scholarly journals A Phylogenetic Analysis of Shape Covariance Structure in the Anthropoid Skull

2016 ◽  
Author(s):  
Guilherme Garcia ◽  
Felipe Bandoni de Oliveira ◽  
Gabriel Marroig
Keyword(s):  
Covariance Structure ◽  
Adaptive Landscape ◽  
Phenotypic Traits ◽  
Functional Relationships ◽  
Skull Development ◽  
Tissue Organization ◽  
Phylogenetic Framework ◽  
Anthropoid Primates ◽  
Mammalian Skull ◽  
The Stability

AbstractPhenotypic traits evolve in a coordinated manner due to developmental and functional interactions, mediated by the dynamics of natural selection; the dependence between traits arising from these three factors is captured by genetic (G) and phenotypic (P) covariance matrices. Mammalian skull development produces an intricate pattern of tissue organization and mutual signaling that integrates this structure, although the set of functions it performs is quite disparate. Therefore, the interplay between these interactions, and their relationships with the adaptive landscape may thus influence divergence in covariance structure among sister lineages. Here, we evaluate the stability of phenotypic covariance structure in skull size and shape along the diversification of Anthropoid Primates under a explicit phylogenetic framework. We estimate diversity in covariance structure, testing hypotheses concerning the phylogenetic distribution ofP-matrix variation and pinpoint which traits are associated with this variation. We find that most changes occurred in the basal split between Platyrrhini and Catarrhini, and that these changes occurred within both Orbital and Basicranial trait sets, while Oral, Nasal and Vault trait sets present stable associations along the Anthropoid phylogeny. Therefore, changes inP-matrix structure among Anthropoids are restricted to trait sets whose functional significance is associated with the accommodation of the two precursor tissues that compose the skull, while the stability in the remaining regions hints at the stability of the underlying functional relationships imposed by the adaptive landscape.

scholarly journals A Bayesian phylogenetic approach to estimating the stability of linguistic features and the genetic biasing of tone

2010 ◽  
Vol 278 (1704) ◽  
pp. 474-479 ◽  
Author(s):  
Dan Dediu
Keyword(s):  
Cultural Transmission ◽  
Linguistic Diversity ◽  
Large Set ◽  
Linguistic Features ◽  
Major Interest ◽  
Software Implementations ◽  
Phylogenetic Framework ◽  
Linguistic Tone ◽  
The Stability ◽  
Stable Characteristic

Language is a hallmark of our species and understanding linguistic diversity is an area of major interest. Genetic factors influencing the cultural transmission of language provide a powerful and elegant explanation for aspects of the present day linguistic diversity and a window into the emergence and evolution of language. In particular, it has recently been proposed that linguistic tone —the usage of voice pitch to convey lexical and grammatical meaning—is biased by two genes involved in brain growth and development, ASPM and Microcephalin . This hypothesis predicts that tone is a stable characteristic of language because of its ‘genetic anchoring’. The present paper tests this prediction using a Bayesian phylogenetic framework applied to a large set of linguistic features and language families, using multiple software implementations, data codings, stability estimations, linguistic classifications and outgroup choices. The results of these different methods and datasets show a large agreement, suggesting that this approach produces reliable estimates of the stability of linguistic data. Moreover, linguistic tone is found to be stable across methods and datasets, providing suggestive support for the hypothesis of genetic influences on its distribution.

A Statistical Test for the Stability of Covariance Structure

2013 ◽  
Vol 63 (2) ◽  
Author(s):  
Nur Syahidah Yusoff ◽  
Maman Abdurachman Djauhari
Keyword(s):  
Covariance Matrix ◽  
Complex Structure ◽  
Covariance Structure ◽  
Statistical Test ◽  
Dispersion Measure ◽  
Data Sets ◽  
Scalar Representation ◽  
Multivariate Dispersion ◽  
Sample Covariance ◽  
The Stability

The stability of covariance matrix is a major issue in multivariate analysis. As can be seen in the literature, the most popular and widely used tests are Box M-test and Jennrich J-test introduced by Box in 1949 and Jennrich in 1970, respectively. These tests involve determinant of sample covariance matrix as multivariate dispersion measure. Since it is only a scalar representation of a complex structure, it cannot represent the whole structure. On the other hand, they are quite cumbersome to compute when the data sets are of high dimension since they do not only involve the computation of determinant of covariance matrix but also the inversion of a matrix. This motivates us to propose a new statistical test which is computationally more efficient and, if it is used simultaneously with M-test or J-test, we will have a better understanding about the stability of covariance structure. An example will be presented to illustrate its advantage

Developmental evolution and the origins of phenotypic variation

2014 ◽  
Vol 5 (4) ◽  
pp. 343-352 ◽  
Author(s):  
Robert Lickliter
Keyword(s):  
Individual Development ◽  
Levels Of Analysis ◽  
Phenotypic Traits ◽  
Evolutionary Explanation ◽  
Social Environments ◽  
Individual Organism ◽  
Developmental Context ◽  
Developmental Evolution ◽  
The Stability ◽  
Conceptual Overview

AbstractBecause of the variability of relevant developmental resources across different environments, and because only a portion of the genome is expressed in any individual organism as a result of its specific developmental context and experience, what is actually realized during the course of individual development represents only one of many possibilities. One conclusion to be drawn from this insight is that the origin of phenotypic traits and their variation can be traced to the process of development. In this conceptual overview, I briefly explore how recent efforts to integrate genetic, epigenetic, and environmental levels of analysis through a developmental lens is advancing our understanding of the generation of the stability and variability of phenotypic outcomes observed within and across generations. A growing body of evidence indicates that phenotypes are the outcomes of the whole developmental system, comprised of the organism, with its particular genetic and cellular make-up in its specific physical, biological, and social environments. I conclude that the emergent products of development are epigenetic, not just genetic, and evolutionary explanation cannot be complete without a developmental mode of analysis.

scholarly journals A complex performance landscape for suction-feeding reveals constraints and adaptations in a population of reef damselfish

2017 ◽  
Author(s):  
Tal Keren ◽  
Moshe Kiflawi ◽  
Christopher H Martin ◽  
Victor China ◽  
Ofri Mann ◽  
...  
Keyword(s):  
Morphological Traits ◽  
Prey Capture ◽  
Mechanistic Model ◽  
Adaptive Landscape ◽  
Phenotypic Traits ◽  
Stabilizing Selection ◽  
Suction Feeding ◽  
Feeding Performance ◽  
Genetic Constraints ◽  
A Performance

AbstractThe ability to predict how multiple traits interact in determining performance is key to understanding the evolution of complex functional systems. Similar to Simpson’s adaptive landscape, which describes the fitness consequences of varying morphological traits, performance landscapes depict the performance consequences of varying morphological traits. Mapping the population’s location with respect to the topographic features of the landscape could inform us on the selective forces operating on the traits that underlie performance. Here, we used a mechanistic model derived from first principles of hydrodynamics to construct a hypothetical performance landscape for zooplankton prey capture using suction feeding. We then used the landscape to test whether a population of Chromis viridis, a coral reef zooplanktivore, is located on a performance peak or ridge based on measurements of kinematic variables recorded in-situ during undisturbed foraging. Observed trait combinations in the wild population closely matched regions of high feeding performance in the landscape, however the population was not located on a local performance peak. This sub-optimal performance was not due to constraints stemming from the observed trait correlations. The predominant directions of variation of the phenotypic traits was tangent to the ‘path of steepest ascent’ that points towards the local peak, indicating that the population does not reside on a “performance ridge”. Rather, our analysis suggests that feeding performance is constrained by stabilizing selection, possibly reflecting a balance between selection on feeding performance and mechanical or genetic constraints.

scholarly journals Phenotypic evolution is more constrained in simpler food webs

2019 ◽  
Author(s):  
Matthew A. Barbour ◽  
Christopher J. Greyson-Gaito ◽  
Arezoo Sootodeh ◽  
Brendan Locke ◽  
Jordi Bascompte
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Ecological Networks ◽  
Community Context ◽  
Relative Fitness ◽  
Adaptive Landscape ◽  
Phenotypic Traits ◽  
Phenotypic Evolution ◽  
Adaptive Landscapes ◽  
Food Web Complexity

AbstractGlobal change is simplifying the structure of ecological networks; however, we are currently in a poor position to predict how these simplified communities will affect the evolutionary potential of remaining populations. Theory on adaptive landscapes provides a framework for predicting how selection constrains phenotypic evolution, but often treats the community context of evolving populations as a “black box”. Here, we integrate ecological networks and adaptive landscapes to examine how changes in food-web complexity shape evolutionary constraints. We conducted a field experiment that manipulated the diversity of insect parasitoids (food-web complexity) that were able to impose selection on an insect herbivore. We then measured herbivore survival as a function of three key phenotypic traits. We found that more traits were under selection in simpler vs. more complex food webs. The adaptive landscape was more neutral in complex food webs because different parasitoid species impose different selection pressures, minimizing relative fitness differences among phenotypes. Our results suggest that phenotypic evolution becomes more constrained in simplified food webs. This indicates that the simplification of ecological communities may constrain the adaptive potential of remaining populations to future environmental change. “What escapes the eye, however, is a much more insidious kind of extinction: the extinction of ecological interactions.” Janzen (1974)

scholarly journals TO THE QUESTION OF LEGAL CONDITIONS PLACE IN THE SYSTEM OF LEGAL FACTS

2020 ◽  
Vol 24 (1) ◽  
pp. 25-45
Author(s):  
Elena Yu. Tsukanova
Keyword(s):  
Social Relations ◽  
Legal Status ◽  
Real Life ◽  
Social Situation ◽  
Research Process ◽  
Physical Reality ◽  
Specific Situation ◽  
Functional Relationships ◽  
Long Time ◽  
The Stability

The article is devoted to the problems of the formation and positioning of the legal status category in legal science. The relevance of this phenomenon in law is due to the lack of its unambiguous perception, which does not allow to fully determine its place and purpose in the theory of legal facts. The purpose of this article is to determine the philosophical and dialectical basis for the inclusion of this concept in the scientific categorical apparatus of jurisprudence. This will allow with sufficient certainty to identify its main characteristics, place in the classification of legal facts, as well as functional relationships with other elements of the legal-factual system. The methodological basis of the article was made by modern achievements of the theory of knowledge. In the research process, theoretical, general philosophical (dialectic, analysis, synthesis, deduction, systemic method,), as well as traditional legal methods (formal-logical, normative-dogmatic and others) were used. In the process of research, based on the ratio of the dialectic categories of movement and rest, the conclusion was formulated that physical reality is a series of static and dynamic situations. Static circumstances characterizing the stability and sustainability of a phenomenon or object are states. The variability of social relations is due to dynamic circumstances, which serve as the basis for a change of state. This approach allowed us to formulate the conclusion that states are natural elements of physical being. They can be qualified as real life circumstances and, provided that the rule of law associates a certain legal consequence with them, they should be recognized as legal facts. An analysis of the place of the state in the system of legal facts allowed us to conclude that the length of time cannot be considered as qualifying it. States are characterized by length in time, and it is precisely the “fluidity” of the phenomenon that matters for a specific situation. When a certain process takes a long time, but as applied to the social situation, it matters as a single whole, then it should be considered as an instantaneous fact.

scholarly journals Australian black field crickets show changes in neural gene expression associated with socially-induced morphological, life-history, and behavioral plasticity

2016 ◽  
Author(s):  
Michael Kasumovic ◽  
Zhiliang Chen ◽  
Marc R Wilkins
Keyword(s):  
Gene Expression ◽  
Life History ◽  
Developmental Plasticity ◽  
Developmental Trajectories ◽  
Field Cricket ◽  
Phenotypic Traits ◽  
Functional Relationships ◽  
Teleogryllus Commodus ◽  
Black Field ◽  
Insight Into

Background: Ecological and evolutionary model organisms have provided extensive insight into the ecological triggers, adaptive benefits, and evolution of life-history driven developmental plasticity. Despite this, we still have a poor understanding of the underlying genetic changes that occur during shifts towards different developmental trajectories. The goal of this study is to determine whether we can identify underlying gene expression patterns that can describe the different life-history trajectories individuals follow in response to social cues of competition. To do this, we use the Australian black field cricket (Teleogryllus commodus), a species with sex-specific developmental trajectories moderated by the density and quality of calls heard during immaturity. In this study, we manipulated the social information males and females could hear by rearing individuals in either calling or silent treatments. We next used RNA-Seq to develop a reference transcriptome to study changes in brain gene expression at two points prior to sexual maturation. Results: We show accelerated development in both sexes when exposed to calling; changes were also seen in growth, lifespan, and reproductive effort. Functional relationships between genes and phenotypes were apparent from ontological enrichment analysis. We demonstrate that increased phenotypic expression was often associated with the expression of a greater number of genes with similar effect, thus providing a suite of candidate genes for future research in this and other invertebrate organisms. Conclusions: Our results provide interesting insight into the genomic underpinnings of developmental plasticity. We highlight the relationship between genes of known effect and behavioral and phenotypic traits that are under strong sexual selection in Teleogryllus commodus. We also demonstrate the variation in suites of genes associated with different developmental trajectories. Our results provide the opportunity for a genomic exploration of other evolutionary theories such as condition dependence and sexual conflict.

scholarly journals EPH/EPHRIN regulates cellular organization by actomyosin contractility effects on cell contacts

2021 ◽  
Vol 220 (6) ◽  
Author(s):  
Abigail A. Kindberg ◽  
Vasudha Srivastava ◽  
Jonathon M. Muncie ◽  
Valerie M. Weaver ◽  
Zev J. Gartner ◽  
...  
Keyword(s):  
Mouse Genetics ◽  
Self Organization ◽  
Cortical Tension ◽  
Force Microscopy ◽  
Tissue Organization ◽  
Angle Measurements ◽  
Actomyosin Contractility ◽  
Directed Cell Migration ◽  
The Stability ◽  
Cell Segregation

EPH/EPHRIN signaling is essential to many aspects of tissue self-organization and morphogenesis, but little is known about how EPH/EPHRIN signaling regulates cell mechanics during these processes. Here, we use a series of approaches to examine how EPH/EPHRIN signaling drives cellular self-organization. Contact angle measurements reveal that EPH/EPHRIN signaling decreases the stability of heterotypic cell:cell contacts through increased cortical actomyosin contractility. We find that EPH/EPHRIN-driven cell segregation depends on actomyosin contractility but occurs independently of directed cell migration and without changes in cell adhesion. Atomic force microscopy and live cell imaging of myosin localization support that EPH/EPHRIN signaling results in increased cortical tension. Interestingly, actomyosin contractility also nonautonomously drives increased EPHB2:EPHB2 homotypic contacts. Finally, we demonstrate that changes in tissue organization are driven by minimization of heterotypic contacts through actomyosin contractility in cell aggregates and by mouse genetics experiments. These data elucidate the biomechanical mechanisms driving EPH/EPHRIN-based cell segregation wherein differences in interfacial tension, regulated by actomyosin contractility, govern cellular self-organization.

scholarly journals Effects of emotions and brand personality on consumer commitment, via the mediating effects of brand trust and attachment

2020 ◽  
Vol 35 (1) ◽  
pp. 84-110
Author(s):  
Rita Valette-Florence ◽  
Pierre Valette-Florence
Keyword(s):  
Brand Personality ◽  
Covariance Structure ◽  
Statistical Processing ◽  
Covariance Structure Analysis ◽  
Mediating Effects ◽  
Mediating Role ◽  
Brand Relationship ◽  
Consumer Commitment ◽  
The Stability ◽  
The Impact

Based on the concepts of brand personality and emotion, this article focuses on their respective impacts on the main variables of brand relationship, trust, attachment and overall commitment with the brand. Based on a large panel of consumers, the statistical processing was conducted according to a covariance structure analysis (CSA) or a partial least squares (PLS) approach, with measurement error carefully taken into account. The corresponding model confirms the impact of brand emotion and personality on consumer commitment through the mediating effects of trust and brand attachment. More precisely, the results show the total mediating role-played by trust in the impact of a brand’s personality on commitment. Finally, the analysis highlights the stability of the results on the six brands tested in this research. However, it also illustrates significant differences between brands depending on their evaluative or hedonic nature.

scholarly journals Macroevolutionary patterns of body plan canalization in euarthropods

Paleobiology ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 569-593
Author(s):  
Cédric Aria
Keyword(s):  
Regulatory Networks ◽  
Morphological Evolution ◽  
Genetic Regulatory Networks ◽  
Cambrian Explosion ◽  
Adaptive Landscape ◽  
Rates Of Evolution ◽  
History Of ◽  
Optimum Type ◽  
Phylogenetic Framework ◽  
Insight Into

AbstractReconstructing patterns of macroevolution has become a central endeavor in paleobiology, because it offers insight into evolutionary models shaping the history of life. As the most diverse and abundant animals since the Cambrian period, arthropods provide copious data to elucidate the emergence of body plans in metazoan lineages. However, information provided by fossils on the tempo and mode of this phenomenon has lacked a recent synthesis. Here, I investigate macroevolutionary patterns of morphological evolution in Euarthropoda using a combined extinct and extant dataset optimized for multivariate analyses. Overall ordination patterns between the main morphogroups are consistent with another, independently coded, extant-only dataset providing molecular and morphological rates of evolution. Based on a “deep split” phylogenetic framework, total-group Mandibulata and Arachnomorpha emerge as directional morphoanatomical lineages, with basal fossil morphogroups showing heterogeneously spread-out occupations of the morphospace. In addition to a more homogeneous morphological variation, new morphogroups arose by successive reductions of translation distances; this pattern was interrupted only by terrestrialization events and the origin of pancrustaceans. A displaced optimum type of model is proposed to explain the fast assembly of canalized body plans during the Cambrian, with basal fossil morphogroups fitting intermediate fitness peaks in a moving adaptive landscape. Given time constraints imposed by the paleontological evidence, and owing to the interplay between canalization and modularity, as well as a decoupling between molecular and morphological rates, the rise of euarthropods would support the view that the swiftness of the Cambrian explosion was mostly associated with the buildup of genetic regulatory networks.

Sign in / Sign up

Export Citation Format

Share Document