scholarly journals Asymmetric reinforcement in Lucania killifish: assessing reproductive isolation when both sexes choose

2020 ◽  
Author(s):  
Michelle E John ◽  
Rebecca C Fuller
Keyword(s):  
The Other ◽  
Costs And Benefits ◽  
Postzygotic Isolation ◽  
Sympatric Population ◽  
Male Preference ◽  
Cross Direction ◽  
Hybrid Offspring ◽  
Behavioral Isolation ◽  
High Preference ◽  
Hybrid Cross

Abstract Reinforcement can occur when maladaptive hybridization in sympatry favors the evolution of conspecific preferences and target traits that promote behavioral isolation (BI). In many systems, enhanced BI is due to increased female preference for conspecifics. In others, BI is driven by male preference, and in other systems both sexes exert preferences. Some of these patterns can be attributed to classic sex-specific costs and benefits of preference. Alternatively, sex differences in conspecific preference can emerge due to asymmetric postzygotic isolation (e.g., hybrid offspring from female A × male B have lower fitness than hybrid offspring from female B × male A), which can lead to asymmetric BI (e.g., female A and male B are less likely to mate than female B and male A). Understanding reinforcement requires understanding how conspecific preferences evolve in sympatry. Yet, estimating conspecific preferences can be difficult when both sexes are choosy. In this study, we use Lucania killifish to test the hypothesis that patterns of reinforcement are driven by asymmetric postzygotic isolation between species. If true, we predicted that sympatric female Lucania goodei and sympatric male L. parva should have lower levels of BI compared with their sympatric counterparts, as they produce hybrid offspring with the highest fitness. To address the problem of measuring BI when both sexes are choosy, we inferred the contribution to BI of each partner using assays where one sex in the mating pair comes from an allopatric population with potentially low preference, whereas the other comes from a sympatric population with high preference. For one hybrid cross direction, we found that both female L. parva and male L. goodei have high contributions to BI in sympatry. In the other hybrid cross direction, we found that only female L. goodei contribute to BI. Sympatric male L. parva readily engaged in hybrid spawnings with allopatric L. goodei females. These results indicate that both asymmetric postzygotic isolation and the traditional sex-specific costs to preference likely affect the nature of selection on conspecific preferences and target traits.

scholarly journals Hybridization and postzygotic isolation promote reinforcement of male mating preferences in a diverse group of fishes with traditional sex roles

2018 ◽  
Author(s):  
Rachel L. Moran ◽  
Muchu Zhou ◽  
Julian M. Catchen ◽  
Rebecca C. Fuller
Keyword(s):  
Morphological Data ◽  
Male Mating ◽  
Postzygotic Isolation ◽  
Male Preference ◽  
Behavioral Isolation ◽  
Species Pairs ◽  
Ratio Distortion ◽  
Multiple Species ◽  
Sex Ratio Distortion ◽  
Male Coloration

AbstractBehavioral isolation is thought to arise early in speciation due to differential sexual and/or natural selection favoring different preferences and traits in different lineages. Alternatively, behavioral isolation can arise due to reinforcement favoring traits and preferences that prevent maladaptive hybridization. In darters, female preference for male coloration has been hypothesized to drive speciation, because behavioral isolation evolves before F1 inviability. However, as with many long-lived organisms, the fitness of second generation hybrids has not been assessed because raising animals to adulthood in the lab is challenging. Recently, reinforcement of male preferences has been implicated in darters because male preference for conspecific females is high in sympatry but absent in allopatry in multiple species pairs. The hypothesis that reinforcement accounts for behavioral isolation in sympatry assumes that hybridization and postzygotic isolation are present. Here, we used genomic and morphological data to demonstrate that hybridization is ongoing between orangethroat and rainbow darters and used hybrids collected from nature to measure postzygotic barriers across two hybrid generations. We observed sex ratio distortion in adult F1s and a dramatic reduction in backcross survival. Our findings indicate that selection to avoid hybridization promotes the evolution of male-driven behavioral isolation via reinforcement in this system.

Can there be a Finite Interpretation of the Kantian Sublime?

Kant Yearbook ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 17-40
Author(s):  
Sacha Golob
Keyword(s):  
Detailed Comparison ◽  
The Other ◽  
Costs And Benefits ◽  
The Sublime ◽  
Other Hand ◽  
The One ◽  
Resultant Theory

Abstract Kant’s account of the sublime makes frequent appeals to infinity, appeals which have been extensively criticised by commentators such as Budd and Crowther. This paper examines the costs and benefits of reconstructing the account in finitist terms. On the one hand, drawing ona detailed comparison of the first and third Critiques, I argue that the underlying logic of Kant’s position is essentially finitist. I defend the approach against longstanding objections, as well as addressing recent infinitist work by Moore and Smith. On the other hand, however, I argue that finitism faces distinctive problems of its own: whilst the resultant theory is a coherent and interesting one, it is unclear in what sense it remains an analysis of the sublime. I illustrate the worry by juxtaposing the finitist reading with analytical cubism.

Critical Approaches to Children’s Work and the Concept of Child Labor

2013 ◽  
Author(s):  
Michael Bourdillon
Keyword(s):  
Child Labor ◽  
The Other ◽  
Family Context ◽  
Costs And Benefits ◽  
Work Activities ◽  
The Family ◽  
Critical Approaches ◽  
Conceptual Problems ◽  
Principal Work ◽  
Children’S Work

In much of human history, and in the majority of the world today, children participate in the work activities of the communities in which they are growing, and thereby learn to become productive members of the societies in which they live. Relatively recently, the principal work of children has switched from productive work to schoolwork, a change that has created conceptual problems for understanding the continuing importance of children’s work outside school. An attempt to divide children’s work into harmful “labor” and benign “work” fails to account for the vast majority of children’s work, which combines potentially positive and negative elements. References to harmful work and exploitative conditions can be found in the Oxford Bibliographies article on Child Labor. More positive accounts of children’s work in different cultural contexts appear in the article on Children’s Work and Apprenticeship, which focuses on unpaid work in the family context and work associated with learning. Neither article defines its topic in relation to the other. This indeterminate division leaves gaps, omitting some literature on children’s work that does not easily fall into either category, such as the benefits that children can derive from employment and how to assess costs and benefits in children’s work. This article, therefore, has two roles: it points to publications that provide a more comprehensive view of children’s work and it fills some of the gaps left by the other two articles.

Laboratory hybridization in green lacewings (Neuroptera: Chrysopidae: Chrysoperla): evidence for genetic incompatibility

1993 ◽  
Vol 71 (2) ◽  
pp. 233-237 ◽  
Author(s):  
Marta Martínez Wells
Keyword(s):  
Hatching Success ◽  
Biological Species ◽  
Egg Laying ◽  
Postzygotic Isolation ◽  
Separate Species ◽  
Genetic Incompatibility ◽  
Second Stage ◽  
Behavioral Isolation ◽  
Two Generations ◽  
Chrysoperla Plorabunda

Courtship songs are an important reproductive barrier in lacewings of the genus Chrysoperla, so heterotypic matings should occur less readily than homotypic matings. In addition, if song morphs have become separate species, there may be some postzygotic isolation between song morphs. Two generations of crosses using sympatric P1 and P3 morphs of Chrysoperla plorabunda provide evidence for both hypotheses. In the first stage of the experiment, egg laying (an indication of mating success) was delayed by a week in heterotypic crosses compared with homotypic crosses, and hatching success of eggs from hybrid crosses was 16% lower than that from control crosses. In the second stage of the experiment, backcrosses involving P3 morph males or females were the least successful in mating. When pairs did mate, they did so a week later than in the other crosses. Thus, behavioral isolation delays heterotypic matings when females are not given a choice of mates. These results provide some genetic evidence that the song morphs of the C. plorabunda complex are biological species.

Epibiont molluscs on neogastropod shells from sandy bottoms, Pacific coast of Mexico

2000 ◽  
Vol 80 (2) ◽  
pp. 291-298 ◽  
Author(s):  
Celia Olabarria
Keyword(s):  
Spatial Distribution ◽  
Pacific Coast ◽  
The Other ◽  
Costs And Benefits ◽  
Mollusc Species ◽  
Soft Bottoms

This study quantifies the prevalence, abundance, and spatial distribution of epibiotic molluscs on six common neogastropod species in sandy bottoms, Hexaplex nigritus, Chicoreus regius, C. erythrostomus, C. brassica, Vasum caestus and Pleuropoca princeps. A total of 1478 epibiont specimens belonging to 74 mollusc species were examined. The most of epibiotic species were typical of hard-bottoms, but a few species were typical of soft-bottoms. The results indicate H. nigritus is significantly more fouled than the other five species. This can be due to a greater availability of small hollows and a strongly ornamented shell in this species. The spatial distribution of epibionts on the neogastropod shells varied significantly among the different areas into which the shell was subdivided for this study. Fifteen sedentary epibiotic species dominated on all host shells. The costs and benefits of epibiosis are reviewed and the epibiont/host relationship appears to be principally beneficial to epibionts, without a clear benefit for hosts.

scholarly journals Capital Structure Theories and Speed of Capital Adjustment towards Target Capital Structure along Life Cycle Stages of Asian Manufacturing Firms

2020 ◽  
Vol 6 (1) ◽  
pp. 53-62
Author(s):  
Muhammad Sajid Amin ◽  
Hashim Khan ◽  
Imran Abbas Jaddon ◽  
Muhammad Tahir
Keyword(s):  
Life Cycle ◽  
Capital Structure ◽  
Manufacturing Firms ◽  
The Other ◽  
Mature Stage ◽  
Costs And Benefits ◽  
Speed Of Adjustment ◽  
Capital Adjustment ◽  
Life Cycle Stages

Purpose: Firms have different costs and benefits and asymmetric information across their life cycle stages and hence each stage has different financial pattern and speed of adjustment towards target capital. Methodology: We use System GMM to test the hypotheses. We use market leverages proxies for the capital structure, life cycle proxies: introduction, growth, mature, shakeout and decline and the control determinants of capital structure such as profitability, tangibility, firm size and growth opportunities. We estimate the financial pattern and speed of adjustment along life cycle stages of manufacturing firms from eleven Asian economies over the period of 2010-2018. Findings: The results show that firms in earlier stages have more long term debt than mature stage. The speed of adjustment towards target capital structure is highest in mature stage than the other stages. The control determinants significantly affect market leverages. Implications: The findings suggest that management has to consider life cycle stages of their firms in order to adjust capital structure. Stockholders should consider stage of firm with relation to profitability and capital structure for long term prospects.

scholarly journals Discovery of Geographically Robust Hybrid Poplar Clones

2019 ◽  
Vol 68 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Neil D. Nelson ◽  
William E. Berguson ◽  
Bernard G. McMahon ◽  
Richard Meilan ◽  
Lawrence B. Smart ◽  
...  
Keyword(s):  
New York ◽  
Total Variation ◽  
Genetic Gain ◽  
Clonal Growth ◽  
Hybrid Poplar ◽  
The Other ◽  
Total Variance ◽  
Costs And Benefits ◽  
Poplar Clones ◽  
Additional Costs

Abstract Hybrid poplar clonal growth in the states (regions) of Minnesota (MN), Indiana (IN), Michigan (MI), and New York (NY) USA was analyzed to discover 10 geographically robust (geo-robust) clones, all P. deltoides x P. nigra (D x N) hybrids previously tested and screened in MN, that were broadly adapted across latitudinal and longitudinal ranges of 9 and 20 degrees, respectively. The clonal effect for growth explained 25 to 36 % of the total variance, 2.5–4.1 times the clone x site interaction. Clone explained 24 to 46 % of total variation in canker occurrence on two sites. Genetic gain in growth was calculated relative to commercial check clones. Genetic gain in growth of geo-robust clones exceeded that of random clones by 24 to 44 %. Geo-robust clones and the best clones on each site were not significantly different on the MN sites, but best clones outperformed geo-robust clones on the other sites by 10 to 39 % genetic gain. Geo-robust clones grew faster than commercial check clones on all but the MI site. The reduction in genetic gain for growth due to using broadly adapted clones relative to the best clones has to be compared to the additional costs and benefits of multiple breeding zones.

Is meer personeel in beweging beter?

2008 ◽  
Vol 21 (4) ◽  
Author(s):  
Sophie De Winne ◽  
Dave Stynen ◽  
Caroline Gilbert ◽  
Luc Sels
Keyword(s):  
Labour Market ◽  
Economic Benefits ◽  
The Other ◽  
Added Value ◽  
Costs And Benefits ◽  
Positive Effects ◽  
Retention Management ◽  
Economic Level ◽  
Employee Mobility ◽  
Labour Market Mobility

Is more employee mobility preferable? Is more employee mobility preferable? S. De Winne, D. Stynen, C. Gilbert & L. Sels, Gedrag & Organisatie, volume 21, November 2008, nr. 4, pp. 344-364 Despite promising positive effects of labour market mobility, the Flemish labour market is synonymous with rigidity. The question is thus whether the rosy picture of the consequences of mobility holds out. Why are people not more mobile if this improves their welfare and prosperity? Why does HRM strongly focus on retention management if mobility enhances productivity? 'More is better' seems a premature conclusion. The purpose of this contribution is to critically reflect on the added value of labour market mobility. We sketch the debate on the macro-economic level and investigate research on the effects of mobility at three levels: we map costs and benefits for labour market functioning (macro), for firms (meso), and for individual careers (micro). With this contribution we show that benefits at one level do not necessarily go hand in hand with benefits at the other levels. We conclude that firm loyalty also yiels economic benefits; that more mobility is welcome, as far as it concerns protected mobility.

ON THE OTHER HAND: THE COSTS AND BENEFITS OF LEFT-HANDEDNESS

2019 ◽  
Vol 17 (1) ◽  
pp. 69-86
Author(s):  
Sarah A. Fritsche ◽  
Annukka K. Lindell
Keyword(s):  
Substance Abuse ◽  
The Other ◽  
Costs And Benefits ◽  
Fitness Costs ◽  
Left Handedness ◽  
Left Handed ◽  
Other Hand ◽  
Lecture Room ◽  
Increased Risk ◽  
Left And Right

Left-handers have been persecuted by right-handers for millennia. This right bias is evident cross-culturally, linguistically (right is literally and figuratively ‘right’, with lefties being described as ‘gauche’, ‘sinister’ and ‘cack-handed’), and environmentally (e.g., equipment design, including power tools, ticket machines, and lecture-room desks). Despite this, the proportion of left-handers has remained constant at approximately 10% of the hominid population, implying that though there are costs associated with left-handedness (if there were not, the proportions of left- and right-handers would be 50:50), left handers must also enjoy fitness advantages that maintain the genes for left-handedness in the population. This paper reviews the costs and benefits of being left-handed, exploring research examining the effects of handedness on brain structure, cognitive function, and human behaviour. The research confirms a variety of left-hander advantages, including some cognitive superiorities, higher wages, and greater sporting and fighting prowess. On the other hand, left-handedness is also associated with significant fitness costs, including an increased risk of accidents, higher substance abuse susceptibility, and earlier death, in comparison with right-handers. In sum, left-handedness confers both costs and benefits, with the latter outweighing the former, maintaining the genes for left-handedness in the population.

For better or worse: Shaming, faming, and human rights abuse

2020 ◽  
pp. 002234332090534
Author(s):  
Sara Kahn-Nisser
Keyword(s):  
Human Rights ◽  
The Other ◽  
External Costs ◽  
Costs And Benefits ◽  
Negatively Associated ◽  
Hr Practices ◽  
Human Rights Abuse ◽  
The One ◽  
The Impact

Does it matter whether human rights (HR) shaming is accompanied by acknowledgments of reforms and progress? Do such acknowledgments weaken or strengthen the impact of shaming? Rulers decide whether to oppress or to comply with HR treaty obligations by considering what compliance entails and by weighing the internal and external costs and benefits of oppression. Research shows that HR shaming alters such considerations and is associated with changes in HR protection levels. Can the same be said of faming? This article examines three forms of HR reporting: faming, which focuses on positive developments; shaming, which focuses on problematic HR practices; and scrutiny, which combines shaming and faming. The article analyzes the association between shaming, faming, and scrutiny by UN treaty bodies, on the one hand, and oppression on the other. The potential associations are conceptualized as mitigation, backsliding, and specification. The analysis finds that shaming with no faming and faming with no shaming are each negatively associated with HR protection. Scrutiny, the combination of shaming and faming, is positively associated with subsequent HR protection levels, and the higher the level of scrutiny the higher the subsequent level of HR protection. The article argues that the reason for this association is that the combination of shaming and faming helps policymakers understand how to properly implement their treaty obligations and how to improve HR protection. The article draws policy and theoretical implications including the need for balanced and detailed HR reporting, and the importance of learning in HR advocacy.

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