scholarly journals Sexual dichromatism in frogs: natural selection, sexual selection and unexpected diversity

2012 ◽  
Vol 279 (1748) ◽  
pp. 4687-4693 ◽  
Author(s):  
Rayna C. Bell ◽  
Kelly R. Zamudio
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Phylogenetic Signal ◽  
Colour Change ◽  
Sexual Dichromatism ◽  
Evolutionary Mechanisms ◽  
Males And Females ◽  
Colour Dimorphism ◽  
Natural And Sexual Selection ◽  
High Diversity

Sexual dichromatism, a form of sexual dimorphism in which males and females differ in colour, is widespread in animals but has been predominantly studied in birds, fishes and butterflies. Moreover, although there are several proposed evolutionary mechanisms for sexual dichromatism in vertebrates, few studies have examined this phenomenon outside the context of sexual selection. Here, we describe unexpectedly high diversity of sexual dichromatism in frogs and create a comparative framework to guide future analyses of the evolution of these sexual colour differences. We review what is known about evolution of colour dimorphism in frogs, highlight alternative mechanisms that may contribute to the evolution of sexual colour differences, and compare them to mechanisms active in other major groups of vertebrates. In frogs, sexual dichromatism can be dynamic (temporary colour change in males) or ontogenetic (permanent colour change in males or females). The degree and the duration of sexual colour differences vary greatly across lineages, and we do not detect phylogenetic signal in the distribution of this trait, therefore frogs provide an opportunity to investigate the roles of natural and sexual selection across multiple independent derivations of sexual dichromatism.

Reproductive behavior

2018 ◽  
Author(s):  
Rachel Olzer ◽  
Rebecca L. Ehrlich ◽  
Justa L. Heinen-Kay ◽  
Jessie Tanner ◽  
Marlene Zuk
Keyword(s):  
Sexual Selection ◽  
Sexual Conflict ◽  
Female Choice ◽  
Reproductive Behavior ◽  
Mating Systems ◽  
Insect Behavior ◽  
Sequential Approach ◽  
Evolutionary Mechanisms ◽  
Anatomy And Physiology ◽  
Males And Females

Sex and reproduction lie at the heart of studies of insect behavior. We begin by providing a brief overview of insect anatomy and physiology, followed by an introduction to the overarching themes of parental investment, sexual selection, and mating systems. We then take a sequential approach to illustrate the diversity of phenomena and concepts behind insect reproductive behavior from pre-copulatory mate signalling through copulatory sperm transfer, mating positions, and sexual conflict, to post-copulatory sperm competition, and cryptic female choice. We provide an overview of the evolutionary mechanisms driving reproductive behavior. These events are linked by the economic defendability of mates or resources, and how these are allocated in each sex. Under the framework of economic defendability, the reader can better understand how sexual antagonistic behaviors arise as the result of competing optimal fitness strategies between males and females.

Differences in male and female cognitive abilities: Sexual selection or division of labor?

1996 ◽  
Vol 19 (2) ◽  
pp. 254-255
Author(s):  
Michael T. Ghiselin
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Sexual Dimorphism ◽  
Division Of Labor ◽  
Cognitive Abilities ◽  
Reproductive Competition ◽  
Male And Female ◽  
Males And Females

AbstractIn Darwinian terminology, “sexual selection” refers to purely reproductive competition and is conceptually distinct from natural selection as it affects reproduction generally. As natural selection may favor the evolution of sexual dimorphism by virtue of the division of labor between males and females, this possibility needs to be taken very seriously.

scholarly journals Sexual selection is a form of social selection

2012 ◽  
Vol 367 (1600) ◽  
pp. 2266-2273 ◽  
Author(s):  
Bruce E. Lyon ◽  
Robert Montgomerie
Keyword(s):  
Sexual Selection ◽  
Social Interactions ◽  
Social Selection ◽  
Reproductive Competition ◽  
Selection Theory ◽  
Males And Females ◽  
Female Roles ◽  
Comprehensive Framework ◽  
Natural And Sexual Selection ◽  
Lines Of Evidence

Social selection influences the evolution of weapons, ornaments and behaviour in both males and females. Thus, social interactions in both sexual and non-sexual contexts can have a powerful influence on the evolution of traits that would otherwise appear to be detrimental to survival. Although clearly outlined by West-Eberhard in the early 1980s, the idea that social selection is a comprehensive framework for the study of ornaments and weapons has largely been ignored. In West-Eberhard's view, sexual selection is a form of social selection—a concept supported by several lines of evidence. Darwin's distinction between natural and sexual selection has been useful, but recent confusion about the limits of sexual selection suggests that some traits are not easily categorized as naturally or sexually selected. Because social selection theory has much to offer the current debates about both sexual selection and reproductive competition in females, it is sometimes viewed, narrowly, to be most useful when considering female roles. However, social selection theory encompasses much more than female reproductive competition. Our goal here was to provide that broader perspective.

scholarly journals Natural and sexual selection act on different axes of variation in avian plumage color

2015 ◽  
Vol 1 (2) ◽  
pp. e1400155 ◽  
Author(s):  
Peter O. Dunn ◽  
Jessica K. Armenta ◽  
Linda A. Whittingham
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Habitat Type ◽  
Sexual Differences ◽  
Plumage Color ◽  
Evolutionary Transitions ◽  
Testes Size ◽  
Selection For ◽  
Bird Coloration ◽  
Natural And Sexual Selection

The bright colors of birds are often attributed to sexual selection on males, but in many species both sexes are colorful and it has been long debated whether sexual selection can also explain this variation. We show that most evolutionary transitions in color have been toward similar plumage in both sexes, and the color of both sexes (for example, bright or dull) was associated with indices of natural selection (for example, habitat type), whereas sexual differences in color were primarily associated with indices of sexual selection on males (for example, polygyny and large testes size). Debate about the evolution of bird coloration can be resolved by recognizing that both natural and sexual selection have been influential, but they have generally acted on two different axes: sexual selection on an axis of sexual differences and natural selection on both sexes for the type of color (for example, bright or dull).

scholarly journals Integrating natural and sexual selection across the biphasic life cycle

2021 ◽  
Author(s):  
Craig Purchase ◽  
Jonathan Evans ◽  
Julissa Roncal
Keyword(s):  
Sexual Selection ◽  
Life Cycle ◽  
Natural Selection ◽  
Conceptual Framework ◽  
Life Cycles ◽  
Parental Effect ◽  
Biphasic Life Cycle ◽  
Evolutionary Trajectories ◽  
Taxonomic Groups ◽  
Natural And Sexual Selection

An alternation between diploid and haploid phases is universal among sexual eukaryotes. Across this biphasic cycle, natural selection and sexual selection occur in both phases. Together, these four stages of selection act on the phenotypes of individuals and influence the evolutionary trajectories of populations, but are rarely studied holistically. Here, we provide a conceptual framework that transcends taxonomic groups, and unifies the entire selection landscape within and across the diploid and haploid phases. Our synthesis produces six direct links among four selection stages, and from this we define four types of parental effect. We argue that knowledge of the complex and intertwined opportunities for selection within biphasic life cycles will offer clearer insights into key ecological and evolutionary processes, with benefits to applied science.

scholarly journals Ontogenetic allometry in the foot size of Oligoryzomys flavescens (Waterhouse, 1837) (Rodentia, Sigmodontinae)

2015 ◽  
Vol 75 (2) ◽  
pp. 435-441 ◽  
Author(s):  
R. Maestri ◽  
R. Fornel ◽  
TRO. Freitas ◽  
JR. Marinho
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Sexual Dimorphism ◽  
Encounter Rate ◽  
Allometric Growth ◽  
Positive Allometry ◽  
Rate Of Growth ◽  
Ontogenetic Allometry ◽  
Males And Females ◽  
Oligoryzomys Flavescens

Ontogenetic allometry is the study of how the size or shape of certain structures changes over the course of an animal’s development. In this study, using Huxley's formula of allometric growth (1932), we assessed the changes in the rate of growth of the feet size of the sigmodontine rodent Oligoryzomys flavescens during its ontogeny and compared differences between males and females. We find evidence of a change of polarity during the ontogenetic development of the species, with the presence of positive allometry during pregnancy and negative allometry in adulthood. Moreover, we note the presence of sexual dimorphism in the size of the feet, in which males of the species have a higher rate of growth than females. This growth pattern is positively related to escape from predators in childhood in both sexes and, in adulthood, provides a higher encounter rate of females by males, due to the larger displacement of the latter. We suggest that both the forces of natural selection and sexual selection have acted to shape the evolution of foot size in this species.

scholarly journals Natural and sexual selection on many loci.

Genetics ◽  
1991 ◽  
Vol 127 (1) ◽  
pp. 229-255 ◽  
Author(s):  
N H Barton ◽  
M Turelli
Keyword(s):  
Sexual Selection ◽  
Linkage Disequilibrium ◽  
Natural Selection ◽  
Arbitrary Number ◽  
Indirect Selection ◽  
Weak Selection ◽  
Nonrandom Mating ◽  
Linkage Disequilibria ◽  
Female Preferences ◽  
Natural And Sexual Selection

Abstract A method is developed that describes the effects on an arbitrary number of autosomal loci of selection on haploid and diploid stages, of nonrandom mating between haploid individuals, and of recombination. We provide exact recursions for the dynamics of allele frequencies and linkage disequilibria (nonrandom associations of alleles across loci). When selection is weak relative to recombination, our recursions provide simple approximations for the linkage disequilibria among arbitrary combinations of loci. We show how previous models of sex-independent natural selection on diploids, assortative mating between haploids, and sexual selection on haploids can be analyzed in this framework. Using our weak-selection approximations, we derive new results concerning the coevolution of male traits and female preferences under natural and sexual selection. In particular, we provide general expressions for the intensity of linkage-disequilibrium induced selection experienced by loci that contribute to female preferences for specific male traits. Our general results support the previous observation that these indirect selection forces are so weak that they are unlikely to dominate the evolution of preference-producing loci.

scholarly journals Selection on phenotypic plasticity favors thermal canalization

2020 ◽  
Author(s):  
Erik I. Svensson ◽  
Miguel Gomez-Llano ◽  
John T. Waller
Keyword(s):  
Climate Change ◽  
Sexual Selection ◽  
Heat Stress ◽  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Reaction Norm ◽  
Thermal Reaction ◽  
Ambient Temperatures ◽  
Thermal Plasticity ◽  
Natural And Sexual Selection

AbstractClimate change affects organisms worldwide with profound ecological and evolutionary consequences, often increasing population extinction risk. Climatic factors can increase the strength, variability or direction of natural selection on phenotypic traits, potentially driving adaptive evolution. Phenotypic plasticity in relation to temperature can allow organisms to maintain fitness in response to increasing temperatures, thereby “buying time” for subsequent genetic adaptation and promoting evolutionary rescue. Although many studies have shown that organisms respond plastically to increasing temperatures, it is unclear if such thermal plasticity is adaptive. Moreover, we know little about how natural and sexual selection operate on thermal reaction norms reflecting such plasticity. Here, we investigate how natural and sexual selection shape phenotypic plasticity in two congeneric and phenotypically similar sympatric insect species. We show that the thermal optima for longevity and mating success differ, suggesting temperature-dependent trade-offs between survival and reproduction. Males in these species have similar thermal reaction norm slopes but have diverged in baseline body temperature (intercepts), being higher for the more northern species. Natural selection favoured reduced thermal reaction norm slopes at high ambient temperatures, suggesting that the current level of thermal plasticity is maladaptive in the context of anthropogenic climate change and that selection now promotes thermal canalization and robustness. Our results show that ectothermic animals also at high latitudes can suffer from overheating and challenge the common view of phenotypic plasticity as being beneficial in harsh and novel environments.Significance StatementOrganisms are increasingly challenged by increasing temperatures due to climate change. In insects, body temperatures are strongly affected by ambient temperatures, and insects are therefore expected to suffer increasingly from heat stress, potentially reducing survival and reproductive success leading to elevated extinction risks. We investigated how ambient temperature affected fitness in two insect species in the temperate zone. Male and female survivorship benefitted more from low temperatures than did reproductive success, which increased with higher temperatures, revealing a thermal conflict between fitness components. Male body temperature plasticity reduced survival, and natural and sexual selection operated on such thermal plasticity. Our results reveal the negative consequences of thermal plasticity and show that these insects have limited ability to buffer heat stress.

The Alignment of Natural and Sexual Selection

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Locke Rowe ◽  
Howard D. Rundle
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Population History ◽  
Annual Review ◽  
Publication Date ◽  
Net Benefit ◽  
Mean Fitness ◽  
The Many ◽  
Natural And Sexual Selection ◽  
Natural Selection Theory

Sexual selection has the potential to decrease mean fitness in a population through an array of costs to nonsexual fitness. These costs may be offset when sexual selection favors individuals with high nonsexual fitness, causing the alignment of sexual and natural selection. We review the many laboratory experiments that have manipulated mating systems aimed at quantifying the net effects of sexual selection on mean fitness. These must be interpreted in light of population history and the diversity of ways manipulations have altered sexual interactions, sexual conflict, and sexual and natural selection. Theory and data suggest a net benefit is more likely when sexually concordant genetic variation is enhanced and that ecological context can mediate the relative importance of these different effects. Comparative studies have independently examined the consequences of sexual selection for population/species persistence. These provide little indication of a benefit, and interpreting these higher-level responses is challenging. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 52 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Interactions of natural and sexual selection: damselfish prioritize brood defense with male–male competition or courtship

Behaviour ◽  
2010 ◽  
Vol 147 (1) ◽  
pp. 37-52 ◽  
Author(s):  
Joseph Leese ◽  
Jennifer Snekser ◽  
Murray Itzkowitz
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Selection Pressure ◽  
Nest Site ◽  
Sexual Competition ◽  
Selection Pressures ◽  
Multiple Factors ◽  
Stegastes Leucostictus ◽  
Brood Defense ◽  
Natural And Sexual Selection

AbstractNatural and sexual selection often act in opposing directions, forcing individuals to prioritize activities necessary for survival with those required for reproduction. We examined the interaction of natural and sexual selection pressures on the behaviour of beaugregory damselfish, Stegastes leucostictus, by presenting territorial males with an egg predator and either a male or female conspecific, requiring males to prioritize brood defense with either courtship or intra-sexual competition. By measuring the time spent near stimuli, we examined the influence of several factors, including stimuli type, variation in predator number, and the presence of eggs in a nest site. Generally, males spent more time with conspecific stimuli than egg predators, suggesting that the sexual selection pressures of deterring rivals and attracting mates outweigh the natural selection pressure to engage in brood defense. This decision was affected by the sex of the conspecific presented, the presence of eggs in a male's territory, and a number of interactions of these factors, indicating that male damselfish consider multiple factors before investing in certain types and intensities of behaviours. Furthermore, observations of behaviours associated with courtship and intrasexual aggression show that a natural selection pressure impacts intra- and inter-sexually selected behaviours differently in this system.

Sign in / Sign up

Export Citation Format

Share Document