scholarly journals Use of Genomic Resources to Assess Adaptive Divergence and Introgression in Oaks

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 690
Author(s):  
Desanka Lazic ◽  
Andrew L. Hipp ◽  
John E. Carlson ◽  
Oliver Gailing
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Model Organisms ◽  
Future Research ◽  
Adaptive Divergence ◽  
Natural Habitats ◽  
Adaptive Introgression ◽  
The Face ◽  
Species Integrity

Adaptive divergence is widely accepted as a contributor to speciation and the maintenance of species integrity. However, the mechanisms leading to reproductive isolation, the genes involved in adaptive divergence, and the traits that shape the adaptation of wild species to changes in climate are still largely unknown. In studying the role of ecological interactions and environment-driven selection, trees have emerged as potential model organisms because of their longevity and large genetic diversity, especially in natural habitats. Due to recurrent gene flow among species with different ecological preferences, oaks arose as early as the 1970s as a model for understanding how speciation can occur in the face of interspecific gene flow, and what we mean by “species” when geographically and genomically heterogeneous introgression seems to undermine species’ genetic coherence. In this review, we provide an overview of recent research into the genomic underpinnings of adaptive divergence and maintenance of species integrity in oaks in the face of gene flow. We review genomic and analytical tools instrumental to better understanding mechanisms leading to reproductive isolation and environment-driven adaptive introgression in oaks. We review evidence that oak species are genomically coherent entities, focusing on sympatric populations with ongoing gene flow, and discuss evidence for and hypotheses regarding genetic mechanisms linking adaptive divergence and reproductive isolation. As the evolution of drought- and freezing-tolerance have been key to the parallel diversification of oaks, we investigate the question of whether the same or a similar set of genes are involved in adaptive divergence for drought and stress tolerance across different taxa and sections. Finally, we propose potential future research directions on the role of hybridization and adaptive introgression in adaptation to climate change.

scholarly journals Molecular Signatures of Reticulate Evolution within the Complex of European Pine Taxa

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 489
Author(s):  
Bartosz Łabiszak ◽  
Witold Wachowiak
Keyword(s):  
Gene Flow ◽  
Reticulate Evolution ◽  
Modeling Framework ◽  
Closely Related Species ◽  
Interspecific Gene Flow ◽  
Nucleotide Sequence Variation ◽  
History Of ◽  
Best Fitting ◽  
Species Integrity

Speciation mechanisms, including the role of interspecific gene flow and introgression in the emergence of new species, are the major focus of evolutionary studies. Inference of taxonomic relationship between closely related species may be challenged by past hybridization events, but at the same time, it may provide new knowledge about mechanisms responsible for the maintenance of species integrity despite interspecific gene flow. Here, using nucleotide sequence variation and utilizing a coalescent modeling framework, we tested the role of hybridization and introgression in the evolutionary history of closely related pine taxa from the Pinus mugo complex and P. sylvestris. We compared the patterns of polymorphism and divergence between taxa and found a great overlap of neutral variation within the P. mugo complex. Our phylogeny reconstruction indicated multiple instances of reticulation events in the past, suggesting an important role of interspecific gene flow in the species divergence. The best-fitting model revealed P. mugo and P. uncinata as sister species with basal P. uliginosa and asymmetric migration between all investigated species after their divergence. The magnitude of interspecies gene flow differed greatly, and it was consistently stronger from representatives of P. mugo complex to P. sylvestris than in the opposite direction. The results indicate the prominent role of reticulation evolution in those forest trees and provide a genetic framework to study species integrity maintained by selection and local adaptation.

Introgression between non-sister species of honeyeaters (Aves: Meliphagidae) several million years after speciation

2019 ◽  
Vol 128 (3) ◽  
pp. 583-591
Author(s):  
Leo Joseph ◽  
Alex Drew ◽  
Ian J Mason ◽  
Jeffrey L Peters
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sex Chromosomes ◽  
Common Ancestor ◽  
Sister Species ◽  
Species Boundaries ◽  
North Eastern ◽  
The City

Abstract We reassessed whether two parapatric non-sister Australian honeyeater species (Aves: Meliphagidae), varied and mangrove honeyeaters (Gavicalis versicolor and G. fasciogularis, respectively), that diverged from a common ancestor c. 2.5 Mya intergrade in the Townsville area of north-eastern Queensland. Consistent with a previous specimen-based study, by using genomics methods we show one-way gene flow for autosomal but not Z-linked markers from varied into mangrove honeyeaters. Introgression barely extends south of the area of parapatry in and around the city of Townsville. While demonstrating the long-term porosity of species boundaries over several million years, our data also suggest a clear role of sex chromosomes in maintaining reproductive isolation.

Cross-cultural testing of face threats to predict apology and thanks intentions

2017 ◽  
Vol 45 (10) ◽  
pp. 1643-1654
Author(s):  
Hye Eun Lee ◽  
Hyunjin Park
Keyword(s):  
Future Research ◽  
North Americans ◽  
Face Threats ◽  
The Face ◽  
Future Research Directions ◽  
Face Threat ◽  
Korean College Students ◽  
Favor Asking ◽  
Negative Face

We examined whether Koreans intended to make an apology and North Americans intended to express thanks in a message asking for a favor. Because one reason for apologizing or thanking is to lessen the face threat occurred by favor asking, four face threats were empirically measured to predict participants' intentions. Participants were 104 North American and 90 Korean college students who took the role of an email sender making a favor request and selected from options for apologizing or thanking the receiver to lessen the four types of face threat. Results showed that North Americans intended to express thanks, and both North Americans and Koreans intended to make an apology when asking a favor; further, for Koreans, a speaker's positive face threat triggered intention to make an apology and, for North Americans, a receiver's negative face threat triggered an intention to express thanks. Implications and future research directions are discussed.

scholarly journals Anatomic and Physiological Bases of Social Blushing: Speculations from Neurology and Psychology

1993 ◽  
Vol 6 (4) ◽  
pp. 181-185 ◽  
Author(s):  
W. D. Cutlip II ◽  
M. R. Leary
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Future Research ◽  
Psychological Processes ◽  
Reflective Thought ◽  
Cutaneous Vasodilatation ◽  
Unusual Combination ◽  
The Face ◽  
Sympathetic Nervous

Although a common and occasionally troubling reaction, social blushing has received little systematic attention from either medical or behavioral researchers. This article reviews what is known of the physiological and psychological processes that mediate social blushing, and speculates regarding the role of central mechanisms in the phenomenon. Blushing is characterized by the unusual combination of cutaneous vasodilatation of the face, neck, and ears, accompanied by activation of the sympathetic nervous system. Psychologically, blushing appears to occur when people receive undesired social attention from others and may be analogous to the appeasement displays observed in non-human primates. Although poorly understood, the central mechanisms that mediate blushing obviously involve both involuntary autonomic effector systems and higher areas that involve self-reflective thought. Questions for future research are suggested.

scholarly journals Climate as an Evolutionary Driver of Nest Morphology in Birds: A Review

2020 ◽  
Vol 8 ◽  
Author(s):  
Daniela M. Perez ◽  
Janet L. Gardner ◽  
Iliana Medina
Keyword(s):  
Local Environment ◽  
Climatic Conditions ◽  
Future Research ◽  
Extended Phenotype ◽  
The Face ◽  
Building Behavior ◽  
Fledgling Success ◽  
Nest Microclimate ◽  
The Relationship

Avian nests are critical for successful reproduction in birds. Nest microclimate can affect egg development, chick growth and fledgling success, suggesting that nest building behavior should be under strong selective pressure to nesting conditions. Given that the internal microclimate of the nest is critical for avian fitness, it is expected that nest morphology is shaped by the local environment. Here we review the relationship between nest morphology and climate across species’ distributions. We collate growing evidence that supports a link between environmental conditions and particular nest traits, within species and across species. We discuss the degree to which phenotypic plasticity in nesting behavior can contribute to observed variation in nest traits, the role of phylogenetic history in determining nest morphology, and which nest traits are likely to be influenced by climatic conditions. Finally, we identify gaps in our understanding of the evolution of nest morphology and suggest topics for future research. Overall, we argue that nests are part of the extended phenotype of a bird, they play a crucial role in their reproductive success, and may be an important factor in determining which species will be able to persist in the face of ongoing climate change.

Mapping a Changing Field

2018 ◽  
Vol 4 (2) ◽  
pp. 11-38
Author(s):  
Louise Jørring ◽  
António Valentim ◽  
Pablo Porten-Cheé
Keyword(s):  
Political Participation ◽  
Future Research ◽  
Digital Citizenship ◽  
Moving Target ◽  
Societal Impact ◽  
Review Of Literature ◽  
The Face ◽  
Alternative Approaches ◽  
Citizenship Norms

Abstract Digitalization is transforming the face of political participation. Citizens increasingly engage in politics in new and creative forms online. The concept of digital citizenship has the potential to capture the shifting role of citizens under online conditions. Yet this concept has been used inconsistently, provoking theoretical and operational shortcomings that complicate its analytical usability and may limit its academic and societal impact. This article provides a systematic review of literature on digital citizenship. Based on a review of 139 articles, we identify three dominant approaches to digital citizenship: the normative, the conditional, and the contextual. Additionally, we provide a systematization of alternative approaches to digital citizenship and discuss their potential to inform literature on this concept. Finally, we put forward a citizenship norms approach that may reconcile the different perspectives on digital citizenship. In sum, this article presents a review of the digital citizenship research and provides new avenues for the concept to be used in future research on the moving target that political participation presents under online conditions.

scholarly journals Altitudinal gradients, plant hybrid zones and evolutionary novelty

2014 ◽  
Vol 369 (1648) ◽  
pp. 20130346 ◽  
Author(s):  
Richard J. Abbott ◽  
Adrian C. Brennan
Keyword(s):  
Gene Flow ◽  
Mount Etna ◽  
Hybrid Zones ◽  
Evolutionary Novelty ◽  
Altitudinal Gradients ◽  
Interspecific Gene Flow ◽  
Adaptive Introgression ◽  
Local Environments ◽  
The Face ◽  
Plant Hybrid

Altitudinal gradients are characterized by steep changes of the physical and biotic environment that present challenges to plant adaptation throughout large parts of the world. Hybrid zones may form where related species inhabit different neighbouring altitudes and can facilitate interspecific gene flow and potentially the breakdown of species barriers. Studies of such hybrid zones can reveal much about the genetic basis of adaptation to environmental differences stemming from changes in altitude and the maintenance of species divergence in the face of gene flow. Furthermore, owing to recombination and transgressive effects, such hybrid zones can be sources of evolutionary novelty. We document plant hybrid zones associated with altitudinal gradients and emphasize similarities and differences in their structure. We then focus on recent studies of a hybrid zone between two Senecio species that occur at high and low altitude on Mount Etna, Sicily, showing how adaptation to local environments and intrinsic selection against hybrids act to maintain it. Finally, we consider the potential of altitudinal hybrid zones for generating evolutionary novelty through adaptive introgression and hybrid speciation. Examples of homoploid hybrid species of Senecio and Pinus that originated from altitudinal hybrid zones are discussed.

scholarly journals Clinal genomic analysis reveals strong reproductive isolation across a steep habitat transition in stickleback fish

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Quiterie Haenel ◽  
Krista B. Oke ◽  
Telma G. Laurentino ◽  
Andrew P. Hendry ◽  
Daniel Berner
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sequence Data ◽  
Genomic Analysis ◽  
Whole Genome Sequence ◽  
Adaptive Divergence ◽  
Entire Genome ◽  
High Dispersal ◽  
A Genome ◽  
Habitat Transition

AbstractHow ecological divergence causes strong reproductive isolation between populations in close geographic contact remains poorly understood at the genomic level. We here study this question in a stickleback fish population pair adapted to contiguous, ecologically different lake and stream habitats. Clinal whole-genome sequence data reveal numerous genome regions (nearly) fixed for alternative alleles over a distance of just a few hundred meters. This strong polygenic adaptive divergence must constitute a genome-wide barrier to gene flow because a steep cline in allele frequencies is observed across the entire genome, and because the cline center closely matches the habitat transition. Simulations confirm that such strong divergence can be maintained by polygenic selection despite high dispersal and small per-locus selection coefficients. Finally, comparing samples from near the habitat transition before and after an unusual ecological perturbation demonstrates the fragility of the balance between gene flow and selection. Overall, our study highlights the efficacy of divergent selection in maintaining reproductive isolation without physical isolation, and the analytical power of studying speciation at a fine eco-geographic and genomic scale.

scholarly journals Plastic Biodegradation through Insects and their Symbionts Microbes: A Review

2021 ◽  
Vol 8 (4) ◽  
pp. 95-103
Author(s):  
Huda Bilal ◽  
Hasnain Raza ◽  
Haseena Bibi ◽  
Tehmina Bibi
Keyword(s):  
Environmental Issues ◽  
Life Forms ◽  
Plastic Waste ◽  
Natural Habitats ◽  
Environmentally Sustainable ◽  
Global Environmental Problems ◽  
Lack Of Information ◽  
Global Environmental ◽  
The Face

Plastic waste has recently been identified as one of the most serious environmental issues, affecting all life forms, natural habitats, and the economy, and is one of the most serious global environmental problems, second only to climate change. Seeking alternative environmentally sustainable options, such as biodegradation instead of conventional disposal, is critical in the face of this challenge. However, there is currently a lack of information about the mechanisms and efficacy of plastic biodegradation. From this perspective, this study aims to illustrate the negative environmental impacts of the plastic waste. It also addresses the role of insects and gut microbiota in the degradation of plastics, emphasizing the important role they will play in the future.

scholarly journals Speciation in the face of gene flow within the toothed whale superfamily Delphinoidea

2020 ◽  
Author(s):  
Michael V Westbury ◽  
Andrea A. Cabrera ◽  
Alba Rey-Iglesia ◽  
Binia De Cahsan ◽  
Stefanie Hartmann ◽  
...  
Keyword(s):  
Gene Flow ◽  
Marine Species ◽  
Interspecific Gene Flow ◽  
Ancestral Gene ◽  
Multifaceted Approach ◽  
Ecological Barriers ◽  
The Face ◽  
Toothed Whale ◽  
Bifurcation Process

AbstractUnderstanding speciation is a central aspect in Biology. The formation of new species was once thought to be a simple bifurcation process. However, recent advances in genomic resources now provide the opportunity to investigate the role of post-divergence gene flow in the speciation process. The diversification of lineages in the presence of gene flow appears almost paradoxical. However, with enough time and in the presence of incomplete physical and/or ecological barriers to gene flow, speciation can and does occur. Speciation without complete isolation seems especially likely to occur in highly mobile, wide ranging marine species, such as cetaceans, which face limited geographic barriers. The toothed whale superfamily Delphinoidea represents a good example to further explore speciation in the presence of interspecific gene flow. Delphinoidea consists of three families (Delphinidae, Phocoenidae, and Monodontidae) and within all three families, contemporary interspecific hybrids have been reported. Here, we utilise publicly available genomes from nine species, representing all three families, to investigate signs of post-divergence gene flow across their genomes, and to address the speciation processes that led to the diversity seen today within Delphinoidea. We use a multifaceted approach including: (i) phylogenetics, (ii) the distribution of shared derived alleles, and (iii) demography-based. We find that the divergence and evolution of lineages in Delphinoidea did not follow a simple bifurcating pattern, but were much more complex. Our results indicate multiple, long-lasting ancestral gene flow events both within and among families, which continued for millions of years after initial divergence.

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