scholarly journals The role of evolutionary modes for trait-based cascades in mutualistic networks

2021 ◽  
Author(s):  
Vinicius A. G. Bastazini ◽  
Vanderlei Debastiani ◽  
Laura Cappelatti ◽  
Paulo Guimaraes ◽  
Valerio De Patta Pillar
Keyword(s):  
Functional Diversity ◽  
Evolutionary Dynamics ◽  
Phylogenetic Signal ◽  
Species Traits ◽  
Network Robustness ◽  
Small Range ◽  
Trait Evolution ◽  
Community Resistance ◽  
Mutualistic Networks

The erosion of functional diversity may foster the collapse of ecological systems. Functional diversity is ultimately defined by the distribution of species traits and, as species traits are a legacy of species evolutionary history, one might expect that the mode of trait evolution influence community resistance under the loss of functional diversity. In this paper, we investigate the role of trait evolutionary dynamics on the robustness of mutualistic networks undergoing the following scenarios of species loss: i) random extinctions, ii) loss of functional distinctiveness and iii) biased towards larger trait values. We simulated networks defined by models of single trait complementary and evolutionary modes where traits can arise in recent diversification events with weak phylogenetic signal, in early diversification events with strong phylogenetic signal, or as a random walk through evolutionary time. Our simulations show that mutualistic networks are especially vulnerable to extinctions based on trait distinctiveness and more robust to random extinction dynamics. The networks show intermediate level of robustness against size-based extinctions. Despite the small range of variation in network robustness, our results show that the mode of trait evolution matters for network robustness in all three scenarios. Networks with low phylogenetic signal are more robust than networks with high phylogenetic signal across all scenarios. As a consequence, our results predict that mutualistic networks based upon current adaptations are more likely to cope with extinction dynamics than those networks that are based upon conserved traits.

scholarly journals High-resolution genomic surveillance of 2014 ebolavirus using shared subclonal variants

2014 ◽  
Author(s):  
Kevin J Emmett ◽  
Albert K Lee ◽  
Hossein Khiabanian ◽  
Raul Rabadan
Keyword(s):  
Sierra Leone ◽  
Disease Transmission ◽  
Evolutionary Dynamics ◽  
Evolutionary Rate ◽  
Phylogenetic Signal ◽  
Founder Population ◽  
Effective Population ◽  
Phylogenetic Resolution ◽  
Analyze Data

Viral outbreaks, such as the 2014 ebolavirus, can spread rapidly and have complex evolutionary dynamics, including coinfection and bulk transmission of multiple viral populations. Genomic surveillance can be hindered when the spread of the outbreak exceeds the evolutionary rate, in which case consensus approaches will have limited resolution. Deep sequencing of infected patients can identify genomic variants present in intrahost populations at subclonal frequencies (i.e. <50%). Shared subclonal variants (SSVs) can provide additional phylogenetic resolution and inform about disease transmission patterns. Here, we use metrics from population genetics to analyze data from the 2014 ebolavirus outbreak in Sierra Leone and identify phylogenetic signal arising from SSVs. We use methods derived from information theory to measure a lower bound on transmission bottleneck size that is larger than one founder population, yet significantly smaller than the intrahost effective population. Our results demonstrate the important role of shared subclonal variants in genomic surveillance.

scholarly journals Spatial Scaling Patterns of Functional Diversity

2021 ◽  
Vol 9 ◽  
Author(s):  
Saeid Alirezazadeh ◽  
Paulo A. V. Borges ◽  
Pedro Cardoso ◽  
Rosalina Gabriel ◽  
François Rigal ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Species Abundance ◽  
Species Traits ◽  
Species Identity ◽  
Spatial Scaling ◽  
Species Area ◽  
Functional Units ◽  
Using Data ◽  
Underlying Processes

Ecology, biogeography and conservation biology, among other disciplines, often rely on species identity, distribution and abundance to perceive and explain patterns in space and time. Yet, species are not independent units in the way they interact with their environment. Species often perform similar roles in networks and their ecosystems, and at least partial redundancy or difference of roles might explain co-existence, competitive exclusion or other patterns reflected at the community level. Therefore, considering species traits, that is, the organisms’ functional properties that interact with the environment, might be of utmost importance in the study of species relative abundances. Several descriptive measures of diversity, such as the species-area relationship (SAR) and the species abundance distribution (SAD), have been used extensively to characterize the communities and as a possible window to gain insight into underlying processes shaping and maintaining biodiversity. However, if the role of species in a community is better assessed by their functional attributes, then one should also study the SAR and the SAD by using trait-based approaches, and not only taxonomic species. Here we merged species according to their similarity in a number of traits, creating functional units, and used these new units to study the equivalent patterns of the SAR and of the SAD (functional units abundance distributions - FUADs), with emphasis on their spatial scaling characteristics. This idea was tested using data on arthropods collected in Terceira island, in the Azorean archipelago. Our results showed that diversity scales differently depending on whether we use species or functional units. If what determines species communities’ dynamics is their functional diversity, then our results suggest that we may need to revaluate the commonly assumed patterns of species diversity and, concomitantly, the role of the underlying processes.

scholarly journals Parallel assemblage structures in Mediterranean marine amphipods revealed by beta diversity partitioning

2020 ◽  
Author(s):  
Bruno Bellisario ◽  
Federica Camisa ◽  
Chiara Abbattista ◽  
Roberta Cimmaruta
Keyword(s):  
Functional Diversity ◽  
Beta Diversity ◽  
Environmental Changes ◽  
Environmental Gradients ◽  
Species Turnover ◽  
Phylogenetic Signal ◽  
Ecological Communities ◽  
Diversity Partitioning ◽  
Distance Information

AbstractRelying on a purely taxonomic view of diversity may ignore the fact that ecological communities can be constituted of species having both distinct evolutionary histories and functional characteristics. Thus, considering how the multiple facets of diversity vary along environmental and geographic gradients may provide insights into the role of historic processes and current environmental changes in determining the divergence or convergence of lineages and functions, ultimately influencing the way species assemble across space. However, analyses can be somehow flawed by the choice of traits being analysed, as they should capture the whole functional variability of species in order to assess the relationship between phylogenetic and functional diversity along a gradient. When continuous measures of functional diversity based on a variety of different traits are absent, the use of functional traits known to show strong phylogenetic signal can help elucidating such relationship. By using distributional, traits and taxonomic-distance information, we explored how the taxon, functional and phylogenetic community composition (co)vary along spatial and environmental gradients in seagrass amphipod metacommunity within the Mediterranean Sea. We used beta diversity partitioning and null models to determine the role of deterministic and stochastic processes on the replacement and the net loss/gain of species, lineages and highly conserved β-niche traits. We showed that dispersal-based processes are the main determinants of the high taxonomic and phylogenetic beta diversity, while niche-based processes explain the low functional dissimilarity among assemblages. Moreover, phylogenetic and functional beta diversity showed contrasting patterns when controlling for the underlying taxonomic composition, with the former being not significantly different and the latter significantly lower than expected. Our results suggest the key role of historical and biogeographic processes in determining the present-day patterns of community assembly and species turnover, providing also evidence for parallel assemblage structures in Mediterranean seagrass amphipods.

Environmental DNA for functional diversity

2018 ◽  
Author(s):  
Pierre Taberlet ◽  
Aurélie Bonin ◽  
Lucie Zinger ◽  
Eric Coissac
Keyword(s):  
Functional Groups ◽  
Functional Diversity ◽  
Environmental Dna ◽  
Soil Organisms ◽  
Meaningful Information ◽  
Dna Metabarcoding ◽  
Pros And Cons ◽  
Target Community

Chapter 10 “Environmental DNA for functional diversity” discusses the potential of environmental DNA to assess functional diversity. It first focuses on DNA metabarcoding and discusses the extent to which this approach can be used and/or optimized to retrieve meaningful information on the functions of the target community. This knowledge usually involves coarsely defined functional groups (e.g., woody, leguminous, graminoid plants; shredders or decomposer soil organisms; pathogenicity or decomposition role of certain microorganisms). Chapter 10 then introduces metagenomics and metatranscriptomics approaches, their advantages, but also the challenges and solutions to appropriately sampling, sequencing these complex DNA/RNA populations. Chapter 10 finally presents several strategies and software to analyze metagenomes/metatranscriptomes, and discusses their pros and cons.

Reprint of: Tree-tree interactions and crown complementarity: the role of functional diversity and branch traits for canopy packing

2021 ◽  
Author(s):  
Michaela Hildebrand ◽  
Maria D. Perles-Garcia ◽  
Matthias Kunz ◽  
Werner Härdtle ◽  
Goddert von Oheimb ◽  
...  
Keyword(s):  
Functional Diversity

scholarly journals Landscape resistance constrains hybridization across contact zones in a reproductively and morphologically polymorphic salamander

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillermo Velo-Antón ◽  
André Lourenço ◽  
Pedro Galán ◽  
Alfredo Nicieza ◽  
Pedro Tarroso
Keyword(s):  
Contact Zone ◽  
Environmental Heterogeneity ◽  
Evolutionary Dynamics ◽  
Morphological Differentiation ◽  
Phenotypic Traits ◽  
Hybrid Zones ◽  
Landscape Resistance ◽  
Phenotypic Differentiation ◽  
Contact Zones

AbstractExplicitly accounting for phenotypic differentiation together with environmental heterogeneity is crucial to understand the evolutionary dynamics in hybrid zones. Species showing intra-specific variation in phenotypic traits that meet across environmentally heterogeneous regions constitute excellent natural settings to study the role of phenotypic differentiation and environmental factors in shaping the spatial extent and patterns of admixture in hybrid zones. We studied three environmentally distinct contact zones where morphologically and reproductively divergent subspecies of Salamandra salamandra co-occur: the pueriparous S. s. bernardezi that is mostly parapatric to its three larviparous subspecies neighbours. We used a landscape genetics framework to: (i) characterise the spatial location and extent of each contact zone; (ii) assess patterns of introgression and hybridization between subspecies pairs; and (iii) examine the role of environmental heterogeneity in the evolutionary dynamics of hybrid zones. We found high levels of introgression between parity modes, and between distinct phenotypes, thus demonstrating the evolution to pueriparity alone or morphological differentiation do not lead to reproductive isolation between these highly divergent S. salamandra morphotypes. However, we detected substantial variation in patterns of hybridization across contact zones, being lower in the contact zone located on a topographically complex area. We highlight the importance of accounting for spatial environmental heterogeneity when studying evolutionary dynamics of hybrid zones.

scholarly journals Biological and extrinsic correlates of extinction risk in Chinese lizards

2021 ◽  
Author(s):  
Yuxi Zhong ◽  
Chuanwu Chen ◽  
Yanping Wang
Keyword(s):  
Body Size ◽  
Extinction Risk ◽  
Species Traits ◽  
Geographic Range ◽  
Range Size ◽  
Habitat Specialization ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Small Range ◽  
Extrinsic Factors

Abstract China is a country with one of the most species rich reptile faunas in the world. However, nearly a quarter of Chinese lizard species assessed by the China Biodiversity Red List are threatened. Nevertheless, to date, no study has explicitly examined the pattern and processes of extinction and threat in Chinese lizards. In this study, we conducted the first comparative phylogenetic analysis of extinction risk in Chinese lizards. We addressed the following three questions: 1) What is the pattern of extinction and threat in Chinese lizards? 2) Which species traits and extrinsic factors are related to their extinction risk? 3) How can we protect Chinese lizards based on our results? We collected data on ten species traits (body size, clutch size, geographic range size, activity time, reproductive mode, habitat specialization, habitat use, leg development, maximum elevation, and elevation range) and seven extrinsic factors (mean annual precipitation, mean annual temperature, mean annual solar insolation, normalized difference vegetation index (NDVI), human footprint, human population density, and human exploitation). After phylogenetic correction, these variables were used separately and in combination to assess their associations with extinction risk. We found that Chinese lizards with small geographic range, large body size, high habitat specialization, and living in high precipitation areas were vulnerable to extinction. Conservation priority should thus be given to species with the above extinction-prone traits so as to effectively protect Chinese lizards. Preventing future habitat destruction should also be a primary focus of management efforts because species with small range size and high habitat specialization are particularly vulnerable to habitat loss.

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