scholarly journals Habitat patchiness drives spatial structure in morphological trait variation and co-variation in spotted salamanders (Ambystoma maculatum)

2020 ◽  
Author(s):  
Elizabeth T. Green ◽  
Anthony I. Dell ◽  
John A. Crawford ◽  
Elizabeth G. Biro ◽  
David R. Daversa
Keyword(s):  
Spatial Structure ◽  
Species Interactions ◽  
Preliminary Evidence ◽  
The Body ◽  
Ambystoma Maculatum ◽  
Strongly Correlated ◽  
Trait Variation ◽  
Intraspecific Trait Variation ◽  
Spatial Differences ◽  
Length Analysis

AbstractThe influence of intraspecific trait variation in species interactions makes trait-based approaches critical to understanding eco-evolutionary processes. Given that species occupy habitats that are patchily distributed in space, advancement in trait-based ecology hinges on understanding how trait variation is spatially structured across the landscape. We sampled larval spotted salamanders (Ambystoma maculatum) across spatially discrete ponds to quantify spatial structure in morphology. Spatial structure explained 7-35% of total observed variation in the length and shape of salamander larvae, depending on the body segment measured (i.e., head, body, tail). Salamander tail morphology was more variable and exhibited more spatial structure than head or body morphology. Salamander mass was also highly variable, and was strongly correlated with total length. Analysis of allometry revealed that the slopes of mass-length relationships were similar across space, but the intercepts differed spatially. Preliminary evidence hints that newly constructed ponds are drivers of spatial differences in allometric intercepts. Pond construction may therefore bolster diversity in trait co-variation, and in so doing instil more adaptive potential of salamanders under current and future environmental change.

scholarly journals Evidence that Intraspecific Trait Variation among Nasal Bacteria Shapes the Distribution of Staphylococcus aureus

2014 ◽  
Vol 82 (9) ◽  
pp. 3811-3815 ◽  
Author(s):  
Ben Libberton ◽  
Rosanna E. Coates ◽  
Michael A. Brockhurst ◽  
Malcolm J. Horsburgh
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Inhibition ◽  
Intraspecific Variation ◽  
Species Interactions ◽  
Bacterial Flora ◽  
Nasal Carriage ◽  
Trait Variation ◽  
Ecological Processes ◽  
Content Type ◽  
Intraspecific Trait Variation

ABSTRACTNasal carriage ofStaphylococcus aureusis a risk factor for infection, yet the bacterial determinants required for carriage are poorly defined. Interactions betweenS. aureusand other members of the bacterial flora may determine colonization and have been inferred in previous studies by using correlated species distributions. However, traits mediating species interactions are often polymorphic, suggesting that understanding how interactions structure communities requires a trait-based approach. We characterizedS. aureusgrowth inhibition by the culturable bacterial aerobe consortia of 60 nasal microbiomes, and this revealed intraspecific variation in growth inhibition and that inhibitory isolates clustered within communities that were culture negative forS. aureus. Across microbiomes, the cumulative community-level growth inhibition was negatively associated withS. aureusincidence. To fully understand the ecological processes structuring microbiomes, it will be crucial to account for intraspecific variation in the traits that mediate species interactions.

scholarly journals Intraspecific trait variation and reversals of trait strategies across key climate gradients in native Hawaiian plants and non-native invaders

2020 ◽  
Author(s):  
Andrea C Westerband ◽  
Tiffany M Knight ◽  
Kasey E Barton
Keyword(s):  
Species Interactions ◽  
Regional Scale ◽  
Leaf Traits ◽  
Data Sets ◽  
Native Plant ◽  
Trait Variation ◽  
Native Plant Species ◽  
Climate Gradients ◽  
Intraspecific Trait Variation ◽  
Sources Of Variation

Abstract Background and Aims Displacement of native plant species by non-native invaders may result from differences in their carbon economy, yet little is known regarding how variation in leaf traits influences native–invader dynamics across climate gradients. In Hawaii, one of the most heavily invaded biodiversity hotspots in the world, strong spatial variation in climate results from the complex topography, which underlies variation in traits that probably drives shifts in species interactions. Methods Using one of the most comprehensive trait data sets for Hawaii to date (91 species and four islands), we determined the extent and sources of variation (climate, species and species origin) in leaf traits, and used mixed models to examine differences between natives and non-native invasives. Key Results We detected significant differences in trait means, such that invasives were more resource acquisitive than natives over most of the climate gradients. However, we also detected trait convergence and a rank reversal (natives more resource acquisitive than invasives) in a sub-set of conditions. There was significant intraspecific trait variation (ITV) in leaf traits of natives and invasives, although invasives expressed significantly greater ITV than natives in water loss and photosynthesis. Species accounted for more trait variation than did climate for invasives, while the reverse was true for natives. Incorporating this climate-driven trait variation significantly improved the fit of models that compared natives and invasives. Lastly, in invasives, ITV was most strongly explained by spatial heterogeneity in moisture, whereas solar energy explains more ITV in natives. Conclusions Our results indicate that trait expression and ITV vary significantly between natives and invasives, and that this is mediated by climate. These findings suggest that although natives and invasives are functionally similar at the regional scale, invader success at local scales is contingent on climate.

scholarly journals Ecological consequences of intraspecific variation in coevolutionary systems

2020 ◽  
Author(s):  
Athmanathan Senthilnathan ◽  
Sergey Gavrilets
Keyword(s):  
Intraspecific Variation ◽  
Species Interactions ◽  
Interspecific Interaction ◽  
Stabilizing Selection ◽  
Trait Variation ◽  
Ecological Consequences ◽  
Intraspecific Trait Variation ◽  
Analytical Approximations ◽  
Invasion Analysis ◽  
The Difference

AbstractThe patterns and outcomes of coevolution are expected to depend on intraspecific trait variation. Various evolutionary factors can change this variation in time. As a result, modeling coevolutionary processes solely in terms of mean trait values may not be sufficient; one may need to study the dynamics of the whole trait distribution. Here, we develop a theoretical framework for studying the effects of evolving intraspecific variation in two-species coevolutionary systems. In particular, we build and study mathematical models of competition, exploiter-victim interactions, and mutualism in which the strength of within- and between-species interactions depends on the difference in continuously varying traits. We use analytical approximations based on the invasion analysis and supplement it with a numerical method. We find that intraspecific variation can be maintained if stabilizing selection is weak in at least one species. When intraspecific variation is maintained, stable coexistence is promoted by small ranges of interspecific interaction in two-species competition and mutualism, and large ranges in exploiter-victim interactions. We show that trait distributions can become multimodal. Our approach and results contribute to the understanding of the ecological consequences of intraspecific variation in coevolutionary systems by exploring its effects on population densities and trait distributions.

scholarly journals Intraspecific trait variation alters the outcome of competition in freshwater ciliates

2021 ◽  
Author(s):  
Sabine Flöder ◽  
Joanne Yong ◽  
Toni Klauschies ◽  
Ursula Gaedke ◽  
Tobias Poprick ◽  
...  
Keyword(s):  
Trait Variation ◽  
Intraspecific Trait Variation ◽  
Freshwater Ciliates

Association between muscle strength and risk factors for metabolic syndrome in children and adolescents: a systematic review

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tiago R. de Lima ◽  
Priscila C. Martins ◽  
Giuseppe L. Torre ◽  
Alice Mannocci ◽  
Kelly S. Silva ◽  
...  
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Metabolic Syndrome ◽  
Muscle Strength ◽  
Children And Adolescents ◽  
Lower Risk ◽  
Preliminary Evidence ◽  
Risk Of Bias ◽  
The Body ◽  
Reference List

AbstractThe aim of this systematic review was to identify and summarize evidence for the association between muscle strength (MS) and metabolic syndrome (MetS), and MS and combinations of risk factors for MetS in children and adolescents. Five databases (Medline/PubMed, EBSCO, Scielo, Scopus, and Web of Knowledge) were searched up to November 2019 with complementary reference list searches. Inclusion criteria were studies that investigated the relationship between MS and MetS or MS and combinations of risk factors for MetS in children and adolescents (≤19 years of age). Risk of bias was assessed using standard procedures. From the total of 15,599 articles initially identified, 13 articles were included, representing 11,641 children and adolescents. Higher MS values were associated with lower risk for MetS or combinations of risk factors for MetS (n=11/13 studies). Of the total of included studies, about 23.1% (03/13) were longitudinal and all included studies were classified as having a moderate risk of bias. This review provides preliminary evidence for a beneficial relationship between MS and MetS among children and adolescents. Additionally, although the body of evidence points to the beneficial relationship between higher MS and lower risk for combination of factors for MetS in children and adolescents, this relationship is inconclusive.

scholarly journals Intraspecific trait variation drives grassland species richness and productivity under changing precipitation

Ecosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Meifeng Deng ◽  
Weixing Liu ◽  
Ping Li ◽  
Lin Jiang ◽  
Shaopeng Li ◽  
...  
Keyword(s):  
Species Richness ◽  
Trait Variation ◽  
Grassland Species ◽  
Intraspecific Trait Variation

scholarly journals Intraspecific trait variation across scales: implications for understanding global change responses

2015 ◽  
Vol 22 (1) ◽  
pp. 137-150 ◽  
Author(s):  
Emily V. Moran ◽  
Florian Hartig ◽  
David M. Bell
Keyword(s):  
Global Change ◽  
Trait Variation ◽  
Intraspecific Trait Variation

scholarly journals Predicting intraspecific trait variation among California's grasses

2021 ◽  
Author(s):  
Brody Sandel ◽  
Claire Pavelka ◽  
Thomas Hayashi ◽  
Lachlan Charles ◽  
Jennifer Funk ◽  
...  
Keyword(s):  
Trait Variation ◽  
Intraspecific Trait Variation

scholarly journals Audit Fee Research on Issues Related to Ethics

2017 ◽  
Vol 11 (2) ◽  
pp. A1-A22 ◽  
Author(s):  
David C. Hay
Keyword(s):  
Audit Quality ◽  
Ethical Issues ◽  
Audit Fees ◽  
Preliminary Evidence ◽  
The Body ◽  
International Ethics ◽  
Ethical Problems ◽  
Audit Fee ◽  
Risk Areas ◽  
Non Audit Services

SUMMARY Audit fees are related to important ethical issues for auditors. There has been increasing research on audit fees recently, including research on potential ethical risks regarding audit fees, which helps to illuminate some of these professional issues. The International Ethics Standards Board for Accountants (IESBA) is very interested in this area and asked me to prepare a paper reviewing the relevant research. This summary reviews research that became available from 2006 to 2016 on four issues related to audit fees—fee level, dependence, non-audit fees, and firms that have a significant non-audit services business. Examining the research shows consistent evidence about two issues, namely that audit fees for new engagements are lower and that non-audit services affect independence in appearance. There are two further issues about which there is some concern. First, there are occasional studies reporting evidence that non-audit services provided by an auditor are associated with a loss of independence indicated by lower audit quality, even though most research does not support this conclusion. Second, there has been recent concern about growth in non-audit services to non-audit clients and there is some preliminary evidence that audit quality is lower in firms that have more extensive non-audit businesses. In general, although audit fee research does not convey a message that there are widespread ethical problems, the body of research shows that there are some risk areas.

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