Primary sexual traits, those structures and processes directly involved in reproduction, are some of the most diverse, specialized, and bizarre in the animal kingdom. Moreover, reproductive traits are often species-specific, suggesting that they evolved very rapidly. This diversity, long the province of taxonomists, has recently attracted broader interest from evolutionary biologists, especially those interested in sexual selection and the evolution of reproductive strategies. Primary sexual characters were long assumed to be the product of natural selection, (...) exclusively. A recent alternative suggests that sexual selection explains much of the diversity of. (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)

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)

Sex, Gender, Ethics, and the Darwinian Evolution of Humanity examines the impact of Darwin's 'Descent of Man' on contemporary biology and the humanities. Its publication in 1871 was a founding event in anthropology. Its content was primarily concerned with the development of sexual life, social life, and intellectual life, not only as outcomes of evolution, but as components that have actively intermixed over time with the evolutionary mechanism of natural selection. The stamp of Darwinism on modern thought is (...) still very important and brings novelties to academic studies. Several fields influenced by Darwinian anthropology developed in recent decades, including evolutionary ethics, the evolution of sociality and sexual communication in animal and plant species. Sociobiology and evolutionary psychology are topics that draw heavily on Darwin's 'Descent of Man'. The understanding of Darwin's thought has also progressed greatly in recent decades, following the systematic study of Darwin's correspondence and notebooks, leading to a reassessment of the development of his thought on humans, social groups, and heredity, and how they come together in his theory of evolution. The book combines a historical perspective on Darwin's achievement and his legacy. It will be of interest to students and scholars in a variety of fields, from experimental biology to the social and historical sciences. (shrink)

Desmond and Moore point out that the key to understanding Darwin’s The Descent of Man is his abolitionist motivation and his advocacy that races constitute subspecies. Roberta Millstein raises some doubts about the importance of this motivation. She points out that the inclusion of the extensive section devoted to non-human animals is not justified by Darwin’s treatment of humans per se, because his explanation of the origin of races is peculiar. In this sense, she argues that Darwin’s specific explanation of (...) the origin of races does not confirm the central importance that Desmond and Moore give to Darwin’s abolitionism. In this paper I have two different aims. On the one hand, to show that the human case actually is based on the treatment of nonhuman animals, and consequently, Darwin’s argument is not as poor as Millstein believes. My second goal, taking Millstein’s challenge seriously, is to show that Darwin’s explanation of the origin of races does confirm the Desmond and Moore thesis in a deeper sense than the one they propose themselves. For the anti-slavery motivation could not only explain the fact that Darwin sees all humans as forming the same species, but the specific explanation he gives for the origin of races. (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)

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)

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)

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)

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)

This essay traces the interlinked origins of two concepts found in Charles Darwin's writings: "unconscious selection," and sexual selection as applied to humanity's anatomical race distinctions. Unconscious selection constituted a significant elaboration of Darwin's artificial selection analogy. As originally conceived in his theoretical notebooks, that analogy had focused exclusively on what Darwin later would call "methodical selection," the calculated production of desired changes in domestic breeds. By contrast, unconscious selection produced its results unintentionally (...) and at a much slower pace. Inspiration for this concept likely came from Darwin's early reading of works on both animal breeding and physical ethnology. Texts in these fields described the slow and unplanned divergence of anatomical types, whether animal or human, under the guidance of contrasting ideals of physical perfection. These readings, it is argued, also led Darwin to his theory of sexual selection as applied to race, a theme he discussed mainly in his book The Descent of Man. There Darwin described how the racial version of sexual selection operated on the same principle as unconscious selection. He thereby effectively reunited these kindred concepts. (shrink)

This article utilizes three premises. There are commonly ecologically oriented, naturally selected specialized differences in frequency and/or quality as well as sexually selected differences between the sexes. Sex in the sense of coming together and going apart or going apart and coming together is trade in these naturally selected differences, i.e., there is a mating market in sexual species. While such trade is beneficial to the population as a whole, sexual competition and selection is conflict over the (...) profits of that trade and can be detrimental to the population as a whole. These premises yield a naturally selected sex allocation theory of the possible directions and forms of sexual selection, i.e., one that includes costs as well as frequencies. This can explain conventional sex roles, the sex-role reversed, inter- as well as intrasexual selection, and passive as well as active choice. Any of these alternatives may be over mates, over gametes, or both. A hypothetical example based on density dependence relative to resources is provided, one that suggests that centrioles may be a cytoplasmic resource in males in multicellular animals, and which are the target of active choice and the mechanism of manipulation in passive female choice. As a whole, the approach yields a truly general theory of sexual selection, provides an alternative to the mechanism for Fisher’s principle, and gives a theoretical explanation for Mayr’s biological species definition. (shrink)

This essay argues that reflection on sexual selection can be theologically generative, and that it presents needed counteremphases to some of the discussions about theological anthropology that have been fueled by theological reflection on natural selection. It introduces sexual selection and provides an overview of different approaches to sexual selection found within evolutionary biology today, before transitioning to a reflection on one theologically relevant insight from sexual selection—namely, the importance of play. (...) It argues that the mating and play behaviors of animals reveal the noncompetitive relationship between necessity and gratuity, and thus provide theologians with an example of grace building upon, and not destroying, nature. While play is sometimes depicted in philosophical and theological accounts as the achievement of culture that supersedes the mundane necessities of nature, sexual selection can also help to illuminate the ways in which culture is dependent upon nature, and play is a thoroughly natural phenomenon that provides resources for human cultural elaboration. (shrink)

This essay traces the interlinked origins of two concepts found in Charles Darwin's writings: "unconscious selection," and sexual selection as applied to humanity's anatomical race distinctions. Unconscious selection constituted a significant elaboration of Darwin's artificial selection analogy. As originally conceived in his theoretical notebooks, that analogy had focused exclusively on what Darwin later would call "methodical selection," the calculated production of desired changes in domestic breeds. By contrast, unconscious selection produced its results unintentionally (...) and at a much slower pace. Inspiration for this concept likely came from Darwin's early reading of works on both animal breeding and physical ethnology. Texts in these fields described the slow and unplanned divergence of anatomical types, whether animal or human, under the guidance of contrasting ideals of physical perfection. These readings, it is argued, also led Darwin to his theory of sexual selection as applied to race, a theme he discussed mainly in his book The Descent of Man (1871). There Darwin described how the racial version of sexual selection operated on the same principle as unconscious selection. He thereby effectively reunited these kindred concepts. (shrink)

Going beyond the creolisation theories of Brathwaite and Glissant, I attempt to develop ideas concerning the gendering of creolisation, and a historicising of affects within it. Addressing affects as ‘physiological things’ contextualised in the history of the Caribbean slave plantation, I seek, importantly, to delineate a trajectory and development of a specific Creole history in relation to affects. Brathwaite's proposition that ‘the most significant (and lasting) inter-cultural creolisation took place’ within the ‘intimate’ space of ‘sexual relations’ is key to (...) my argument. In the light of this, I consider how Creole cultural knowledge about affect—as the primary motivational system inclusive of fear, anger, outrage and so on — might be identified, and what constitutes such Creole knowledge within which affect might be embedded. How might Glissant's relationality and Creole literary texts add to this knowledge? I focus primarily on three texts: Clarke's The Polished Hoe, Collins’ The Colour of Forgetting and Morejón's ‘Amo a mi amo’/‘l Love My Master’. Each text on which I draw is selected for its intersectional representation of gender relations, ‘knowledge about sexual difference’ and its representation of Creole subjectivities within the context problematised here as the ‘demonic ground’. Moreover, as auto-theorising texts, they represent both narrative and meta-narrative of a creolising of affects in and against the economy of the slave plantation. Each represents also a stage or aspect of the development of subjectivities and an affective community that inform this intervention concerned with theorising against consolidated, universalising and Eurocentric conceptualisations of affect. In the process, I attempt to offer a differentiated cartography and literary archaeology of affect. (shrink)

In 1859, Charles Darwin proposed a mechanism for biological evolution in his most famous work, On the Origin of Species. However, Origin makes little mention of humans. Despite this, Darwin thought deeply about humans and in 1871 published The Descent of Man, his influential and controversial book in which he applied evolutionary theory to humans and detailed his theory of sexual selection. February 2021 will mark the 150th anniversay of it's publication. In A Most Interesting Problem, twelve leading (...) anthropologists, biologists, and journalists revisit The Descent. Following the same organization as the first edition of Descent - less the large section on sexual selection -- each author reviews what Darwin wrote in Descent, comparing his words to what we now know now. There are chapters on evidence for human evolution, our place in the family tree, the origins of civilization, human races, intelligence, and sex differences. An introduction by Darwin biolographer and historian Janet Browne provides context for Descent and a conclusion by Science magazine journalist Ann Gibbons looks to the future of the study of human evolution. All the chapters are written with a broad audience in mind. Ultimately, readers learn that Darwin was remarkably prophetic in some of his predictions, such as that the earliest human fossils would be discovered in Africa. But he was wrong in other areas, particularly in regards to variations between the sexes and races. Thus, A Most Interesting Problem is not so much a celebration of Darwin as it is a tribute to how science works, how scientific ideas are tested, and the role of evidence in helping structure narratives of human origins. The reader is left with a view of how far we have come in our quest for understanding human origins, biological variation, behavior, and evolution. (shrink)

Divided into three parts, this book's purpose, as given in the introduction, is to consider whether or not man is descended from a pre-existing form, his manner ...

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)

We consider Sussman et al. 's suggestion that auditory biases for processing low-noise relationships among pairs of acoustic variables is a preadaptation for human speech processing. Data from other animal communication systems, especially those involving sexual selection, also suggest that neural biases in the receiver system can generate strong selection on the form of communication signals.

This paper proposes that the human mind in its creativity and emotional self-awareness is the result of the evolutionary transition from sexuality to eroticism. Eroticism is arrived at and defined by the high amount of energy displayed in animal sexuality. We propose that the unique human emotional intelligence is due to this “overflow” of mating energy. What from the survival viewpoint looks like an enormous waste of time and energy reveals itself to be an unexpected psychological benefit. The diversion of (...) sexual energy from procreation — a process that results in erotic fantasies — turns intimacy into a source of human self -consciousness. This places different emphasis on the meaning of eroticism and provides a coherent scenario of mental development beyond mere cognitive capacities. Arguments are presented on how erotic imagination, or sexual excitation as an end in itself, promotes the human propensity for explorative curiosity; data from ethology, psychology, sociology, and neuroscience are presented to support these arguments. As philosophical anthropologists, we do not provide new empirical data, but the available results of comparative behavioral research confirm our hypothesis. (shrink)

In America by the 1930s, albino rats had become a kind of generic standard in research on physiology and behavior that de-emphasized diversity across species. However, prior to about 1915, the early work of many of the pioneer rat researchers in America and in central Europe reflected a strong interest in species differences and a deep regard for diversity. These scientists sought broad, often medical, generality, but their quest for generality using a standard animal did not entail a de-emphasis of (...) organic diversity. They chose white rats as test animals for two primary reasons. First, rats develop very slowly. They therefore made features of physiological, neural and psychological development accessible to the experimental method at a time when its application to the phenomena of development remained controversial. Secondly, rats were thought to have unusually strong sex drives. For this reason they became central to the experimental study of sexuality and, in the work of the reproductive physiologist Eugen Steinach, sexual development. Connections among three research institutes that stressed experimental approaches to the study of brain and development demonstrate the importance of the rat's institutional role. As the emphasis on experimentation in the study of development grew, two of these institutes bred rats to provide uniform materials. Eventually, however, their reasons for selecting rats were lost; and the ready availability of a uniform test animal led to a shift in scientists' presumptions about diversity, as the standard rat became a tool for assuring generality. (shrink)

This article explores the origin and evolutionary implications of anthropomorphism in the context of our relationships with animal companions. On the human side, anthropomorphic thinking enables animal companions' social behavior to be construed in human terms, thereby allowing these nonhuman animals to function for their human owners or guardians as providers of nonhuman social support. Absence of social support is known to be detrimental to human health and well being. Therefore, anthropomorphism and its corollary, pet keeping, have obvious biological fitness (...) implications. On the animal side, anthropomorphism constitutes a unique evolutionary selection pressure, analogous to sexual selection, which has molded the appearance, anatomy, and behavior of companion animal species so as to adapt them to their unusual ecological niche as social support providers. Although such species undoubtedly have benefited numerically from the effects of this process, the consequences of anthropomorphism are less benign when viewed from the perspective of individual animals. Indeed, anthropomorphic selection probably is responsible for some of the more severe welfare problems currently found in companion animals. (shrink)

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)

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)

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)

This case study examines differences between how the animal-behavior-research fields of ethology and sociobiology account for female ornamental traits. I address three questions: 1) Why were female traits noted in early animal-behavior writings but not systematically studied like male traits? 2) Why did ethology attend to female signals before sexual-selection studies did? 3) And why didn't sexual-selection researchers cite the earlier ethological literature when they began studying female traits? To answer these questions, I turn to feminist (...) and other science-studies scholars and philosophers of science. My main framework is provided by Bruno Latour, whose model I position within relevant feminist critique . This approach provides an interactive account of how scientific knowledge develops. I argue that this embedded approach provides a more compelling reading of the relationship between gender and science than does focusing on androcentric biases. My overall aim is to counter arguments by some feminist biologists that feminist tools should emphasize the correction and removal of biases, and to address their fears that more rigorous critiques would lead to relativism or otherwise remove science as a tool for feminist use. (shrink)

In biosemiotics, living beings are not conceived of as the passive result of anonymous selection pressures acted upon through the course of evolution. Rather, organisms are considered active participants that influence, shape and re-shape other organisms, the surrounding environment, and eventually also their own constitutional and functional integrity. The traditional Darwinian division between natural and sexual selection seems insufficient to encompass the richness of these processes, particularly in light of recent knowledge on communicational processes in the realm (...) of life. Here, we introduce the concepts of semiotic selection and semiotic co-option which in part represent a reinterpretation of classical biological terms and, at the same time, keep explanations sensitive to semiosic processes taking place in living nature. We introduce the term ‘semiotic selection’ to emphasize the fact that actions of different semiotic subjects (selectors) will produce qualitatively different selection pressures. Thereafter, ‘semiotic co-option’ explains how semiotic selection may shape appearance in animals through remodelling existing forms and relations. Considering the event of co-option followed by the process of semiotic selection enables us to describe the evolution of semantic organs. (shrink)

Major histocompatibility complex (MHC)‐associated mate choice is thought to give offspring a fitness advantage through disease resistance. Primates offer a unique opportunity to understand MHC‐associated mate choice within our own zoological order, while their social diversity provides an exceptional setting to examine the genetic determinants and consequences of mate choice in animal societies. Although mate choice is constrained by social context, increasing evidence shows that MHC‐dependent mate choice occurs across the order in a variety of socio‐sexual systems and favours (...) mates with dissimilar, diverse or specific genotypes non‐exclusively. Recent research has also identified phenotypic indicators of MHC quality. Moreover, novel findings rehabilitate the importance of olfactory cues in signalling MHC genes and influencing primate mating decisions. These findings underline the importance to females of selecting a sexual partner of high genetic quality, as well as the generality of the role of MHC genes in sexual selection. (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)

The concept of animal personality is based on consistent individual differences in behaviour, yet little is known about the factors responsible for such variation. Theory based on sex-specific selection predicts sexual dimorphism in personality-related traits and, in some cases, differences in trait variances between the sexes. In this study, we examined the sources of individual variation for boldness behaviour in guppies (Poecilia reticulata). We first demonstrated heightened boldness expression in males relative to females across feral wild types, artificially (...) selected domestic ‘designer’ guppies, and putative hybrids of the two. Boldness and body size covaried at the strain level but were not associated among individuals within strains. We also found high and repeatable behavioural differences among individuals (0.40 > intraclass r > 0.60) in all sex/strain groups except hybrid strain females. However, there was no evidence for the heightened inter-individual male variance anticipated for personality traits subject to certain forms of directional sex-specific selection. Domestic fish were boldest overall, and indicated the largest sex difference, which is consistent with genetic linkage between boldness and male ornamental colouration. Consistently high intrinsic variation in boldness behaviour, which extends to inbred domesticated fish, may in part underpin the invasive potential of this species. (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.

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)

The role of behaviour in biological evolution is examined within the context of Darwinism. All Darwinian models are based on the distinction of two mechanisms: one that permits faithful transmission of a feature from one generation to another, and another that differentially regulates the degree of this transmission. Behaviour plays a minimal role as an agent of transmission in the greater part of the animal kingdom; by contrast, the forms it may assume strongly influence the mechanisms of selection regulating (...) the different rates of transmission. We consider the decisive feature of the human species to be the existence of a phenotypical system of cultural coding characterized by precision and reliability which are the distinctive features of genetic coding in animals. We examine the consequences for the application of the Darwinian model to human history. (shrink)

Classical Arabic poetry is replete with animal and fruit metaphors commonly used for endearment purposes. The comparative analysis of love metaphors in classical ghazal shows, however, a shift in the poetics of love from the use of animal metaphors in Badi poetry to the occurrence of fruit imagery in Bedouin ghazal. Based on a selection of classical Arabic love poetry, the paper traces the journey of love and sexuality to illustrate the conceptual change from the prevalence of the gazelle (...) metaphor in Bedouin ghazal of pre- and early Islam times to the emergence of fruit metaphors in Badi poetry of the Abbasid era. Evidenced in poetry, the metaphorical shit mirrors a change in the portrayal of women, who cease to be conceived as wild preys, fearing and fleeing male hunters to become exotic ripe fruits, waiting for the male to pick. Seemingly fortuitous, the shift in love imagery is reminiscent of sociocultural changes that help redefine the poetics of love in classical Arabic literature and inform gender dynamics in medieval Arabia. (shrink)

This book inquires into the swarm of ontological, epistemological, and ethical questions provoked by psychedelic experience in the context of global ecological crisis. Richard M. Doyle is professor of English and science, technology, and society at Pennsylvania State University. He is the author of On Beyond Living and Wetwares.

Both male ornamentation and male combat result in increased male mortality. Because population sizes are limited by a carrying capacity, increased age-specific adult male mortality will result in decreased age-specific adult female mortality, as well as decreased juvenile mortality. As intersexual competition is one form of intraspecific competition, through choosing to mate with ornamented and/or combative males, females in polygamous systems reduce intraspecific competition. Because average male fitness must exactly equal average female fitness, male fitness will paradoxically rise with increasing (...) male mortality. This theory also offers new perspectives on peripheral problems to sexual theory, such as mate location, resource guarding, leks, harems, and others. (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)

The view that female mammals are more docile appears to arise in part from imposing human values on animal studies. Many reports of sexual dimorphism in physical aggression favouring the male in laboratory rodents appear to select circumstances where that expectation is supported. Other situations that favour the expression of conflict in females have been (until recently) relatively little studied. Although female rodents generally do not show the “ritualised” forms of conflict that characterise male sexual competition, they can (...) use notably damaging strategies (especially if they are of short duration). Such considerations might weigh in the selection of strategies by our own species. (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)

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 recent years, the research field of the evolution of art has witnessed contributions from a wide range of disciplines across the "three cultures". In this thesis, I make both a critical review of existing explanations, and try to do elucidate the evolution of art by employing insights, methods and concepts from different disciplines. First, I critically evaluate the evidentiary criteria from standard evolutionary psychology some accounts employ to demonstrate that art qualifies as a human biological adaptation. I argue that (...) these criteria do not suffice to make that claim. Furthermore, I make the case for a cultural evolutionary approach to the arts. One commonly used evidentiary criterion for art as adaptation is the “tight fit” between artnbsp;human cognition, which is interpreted as suggesting that cognition has undergone selection to produce and appreciate art. However, disentangling cultural and genetic evolution allows formulating thenbsp;hypothesis that art has evolved culturally to match human cognition. Second, I observe that in ancient and modern hunter gatherer societies, artistic activities are virtually alwaysnbsp;with ritual. I discuss what this implies for the adaptive significance of art. Specifically, if the arts have culturally evolved in function of ritualistic purposes, their adaptive value has depended on the adaptiveness of ritual. Third, because architecture is characterized by the combination of utilitarian and aesthetic aspects, it is particularly interesting from an evolutionary perspective and therefore I devote special attention to it. Employing the cross-species comparative approach, I investigate two main purposes human architecture has in common with nonhuman animal constructions: protection andnbsp;Based on the phylogenetic approach I establish that protection may have been the primary function of building aptitudes in humannbsp;and that building was later co-opted for signaling purposes. Subsequently, I comparatively evaluate thenbsp;of signaling models in the cultural evolution of architectural aesthetics. Furthermore I combine insights from environmental psychology, niche construction and cultural evolution theory to develop the hypothesis that a function of religious monumental architecture may have been to support nbsp;or even to galvanize nbsp;social learning. Finally, I connect the account I developed to the cognitive science of religion. I complement the frequently held view that religious monumental architecture is a costly signal with the mechanism of sensory exploitation. I attempt to demonstrate that by exploiting thenbsp;response of awe in religious followers, religious monumental architecture promotes and regulates prosocial behavior and creates in them an openness to adopt supernatural beliefs. Fourth, I dealnbsp;the evolution of visual art, paying again special attention to cultural evolution andnbsp;explanatory value of sensory exploitation. I assert that the relatively late appearance of figurative art in the course of human evolution may be attributed to an increase in the number of social learning opportunities within and between human populations at that time. I support this assertion with archaeological data that indicate overall population growth and increased population densities at that time. These demographic changes, I argue, have allowed the retention and accumulation of innovations required for figurative art making. Contrary to previous accounts, I furthermore aim to show that this process doesnbsp;require figurative art to have served adaptive purposes. Employing sensory exploitation, I establish that figurative art could have evolved by exploiting pre-existing biases of evolved psychology. The dominant themes of upper Paleolithic and late stone age figurative art, animals and humans, seem to support this contention. Fifth, I present a number of experimental studies I conducted to verify whether contemporary art experts would have socially learned to resist exploitation of evolved psychology. One aspect ofrsquo;s exploitative power may be that it elicits aesthetic pleasure by pushing “pleasure buttons” that evolved for other purposes. Consequently, spectators may trade-off rewards from indulging in art and biological activities, resulting in less effort being allocated to reproduction. I contend that, while the generalnbsp; may indeed be exploited, experts, who are typically being exposed to high doses of art, may have socially learned to resist exploitation by selectively preferring art from prestigious art contexts. The latter would be in line with the claim that prestige bias may trump content biases of evolved psychology. The results of three experimental studies supportnbsp;contention. I find that laypeople's art appreciation is positively affected by a content bias for attractive faces, mediated by aesthetic pleasure, whereas experts' appreciation is positively affected by prestige and mediated by admiration for the artist. Moreover, experts confer lower appreciation to attractive compared to moderately attractive content, which is consistentnbsp;the contention that expertise and the use of prestige are associatednbsp;resistance against beautiful content that exploits evolved preferences. This research thus suggests that expertise moderates content and context biases, which may be of relevance to an ongoing debate about their relative importance as drivers of cultural evolution. In addition, this study provides a tentative but novel explanation for the fact, famously established by philosopher Arthur Danto, that beauty lost its central position in Western art during the 20th century. However my findings cannot exclude alternative explanations for the fact that art expert appreciation deviates from evolved aesthetic preferences. Further research may experimentally assess the role of prestige bias and resistance as drivers of this deviation versus other, previously suggested, potential processes. For example, preferences of experts may deviate on account of the fact that art serves as a badge of elite group membership and thus expert art appreciation as a means to distinguish oneself from the masses. Alternatively, art experts may seek intellectual challenges instead of pushing pleasure buttons. Future research may experimentally verify the respective roles of these different hypothesized mechanisms. In addition, it may be investigated how insights from sexual selection research may help elucidating the different processes at play in cultural evolution and particularly in the cultural evolution of art appreciation, given the commonalities between sexual selection and cultural selection models. (shrink)

I propose that the underlying adaptation enabling the reproductive strategy of birthing live young (viviparity) is retraction of the site of fertilization within the female reproductive tract, and that this evolved as a means of postcopulatory sexual selection. There are three conspicuous aspects associated with viviparity: (i) internal development is a complex trait often accompanied by a suite of secondary adaptations, yet it is unclear how the intermediate state of this trait – egg retention – could have evolved; (...) (ii) viviparity often results in a reduction in fecundity; (iii) viviparity has evolved independently many times across a diverse array of animal groups. Focusing on the Diptera (true flies), I provide explanations for these observations. I further propose that fecundity is not traded‐off to enable potential benefits of viviparity, but rather that loss of fecundity is directly selected and egg retention is an indirect consequence – a model that provides a unifying common basis for the ubiquity of viviparity. (shrink)