scholarly journals A scientometric analysis on pre- and post-copulatory traits in Odonata

2021 ◽  
Vol 24 ◽  
pp. 215-226
Author(s):  
Gabrielle Cristina Pestana ◽  
Erick Mateus-Barros ◽  
Leandro Schlemmer Brasil ◽  
Rhainer Guillermo-Ferreira
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Sperm Quality ◽  
Large Body ◽  
Size Variation ◽  
Integrative Approach ◽  
Scientometric Analysis ◽  
Sexual Ornaments ◽  
Male Characters ◽  
Male Wing

In the last decades, studies on sexual selection in odonates have shown a relationship between mating success and costly sexual ornaments, mainly male characters. Here, we conducted a scientometric analysis to assess the state of art of studies on sexual selection in odonates, especially on the role of male ornamentation (pre-copulatory traits) and sperm competition (post-copulatory traits). We found 51 papers focused on sexual ornamentation and 34 on sperm competition. Only one study simultaneously addressed both pre- and post-copulatory traits, nevertheless without an integrative approach. Results show that calopterygids are extensively studied regarding pre-copulatory traits (i.e., male wing pigmentation), while libellulids are mostly studied in post- copulatory traits (e.g., sperm competition) focused research. These preferences seem to be related to characteristics like presence of ornamentation and territoriality, large body size, variation and complexity of sperm removal structures, respectively. For the post-copulatory traits, sperm removal is frequently addressed, but few other strategies, like the investment in sperm quality and quantity, are investigated. Finally, we demonstrate that it is necessary to conduct studies focused on addressing the relationship between pre- and post- mating sexual traits.

scholarly journals Independent evolution towards larger body size in the distinctive Faroe Island mice

2021 ◽  
Author(s):  
Ricardo Wilches ◽  
William H Beluch ◽  
Ellen McConnell ◽  
Diethard Tautz ◽  
Yingguang Frank Chan
Keyword(s):  
Body Size ◽  
Meta Analysis ◽  
Small Body ◽  
Laboratory Mouse ◽  
Large Body ◽  
Natural Populations ◽  
Size Variation ◽  
Phenotypic Traits ◽  
Island Population ◽  
Multiple Loci

Abstract Most phenotypic traits in nature involve the collective action of many genes. Traits that evolve repeatedly are particularly useful for understanding how selection may act on changing trait values. In mice, large body size has evolved repeatedly on islands and under artificial selection in the laboratory. Identifying the loci and genes involved in this process may shed light on the evolution of complex, polygenic traits. Here, we have mapped the genetic basis of body size variation by making a genetic cross between mice from the Faroe Islands, which are among the largest and most distinctive natural populations of mice in the world, and a laboratory mouse strain selected for small body size, SM/J. Using this F2 intercross of 841 animals, we have identified 111 loci controlling various aspects of body size, weight and growth hormone levels. By comparing against other studies, including the use of a joint meta-analysis, we found that the loci involved in the evolution of large size in the Faroese mice were largely independent from those of a different island population or other laboratory strains. We hypothesize that colonization bottleneck, historical hybridization, or the redundancy between multiple loci have resulted in the Faroese mice achieving an outwardly similar phenotype through a distinct evolutionary path.

scholarly journals Gamete-mediated mate choice: towards a more inclusive view of sexual selection

2018 ◽  
Vol 285 (1883) ◽  
pp. 20180836 ◽  
Author(s):  
Jukka Kekäläinen ◽  
Jonathan P. Evans
Keyword(s):  
Sexual Selection ◽  
Mate Choice ◽  
Sperm Competition ◽  
Female Choice ◽  
Mating Systems ◽  
Molecular Level ◽  
Evolutionary Significance ◽  
Random Interactions ◽  
Physiological Processes ◽  
The Everyday

‘Sperm competition’—where ejaculates from two or more males compete for fertilization—and ‘cryptic female choice’—where females bias this contest to suit their reproductive interests—are now part of the everyday lexicon of sexual selection. Yet the physiological processes that underlie these post-ejaculatory episodes of sexual selection remain largely enigmatic. In this review, we focus on a range of post-ejaculatory cellular- and molecular-level processes, known to be fundamental for fertilization across most (if not all) sexually reproducing species, and point to their putative role in facilitating sexual selection at the level of the cells and gametes, called ‘gamete-mediated mate choice’ (GMMC). In this way, we collate accumulated evidence for GMMC across different mating systems, and emphasize the evolutionary significance of such non-random interactions among gametes. Our overall aim in this review is to build a more inclusive view of sexual selection by showing that mate choice often acts in more nuanced ways than has traditionally been assumed. We also aim to bridge the conceptual divide between proximal mechanisms of reproduction, and adaptive explanations for patterns of non-random sperm–egg interactions that are emerging across an increasingly diverse array of taxa.

Post-Copulatory Sexual Selection

2021 ◽  
Author(s):  
Patricia L.R. Brennan ◽  
Dara N. Orbach
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Reproductive Tract ◽  
Seminal Fluid ◽  
Fertilization Success ◽  
Female Reproductive Tract ◽  
Cryptic Female Choice ◽  
Trade Offs ◽  
Morphological Criteria

The field of post-copulatory sexual selection investigates how female and male adaptations have evolved to influence the fertilization of eggs while optimizing fitness during and after copulation, when females mate with multiple males. When females are polyandrous (one female mates with multiple males), they may optimize their mating rate and control the outcome of mating interactions to acquire direct and indirect benefits. Polyandry may also favor the evolution of male traits that offer an advantage in post-copulatory male-male sperm competition. Sperm competition occurs when the sperm, seminal fluid, and/or genitalia of one male directly impacts the outcome of fertilization success of a rival male. When a female mates with multiple males, she may use information from a number of traits to choose who will sire her offspring. This cryptic female choice (CFC) to bias paternity can be based on behavioral, physiological, and morphological criteria (e.g., copulatory courtship, volume and/or composition of seminal fluid, shape of grasping appendages). Because male fitness interests are rarely perfectly aligned with female fitness interests, sexual conflict over mating and fertilization commonly occur during copulatory and post-copulatory interactions. Post-copulatory interactions inherently involve close associations between female and male reproductive characteristics, which in many species potentially include sperm storage and sperm movement inside the female reproductive tract, and highlight the intricate coevolution between the sexes. This coevolution is also common in genital morphology. The great diversity of genitalia among species is attributed to sexual selection. The evolution of genital attributes that allow females to maintain reproductive autonomy over paternity via cryptic female choice or that prevent male manipulation and sexual control via sexually antagonistic coevolution have been well documented. Additionally, cases where genitalia evolve through intrasexual competition are well known. Another important area of study in post-copulatory sexual selection is the examination of trade-offs between investments in pre-copulatory and post-copulatory traits, since organisms have limited energetic resources to allocate to reproduction, and securing both mating and fertilization is essential for reproductive success.

scholarly journals Evolutionary insight from a humble fly: sperm competition and the yellow dungfly

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200062
Author(s):  
Leigh W. Simmons ◽  
Geoff A. Parker ◽  
David J. Hosken
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Paradigm Shift ◽  
Mate Guarding ◽  
Reproductive Behaviour ◽  
Costs And Benefits ◽  
Theme Issue ◽  
Male And Female ◽  
Sexual Selection Theory ◽  
The 1960S

Studies of the yellow dungfly in the 1960s provided one of the first quantitative demonstrations of the costs and benefits associated with male and female reproductive behaviour. These studies advanced appreciation of sexual selection as a significant evolutionary mechanism and contributed to the 1970s paradigm shift toward individual selectionist thinking. Three behaviours in particular led to the realization that sexual selection can continue during and after mating: (i) female receptivity to remating, (ii) sperm displacement and (iii) post-copulatory mate guarding. These behaviours either generate, or are adaptations to sperm competition, cryptic female choice and sexual conflict. Here we review this body of work, and its contribution to the development of post-copulatory sexual selection theory. This article is part of the theme issue ‘Fifty years of sperm competition’.

scholarly journals Sperm removal during copulation confirmed in the oldest extant damselfly,Hemiphlebia mirabilis

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2077 ◽  
Author(s):  
Adolfo Cordero-Rivera
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Short Range ◽  
Body Position ◽  
Reproductive Behaviour ◽  
Scramble Competition ◽  
Stage I ◽  
Female Genitalia ◽  
Second Stage ◽  
Male Genital

Postcopulatory sexual selection may favour mechanisms to reduce sperm competition, like physical sperm removal by males. To investigate the origin of sperm removal, I studied the reproductive behaviour and mechanisms of sperm competition in the only living member of the oldest damselfly family,Hemiphlebia mirabilis, one species that was considered extinct in the 1980s. This species displays scramble competition behaviour. Males search for females with short flights and both sexes exhibit a conspicuous “abdominal flicking”. This behaviour is used by males during an elaborate precopulatory courtship, unique among Odonata. Females use a similar display to reject male attempts to form tandem, but eventually signal receptivity by a particular body position. Males immobilise females during courtship using their legs, which, contrarily to other damselflies, never autotomise. Copulation is short (range 4.1–18.7 min), and occurs in two sequential stages. In the first stage, males remove part of the stored sperm, and inseminate during the second stage, at the end of mating. The male genital ligula matches the size and form of female genitalia, and ends by two horns covered by back-oriented spines. The volume of sperm in females before copulation was 2.7 times larger than the volume stored in females whose copulation was interrupted at the end of stage I, indicative of a significant sperm removal. These results point out that sperm removal is an old character in the evolution of odonates, possibly dating back to the Permian.

scholarly journals A LIFE-HISTORY PERSPECTIVE ON SEXUAL SELECTION IN A POLYGAMOUS SPECIES

2019 ◽  
Author(s):  
Gao Ke ◽  
Michiel van Wijk ◽  
Zoe Clement ◽  
Martijn Egas ◽  
Astrid Groot
Keyword(s):  
Sexual Selection ◽  
Life History ◽  
Sperm Competition ◽  
Reproductive Output ◽  
Relative Fitness ◽  
Quadratic Model ◽  
Costs And Benefits ◽  
Bateman Gradient ◽  
Multiple Matings ◽  
Males And Females

Abstract Background Ever since Darwin, evolutionary biologists have studied sexual selection driving differences in appearance and behaviour between males and females. An unchallenged paradigm in such studies is that one sex (usually the male) signals its quality as a mate to the other sex (usually the female), who is choosy in accepting a partner. Here, we argue that in polygamous species these roles may change dynamically with the mating status of males and females, depending on direct reproductive costs and benefits of multiple matings, and on sperm competition. We test this hypothesis using a polygamous moth species, as in moths not males but females are the signalers and males are the responders. Results We found that multiple matings are beneficial as well as costly for both sexes. Specifically, the number of matings did not affect the longevity of males or females, but when paired with a new virgin mate every night for five nights, only 67% of the males and 14% of the females mated successfully in all five nights. The female’s reproductive output increased with multiple matings, although when paired with a new virgin male every night, additional matings beyond 3 decreased her reproductive output, so that the Bateman gradient for females fit a quadratic model better than a linear model. The male’s reproductive success was positively affected by the number of matings and a linear regression line best fit the data. Simulations of the effect of sperm competition showed that increasing last-male paternity increases the steepness of the male Bateman gradient and thus the male’s relative fitness gain from additional mating. Irrespective of last-male paternity value, the female Bateman gradient is steeper than the male one for up to three matings. Conclusion Our results suggest that choosiness in moths may well change throughout the mating season, with males being more choosy early in the season and females being more choosy after having mated at least three times. This life-history perspective on the costs and benefits of multiple matings for both sexes sheds new light on sexual selection forces acting on sexual signals and responses.

scholarly journals Sperm removal during copulation confirmed in the oldest extant damselfly, Hemiphlebia mirabilis

2016 ◽  
Author(s):  
Adolfo Cordero-Rivera
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Short Range ◽  
Body Position ◽  
Reproductive Behaviour ◽  
Scramble Competition ◽  
Stage I ◽  
Female Genitalia ◽  
Second Stage ◽  
Two Stages

Postcopulatory sexual selection may favour mechanisms to reduce sperm competition, like physical sperm removal by males. To investigate the origin of sperm removal, I studied the reproductive behaviour and mechanisms of sperm competition in the only living member of the oldest damselfly family, Hemiphlebia mirabilis, one species that was considered extinct in the 1980s. This species displays scramble competition behaviour, whose males search for females with short flights and both sexes exhibit a conspicuous “abdominal flicking”. This behaviour is used by males during an elaborate precopulatory courtship, unique among the Odonata. Females use a similar display to reject male attempts to form tandem, but eventually signal receptivity by a particular body position. Males immobilise females during courtship using their legs, which, contrarily to other damselflies, never autotomize. Copulation is short (range 4.1-18.7 min), and has two stages. In the first stage, males remove part of the stored sperm, and inseminate during the second stage, at the end of mating. The examination of genitalia indicates that males have two horns covered by back-oriented spines, which match the size and form of female genitalia. The volume of sperm in females after copulation was 2.8 times larger than the volume stored in females whose copulation was interrupted at the end of stage I, indicative of a significant sperm removal. These results point out that sperm removal is an old character in the evolution of odonates, probably dating back to the Permian.

scholarly journals Imminent risk of predation reduces the relative strength of postcopulatory sexual selection in the guppy

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200076
Author(s):  
Alexandra Glavaschi ◽  
Silvia Cattelan ◽  
Alessandro Grapputo ◽  
Andrea Pilastro
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Repeated Measures ◽  
Poecilia Reticulata ◽  
Male Reproductive Success ◽  
Sperm Production ◽  
Postcopulatory Sexual Selection ◽  
Repeated Measures Design ◽  
Risk Of Predation ◽  
Livebearing Fish

Fifty years of research on sperm competition has led to a very good understanding of the interspecific variation in sperm production traits. The reasons why this variation is often very large within populations have been less investigated. We suggest that the interaction between fluctuating environmental conditions and polyandry is a key phenomenon explaining such variation. We focus here on imminent predation risk (IPR). IPR impacts significantly several aspects of prey behaviour and reproduction, and it is expected to influence the operation of sexual selection before and after mating. We estimated the effect of IPR on the male opportunity for pre- and postcopulatory sexual selection in guppies ( Poecilia reticulata ), a livebearing fish where females prefer colourful males and mate multiply. We used a repeated-measures design, in which males were allowed to mate with different females either under IPR or in a predator-free condition. We found that IPR increased the total opportunity for sexual selection and reduced the relative contribution of postcopulatory sexual selection to male reproductive success. IPR is inherently variable and our results suggest that interspecific reproductive interference by predators may contribute towards maintaining the variation in sperm production within populations. This article is part of the theme issue ‘Fifty years of sperm competition'.

scholarly journals Sexual selection after gamete release in broadcast spawning invertebrates

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200069 ◽  
Author(s):  
Jonathan P. Evans ◽  
Rowan A. Lymbery
Keyword(s):  
Sexual Selection ◽  
Mate Choice ◽  
Sperm Competition ◽  
Sexual Conflict ◽  
Gamete Release ◽  
Theme Issue ◽  
Animal Kingdom ◽  
External Fertilization ◽  
Broadcast Spawning ◽  
Males And Females

Broadcast spawning invertebrates offer highly tractable models for evaluating sperm competition, gamete-level mate choice and sexual conflict. By displaying the ancestral mating strategy of external fertilization, where sexual selection is constrained to act after gamete release, broadcast spawners also offer potential evolutionary insights into the cascade of events that led to sexual reproduction in more ‘derived’ groups (including humans). Moreover, the dynamic reproductive conditions faced by these animals mean that the strength and direction of sexual selection on both males and females can vary considerably. These attributes make broadcast spawning invertebrate systems uniquely suited to testing, extending, and sometimes challenging classic and contemporary ideas in sperm competition, many of which were first captured in Parker's seminal papers on the topic. Here, we provide a synthesis outlining progress in these fields, and highlight the burgeoning potential for broadcast spawners to provide both evolutionary and mechanistic understanding into gamete-level sexual selection more broadly across the animal kingdom. This article is part of the theme issue ‘Fifty years of sperm competition’.

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