A primary aim of microbial ecology is to determine patterns and drivers of community distribution, interaction, and assembly amidst complexity and uncertainty. Microbial community composition has been shown to change across gradients of environment, geographic distance, salinity, temperature, oxygen, nutrients, pH, day length, and biotic factors 1-6 . These patterns have been identified mostly by focusing on one sample type and region at a time, with insights extra polated across environments and geography to produce generalized principles. To assess how microbes are distributed across environments globally-or whether microbial community dynamics follow funda mental ecological 'laws' at a planetary scale-requires either a massive monolithic cross environment survey or a practical methodology for coordinating many independent surveys. New studies of microbial environments are rapidly accumulating; however, our ability to extract meaningful information from across datasets is outstripped by the rate of data generation. Previous meta analyses have suggested robust gen eral trends in community composition, including the importance of salinity 1 and animal association 2 . These findings, although derived from relatively small and uncontrolled sample sets, support the util ity of meta analysis to reveal basic patterns of microbial diversity and suggest that a scalable and accessible analytical framework is needed.The Earth Microbiome Project (EMP, http://www.earthmicrobiome. org) was founded in 2010 to sample the Earth's microbial communities at an unprecedented scale in order to advance our understanding of the organizing biogeographic principles that govern microbial commu nity structure 7,8 . We recognized that open and collaborative science, including scientific crowdsourcing and standardized methods 8 , would help to reduce technical variation among individual studies, which can overwhelm biological variation and make general trends difficult to detect 9 . Comprising around 100 studies, over half of which have yielded peer reviewed publications (Supplementary Table 1), the EMP has now dwarfed by 100 fold the sampling and sequencing depth of earlier meta analysis efforts 1,2 ; concurrently, powerful analysis tools have been developed, opening a new and larger window into the distri bution of microbial diversity on Earth. In establishing a scalable frame work to catalogue microbiota globally, we provide both a resource for the exploration of myriad questions and a starting point for the guided acquisition of new data to answer them. As an example of using this Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of r...
Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.Amazonia | floristics | rain forests | seed plants | species diversity
Summary Pollination syndromes describe recurring adaptation to selection imposed by distinct pollinators. We tested for pollination syndromes in Merianieae (Melastomataceae), which contain bee‐ (buzz‐), hummingbird‐, flowerpiercer‐, passerine‐, bat‐ and rodent‐pollinated species. Further, we explored trait changes correlated with the repeated shifts away from buzz‐pollination, which represents an ‘adaptive plateau’ in Melastomataceae. We used random forest analyses to identify key traits associated with the different pollinators of 19 Merianieae species and estimated the pollination syndromes of 42 more species. We employed morphospace analyses to compare the morphological diversity (disparity) among syndromes. We identified three pollination syndromes (‘buzz‐bee’, ‘mixed‐vertebrate’ and ‘passerine’), characterized by different pollen expulsion mechanisms and reward types, but not by traditional syndrome characters. Further, we found that ‘efficiency’ rather than ‘attraction’ traits were important for syndrome circumscription. Contrary to syndrome theory, our study supports the pooling of different pollinators (hummingbirds, bats, rodents and flowerpiercers) into the ‘mixed‐vertebrate’ syndrome, and we found that disparity was highest in the ‘buzz‐bee’ syndrome. We conclude that the highly adaptive buzz‐pollination system may have prevented shifts towards classical pollination syndromes, but provided the starting point for the evolution of a novel set of distinct syndromes, all having retained multifunctional stamens that provide pollen expulsion, reward and attraction.
Miconieae is the most diverse tribe of Melastomataceae, with 30 genera and over 2200 species. The tribe is characterized by fleshy fruits and partially to totally inferior ovaries. To test monophyly of the tribe and assess phylogenetic relationships within it, sequence data from nrITS were gathered and analyzed for 110 taxa in Miconieae and 32 putative outgroups. The tribe Miconieae is not resolved as monophyletic, but rather composed of two distinct clades: one composed of the cauliflorous genera Henriettea, Henriettella, Loreya and Bellucia, and a second clade with all other taxa in Miconieae, sister to a polytomy that includes representatives from tribes Merianieae and Blakeeae. Terminal inflorescences are optimized as basal within Miconieae, with lateral inflorescences evolving in at least four different instances. Cauliflory does not appear to be derived from truly axillary inflorescences; instead it seems to have evolved independently. The terminal–flowered genera Tococa, Conostegia, Tetrazygia, Anaectocalyx, Charianthus, Calycogonium, and Leandra pro parte seem to be derived from within the large genus Miconia, as is Clidemia, a genus with both axillary inflorescences and terminal inflorescences that are deflexed to a lateral position by an axillary branch. Maieta and Necranium, both with axillary inflorescences, are resolved as derived from within Clidemia.
In this study we present a phylogenetic analysis of Melastomeae, focusing on the Neotropical members of the tribe, a group of c. 70 species in 30 genera. In total, 236 species, including outgroups (Miconieae and Merianieae) and representatives of the Microlicieae and Rhexieae, were sequenced for the nuclear ribosomal internal transcribed spacer (nrITS), and the plastid spacers accD‐psaI and psbK‐psbL. Melastomeae are not resolved as monophyletic because a group of mostly herbs and small trees with mostly tetramerous flowers (Acanthella, Aciotis, Acisanthera, Appendicularia, Comolia, Ernestia, Fritzschia, Marcetia, Macairea, Nepsera, Sandemania and Siphanthera) is nested between Rhexieae and Microlicieae. The remaining New World Melastomeae are not resolved as monophyletic, because a group of Old World genera (Osbeckia, Melastoma, Tristemma and allied genera) are nested in the tribe. The large genus Tibouchina is not monophyletic because Brachyotum, Bucquetia, Castratella, Centradenia, Chaetolepis, Heterocentron, Itatiaia, Microlepis, Monochaetum, Pilocosta, Svitramia, and Tibouchinopsis are nested in it, even although all of these genera are recovered as monophyletic. Each major clade has remarkable habitat and geographical integrity. The clade formed by Tibouchina and allies appears to have arisen in savannas in lowland South America and later expanded to forest, campo and high Andean biomes. At least two groups have radiated in eastern Brazil, and two other groups in the Andes and mountains of Central America. Niche conservatism and colonization of adjacent environments seem to have driven speciation in Neotropical Melastomeae. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ●●, ●●–●●.
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The University of Chicago Press is collaborating with JSTOR to digitize, preserve and extend access to International Journal of Plant Sciences.Phylogenetic relationships within Miconia and other genera in the Neotropical tribe Miconieae were investigated using a maximum parsimony analysis of nuclear internal transcribed spacer and ndhF nucleotide sequences. Included were all sections in Miconia (212 species, ;20% of the genus) and 12 of the 15 remaining genera assigned to the tribe (an additional 239 species). Given the tribe's reputation for problematic generic distinctions, it was not surprising that most traditionally recognized taxonomic groups-both genera and sections-were shown to be polyphyletic or paraphyletic. Nevertheless, Miconia is composed of several distinct monophyletic groups, with a large majority of the species belonging to only four clades. Some of these groups represent parts of sections proposed in the last revision of the genus, but most of the diversification seems to have occurred in geographical areas that are more restricted than would have been predicted by the distribution of these sections. Moreover, parallel evolutionary trends are seen in anther form, i.e., shifts from elongate to shorter anthers and from minute-pored to large-pored or slitlike dehiscent anthers. These changes may relate to pollinator shifts, especially from buzz pollination to nonvibrational pollination. Thus, the major evolutionary diversifications within the tribe have been obscured by convergence in stamen morphology, leading to many arbitrary generic and sectional circumscriptions.
A phylogenetic analysis of the Poales was conducted to assess relationships among Poaceae and allied families. The analysis included 40 taxa, representing all families of the Poales as circumscribed by the Angiosperm Phylogeny Group (APG), plus five of the six unplaced Commelinid families in the APG system. The data matrix included 98 informative characters representing variation in morphology and chloroplast genome structure (including three inversions in the chloroplast genome), and 563 informative characters derived from rbcL and atpA nucleotide sequences. Ecdeiocolea has the 6-kilobase (kb) chloroplast genome inversion previously reported in Joinvillea and Poaceae, and like Joinvillea it lacks the trnT inversion that occurs in grasses. Analysis of the morphological data places Poaceae in an unresolved relationship relative to several other taxa, including Joinvillea and Ecdeiocolea, while analysis of the molecular and combined data resolves Ecdeiocolea as sister of Poaceae, with Joinvillea the sister of this group. Although the 6-kb and trnT inversions are non-homoplasious in the phylogenies obtained in this study, the 28-kb inversion is optimized as having originated twice (once in Restionaceae and another time in the most recent common ancestor of Ecdeiocolea, Joinvillea, and the grasses); an alternative interpretation is that it arose once and was later lost in Anarthria. Ecdeiocolea shares with Poaceae the presence of operculate, annulate pollen that lacks scrobiculi, and a dry, indehiscent fruit.
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