This article considers the application of sexual selection theory to the study of religion by discussing the basic concepts and theories in sexual selection and then outlines possibilities of its application to the study of the evolution of religion. The first section outlines basic principles in the sexual selection account, including the evolution of human mating strategies based on dimorphism, gender differences in human mating strategies, and the role of different cultural activities in mating (...) dynamics. Such an overview may be useful for the readers who are less familiar with the basic assumptions of the sexual selection theory. The remaining sections demonstrate how religion may function as a signal for mating qualities associated with a long-term mating strategy and how different facets of religiosity may help to support long-term mating strategies. The key idea of the article is that there are good reasons to try to explain the evolution of at least some of the components of religion in terms of sexual selection. (shrink)

Sexual selection processes have received much attention in recent years, attention reflected in interest in human mate preferences. Among these mate preferences are preferences for physical attractiveness. Preferences in and of themselves, however, do not fully explain the nature of the relationships that individuals attain. A tacit negotiation process underlies relationship formation and maintenance. The notion that preferences for physical attractiveness evolved under parasite-driven “good genes” sexual selection leads to predictions about the nature of trade-offs that (...) individuals make between mates’ physical attractiveness and investment potential. These predictions and relevant data are explored, with a primary emphasis on women’s preferences for men’s qualities. In addition, further implications of trade-offs are examined, most notably (a) the impact of environmental variations on the nature of mating and (b) some effects of trade-offs on infidelity and male attempts to control women. (shrink)

I argue that the magnitude and nature of sex differences in aggression, their development, causation, and variability, can be better explained by sexual selection than by the alternative biosocial version of social role theory. Thus, sex differences in physical aggression increase with the degree of risk, occur early in life, peak in young adulthood, and are likely to be mediated by greater male impulsiveness, and greater female fear of physical danger. Male variability in physical aggression is consistent with (...) an alternative life history perspective, and context-dependent variability with responses to reproductive competition, although some variability follows the internal and external influences of social roles. Other sex differences, in variance in reproductive output, threat displays, size and strength, maturation rates, and mortality and conception rates, all indicate that male aggression is part of a sexually selected adaptive complex. Physical aggression between partners can be explained using different evolutionary principles, arising from the conflicts of interest between males and females entering a reproductive alliance, combined with variability following differences in societal gender roles. In this case, social roles are particularly important since they enable both the relatively equality in physical aggression between partners from Western nations, and the considerable cross-national variability, to be explained. (shrink)

The principles of sexual selection were used as an organizing framework for interpreting cross-national patterns of sex differences in mathematical abilities. Cross-national studies suggest that there are no sex differences in biologically primary mathematical abilities, that is, for those mathematical abilities that are found in all cultures as well as in nonhuman primates, and show moderate heritability estimates. Sex differences in several biologically secondary mathematical domains are found throughout the industrialized world. In particular, males consistently outperform females in (...) the solving of mathematical word problems and geometry. Sexual selection and any associated proximate mechanisms influence these sex differences in mathematical performance indirectly. First, sexual selection resulted in greater elaboration in males than in females of the neurocognitive systems that support navigation in three-dimensional space. Knowledge implicit in these systems reflects an understanding of basic Euclidean geometry, and may thus be one source of the male advantage in geometry. Males also use more readily than females these spatial systems in problem-solving situations, which provides them with an advantage in solving word problems and geometry. In addition, sex differences in social styles and interests, which also appear to be related in part to sexual selection, result in sex differences in engagement iii mathematics-related activities, thus further increasing the male advantage in certain mathematical domains. A model that integrates these biological influences with sociocultural influences on the sex differences in mathematical performance is presented in this article. (shrink)

Darwin hypothesized that some animals, when selecting sexual partners, possess a genuine “sense of beauty” that cannot be accounted for by the logic of natural selection. This hypothesis has been notoriously controversial. In this chapter I propose that the concept of agency can be useful to operationalize the “sense of beauty”, and can help identify the conditions under which one can infer that animals are acting as (aesthetic) agents. Focusing on a case study of the behavior of the (...) Pavo cristatus, I identify the types of evidence that would allow for the inference of agency through aesthetic choice. (shrink)

The evolution of human language, and the kind of thought the communication of which requires it, raises considerable explanatory challenges. These systems of representation constitute a radical discontinuity in the natural world. Even species closely related to our own appear incapable of either thought or talk with the recursive structure, generalized systematicity, and task-domain neutrality that characterize human talk and the thought it expresses. W. Tecumseh Fitch’s proposal (2004, in press) that human language is descended from a sexually selected, prosodic (...) proto-language that approximated its syntactic complexity, and later acquired semantics thanks to kin selection for its use as a means of pedagogical transmission, has the promise of meeting these explanatory challenges. However, Fitch’s theory raises two problems of its own: (1) according to Boyd and Richerson (1996, Proc. Br. Acad. 88: 77–93), circumstances in which pedagogy is adaptive are inevitably rare in nature, and (2) it is unlikely that our non-discursive precursors had generally systematic, task-domain neutral thoughts to communicate to their offspring. I propose solutions to these problems. Pedagogy would be favored in a population where complex rituals dominated diverse aspects of life. Prosodic proto-language could emerge as the medium of pedagogic transmission. As this medium was used to teach a greater variety of tasks, it would become increasingly general and domain neutral. The presence and importance of such a system of communication in hominid populations could then drive, via Baldwinian mechanisms, the evolution of a kind of ‘thinking for speaking’ (Slobin 1991, Pragmatics 1: 7–25) characterized by recursive structure, generalized systematicity, and task-domain neutrality. (shrink)

The capacity to engage with art is a human universal present in all cultures and just about every individual human. This indicates that this capacity is evolved. In this Critical Notice of Denis Dutton's The Art Instinct, I discuss various evolutionary scenarios and their consequences. Dutton and I both reject the "spandrel" approach that originates from the work of Gould and Lewontin. Dutton proposes, following work of Geoffrey Miller, that art is sexually selected--that art-production is a sign of a fit (...) genome in males. I argue that while assortative mating may well have had a role in the evolution of "the art instinct", group selection is a better explanation. I also take issue with Dutton's "cluster concept" approach to defining art, and argue that it is a universal and essential characteristic of art that it is appreciated both for what it expresses and for the way that it expresses. It thus requires a reflexive capacity that is not operative in the appreciation of sport spectacles and pornography. (shrink)

In a recent issue of this journal, Vandermassen suggested that feminists should include sexual selection theory and evolutionary psychology in a unifying theory of human nature. In response, this article aims to offer some insight into the development of sexual selection theory, to caution against Vandermassen's unreserved assimilation and to promote the opposite ongoing integration — an inclusion of gender perspectives into evolutionary biology. In society today, opinions about maintaining traditional sex roles are often put forward (...) on the basis of what is natural and how animals behave. However, the natural sciences have proved to be pervaded by gendered values and interests; Darwin's theory of sexual selection has been criticized for being male biased, and partly due to the unwillingness of Darwin's scientific contemporaries to accept female choice, research has been overwhelmingly focused on males. More recently, theory has become less gender biased and research has come to include a large variety of issues not present in the first version of the theory. However, there is a need to increase the awareness of gender bias in order to develop a gender-neutral evolutionary biology. (shrink)

이 논문은 인류의 진화사에서 과거 조상들이 미적 감각과 미적 감성을 획득하게 된 데에 성선택sexual selection과의 관련이 작용했을 가능성을 살펴보려는 목적을 갖는다. 이를 위해 찰스 다윈과 데이비드 버스 및 제프리 밀러를 참조하는데, 다윈은 성선택 이론을 정초하였고 데이비드 버스와 제프리 밀러는 다윈 이후 성선택 이론을 정교하게 다듬은 동시대의 진화심리학자들이다. 다윈은 『종의 기원』을 통해 제출했던 자연선택 이론으로 잘 설명되지 않는 문제들, 곧 번식의 문제와 성의 진화 문제를 성선택 이론으로 다루었다. 어떤 수컷이 다른 수컷에게는 없는 어떤 감각기관과 같은 구조를 획득하고 있는 것은 생존경쟁에 적합하기 (...) 때문이 아니라 번식과 생식에서 다른 수컷보다 유리한 이점이 그들의 수컷 새끼들에게 전달되었기 때문이며, 이러한 경우가 자연선택이 아닌 성선택이 작용한 결과라는 것이 다윈의 설명이다. 데이비드 버스는 남녀 간의 짝짓기 전략을 중심으로 성의 진화와 관련한 인간의 심리 메커니즘을 실증적으로 밝혀내고 있는데, 건강과 헌신성에 대한 선호와 함께 신체의 적정한 비율과 대칭적 얼굴에 대한 선호 성향들이 성선택에서 배우자에 대한 미적 선호의 기준이 되었음을 보여준다. 데이비드 버스는 인간의 미적 감각이 후천적으로 습득되기 전에 선천적으로 타고나는 형질이라는 점에도 주목하고 있다. 제프리 밀러는 자연선택과 관련한 생존주의 가설로는 인간 문화의 유희적인 측면들과 장식적인 요소들, 그리고 음악, 미슬, 스포츠, 드라마, 코미디, 정치적 이상 등에 대해서 납득할 만한 설명을 내놓지 못한다는 점을 말하면서, 인간의 마음에서 가장 독특한 측면의 대부분이 우리 조상들의 짝 고르기를 통해 진화해왔음을 강조한다. 미적 감성과 같은 인간 마음은 성선택을 통한 번식이익 추구의 기능을 면밀히 들여다보아야만 마음의 진화를 제대로 파악할 수 있다는 입장이다. 논문의 검토를 통하여 성선택 이론을 중심으로 한 이들의 논의가 인간이 갖는 풍부한 미적 감성과 미적 소양에 대한 충분한 설명이 되지는 않는다 하더라도, 인류가 지닌 특유의 미적 감각이 형성되고 획득된 계기와 배경에 대한 설명으로는 유효한 것임을 확인하였다. (shrink)

In this article, I advance a novel hypothesis on the evolution of hominin bipedalism. I begin by arguing extensively for how the transition to bipedalism must have been problematic for hominins during the Neogene. Due to this and the fact that no other primate has made the unusual switch to bipedalism, it seems likely that the selection pressure towards bipedalism was unusually strong. With this in mind, I briefly lay out some of the most promising hypotheses on the evolutionary (...) origin of hominin bipedalism and show how most, if not all, fail in the face of the need for an unusually strong selection pressure. For example, some hypotheses maintain that hominins became bipedal so they could use their hands for carrying infants, food, or other valuable objects. But extant apes are able to carry objects in one of their front limbs (while walking with the other three), and thus it does not seem plausible that our hominin ancestors went through the troublesome transition to bipedalism just so they could carry objects a little more efficiently. After I show that past hypotheses are wanting in the face of this challenge, I argue that there is only one selection pressure powerful enough to instigate a strange and problematic evolutionary adaptation like bipedalism, and that is sexual selection. Specifically, from the fact that bipedal locomotion is an important strategy for intimidating others and ascending the dominance hierarchy in extant apes, I argue that for no particular selective reason bipedal locomotion became a signal for high fitness (much as a large and intricate tail became a signal for high fitness for peahens), and this led to the trait being continuously reinforced in spite of all its deleterious fitness consequences. (shrink)

Today the modern Darwinian theory of evolution is the unifying theory within the biological sciences. A consideration of its implications for feminism is, however, impossible without a critical evaluation of its history of male bias. The aim of this article is therefore threefold. First, to explain what sexual selection entails. Second, to discuss male bias in and feminist reactions to Darwinian theory in general and sexual selection theory in particular. Third, to demonstrate that it would be (...) a loss for feminism to keep rejecting an evolutionary framework if we want to understand the roots of gender difference. This article is informed by a Darwinian feminist perspective. (shrink)

Sexual selection traditionally involves male-male competition and female choice, but in some species, including humans, sexual selection can also involve female-female competition and male choice. The degree to which one aspect of sexual selection or another is manifest in human populations will be influenced by a host of social and ecological variables, including the operational sex ratio. These variables are discussed in connection with the relative contribution of sexual selection and the division (...) of labor to the evolution of human sex differences. (shrink)

This root-and-branch reevaluation of Darwin's concept of sexual selection tackles the subject from historical, epistemological and theoretical perspectives. Contributions from a wealth of disciplines have been marshaled for this volume, with key figures in behavioural ecology, philosophy, and the history of science adding to its wide-ranging relevance. Updating the reader on the debate currently live in behavioural ecology itself on the centrality of sexual selection, and with coverage of developments in the field of animal aesthetics, the (...) book details the current state of play, while other chapters trace the history of sexual selection from Darwin to today and inquire into the neurobiological bases for partner choices and the comparisons between the hedonic brain in human and non-human animals. Welcome space is given to the social aspects of sexual selection, particularly where Darwin drew distinctions between eager males and coy females and rationalized this as evolutionary strategy. Also explored are the current definition of sexual selection (as opposed to natural selection) and its importance in today's biological research, and the impending critique of the theory from the nascent field of animal aesthetics. As a comprehensive assessment of the current health, or otherwise, of Darwin's theory, 140 years after the publication of his Descent of Man, the book offers a uniquely rounded view that asks whether 'sexual selection' is in itself a progressive or reactionary notion, even as it explores its theoretical relevance in the technical biological study of the twenty-first century. (shrink)

Psychological altruism (being motivated by the needs of others) has a tendency to produce behaviour that is costly in evolutionary terms. How, then, could the capacity for psychological altruism evolve? One suggestion is that it is the result of sexual selection. There are, however, two problems that face such an account: first, it is not clear that the resulting behaviour would be altruistic in the relevant sense, and second, it does not seem to fit with key features of (...) our actual helping behaviour. I will argue that both of these problems can be avoided if we adopt a modular account of desire formation. (shrink)

Archer provides seemingly compelling evidence for his claim that sexual selection explains sex differences in human aggression better than social role theory. I challenge Archer's interpretation of some of this evidence. I argue that the same evidence could be used to support the claim that what has been selected for is the ability to curb aggression and discuss implications for Archer's theory.

Our social role/biosocial theory provides a more adequate account of aggression sex differences than does Archer's sexual selection theory. In our theory, these sex differences arise flexibly from sociocultural and ecological forces in interaction with humans' biology, as defined by female and male physical attributes and reproductive activities. Our comments elaborate our theory's explanations for the varied phenomena that Archer presents.

Although "intrasexual selection" has been accepted as the mechanism by which males evolve elaborate secondary sexual traits which are used in aggressive contests, the importance of "intersexual selection" as a mechanism by which males have acquired exaggerated traits to display to females during courtship was less readily accepted. In spite of this scepticism, several genetic models have supported the latter idea, and many empirical studies showed that females were generally more discriminating in mate choice than males, because (...) of differences in relative investment between sexes. Nowadays, this idea is reinforced by various concepts (parental investment, potential reproductive rate, environmental potential for polygamy...) which stress that the strength of sexual selection is related to many interdependent factors, such as mating systems, resource distribution (food, habitat, mate), life history and other ecological characteristics. The case of Salmonids is presented here to show how novel information on sexual selection has contributed to the understanding of the plasticity of breeding patterns in the context of evolutionary biology. (shrink)

The importance of mate choice and sexual selection has been emphasized by the majority of evolutionary psychologists. This paper assesses three cases of work on mate choice and sexual selection in evolutionary psychology: David Buss on cross-cultural human mate preferences, Randy Thornhill and Steve Gangestad on the link between mate preferences and fluctuating asymmetry, and Geoffrey Miller on the role of Fisher’s runaway process in human evolution. A mixture of conceptual and empirical problems in each case (...) highlights the general weakness of work in evolutionary psychology on these issues. (shrink)

Nothing is gained by opposing and or by proclaiming the supremacy of one over the other. Instead, we should develop a unitary model of gene-culture coevolution, allowing for the complex interaction of both, and varying importance of each, all within our double, species-specific, adaptive, evolutionary track.

We evaluate three of Geary's claims, finding that there is little evidence for sex differences in object- vs. person-orientation; sex differences in competition, even if biologically caused, lead to sex differences in mathematics only given a certain style of teaching; and sex differences in mental rotation, though real, are not well explained in a sociobiological framework or by the proximate biological variables assumed by Geary.

This study situates Henry Havelock Ellis’s sexological research within the nineteenth-century evolutionary debates, especially the discussion over sexual selection’s applicability to humanity. For example, Ellis’s monograph on sexual behavior, _Sexual Inversion_ (1897), treated inborn homosexuality as a natural variation of evolutionary mechanisms. This book was situated within a longer study of human sexuality in relation to evolutionary selection. His later works dealt even more directly with Charles Darwin’s concept of selection, such as _Sexual Selection (...) in Man_ (1905). Through _Sexual Selection in Man_, Ellis asserted that sexual attraction stemmed from a physical cause rather than an innate aesthetic sense. I argue that Ellis’s best-known historical publications, including his work on sexual inversion, were intended to intervene in the contemporary evolutionary debates. This analysis also identifies a specific point where evolutionary theory informed the foundation of sexology as a scientific discipline. (shrink)

Sexual selection drives the evolution of some of the most exaggerated traits in nature. Studies on sexual selection often focus on the size of these traits relative to body size, but few focus on energetic maintenance costs of the tissues that compose them, and the ways in which these costs vary with body size. The relationships between energy use and body size have consequences that may allow large individuals to invest disproportionally more in sexually selected structures, (...) or lead to the reduced per‐gram maintenance cost of enlarged structures. Although sexually selected traits can incur energetic maintenance costs, these costs are not universally high; they are dependent on the relative mass and metabolic activity of tissues associated with them. Energetic costs of maintenance may play a pervasive yet little‐explored role in shaping the relative scaling of sexually selected traits across diverse taxa. Also see the video abstract here: https://youtu.be/JyuoQIeA33Q. (shrink)

Recently Geoffrey Miller has suggested that humor evolved through sexual selection as a signal of "creativity," which in turn implies youthfulness, intelligence, and adaptive unpredictability. Drawing upon available empirical studies, I argue that the evidence for a link between humor and creativity is weak and ambiguous. I also find only tenuous support for Miller’s assumption that the attractiveness of the "sense of humor" is to be found in the wittiness of its possessor, since those who use the phrase (...) often seem to associate it with the affects of relatively mirthless "bonding" laughter. Humor, I conclude, may have evolved as an instrument for achieving broad social adhesiveness and for facilitating the individual’s maneuverability within the group, but that it evolved through sexual selection has yet to be convincingly demonstrated. (shrink)

A number of theories about the origins of musicality have incorporated biological and social perspectives. Darwin argued that musicality evolved by sexual selection, functioning as a courtship display in reproductive partner choice. Darwin did not regard musicality as a sexually dimorphic trait, paralleling evidence that both sexes produce and enjoy music. A novel research strand examines the effect of musicality on sexual attraction by acknowledging the importance of facial attractiveness. We previously demonstrated that music varying in emotional (...) content increases the perceived attractiveness and dating desirability of opposite-sex faces only in females, compared to a silent control condition. Here, we built upon this approach by presenting the person depicted (target) as the performer of the music (prime), thus establishing a direct link. We hypothesized that musical priming would increase sexual attraction, with high-arousing music inducing the largest effect. Musical primes (25 s, piano solo music) varied in arousal and pleasantness, and targets were photos of other-sex faces of average attractiveness and with neutral expressions (2 s). Participants were 35 females and 23 males (heterosexual psychology students, single, and no hormonal contraception use) matched for musical background, mood, and liking for the music used in the experiment. After musical priming, females’ ratings of attractiveness and dating desirability increased significantly. In males, only dating desirability was significantly increased by musical priming. No specific effects of music-induced pleasantness and arousal were observed. Our results, together with other recent empirical evidence, corroborate the sexual selection hypothesis for the evolution of human musicality. (shrink)

One of the explicit objectives of Darwin's Descent of Man, and Selection in Relation to Sex was to explain cultural differences seen in human beings. Such an explanation, Darwin believed, was to rest upon an understanding of sexual selection. I examine the role that the beautiful plays within the mechanism of sexual selection as it works to differentiate isolated groups. It is suggested that an examination of the relationship between sexual selection and artificial (...) selection — a relationship mediated by the beautiful — will illuminate key issues of the Descent as well as contemporary debates regarding the relationship between evolution and ethics. The beautiful, originally rooted in sexual selection, can become de-coupled from sexual selection and utilized in some selective process which is conscious. (shrink)

Geary's model is a worthy effort, but ambiguous on important issues. It ignores differential resource allocation, although this follows directly from sexual selection via differential parental investment. Dimorphism in primary traits is arbitrarily attributed to sexual selection via intramale competition, rather than direct evolutionary pressures. Dubious predictions are made about the consequences of raising mathematics achievement.

My response is organized into three sections. The first revisits the theme of the target article, the explanatory power of sexual selection versus social role theory. The second considers the range and scope of sexual selection, and its application to human sex differences. Two topics are examined in more detail: (1) the paternity uncertainty theory of partner violence; (2) evolution of inter-group aggression. Section 4 covers ultimate and proximal explanations and their integration within an ethological approach. (...) I consider the development of sex differences in aggression, and their causal mechanisms, within this framework. (shrink)

In Darwin’s Sacred Cause, Adrian Desmond and James Moore contend that “Darwin would put his utmost into sexual selection because the subject intrigued him, no doubt, but also for a deeper reason: the theory vindicated his lifelong commitment to human brotherhood”. Without questioning Desmond and Moore’s evidence, I will raise some puzzles for their view. I will show that attention to the structure of Darwin’s arguments in the Descent of Man shows that they are far from straightforward. As (...) Desmond and Moore note, Darwin seems to have intended sexual selection in non-human animals to serve as evidence for sexual selection in humans. However, Darwin’s account of sexual selection in humans was different from the canonical cases that Darwin described at great length. If explaining the origin of human races was the main reason for introducing sexual selection, and if sexual selection was a key piece of Darwin’s anti-slavery arguments, then it is puzzling why Darwin would have spent so much time discussing cases that did not really support his argument for the origin of human races, and it is also puzzling that his argument for the origin of human races would be so poor. (shrink)

The fitness of a eukaryote hinges on the coordinated function of the products of its nuclear and mitochondrial genomes in achieving oxidative phosphorylation. I propose that sexual selection plays a key role in the maintenance of mitonuclear coadaptation across generations because it enables pre-zygotic sorting for coadapted mitonuclear genotypes. At each new generation, sexual reproduction creates new combinations of nuclear and mitochondrial genes, and the potential arises for mitonuclear incompatibilities and reduced fitness. In reviewing the literature, I (...) hypothesize that individuals engaged in mate choice select partners with correct species-typical mitochondrial and nuclear genotypes as well as individuals with highly functional cellular respiration. The implication is that mate choice for compatible nuclear and mitochondrial genes can play a significant role in generating the patterns of ornamentation and preferences observed in animals. A number of testable predictions emerge from this mitonuclear compatibility hypothesis of sexual selection. Products of mitochondrial and nuclear genes co-function to enable cellular respiration, so it is critical that compatible mitochondrial and nuclear genes be matched each generation. I propose that a core function of mate choice is selection for mitochondrial and nuclear genes that create compatible and functional combinations in offspring. (shrink)

We report three studies which test a sexual selection hypothesis for male war heroism. Based on evolutionary theories of mate choice we hypothesize that men signal their fitness through displaying heroism in combat. First, we report the results of an archival study on US-American soldiers who fought in World War II. We compare proxies for reproductive success between a control sample of 449 regular veterans and 123 surviving Medal of Honor recipients of WWII. Results suggest that the heroes (...) sired more offspring than the regular veterans. Supporting a causal link between war heroism and mating success, we then report the results of two experimental studies. We find evidence that female participants specifically regard men more sexually attractive if they are war heroes. This effect is absent for male participants judging female war heroes, suggesting that bravery in war is a gender specific signal. Finally, we discuss possible implications of our results. (shrink)

Sexually‐selected exaggerated traits tend to be unusually reliable signals of individual condition, as their expression tends to be more sensitive to nutritional history and physiological circumstance than that of other phenotypes. As such, these traits are the foundation for many models of sexual selection and animal communication, such as “handicap” and “good genes” models. Exactly how expression of these traits is linked to the bearer's condition has been a central yet unresolved question, in part because the underlying physiological (...) mechanisms regulating their development have remained largely unknown. Recent discoveries across animals as diverse as deer, beetles, and flies now implicate the widely conserved insulin‐like signaling pathway, as a common physiological mechanism regulating condition‐sensitive structures with extreme growth. This raises the exciting possibility that one highly conserved pathway may underlie the evolution of trait exaggeration in a multitude of sexually‐selected signal traits across the animal kingdom. (shrink)

By conceptualizing Sexual Selection, Darwin showed a way to analyze intra-specific individual differences within an evolutionary perspective. Interestingly, Sexual Selection is often used to investigate the origins of sports, arts, humor, religion and other phenomena that, in several languages, are simply called “play.” Despite their manifested differences, these phenomena rely on shared psychological processes, including playfulness. Further, in such behaviors there is usually considerable individual variability, including sex differences, and positive relationship with mating success. However, (...) class='Hi'>Sexual Selection is rarely applied in the study of play, with exception to what is concerned as infant training behavior for adult sex roles. We offer an integrated grounding of playful phenomena aligning evolutionary propositions based on sexual selection, which might stimulate further exploration of playfulness within evolutionary perspective. (shrink)

Geoffrey Miller argues that we can account for the evolution of human art and altruism via the action of sexual selection. He identifies five characteristics supposedly unique to sexual adaptations: fitness indicating cost; involvement in courtship; heritability; variability; and sexual differentiation. Miller claims that art and altruism possess these characteristics. I argue that not only does he not demonstrate that art and altruism possess these characteristics, one can also explain the origins of altruism via a form (...) of group selection and traits with the five characteristics in terms of a process I call "cultural sexual selection.". (shrink)

Turtles are among the most intriguing amniotes but their communication and signaling have rarely been studied. Traditionally, they have been seen as basically just silent armored ‘walking stones’ with complex physiology but no altruism, maternal care, or aesthetic perception. Recently, however, we have witnessed a radical change in the perception of turtle behavioral and cognitive skills. In our study, we start by reviewing some recent findings pertaining to various highly developed behavioral and cognitive patterns with special emphasis on turtles. Then (...) we focus on freshwater turtles and use data about their sexual behavior and size sexual dimorphism to test whether conspicuous coloration of the head is in these animals related to sexual processes. We found that absence of aggressive mating behavior is statistically associated with the presence of conspicuous coloration on turtles’ heads. It also seems that while species with female-biased SSD are characterised by conspicuously colored head ornaments, in species with male-biased SSD conspicuous coloration is absent. Unlike large females, males thus seem to be under pressure to develop conspicuous coloration and engage in non-aggressive behavior using signaling to succeed in courtship. And finally, we discuss possible roles of head color patterns in turtle communication during mating. (shrink)