scholarly journals Building a Robust, Densely-Sampled Spider Tree of Life for Ecosystem Research

Diversity ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 288
Author(s):  
Nuria Macías-Hernández ◽  
Marc Domènech ◽  
Pedro Cardoso ◽  
Brent C. Emerson ◽  
Paulo Alexandre Vieira Borges ◽  
...  

Phylogenetic relatedness is a key diversity measure for the analysis and understanding of how species and communities evolve across time and space. Understanding the nonrandom loss of species with respect to phylogeny is also essential for better-informed conservation decisions. However, several factors are known to influence phylogenetic reconstruction and, ultimately, phylogenetic diversity metrics. In this study, we empirically tested how some of these factors (topological constraint, taxon sampling, genetic markers and calibration) affect phylogenetic resolution and uncertainty. We built a densely sampled, species-level phylogenetic tree for spiders, combining Sanger sequencing of species from local communities of two biogeographical regions (Iberian Peninsula and Macaronesia) with a taxon-rich backbone matrix of Genbank sequences and a topological constraint derived from recent phylogenomic studies. The resulting tree constitutes the most complete spider phylogeny to date, both in terms of terminals and background information, and may serve as a standard reference for the analysis of phylogenetic diversity patterns at the community level. We then used this tree to investigate how partial data affect phylogenetic reconstruction, phylogenetic diversity estimates and their rankings, and, ultimately, the ecological processes inferred for each community. We found that the incorporation of a single slowly evolving marker (28S) to the DNA barcode sequences from local communities, had the highest impact on tree topology, closely followed by the use of a backbone matrix. The increase in missing data resulting from combining partial sequences from local communities only had a moderate impact on the resulting trees, similar to the difference observed when using topological constraints. Our study further revealed substantial differences in both the phylogenetic structure and diversity rankings of the analyzed communities estimated from the different phylogenetic treatments, especially when using non-ultrametric trees (phylograms) instead of time-stamped trees (chronograms). Finally, we provide some recommendations on reconstructing phylogenetic trees to infer phylogenetic diversity within ecological studies.

2017 ◽  
Vol 114 (10) ◽  
pp. 2645-2650 ◽  
Author(s):  
Kyle G. Dexter ◽  
Mathew Lavin ◽  
Benjamin M. Torke ◽  
Alex D. Twyford ◽  
Thomas A. Kursar ◽  
...  

We investigate patterns of historical assembly of tree communities across Amazonia using a newly developed phylogeny for the species-rich neotropical tree genusInga. We compare our results with those for three other ecologically important, diverse, and abundant Amazonian tree lineages,Swartzia, Protieae, andGuatteria. Our analyses using phylogenetic diversity metrics demonstrate a clear lack of geographic phylogenetic structure, and show that local communities ofIngaand regional communities of all four lineages are assembled by dispersal across Amazonia. The importance of dispersal in the biogeography ofIngaand other tree genera in Amazonian and Guianan rain forests suggests that speciation is not driven by vicariance, and that allopatric isolation following dispersal may be involved in the speciation process. A clear implication of these results is that over evolutionary timescales, the metacommunity for any local or regional tree community in the Amazon is the entire Amazon basin.


2018 ◽  
Vol 49 (1) ◽  
pp. 477-497 ◽  
Author(s):  
Pille Gerhold ◽  
Marcos B. Carlucci ◽  
Şerban Procheş ◽  
Andreas Prinzing

Coexisting species may be evolutionarily proximate or distant, resulting in phylogenetically poor or rich communities. This variation is often considered to result from present assembly processes. We argue that, under certain conditions, deep-past processes might control the phylogenetic diversity of communities. First, deep-past effects involve macroevolutionary processes, such as diversification rate, niche conservatism, or dispersal, in the lineages that constitute communities. Second, deep-past processes in the respective region or in the habitat type play a role, for instance, through age, area, stability, or connectivity. Third, the deep past may affect communities via trophic interactions (i.e., communities of enemies or mutualists or communities of hosts). We suggest that deep-past effects can be identified in local communities by measuring phylogenetic diversity in different species pools. We also show how community phylogenetic diversity results in positive or negative eco-evolutionary feedback, and we identify present-day conservation challenges that may profit from a deep-time perspective.


Author(s):  
Pierre Taberlet ◽  
Aurélie Bonin ◽  
Lucie Zinger ◽  
Eric Coissac

Environmental DNA (eDNA), i.e. DNA released in the environment by any living form, represents a formidable opportunity to gather high-throughput and standard information on the distribution or feeding habits of species. It has therefore great potential for applications in ecology and biodiversity management. However, this research field is fast-moving, involves different areas of expertise and currently lacks standard approaches, which calls for an up-to-date and comprehensive synthesis. Environmental DNA for biodiversity research and monitoring covers current methods based on eDNA, with a particular focus on “eDNA metabarcoding”. Intended for scientists and managers, it provides the background information to allow the design of sound experiments. It revisits all steps necessary to produce high-quality metabarcoding data such as sampling, metabarcode design, optimization of PCR and sequencing protocols, as well as analysis of large sequencing datasets. All these different steps are presented by discussing the potential and current challenges of eDNA-based approaches to infer parameters on biodiversity or ecological processes. The last chapters of this book review how DNA metabarcoding has been used so far to unravel novel patterns of diversity in space and time, to detect particular species, and to answer new ecological questions in various ecosystems and for various organisms. Environmental DNA for biodiversity research and monitoring constitutes an essential reading for all graduate students, researchers and practitioners who do not have a strong background in molecular genetics and who are willing to use eDNA approaches in ecology and biomonitoring.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michal Motyka ◽  
Dominik Kusy ◽  
Michal Masek ◽  
Matej Bocek ◽  
Yun Li ◽  
...  

AbstractBiologists have reported on the chemical defences and the phenetic similarity of net-winged beetles (Coleoptera: Lycidae) and their co-mimics. Nevertheless, our knowledge has remained fragmental, and the evolution of mimetic patterns has not been studied in the phylogenetic context. We illustrate the general appearance of ~ 600 lycid species and ~ 200 co-mimics and their distribution. Further, we assemble the phylogeny using the transcriptomic backbone and ~ 570 species. Using phylogenetic information, we closely scrutinise the relationships among aposematically coloured species, the worldwide diversity, and the distribution of aposematic patterns. The emitted visual signals differ in conspicuousness. The uniform coloured dorsum is ancestral and was followed by the evolution of bicoloured forms. The mottled patterns, i.e. fasciate, striate, punctate, and reticulate, originated later in the course of evolution. The highest number of sympatrically occurring patterns was recovered in New Guinea and the Andean mountain ecosystems (the areas of the highest abundance), and in continental South East Asia (an area of moderate abundance but high in phylogenetic diversity). Consequently, a large number of co-existing aposematic patterns in a single region and/or locality is the rule, in contrast with the theoretical prediction, and predators do not face a simple model-like choice but cope with complex mimetic communities. Lycids display an ancestral aposematic signal even though they sympatrically occur with differently coloured unprofitable relatives. We show that the highly conspicuous patterns evolve within communities predominantly formed by less conspicuous Müllerian mimics and, and often only a single species displays a novel pattern. Our work is a forerunner to the detailed research into the aposematic signalling of net-winged beetles.


2019 ◽  
Author(s):  
Benjamin M. Titus ◽  
Charlotte Benedict ◽  
Robert Laroche ◽  
Luciana C. Gusmão ◽  
Vanessa Van Deusen ◽  
...  

AbstractThe clownfish-sea anemone symbiosis has been a model system for understanding fundamental evolutionary and ecological processes. However, our evolutionary understanding of this symbiosis comes entirely from studies of clownfishes. A holistic understanding of a model mutualism requires systematic, biogeographic, and phylogenetic insight into both partners. Here, we conduct the largest phylogenetic analysis of sea anemones (Order Actiniaria) to date, with a focus on expanding the biogeographic and taxonomic sampling of the 10 nominal clownfish-hosting species. Using a combination of mtDNA and nuDNA loci we test 1) the monophyly of each clownfish-hosting family and genus, 2) the current anemone taxonomy that suggests symbioses with clownfishes evolved multiple times within Actiniaria, and 3) whether, like the clownfishes, there is evidence that host anemones have a Coral Triangle biogeographic origin. Our phylogenetic reconstruction demonstrates widespread poly-and para-phyly at the family and genus level, particularly within the family Stichodactylidae and genus Sticodactyla, and suggests that symbioses with clownfishes evolved minimally three times within sea anemones. We further recover evidence for a Tethyan biogeographic origin for some clades. Our data provide the first evidence that clownfish and some sea anemone hosts have different biogeographic origins, and that there may be cryptic species of host anemones. Finally, our findings reflect the need for a major taxonomic revision of the clownfish-hosting sea anemones.


2021 ◽  
Author(s):  
Jaana Bäck ◽  
Werner Kutsch ◽  
Michael Mirtl

<p>Ecosystem Research Infrastructures around the world have been designed, constructed, and are now operational as a distributed effort. The common goal is to address research questions that require long-term ecosystem observations and other service components at national to continental scales, which cannot be tackled in the framework of single and time limited projects.  By design, these Research Infrastructures capture data and provide a wider range of services including access to data and well instrumented research sites. The coevolution of supporting infrastructures and ecological sciences has developed into new science disciplines such as macrosystems ecology, whereby large-scale and multi-decadal-scale ecological processes are being explored. </p><p>Governments, decision-makers, researchers and the public have all recognized that the global economy, quality of life, and the environment are intrinsically intertwined and that ecosystem services ultimately depend on resilient ecological processes. These have been altered and threatened by various components of Global Change, e.g. land degradation, global warming and species loss. These threats are the unintended result of increasing anthropogenic activities and have the potential to change the fundamental trajectory of mankind.  This creates a unique challenge never before faced by society or science—how best to provide a sustainable economic future while understanding and globally managing a changing environment and human health upon which it relies.</p><p>The increasing number of Research Infrastructures around the globe now provides a unique and historical opportunity to respond to this challenge. Six major ecosystem Research Infrastructures (SAEON/South Africa, TERN/Australia, CERN/China, NEON/USA, ICOS/Europe, eLTER/Europe) have started federating to tackle the programmatic work needed for concerted operation and the provisioning of interoperable data and services. This Global Ecosystem Research Infrastructure (GERI) will be presented with a focus on the involved programmatic challenges and the GERI science rationale.</p>


Development ◽  
1994 ◽  
Vol 1994 (Supplement) ◽  
pp. 15-25
Author(s):  
Hervé Philippe ◽  
Anne Chenuil ◽  
André Adoutte

Most of the major invertebrate phyla appear in the fossil record during a relatively short time interval, not exceeding 20 million years (Myr), 540-520 Myr ago. This rapid diversification is known as the `Cambrian explosion'. In the present paper, we ask whether molecular phylogenetic reconstruction provides confirmation for such an evolutionary burst. The expectation is that the molecular phylogenetic trees should take the form of a large unresolved multifurcation of the various animal lineages. Complete 18S rRNA sequences of 69 extant representatives of 15 animal phyla were obtained from data banks. After eliminating a major source of artefact leading to lack of resolution in phylogenetic trees (mutational saturation of sequences), we indeed observe that the major lines of triploblast coelomates (arthropods, molluscs, echinoderms, chordates...) are very poorly resolved i.e. the nodes defining the various clades are not supported by high bootstrap values. Using a previously developed procedure consisting of calculating bootstrap proportions of each node of the tree as a function of increasing amount of nucleotides (Lecointre, G., Philippe, H. Le, H. L. V. and Le Guyader, H. (1994) Mol. Phyl. Evol., in press) we obtain a more informative indication of the robustness of each node. In addition, this procedure allows us to estimate the number of additional nucleotides that would be required to resolve confidently the currently uncertain nodes; this number turns out to be extremely high and experimentally unfeasible. We then take this approach one step further: using parameters derived from the above analysis, assuming a molecular clock and using palaeontological dates for calibration, we establish a relationship between the number of sites contained in a given data set and the time interval that this data set can confidently resolve (with 95% bootstrap support). Under these assumptions, the presently available 18S rRNA database cannot confidently resolve cladogenetic events separated by less than about 40 Myr. Thus, at the present time, the potential resolution by the palaeontological approach is higher than that by the molecular one.


2019 ◽  
Author(s):  
◽  
Sarah Unruh

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Phylogenetic trees show us how organisms are related and provide frameworks for studying and testing evolutionary hypotheses. To better understand the evolution of orchids and their mycorrhizal fungi, I used high-throughput sequencing data and bioinformatic analyses, to build phylogenetic hypotheses. In Chapter 2, I used transcriptome sequences to both build a phylogeny of the slipper orchid genera and to confirm the placement of a polyploidy event at the base of the orchid family. Polyploidy is hypothesized to be a strong driver of evolution and a source of unique traits so confirming this event leads us closer to explaining extant orchid diversity. The list of orthologous genes generated from this study will provide a less expensive and more powerful method for researchers examining the evolutionary relationships in Orchidaceae. In Chapter 3, I generated genomic sequence data for 32 fungal isolates that were collected from orchids across North America. I inferred the first multi-locus nuclear phylogenetic tree for these fungal clades. The phylogenetic structure of these fungi will improve the taxonomy of these clades by providing evidence for new species and for revising problematic species designations. A robust taxonomy is necessary for studying the role of fungi in the orchid mycorrhizal symbiosis. In chapter 4 I summarize my work and outline the future directions of my lab at Illinois College including addressing the remaining aims of my Community Sequencing Proposal with the Joint Genome Institute by analyzing the 15 fungal reference genomes I generated during my PhD. Together these chapters are the start of a life-long research project into the evolution and function of the orchid/fungal symbiosis.


2009 ◽  
Vol 69 (3) ◽  
pp. 843-849 ◽  
Author(s):  
IA. Silva ◽  
MA. Batalha

Ecological communities are the result of not only present ecological processes, such as competition among species and environmental filtering, but also past and continuing evolutionary processes. Based on these assumptions, we may infer mechanisms of contemporary coexistence from the phylogenetic relationships of the species in a community. We studied the phylogenetic structure of plant communities in four cerrado sites, in southeastern Brazil. We calculated two raw phylogenetic distances among the species sampled. We estimated the phylogenetic structure by comparing the observed phylogenetic distances to the distribution of phylogenetic distances in null communities. We obtained null communities by randomizing the phylogenetic relationships of the regional pool of species. We found a phylogenetic overdispersion of the cerrado species. Phylogenetic overdispersion has several explanations, depending on the phylogenetic history of traits and contemporary ecological interactions. However, based on coexistence models between grasses and trees, density-dependent ecological forces, and the evolutionary history of the cerrado flora, we argue that the phylogenetic overdispersion of cerrado species is predominantly due to competitive interactions, herbivores and pathogen attacks, and ecological speciation. Future studies will need to include information on the phylogenetic history of plant traits.


2019 ◽  
Vol 190 (4) ◽  
pp. 333-344 ◽  
Author(s):  
Hong Qian ◽  
Brody Sandel ◽  
Tao Deng ◽  
Ole R Vetaas

AbstractEcologists have embraced phylogenetic measures of assemblage structure, in large part for the promise of better mechanistic inferences. However, phylogenetic structure is driven by a wide array of factors from local biotic interactions to biogeographical history, complicating the mechanistic interpretation of a pattern. This may be particularly problematic along elevational gradients, where rapidly changing physical and biological conditions overlap with geological and biogeographical history, potentially producing complex patterns of phylogenetic dispersion (relatedness). We focus on the longest elevational gradient of vegetation in the world (i.e. c. 6000 m in Nepal) to explore patterns of phylogenetic dispersion for angiosperms (flowering plants) along this elevational gradient. We used the net relatedness index to quantify phylogenetic dispersion for each elevational band of 100 m. We found a zig-zag pattern of phylogenetic dispersion along this elevational gradient. With increasing elevation, the phylogenetic relatedness of species decreased for the elevational segment between 0 and c. 2100 m, increased for the elevational segment between 2100 and c. 4200 m, and decreased for the elevational segment above c. 4200 m. We consider this pattern to be a result of the interaction of geophysical (e.g. plate tectonics) and eco-evolutionary processes (e.g. niche conservatism and trait convergence). We speculate on the mechanisms that might have generated this zig-zag pattern of phylogenetic dispersion.


Sign in / Sign up

Export Citation Format

Share Document