scholarly journals Micropyle number is associated with elevated female promiscuity in Lepidoptera

2016 ◽  
Vol 12 (12) ◽  
pp. 20160782 ◽  
Author(s):  
Graziella Iossa ◽  
Matthew J. G. Gage ◽  
Paul E. Eady
Keyword(s):  
Sexual Selection ◽  
Comparative Analysis ◽  
Female Choice ◽  
Phylogenetic Signal ◽  
Mating Pattern ◽  
Sperm Limitation ◽  
Female Mating ◽  
Female Promiscuity ◽  
The Relationship ◽  
Unexplained Variation

In the majority of insects, sperm fertilize the egg via a narrow canal through the outer chorion called the micropyle. Despite having this one primary function, there is considerable unexplained variation in the location, arrangement and number of micropyles within and between species. Here, we examined the relationship between micropyle number and female mating pattern through a comparative analysis across Lepidoptera. Three functional hypotheses could explain profound micropylar variation: (i) increasing micropyle number reduces the risk of infertility through sperm limitation in species that mate infrequently; (ii) decreasing micropyle number reduces the risk of pathological polyspermy in species that mate more frequently; and (iii) increasing micropyle number allows females to exert greater control over fertilization within the context of post-copulatory sexual selection, which will be more intense in promiscuous species. Micropyle number was positively related to the degree of female promiscuity as measured by spermatophore count, regardless of phylogenetic signal, supporting the hypothesis that micropyle number is shaped by post-copulatory sexual selection. We discuss this finding in the context of cryptic female choice, sperm limitation and physiological polyspermy.

scholarly journals Sexual selection favours male parental care, when females can choose

2011 ◽  
Vol 279 (1734) ◽  
pp. 1784-1790 ◽  
Author(s):  
Suzanne H. Alonzo
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Female Choice ◽  
Mating Success ◽  
Current Theory ◽  
Sharp Contrast ◽  
Recent Theory ◽  
Extra Pair Paternity ◽  
Female Promiscuity ◽  
Male Care

Explaining the evolution of male care has proved difficult. Recent theory predicts that female promiscuity and sexual selection on males inherently disfavour male care. In sharp contrast to these expectations, male-only care is often found in species with high extra-pair paternity and striking variation in mating success, where current theory predicts female-only care. Using a model that examines the coevolution of male care, female care and female choice; I show that inter-sexual selection can drive the evolution of male care when females are able to bias mating or paternity towards parental males. Surprisingly, female choice for parental males allows male care to evolve despite low relatedness between the male and the offspring in his care. These results imply that predicting how sexual selection affects parental care evolution will require further understanding of why females, in many species, either do not prefer or cannot favour males that provide care.

"The Cock of Lordly Plume": Sexual Selection and The Egoist

1995 ◽  
Vol 50 (1) ◽  
pp. 51-77 ◽  
Author(s):  
Jonathan Smith
Keyword(s):  
Sexual Selection ◽  
Female Choice ◽  
Moral Sense ◽  
Evolutionary Development ◽  
Woman Question ◽  
The Novel ◽  
The Relationship ◽  
Descent Of Man

Despite a long-standing acknowledgment of the evolutionary chracter of George Meredith's poetry and fiction, and a more recent delineation of the specifically Darwinian elements of The Egoist (1879), the relationship between that novel and Darwin's The Descent of Man, and Selection in Relation to Sex (1871) has been overlooked. Both works focus on the evolutionary development of the human moral sense and on the process of courtship between the sexes, but Meredith's novel links these issues while Darwin's book keeps them separate. Through his characterization of Sir Willoughby Patterne, Meredith shows that "civilized" egoism is a sign of moral reversion most likely to occur during courtship, and he critiques Darwin's discussion of sexual selection in humans, exposing its inconsistencies and in particular challenging its portrayal of female choice. While modern feminist critics have rightly identified problems with the novel and the theory of comedy that governs it, Meredith's attack on Darwin's culturally powerful view of the sexes endorses a postion on "the woman question" close to John Stuart Mill's, and the novel's problems are best seen as part of this attack rather than as naive self-contradictions of Meredith's feminism.

scholarly journals Legs morphometric characters of the Dolichopus Latreille species, 1796 (Diptera, Dolichopodidae)

2020 ◽  
Vol 9 (1) ◽  
pp. 106-112
Author(s):  
Mariya Alexandrovna Chursina ◽  
Oleg Pavlovich Negrobov
Keyword(s):  
Sexual Selection ◽  
Comparative Analysis ◽  
Phylogenetic Signal ◽  
Hind Tibia ◽  
Interspecific Variation ◽  
The Other ◽  
Insertion Point ◽  
Morphometric Traits ◽  
Closely Related Species ◽  
Morphometric Characters

A comparative analysis of 30 species of the Dolichopodidae family in a phylogenetic context was conducted to examine interspecific variation in the legs morphometry. Five relative traits of legs from 12 and seven absolute traits from nine showed significant phylogenetic signal. A set of traits, such as relatively short hind tibia and relatively long fore and middle tibia and the first segments of the hind legs allowed to allocate Dolichopus species from the other ones. The projection of the phylogenetic tree of Dolichopus species into the morphospace allowed us to divide it into four individual areas: not closely related species, but species having similar modifications of males legs tended to cluster. This suggests that the legs morphometric traits should be mainly under pressure of sexual selection. It has also been revealed that the elongation of the first segment of hind tarsi in Dolichopus species is associated with the distal displacement of the insertion point of dm-m with M4 and the decrease of the length of R4+5 . The functional significance of these characters set is discussed.

Cephalopod mating systems as models for the study of sexual selection and alternative reproductive tactics: a review

2020 ◽  
Vol 96 (2) ◽  
pp. 375-398
Author(s):  
Lígia Haselmann Apostólico ◽  
José Eduardo Amoroso RodriguezMarian
Keyword(s):  
Sexual Selection ◽  
Female Choice ◽  
Mantle Cavity ◽  
Alternative Reproductive Tactics ◽  
Male Mating ◽  
Reproductive Tactics ◽  
Mating Period ◽  
Alternative Pathways ◽  
Female Promiscuity ◽  
Striking Change

Cephalopods are a remarkable group for studies on sexual selection, due to their complex reproductive behavior, pronounced sexual dimorphism, polygamous behavior, as well as cumulative evidence of pre- and postcopulatory male-male competition and female choice in the group. is paper provides a review of sexual selection studies on cephalopods, with an emphasis on the loliginid squid mating system. In this system, males may adopt alternative reproductive tactics (ART) and display male intrasexual dimorphism, with each morph generally exhibiting distinct behaviors and ejaculate traits. Consort males typically transfer ejaculates to the female mantle cavity, while sneaker males typically transfer ejaculates to the female buccal region, where a sperm storage organ is located. Each site provides distinct fertilization environments for the ejaculates of each morph, differing in the availability of eggs, gamete protection, and timing between mating and fertilization. Accordingly, the ejaculates of each morph show putative adaptations for each site, differing in size, morphology, sperm release duration, and sperm behavior. Although solid evidence is lacking for most loliginids, cryptic female choice may occur in this system through, for example, spermatangia removal or egg string manipulation during fertilization. In addition, recent evidence for one loliginid species indicates that adoption of male ART is ontogenetic and may represent two alternative pathways: from immature males (i) directly to consort phenotype or (ii) going through a sneaker phase, then switching to consort morph. The second pathway would, therefore, imply striking change in behavior, physiology, and ejaculates. Moreover, data on the age of this species suggests that the adoption of sneaker tactic early in life may be associated with extending the male mating period by 25%. With such a peculiar system, loliginids should prove useful not only for comprehending the evolution of female promiscuity and ART in cephalopods, but also as an emerging nonvertebrate and nonarthropod model for testing sperm competition models.

The number of employed as a macroeconomic indicator of working time dynamics

2020 ◽  
Vol 16 (5) ◽  
pp. 935-945
Author(s):  
I.A. Zaikova
Keyword(s):  
Comparative Analysis ◽  
Manufacturing Sector ◽  
Working Hours ◽  
Working Time ◽  
Labor Costs ◽  
Factors Affecting ◽  
Time Dynamics ◽  
Developed Economies ◽  
The Relationship ◽  
Macroeconomic Indicator

Subject. The working time of workers at any stage of economic development is a value reflecting the level of labor productivity. Any progress in productivity contributes to changes in the volume of labor costs and the number of employed. Depending on the relationship between the total volume of labor costs and the number of employed, the duration of working time per one worker may change (it may increase, decrease, or remain unchanged). Objectives. The study aims to confirm the importance of such a macroeconomic indicator as the number of employed in varying working hours. Methods. The study rests on the comparative analysis of countries with developed economies based on some indicators like dynamics of the working time fund, dynamics of the number of employed, average number of hours worked during the year per employee, etc. The analyzed timespan is 25 years (from 1991 to 2016). Results. The comparative analysis revealed that in the non-production sphere and the economy as a whole the macroeconomic determinants correlate so that the length of working time per worker reduces. When considering the analysis results for the manufacturing sector, no single trend was identified. Conclusions. One of the key factors affecting the change in working hours is the number of employed. The relationship between the working time fund and the number of employed directly determines the dynamics of working time per worker.

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.

scholarly journals Research on the Relationship between Shared Leadership and Individual Creativity-Qualitative Comparative Analysis on the Basis of Clear Set

2021 ◽  
Vol 13 (10) ◽  
pp. 5445
Author(s):  
Muyun Sun ◽  
Jigan Wang ◽  
Ting Wen
Keyword(s):  
Comparative Analysis ◽  
Environmental Factors ◽  
Shared Leadership ◽  
Management Practices ◽  
Qualitative Comparative Analysis ◽  
Necessary Condition ◽  
The Individual ◽  
The Impact ◽  
The Relationship ◽  
Sufficient And Necessary Condition

Creativity is the key to obtaining and maintaining competitiveness of modern organizations, and it has attracted much attention from academic circles and management practices. Shared leadership is believed to effectively influence team output. However, research on the impact of individual creativity is still in its infancy. This study adopts the qualitative comparative analysis method, taking 1584 individuals as the research objects, underpinned by a questionnaire-based survey. It investigates the influence of the team’s shared leadership network elements and organizational environmental factors on the individual creativity. We have found that there are six combination of conditions of shared leadership and organizational environmental factors constituting sufficient combination of conditions to increase or decrease individual creativity. Moreover, we have noticed that the low network density of shared leadership is a sufficient and necessary condition of reducing individual creativity. Our results also provide management suggestions for practical activities during the team management.

scholarly journals What Do Those Cohabiting Believe about Relationship Social Support and Premarital Counseling? A Comparative Analysis

2021 ◽  
Vol 10 (5) ◽  
pp. 183
Author(s):  
Jennifer McGhee ◽  
Brandon Burr ◽  
Allison Vanrosendale ◽  
Deisy Figueroa
Keyword(s):  
Social Support ◽  
Comparative Analysis ◽  
Relationship Satisfaction ◽  
Human Ecology ◽  
Premarital Counseling ◽  
Relationship Status ◽  
Family Practitioners ◽  
Study Results ◽  
Relationship Success ◽  
The Relationship

Relationship researchers have long studied factors that boost or detract from relationship success. Social support and premarital counseling are factors that have been shown to boost relationship satisfaction and relationship success. However, little is known about how relationship status may influence attitudes toward social support and premarital counseling. Using a human ecology lens, this study explores the relationship between relationship status and attitudes toward social support and premarital counseling from a sample of 385 individuals. Implications for family practitioners and future researchers are provided based on study results.

scholarly journals The relationship between sexual selection and speciation

2012 ◽  
Vol 58 (3) ◽  
pp. 413-415 ◽  
Author(s):  
Maria R. Servedio
Keyword(s):  
Sexual Selection ◽  
The Relationship
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