may vary due to phylogenetic uncertainty (polytomies and nodes with posterior probability <100%). Using this method, the ancestral distribution at Y can be estimated to provide inference of the geographic origins of the specific crown group of interest. This approach takes into account phylogenetic uncertainty as well as uncertainty from DIVA optimization. It is an extension of the previously described method called Bayes-DIVA, which pairs Bayesian phylogenetic analysis with biogeographic analysis using DIVA. Further, we show that the probability P of an ancestral range at Y calculated using this method does not equate to pp*F(rY) on the Bayesian consensus tree when both variables are <100%, where pp is the posterior probability and F(rY) is the frequency of range r for the node containing the specific crown group. We tested our DIVA-Bayes approach using Aesculus L., which has major lineages unresolved as a polytomy. We inferred the most probable geographic origins of the five traditional sections of Aesculus and of Aesculus californica Nutt. and examined range subdivisions at parental nodes of these lineages. Additionally, we used the DIVA-Bayes data from Aesculus to quantify the effects on biogeographic inference of including two wildcard fossil taxa in phylogenetic analysis. Our analysis resolved the geographic ranges of the parental nodes of the lineages of Aesculus with moderate to high probabilities. The probabilities were greater than those estimated using the simple calculation of pp*F(ry) at a statistically significant level for two of the six lineages. We also found that adding fossil wildcard taxa in phylogenetic analysis generally increased P for ancestral ranges including the fossil's distribution area. The ,P was more dramatic for ranges that include the area of a wildcard fossil with a distribution area underrepresented among extant taxa. This indicates the importance of including fossils in biogeographic analysis. Exmination of range subdivision at the parental nodes revealed potential range evolution (extinction and dispersal events) along the stems of A. californica and sect. Parryana. [source] | ||||||||||