scholarly journals How Facilitation May Interfere with Ecological Speciation

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
P. Liancourt ◽  
P. Choler ◽  
N. Gross ◽  
X. Thibert-Plante ◽  
K. Tielbörger
Keyword(s):  
Ecological Speciation ◽  
Theoretical Research ◽  
Secondary Contact ◽  
Positive Interactions ◽  
Evolutionary Diversification ◽  
Incipient Species ◽  
Modelling Framework ◽  
Vast Literature ◽  
Marginal Habitats

Compared to the vast literature linking competitive interactions and speciation, attempts to understand the role of facilitation for evolutionary diversification remain scarce. Yet, community ecologists now recognize the importance of positive interactions within plant communities. Here, we examine how facilitation may interfere with the mechanisms of ecological speciation. We argue that facilitation is likely to (1) maintain gene flow among incipient species by enabling cooccurrence of adapted and maladapted forms in marginal habitats and (2) increase fitness of introgressed forms and limit reinforcement in secondary contact zones. Alternatively, we present how facilitation may favour colonization of marginal habitats and thus enhance local adaptation and ecological speciation. Therefore, facilitation may impede or pave the way for ecological speciation. Using a simple spatially and genetically explicit modelling framework, we illustrate and propose some first testable ideas about how, when, and where facilitation may act as a cohesive force for ecological speciation. These hypotheses and the modelling framework proposed should stimulate further empirical and theoretical research examining the role of both competitive and positive interactions in the formation of incipient species.

scholarly journals A genetic switch for male UV-iridescence in an incipient species pair of sulphur butterflies

2021 ◽  
Author(s):  
Vincent Ficarrotta ◽  
Joseph J Hanly ◽  
Ling S Loh ◽  
Caroline M Francescutti ◽  
Anna Ren ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Secondary Contact ◽  
Sexual Signals ◽  
Genetic Switch ◽  
Knock Out ◽  
Incipient Species ◽  
Courtship Signal ◽  
Species Formation ◽  
Genomic Landscape

Mating cues evolve rapidly and can contribute to species formation and maintenance. However, little is known about how sexual signals diverge and how this variation integrates with other barrier loci to shape the genomic landscape of reproductive isolation. Here, we elucidate the genetic basis of UV iridescence, a courtship signal that differentiates the males of Colias eurytheme butterflies from a sister species, allowing females to avoid costly heterospecific matings. Anthropogenic range expansion of the two incipient species established a large zone of secondary contact across the eastern US with strong signatures of genomic admixtures spanning all autosomes. In contrast, Z chromosomes are highly differentiated between the two species, supporting a disproportionate role of sex chromosomes in speciation known as the large-X effect. Within this chromosome-wide reproductive barrier, cis-regulatory variation of bric a brac (bab) drives the male UV-iridescence polymorphism between the two species. Bab is expressed in all non-UV scales, and butterflies of either species or sex acquire widespread ectopic iridescence following its CRISPR knock-out, demonstrating that Bab functions as a suppressor of UV-scale differentiation that potentiates mating cue divergence. These results provide new insights into the diversification of sexual signals and the species concept.

scholarly journals A genetic switch for male UV iridescence in an incipient species pair of sulphur butterflies

2022 ◽  
Vol 119 (3) ◽  
pp. e2109255118
Author(s):  
Vincent Ficarrotta ◽  
Joseph J. Hanly ◽  
Ling S. Loh ◽  
Caroline M. Francescutti ◽  
Anna Ren ◽  
...  
Keyword(s):  
Linkage Mapping ◽  
Secondary Contact ◽  
Eastern United States ◽  
Genetic Switch ◽  
Incipient Species ◽  
Intermediate Phases ◽  
Courtship Signal ◽  
Species Formation ◽  
Genomic Landscape

Mating cues evolve rapidly and can contribute to species formation and maintenance. However, little is known about how sexual signals diverge and how this variation integrates with other barrier loci to shape the genomic landscape of reproductive isolation. Here, we elucidate the genetic basis of ultraviolet (UV) iridescence, a courtship signal that differentiates the males of Colias eurytheme butterflies from a sister species, allowing females to avoid costly heterospecific matings. Anthropogenic range expansion of the two incipient species established a large zone of secondary contact across the eastern United States with strong signatures of genomic admixtures spanning all autosomes. In contrast, Z chromosomes are highly differentiated between the two species, supporting a disproportionate role of sex chromosomes in speciation known as the large-X (or large-Z) effect. Within this chromosome-wide reproductive barrier, linkage mapping indicates that cis-regulatory variation of bric a brac (bab) underlies the male UV-iridescence polymorphism between the two species. Bab is expressed in all non-UV scales, and butterflies of either species or sex acquire widespread ectopic iridescence following its CRISPR knockout, demonstrating that Bab functions as a suppressor of UV-scale differentiation that potentiates mating cue divergence. These results highlight how a genetic switch can regulate a premating signal and integrate with other reproductive barriers during intermediate phases of speciation.

scholarly journals The role of habitat configuration in shaping animal population processes: a framework to generate quantitative predictions

Oecologia ◽  
2021 ◽  
Author(s):  
Peng He ◽  
Pierre-Olivier Montiglio ◽  
Marius Somveille ◽  
Mauricio Cantor ◽  
Damien R. Farine
Keyword(s):  
Population Level ◽  
R Package ◽  
Habitat Configuration ◽  
Modelling Framework ◽  
Alternative Habitat ◽  
Animal Populations ◽  
Research Questions ◽  
Habitat Networks ◽  
Animal Habitat

AbstractBy shaping where individuals move, habitat configuration can fundamentally structure animal populations. Yet, we currently lack a framework for generating quantitative predictions about the role of habitat configuration in modulating population outcomes. To address this gap, we propose a modelling framework inspired by studies using networks to characterize habitat connectivity. We first define animal habitat networks, explain how they can integrate information about the different configurational features of animal habitats, and highlight the need for a bottom–up generative model that can depict realistic variations in habitat potential connectivity. Second, we describe a model for simulating animal habitat networks (available in the R package AnimalHabitatNetwork), and demonstrate its ability to generate alternative habitat configurations based on empirical data, which forms the basis for exploring the consequences of alternative habitat structures. Finally, we lay out three key research questions and demonstrate how our framework can address them. By simulating the spread of a pathogen within a population, we show how transmission properties can be impacted by both local potential connectivity and landscape-level characteristics of habitats. Our study highlights the importance of considering the underlying habitat configuration in studies linking social structure with population-level outcomes.

Exclusion of the Role of Secondary Contact in an Allele Frequency Cline in the Mussel Mutilus edulis

Evolution ◽  
1985 ◽  
Vol 39 (2) ◽  
pp. 432 ◽  
Author(s):  
Thomas J. Hilbish ◽  
Richard K. Koehn
Keyword(s):  
Allele Frequency ◽  
Secondary Contact

scholarly journals Use of flexible work practices and employee outcomes: the role of work–life balance and employee age

2021 ◽  
pp. 1-21
Author(s):  
Tahrima Ferdous ◽  
Muhammad Ali ◽  
Erica French
Keyword(s):  
Turnover Intentions ◽  
Theoretical Research ◽  
Work Practices ◽  
Flexible Work ◽  
Employee Outcomes ◽  
Life Balance ◽  
Flexible Work Practices ◽  
The Relationship ◽  
Employee Age

Abstract Flexible work practices (FWPs) give employees some control over when and where they work. Using boundary theory and role balance theory, this study proposes and tests a mediation model focusing on how the relationships between FWPs usage and employee outcomes (i.e., wellbeing and turnover intention) are mediated by work−life balance (WLB). It also tests the moderating role of employee age on the relationship between WLB and employee outcomes using socioemotional selectivity theory. The model was tested using survey data from 293 employees of an Australian for-profit organization. The findings indicate that FWPs usage is positively associated with WLB, WLB is positively associated with wellbeing and negatively with turnover intentions, and WLB partially mediates the relationships between FWPs usage and employee outcomes. The results provide partial support that employee age moderates the relationship between WLB and turnover intentions. Theoretical, research and practical contributions are discussed.

scholarly journals The challenges of adopting BIM for setting and infrastructure management of University of Minho

2018 ◽  
Vol 48 ◽  
pp. 02002 ◽  
Author(s):  
Paulo J. S. Cruz ◽  
Miguel Azenha
Keyword(s):  
Shared Knowledge ◽  
Facilities Management ◽  
Infrastructure Management ◽  
Knowledge Resources ◽  
Global Challenge ◽  
Modelling Framework ◽  
Building Information ◽  
Relevant Role ◽  
The University

The University of Minho (UMinho) is aware of the relevant role of higher education institutions in the global challenge of sustainability. The integration of sustainability values into its strategy encompasses all the fields of its activity. Taking into account the growing importance of shared knowledge resources as a reliable basis for decisions during infrastructures life cycle, the UMinho is currently undergoing an important process of implementing a ‘Building Information Modelling’ framework (BIM). This paper briefly describes the implementation steps that are current towards such a goal, in particular in terms of facilities management aspects.

scholarly journals Temporal fine structure influences voicing confusions for consonant identification in multi-talker babble

2021 ◽  
Author(s):  
Vibha Viswanathan ◽  
Barbara G. Shinn-Cunningham ◽  
Michael G. Heinz
Keyword(s):  
Fine Structure ◽  
Cochlear Implants ◽  
Background Noise ◽  
Speech Intelligibility ◽  
Temporal Fine Structure ◽  
Vast Literature ◽  
Listening Environments ◽  
Intact Condition ◽  
Speech Content

To understand the mechanisms of speech perception in everyday listening environments, it is important to elucidate the relative contributions of different acoustics cues in transmitting phonetic content. Previous studies suggest that the energy envelopes of speech convey most speech content, while the temporal fine structure (TFS) can aid in segregating target speech from background noise. Despite the vast literature on TFS and speech intelligibility, the role of TFS in conveying additional speech content over what envelopes convey in complex acoustic scenes is poorly understood. The present study addresses this question using online psychophysical experiments to measure consonant identification in multi-talker babble for intelligibility-matched intact and 64-channel envelope-vocoded stimuli. Consonant confusion patterns revealed that listeners had a greater tendency in the vocoded (versus intact) condition to be biased towards reporting that they heard an unvoiced consonant, despite envelope and place cues being largely preserved. This result was replicated when babble instances were varied across independent experiments, suggesting that TFS conveys important voicing cues over what envelopes convey in multi-talker babble, a masker that is ubiquitous in everyday environments. This finding has implications for assistive listening devices that do not currently provide TFS cues, such as cochlear implants.

scholarly journals The Role of Perforin

2021 ◽  
Vol 5 (1) ◽  
pp. 75-82
Author(s):  
Davorka Švegar
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Theoretical Research ◽  
Target Cells ◽  
Colon Cancer Cell Lines ◽  
Literature Reviews ◽  
Ebsco Host ◽  
Ht 29

Some literature reviews have been carried out about the role of perforin in medicine. The first step involved a systematic search to identify relevant studies published between 2001 and 2019 in the following electronic databases - EBSCO host, Scopus, Science Direct, Web of Science, and Elsevier. By analyzing the available literature, it can be concluded that perforin plays an important role in cytoxical activity of natural killer cells (NK) and CD8+ T cell. NK and CD8+use the same mechanism for destroying target cells. This article cites the disease hemophagocytic lymphohistiocytosis (HLH) which is characterized by heavy abnormalities in the immune system. The point is that this disease is caused by perforin gene mutation. The key is the application of properly sensitized dendritic cells (DCs) because they are effective in immunotherapy against cancer. It may be effective in γ-irradiated colon cancer cell lines HT-29. Growth hormone inhibiting hormone (GIH) induces maturation and activation of DCs. In that way, GIH-Dcs shows increased cytotoxic activity and higher perforin and granzyme expression. So, this means that theoretical research has shown that efficient activity against cancer is induced when DCs are sensitized with γ-irradiated cancer cells. In that way, through a direct increase of cytotoxicity and indirect T cell activation,there can beanti-tumor activity. It is suggested to continue scientific research about the role of perforin in the future.

scholarly journals Archives, libraries and museums in the Nordic model of the public sphere

2018 ◽  
Vol 74 (1) ◽  
pp. 187-194 ◽  
Author(s):  
Håkon Larsen
Keyword(s):  
Public Sphere ◽  
Information Science ◽  
Theoretical Research ◽  
Library And Information Science ◽  
Archival Science ◽  
Content Type ◽  
Public Spheres ◽  
The Public ◽  
The Public Sphere

Purpose The purpose of this paper is to discuss the role of ALM organizations within a Nordic model of the public sphere. Design/methodology/approach This is a conceptual paper discussing the role of archives, libraries and museums in light of a societal model of the Nordic public sphere. Throughout the discussions, the author draw on empirical and theoretical research from sociology, political science, media studies, cultural policy studies, archival science, museology, and library and information science to help advance our understanding of these organizations in a wider societal context. Findings The paper shows that ALM organizations play an important role for the infrastructure of a civil public sphere. Seen as a cluster, these organizations are providers of information that can be employed in deliberative activities in mediated public spheres, as well as training arenas for citizens to use prior to entering such spheres. Furthermore, ALM organizations are themselves public spheres, as they can serve specific communities and help create and maintain identities, and solidarities, all of which are important parts of a civil public sphere. Research limitations/implications Future research should investigate whether these roles are an important part of ALM organizations contribution to public spheres in other regions of the world. Originality/value Through introducing a theoretical model developed within sociology and connecting it to ongoing research in archival science, museology, and library and information science, the author connects the societal role of archives, libraries, and museums to broader discussions within the social sciences.

Emergence

2015 ◽  
Author(s):  
Paul Humphreys
Keyword(s):  
Philosophy Of Mind ◽  
Downward Causation ◽  
Comprehensive Account ◽  
Weak Emergence ◽  
Vast Literature ◽  
Ontological Emergence

This chapter surveys contemporary theories of emergence and argues that no comprehensive account currently exists. It separates ontological emergence, epistemological emergence, and conceptual emergence, as well as discussing synchronic and diachronic forms of each. It further argues that the emphasis on emergence in the philosophy of mind has led to a neglect of diachronic emergence and that the contrast between reduction and emergence has reinforced that bias. Downward causation is assessed as being less of a problem for ontological emergence than usually supposed; recent presentations of weak emergence and of undecidability results are discussed. Universality and nonlinearity as sources of emergence are examined, as is the role of holism in emergence and skepticism about the existence of emergence. Finally, a tentative suggestion is made about how to bring order to this vast literature.

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