scholarly journals Digest: The role of postzygotic isolation in Mimulus speciation*

Evolution ◽  
2021 ◽  
Author(s):  
Nina Joffard ◽  
Willian T.A.F. Silva ◽  
Alex D. Twyford
Keyword(s):  
Postzygotic Isolation

scholarly journals The strength and genetic basis of reproductive isolating barriers in flowering plants

2008 ◽  
Vol 363 (1506) ◽  
pp. 3009-3021 ◽  
Author(s):  
David B Lowry ◽  
Jennifer L Modliszewski ◽  
Kevin M Wright ◽  
Carrie A Wu ◽  
John H Willis
Keyword(s):  
Reproductive Isolation ◽  
Chromosomal Rearrangements ◽  
Variable Number ◽  
Future Research ◽  
Relative Role ◽  
Postzygotic Isolation ◽  
Direct Role ◽  
Evolutionary Forces ◽  
Geographical Scale

Speciation is characterized by the evolution of reproductive isolation between two groups of organisms. Understanding the process of speciation requires the quantification of barriers to reproductive isolation, dissection of the genetic mechanisms that contribute to those barriers and determination of the forces driving the evolution of those barriers. Through a comprehensive analysis involving 19 pairs of plant taxa, we assessed the strength and patterns of asymmetry of multiple prezygotic and postzygotic reproductive isolating barriers. We then reviewed contemporary knowledge of the genetic architecture of reproductive isolation and the relative role of chromosomal and genic factors in intrinsic postzygotic isolation. On average, we found that prezygotic isolation is approximately twice as strong as postzygotic isolation, and that postmating barriers are approximately three times more asymmetrical in their action than premating barriers. Barriers involve a variable number of loci, and chromosomal rearrangements may have a limited direct role in reproductive isolation in plants. Future research should aim to understand the relationship between particular genetic loci and the magnitude of their effect on reproductive isolation in nature, the geographical scale at which plant speciation occurs, and the role of different evolutionary forces in the speciation process.

scholarly journals Explaining Darwin’s Corollary to Haldane’s Rule: The Role of Mitonuclear Interactions in Asymmetric Postzygotic Isolation Among Toads

Genetics ◽  
2014 ◽  
Vol 197 (2) ◽  
pp. 743-747 ◽  
Author(s):  
Yaniv Brandvain ◽  
Gregory B. Pauly ◽  
Michael R. May ◽  
Michael Turelli
Keyword(s):  
Postzygotic Isolation ◽  
Haldane’S Rule ◽  
Haldane's Rule

scholarly journals Spermatogenesis in house mouse in a Robertsonian polymorphism zone

Reproduction ◽  
2010 ◽  
Vol 140 (4) ◽  
pp. 569-581 ◽  
Author(s):  
Ma Assumpció Sans-Fuentes ◽  
José García-Valero ◽  
Jacint Ventura ◽  
Ma José López-Fuster
Keyword(s):  
Diploid Number ◽  
Postzygotic Isolation ◽  
Homozygous State ◽  
Large Numbers ◽  
Structural Heterozygosity ◽  
Multilevel Sampling ◽  
Morphological Variables ◽  
Monobrachial Homology ◽  
Rb Translocations

Robertsonian (Rb) translocations can be important in speciation as a mechanism of postzygotic isolation between populations. Meiotic non-disjunction, gametogenic impairment, and association of impaired autosomal segments with sex chromosomes have been postulated as mechanisms responsible for reducing fertility in Rb mice. Quantitative histological studies needed to understand the role of Rb fusions in gametogenic impairment are scarce. Most research on Rb mice has analyzed meiotic non-disjunction of laboratory and wild-derived strains, which have complex or simple structural heterozygosity with large numbers of fusions. Using histological multilevel sampling, we examined spermatogenesis in mice from the Rb polymorphism area of Barcelona. We studied four chromosomal groups having: a) one Rb heterozygote fusion and 2n=39, b) one Rb heterozygote fusion and 2n=31, c) three Rb heterozygote fusions without monobrachial homology and with diploid number ranging from 2n=29 to 2n=37, and d) only Rb homozygote fusions with diploid number ranging from 2n=28 to 2n=30. Standard mice from the area surrounding the Rb zone were used as control. We analyzed morphological variables of the testes, relative frequency of stages in the seminiferous epithelium cycle, the ‘round spermatids:primary spermatocytes’ ratio, and other derived parameters. Our results reveal that structural homozygote mice and simple heterozygote mice having as few as one to three Rb fusions undergo greater germ cell death (GCD) than standard mice, suggesting that Rb fusions are related to increased GCD (in both the heterozygous and homozygous state) and may be the main cause of decreased gene flow between mice populations from this area.

scholarly journals DNA methylation reprogramming, TE derepression, and postzygotic isolation of nascent animal species

2019 ◽  
Vol 5 (10) ◽  
pp. eaaw1644 ◽  
Author(s):  
M. Laporte ◽  
J. Le Luyer ◽  
C. Rougeux ◽  
A.-M. Dion-Côté ◽  
M. Krick ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Species Complex ◽  
Animal Species ◽  
Expression Patterns ◽  
Significant Proportion ◽  
Coregonus Clupeaformis ◽  
Postzygotic Isolation ◽  
Heterochromatin Formation ◽  
Transcriptional Derepression

The genomic shock hypothesis stipulates that the stress associated with divergent genome admixture can cause transposable element (TE) derepression, which could act as a postzygotic isolation mechanism. TEs affect gene structure, expression patterns, and chromosome organization and may have deleterious consequences when released. For these reasons, they are silenced by heterochromatin formation, which includes DNA methylation. Here, we show that a significant proportion of TEs are differentially methylated between the “dwarf” (limnetic) and the “normal” (benthic) whitefish, two nascent species that diverged some 15,000 generations ago within the Coregonus clupeaformis species complex. Moreover, TEs are overrepresented among loci that were demethylated in hybrids, indicative of their transcriptional derepression. These results are consistent with earlier studies in this system that revealed TE transcriptional derepression causes abnormal embryonic development and death of hybrids. Hence, this supports a role of DNA methylation reprogramming and TE derepression in postzygotic isolation of nascent animal species.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The role of affect in feelings of obligation

2020 ◽  
Vol 43 ◽  
Author(s):  
Stefen Beeler-Duden ◽  
Meltem Yucel ◽  
Amrisha Vaish
Keyword(s):  
Positive Emotions ◽  
The Creation ◽  
Sense Of Obligation

Abstract Tomasello offers a compelling account of the emergence of humans’ sense of obligation. We suggest that more needs to be said about the role of affect in the creation of obligations. We also argue that positive emotions such as gratitude evolved to encourage individuals to fulfill cooperative obligations without the negative quality that Tomasello proposes is inherent in obligations.

Refining our understanding of the “elephant in the room”

2020 ◽  
Vol 43 ◽  
Author(s):  
Andrew Whiten
Keyword(s):  
Social Cognition ◽  
Cultural Evolution ◽  
Cognitive Abilities ◽  
Critical Factors ◽  
Technological Culture

Abstract The authors do the field of cultural evolution a service by exploring the role of non-social cognition in human cumulative technological culture, truly neglected in comparison with socio-cognitive abilities frequently assumed to be the primary drivers. Some specifics of their delineation of the critical factors are problematic, however. I highlight recent chimpanzee–human comparative findings that should help refine such analyses.

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