scholarly journals Macroevolutionary consequences of sexual conflict

2018 ◽  
Vol 14 (6) ◽  
pp. 20180186
Author(s):  
Jo S. Hermansen ◽  
Jostein Starrfelt ◽  
Kjetil L. Voje ◽  
Nils C. Stenseth
Keyword(s):  
Sexual Selection ◽  
Genetic Architecture ◽  
Time Frame ◽  
Sexual Conflicts ◽  
Males And Females ◽  
Selection For ◽  
Evolutionary Consequences ◽  
Future Work ◽  
Shared Genetic

Intralocus sexual conflicts arise whenever the fitness optima for a trait expressed in both males and females differ between the sexes and shared genetic architecture constrains the sexes from evolving independently towards their respective optima. Such sexual conflicts are commonplace in nature, yet their long-term evolutionary consequences remain unexplored. Using a Bayesian phylogenetic comparative framework, we studied the macroevolutionary dynamics of intersexual trait integration in stalk-eyed flies (Diopsidae) spanning a time frame of more than 25 Myr. We report that increased intensity of sexual selection on male eyestalks is associated with reduced intersexual eyestalk integration, as well as sex-specific rates of eyestalk evolution. Despite this, lineages where males have been under strong sexual selection for millions of years still exhibit high levels of intersexual trait integration. This low level of decoupling between the sexes may indicate that exaggerated female eyestalks are in fact adaptive—or alternatively, that there are strong constraints on reducing trait integration between the sexes. Future work should seek to clarify the relative roles of constraints and selection in contributing to the varying levels of intersexual trait integration in stalk-eyed flies, and in this way clarify whether sexual conflicts can act as constraints on adaptive evolution even on macroevolutionary time scales.

Rhythms and Reproduction

2020 ◽  
pp. 472-502
Author(s):  
Stefan Dennenmoser ◽  
John H. Christy ◽  
Martin Thiel
Keyword(s):  
Sexual Selection ◽  
Predation Risk ◽  
Operational Sex Ratio ◽  
Factors Affecting ◽  
Broadcast Spawning ◽  
Males And Females ◽  
Selection For ◽  
Depth Gradients ◽  
Newly Hatched Larvae ◽  
Density Dependent Selection

Reproductive rhythms can be found in numerous crustacean species. This chapter reviews the temporal scales of rhythms and how these rhythms are entrained and maintained by external cues and endogenous clocks. The occurrence and synchrony of rhythms vary along latitudinal and depth gradients, which may depend on the availability of zeitgebers (e.g., temperature and photoperiod), changing selective pressures such as predation risk, and variability in larval development rates that affect the timing and synchrony of reproductive rhythms. Commonly observed rhythms are reproductive migrations and synchronized larval release, which are often timed to reduce predation risk for newly hatched larvae. In crustaceans, reproductive rhythms rarely evolve under pure density-dependent selection for synchrony. Pure density dependence is common in marine broadcast-spawning invertebrates like corals, which rely on accumulation of gametes in time and space to ensure fertilization. Instead, (density-independent) selection for synchrony with environmental cycles that track changes in factors affecting fitness such as energy expenditure, predation risk, or food availability seems to be the rule, although some exceptions may exist. In contrast to natural selection, the possible contribution of sexual selection on reproductive rhythms has rarely been considered. Selection for enhanced mating possibilities should favor reproductive synchrony, but deviations from synchrony will affect the operational sex ratio and influence sexual selection. Finally, the chapter discusses the possibility of sexual conflict over reproductive timing between males and females and explores circumstances under which synchronous reproductive rhythms might be abandoned.

scholarly journals Evolutionary inevitability of sexual antagonism

2014 ◽  
Vol 281 (1776) ◽  
pp. 20132123 ◽  
Author(s):  
Tim Connallon ◽  
Andrew G. Clark
Keyword(s):  
Sex Differences ◽  
Natural Populations ◽  
Evolutionary Divergence ◽  
Sexual Antagonism ◽  
Evolutionary Theories ◽  
Sex Effects ◽  
Evolutionary Trajectories ◽  
Males And Females ◽  
Evolutionary Consequences

Sexual antagonism, whereby mutations are favourable in one sex and disfavourable in the other, is common in natural populations, yet the root causes of sexual antagonism are rarely considered in evolutionary theories of adaptation. Here, we explore the evolutionary consequences of sex-differential selection and genotype-by-sex interactions for adaptation in species with separate sexes. We show that sexual antagonism emerges naturally from sex differences in the direction of selection on phenotypes expressed by both sexes or from sex-by-genotype interactions affecting the expression of such phenotypes. Moreover, modest sex differences in selection or genotype-by-sex effects profoundly influence the long-term evolutionary trajectories of populations with separate sexes, as these conditions trigger the evolution of strong sexual antagonism as a by-product of adaptively driven evolutionary change. The theory demonstrates that sexual antagonism is an inescapable by-product of adaptation in species with separate sexes, whether or not selection favours evolutionary divergence between males and females.

6. Sexual conflict

2018 ◽  
pp. 88-103
Author(s):  
Leigh W. Simmons
Keyword(s):  
Sexual Selection ◽  
Sexual Conflict ◽  
Arms Race ◽  
Arms Races ◽  
Antagonistic Selection ◽  
Before And After ◽  
Sexually Antagonistic Selection ◽  
Males And Females ◽  
Evolutionary Consequences

The reproductive interests of males and females will almost always differ, for example over whether to mate and how often, when to produce offspring and how many, or how much to invest in each offspring. Whenever the reproductive interests of males and females differ, opposing selection on males and females to achieve their preferred outcome will generate sexually antagonistic selection. Such sexual conflict is reflected in differences in the appearance and behaviour of the sexes as each evolves to gain the advantage in a fitness ‘arms race’. ‘Sexual conflict’ explores the evolutionary consequences of these arms races in the context of sexual selection as it occurs both before and after mating.

Device Selection for Short- and Long-Term Mechanical Circulatory Support

2019 ◽  
pp. 61-69
Author(s):  
Rabea Asleh ◽  
Sarah Schettle
Keyword(s):  
Mechanical Circulatory Support ◽  
Tissue Perfusion ◽  
Time Frame ◽  
Total Artificial Heart ◽  
Circulatory Support ◽  
Short Term ◽  
Ventricular Assist ◽  
Device Selection ◽  
Selection For

Mechanical circulatory support has expanded to meet the needs of a variety of patient populations requiring short-term and long-term applications and is utilized internationally. Short-term support devices offer treatment for cardiogenic shock and consist of varying support mechanisms, including univentricular and biventricular support options to improve hemodynamics and tissue perfusion. Investigational devices offer additional options to consider in device selection. Long-term support with ventricular assist devices or total artificial heart offers dischargeable options for lifelong support, recovery, or while patients await organ transplantation. Consideration of device availability, expenses and coverage, operator expertise, and technical challenges should be undertaken when determining patient support strategies. Reviewing patient comorbidities and time frame needed for support is imperative when considering device options to ensure appropriate device selection for each individual patient, thus mitigating risks and maximizing outcomes. Innovation will continue to drive progress in mechanical circulatory support with ongoing development of novel strategies to afford new options to optimize support of patients with heart failure.

scholarly journals The Genetic Architecture of Response to Long-Term Artificial Selection for Oil Concentration in the Maize Kernel

Genetics ◽  
2004 ◽  
Vol 168 (4) ◽  
pp. 2141-2155 ◽  
Author(s):  
Cathy C. Laurie ◽  
Scott D. Chasalow ◽  
John R. LeDeaux ◽  
Robert McCarroll ◽  
David Bush ◽  
...  
Keyword(s):  
Artificial Selection ◽  
Genetic Architecture ◽  
Maize Kernel ◽  
Oil Concentration ◽  
Selection For

A genetic mechanism for sexual dichromatism in birds

Science ◽  
2020 ◽  
Vol 368 (6496) ◽  
pp. 1270-1274 ◽  
Author(s):  
Małgorzata A. Gazda ◽  
Pedro M. Araújo ◽  
Ricardo J. Lopes ◽  
Matthew B. Toomey ◽  
Pedro Andrade ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Molecular Mechanisms ◽  
Major Effect ◽  
Common Mechanism ◽  
Sexual Dichromatism ◽  
Specific Variation ◽  
Males And Females ◽  
Selection For ◽  
Β Carotene ◽  
Carotenoid Degradation

Sexual dichromatism, a difference in coloration between males and females, may be due to sexual selection for ornamentation and mate choice. Here, we show that carotenoid-based dichromatism in mosaic canaries, a hybrid phenotype that arises in offspring of the sexually dichromatic red siskin and monochromatic canaries, is controlled by the gene that encodes the carotenoid-cleaving enzyme β-carotene oxygenase 2 (BCO2). Dichromatism in mosaic canaries is explained by differential carotenoid degradation in the integument, rather than sex-specific variation in physiological functions such as pigment uptake or transport. Transcriptome analyses suggest that carotenoid degradation in the integument might be a common mechanism contributing to sexual dichromatism across finches. These results suggest that differences in ornamental coloration between sexes can evolve through simple molecular mechanisms controlled by genes of major effect.

Mating success and wing morphometry in Drosophila melanogaster after long-term rearing on different diets

Behaviour ◽  
2013 ◽  
Vol 150 (12) ◽  
pp. 1431-1448 ◽  
Author(s):  
Jelena Trajković ◽  
Sofija Pavković-Lučić ◽  
Tatjana Savić
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Environmental Factors ◽  
Mate Choice ◽  
Mating Success ◽  
Phenotypic Variation ◽  
Wing Size ◽  
Males And Females ◽  
Ethological Isolation

Different environmental factors are important for development, physiology, behaviour and, therefore, adaptation of Drosophila species. Additionally, the presence of genetic and phenotypic variation in traits affecting mate choice forms the basis for sexual selection that may lead to isolation between populations in different nutritive environments. The aim of this research was to determine mating success and wing morphometry of Drosophila melanogaster flies after more than a decade of growing on banana and carrot substrates. Males and females reared on carrot medium were more successful in mating than flies reared on banana diet. Females originating from banana medium rather chose males originating from carrot substrate, while females developed on carrot medium equally chose males developed on both substrates. Differences in wing size and shape were observed between sexes and nutritional strains. Furthermore, the results showed absence of ethological isolation between two ‘nutritional’ strains.

scholarly journals Body size and climate as predictors of plumage colouration and sexual dichromatism in parrots

2020 ◽  
Author(s):  
Luisana Carballo ◽  
Kaspar Delhey ◽  
Mihai Valcu ◽  
Bart Kempenaers
Keyword(s):  
Sexual Selection ◽  
Social Interactions ◽  
Life Histories ◽  
Sexual Dichromatism ◽  
Cavity Nesting ◽  
Mutual Mate Choice ◽  
Parrot Species ◽  
Males And Females ◽  
Selection For ◽  
Nesting Habits

AbstractPsittaciformes (parrots, cockatoos and lorikeets) comprise one of the most colourful clades of birds. Their unique pigments and cavity nesting habits are two potential explanations for their colourful character. However, plumage colour varies substantially between parrot species and sometimes also between males and females of the same species. Here, we use comparative analyses to evaluate what factors correlate with colour elaboration, colour diversity and sexual dichromatism. Specifically, we test the association between different aspects of parrot colouration and (1) the intensity of sexual selection and social interactions, (2) variation along the slow-fast life-history continuum and (3) climatic variation. We show that larger species and species that live in warm environments display more elaborated colours, yet smaller species have higher levels of sexual dichromatism. Larger parrots tend to have darker and more blue and red colours. Parrots that live in humid environments are darker and redder, whilst species inhabiting warm regions have more blue plumage colours. In general, the variables we considered explain small to moderate amounts of variation in parrot colouration (up to 20%). Our data suggest that sexual selection may be acting more strongly on males in small, short-lived parrots leading to sexual dichromatism. More elaborate colouration in both males and females of the larger, long-lived species with slow tropical life-histories suggests that mutual mate choice and reduced selection for crypsis may be important in these species, as has been shown for passerines.

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