The intensity of sexual selection in relation to male sexual behaviour, female choice, and sperm precedence

AbstractIn the dynamic process of courtship, males often must perform behaviour patterns that function to persuade females that are initially unresponsive to mate. But, to what extent is the outcome of a sexual encounter determined by a male's persuasiveness versus a female's responsiveness? We addressed this question in three laboratory experiments using a plethodontid salamander, Desmognathus ocoee, for which persuasion by males appears to be obligatory. We found considerable variation in mating success among individuals of both sexes, indicating variation in both male persuasiveness and female responsiveness (Experiment 1). In addition, males of high persuasiveness mated more often than males of lower persuasiveness, regardless of the levels of responsiveness of the females that they encountered (Experiment 2). Finally, we found that males of high persuasiveness performed certain sexual behaviour patterns more frequently and more rapidly than males of lower persuasiveness (Experiment 3). Our results suggest that male D. ocoee of high persuasiveness can mate successfully even with unresponsive females, which may be especially choosy about which males they accept. Thus, those male behaviour patterns that increase female motivation to mate likely are targets of sexual selection by female choice. Whether females that mate with persuasive males enjoy increased fitness awaits further study.

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Reproductive behavior

10.1093/oso/9780198797500.003.0013 ◽

2018 ◽

Cited By ~ 1

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.

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

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.0836 ◽

2018 ◽

Vol 285 (1883) ◽

pp. 20180836 ◽

Cited By ~ 21

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.

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Sexual selection favours male parental care, when females can choose

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2011.2237 ◽

2011 ◽

Vol 279 (1734) ◽

pp. 1784-1790 ◽

Cited By ~ 54

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.

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Post-Copulatory Sexual Selection

Evolutionary Biology ◽

10.1093/obo/9780199941728-0131 ◽

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.

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Sexual behaviour, reward, and brain function; sexual selection of behaviour

Emotion Explained ◽

10.1093/acprof:oso/9780198570035.003.0009 ◽

2005 ◽

pp. 358-399 ◽

Cited By ~ 1

Author(s):

Edmund T. Rolls

Keyword(s):

Sexual Selection ◽

Sexual Behaviour ◽

Brain Function ◽

Selection Of

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4. Sex roles and stereotypes

Sexual Selection: A Very Short Introduction ◽

10.1093/actrade/9780198778752.003.0004 ◽

2018 ◽

pp. 52-68

Author(s):

Leigh W. Simmons

Keyword(s):

Sexual Selection ◽

Mate Choice ◽

Sexual Behaviour ◽

Sex Roles ◽

Animal Species ◽

Male And Female ◽

Mating Competition ◽

Characteristic Behaviour ◽

Males And Females ◽

Female Roles

‘Sex roles and stereotypes’ examines the notion, implicit in many of the original ideas about sexual selection, that males and females have natural ‘roles’ with characteristic behaviour associated with each sex. It also explores further the reasons behind deviations from the ‘typical’ sex roles in mate choice and in mating competition. Are there ‘standard’ male and female roles in both humans and other animal species? One version of sex roles holds that males are generally dominant and females submissive, stemming from the way that sexual selection favours different behaviours in each sex. This could mean that sexual selection dictates particular behaviours in males and females. But in fact, sexual behaviour is extraordinarily varied in nature.

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Sexual selection favours good or bad genes for pathogen resistance depending on males' pathogen exposure

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.0226 ◽

2019 ◽

Vol 286 (1902) ◽

pp. 20190226 ◽

Cited By ~ 5

Author(s):

Patrick Joye ◽

Tadeusz J. Kawecki

Keyword(s):

Drosophila Melanogaster ◽

Sexual Selection ◽

Female Choice ◽

Experimental Studies ◽

Pathogen Resistance ◽

Condition Dependence ◽

Indirect Benefit ◽

Intestinal Pathogen ◽

Sexual Traits ◽

Pathogen Exposure

Resistance to pathogens is often invoked as an indirect benefit of female choice, but experimental evidence for links between father's sexual success and offspring resistance is scarce and equivocal. Two proposed mechanisms might generate such links. Under the first, heritable resistance to diverse pathogens depends on general immunocompetence; owing to shared condition dependence, male sexual traits indicate immunocompetence independently of the male's pathogen exposure. By contrast, other hypotheses (e.g. Hamilton–Zuk) assume that sexual traits only reveal heritable resistance if the males have been exposed to the pathogen. The distinction between the two mechanisms has been neglected by experimental studies. We show that Drosophila melanogaster males that are successful in mating contests (one female with two males) sire sons that are substantially more resistant to the intestinal pathogen Pseudomonas entomophila —but only if the males have themselves been exposed to the pathogen before the mating contest. By contrast, sons of males sexually successful in the absence of pathogen exposure are less resistant than sons of unsuccessful males. We detected no differences in daughters’ resistance. Thus, while sexual selection may have considerable consequences for offspring resistance, these consequences may be sex-specific. Furthermore, contrary to the ‘general immunocompetence’ hypothesis, these consequences can be positive or negative depending on the epidemiological context under which sexual selection operates.

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