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The Descent of Man, and Selection in Relation to Sex
Abstract
Introduction
The nature of the following work will be best understood by a brief account of how it came to be written. During many years I collected notes on the origin or descent of man, without any intention of publishing on the subject, but...
... 1.2 Eye-color evolution by sexual selection: the trouble with the "rare/novel color advantage" hypothesis If it cannot be explained by ordinary natural selection, the prodigious ascent of blue eyes may have been driven by sexual selection: that is, by their carriers gaining some advantages over rivals "in battle or courtship, " being such advantages "in the long run greater than those derived from rather more perfect adaptation to their conditions of life" (Darwin, 1871). In short, potential mates with blue eyes must have been liked a great deal, for reasons that have as yet escaped us (Cavalli-Sforza et al., 1994;Duffy, 2015;Liu et al., 2013). ...
... Indeed, runaway parental selection can be seen as the self-reinforcing coevolution of parental preference and offspring ornament in much the same way as runaway sexual selection is the self-reinforcing coevolution of female preference and male sexual ornament. Note that both processes are driven by social competition between peerscampaigning to be chosen by, respectively, parents and mates-and can hence be pictured as examples of social, as distinct from natural, selection (Darwin, 1871;West-Eberhard, 1983). Although both sorts of selection boil down to a reproductive advantage, social selection does not hinge on environmental contingencies but on parents' or mates' choices, and relies heavily on what one's rivals are doing or look like (Darwin, 1871;Lyon and Montgomerie, 2012;Tobias et al., 2012;West-Eberhard, 2014). ...
... Note that both processes are driven by social competition between peerscampaigning to be chosen by, respectively, parents and mates-and can hence be pictured as examples of social, as distinct from natural, selection (Darwin, 1871;West-Eberhard, 1983). Although both sorts of selection boil down to a reproductive advantage, social selection does not hinge on environmental contingencies but on parents' or mates' choices, and relies heavily on what one's rivals are doing or look like (Darwin, 1871;Lyon and Montgomerie, 2012;Tobias et al., 2012;West-Eberhard, 2014). For instance, the reproductive returns of displaying blue eyes depend on how much they are liked by others and on whether one's competitors, siblings first and mating adversaries later on, sport blue or nonblue eyes themselves. ...
A surprising number of humans are equipped with a subpar eye model—featuring pale, colorful irides that are nowhere as good as the original dark ones at guarding the retina from sunlight and do, in fact, raise one’s risk of eye disease. Here I apply evolutionary theory to understand why. I propose that the allele for human blue eyes, which arose just once, managed to spread from one individual to millions at an astonishing speed because it is a greenbeard. “Greenbeards”—imaginary genes, or groups of genes, that produce both a green beard and a behavior that favors other bearers of a green beard—have been deemed exceedingly unlikely to show up in the real world. And yet, as individuals who prefer blue eyes are more inclined to mate with blue-eyed partners and invest in blue-eyed offspring, any blue-eye preference (whether random or arising from the bias for colorful stimuli shared by all recognition systems) becomes rapidly linked to the blue-eye trait. Thus, blue eyes gain an edge by working like a peacock’s colorful tail and a nestling’s colorful mouth: twice self-reinforcing, “double runaway” evolution via sexual and parental selection. The blue-eye ornament gene, by binding to a behavior that favors other bearers of the blue-eye ornament gene, is ultimately recognizing and helping copies of itself in both kin and strangers—and greatly prospering, just like theory predicts.
... Heatwaves, are known to have stronger impacts on life than 63 directional changes (Sheldon & Dillon, 2016) by directly influencing individual survival, physiological 64 processes, and reproductive efficacy (Boni, 2019) with these effects being more pronounced in 65 ectothermic species (Kingsolver et al., 2013;Ma et al., 2021;Neven, 2000;Walsh et al., 2019). Under 66 such conditions populations may be selected to evolve towards enhanced thermal tolerance, with 67 traits that may enhance survival in high-temperature environments being favoured, potentially 68 allowing "evolutionary rescue" to occur (Bell, 2017). However, adaptation may be severely limited 69 when populations decline to the size limiting the amount of genetic variance available for selection 70 (Frankham, 2010). ...
... As a result, temperature stress can alter sexual 81 selection dynamics, potentially impacting population persistence (García-Roa et al., 2020). 82 Sexual selection is a process arising from competition for mates and their gametes that 83 favours traits which bestow competitive advantages in the context of mating, such as intricate 84 displays serving to attract mates, armaments and behaviours useful in direct competition for them or 85 seminal fluids aiding competition for gametes (Andersson, 1994;Darwin, 1871). Additionally, traits 86 used in reproductive competition are costly and therefore only the males in good condition, reflecting 87 their adequate adaptation and/or low mutation load should achieve higher reproductive success 88 (Zahavi, 1979;Rowe and Houle, 1996). ...
... 61 64 For this study, we used soil mites (Sancassania berlesei), originally collected from poultry litter 65 from a farm in Dluga Goslina, Wielkopolska region of Poland, in 2022. These populations have since 66 been maintained under controlled conditions, with overlapping generations and large population sizes 67 (>1000 adults). Populations were housed in two custom-designed bottle-top enclosures consisting of 68 was not certified by peer review) is the author/funder. ...
Sexual selection is a potent evolutionary force with complex effects. Strong sexual selection can enhance adaptation and reduce mutational load, while simultaneously reducing survival, or causing sexual conflict that reduces fitness for one or both sexes. Many populations today face not only gradual environmental changes but also extreme, short-term stress events like droughts or heatwaves. The combined effects of sexual and environmental selection on population demography during and after such events remain poorly understood, even though such combined effects could be crucial for the persistence of small, endangered populations under climate change. In this study, we investigated how sexual selection affects survival during environmental stress by manipulating the expression of an aggressive fighter morph in small populations of the male-dimorphic soil mite Sancassania berlesei, exposing some of these populations to recurrent periods of extreme heat and monitoring survival over eight generations. We found that heat exposure reduced survival, more severely in females than in males, and survival was lower in populations with higher fighter prevalence, but there was no interaction between temperature and fighter morph prevalence. Furthermore, survival declined across generations, and the decline was steeper in populations with lower prevalence of fighters, leading to the loss of their initial survival advantage by the last generation. T265625hree populations exposed to heat became extinct during the experiment, all from the reduced fighter expression treatment. Our findings imply that despite its cost to individual survival, sexual selection does not modulate population sensitivity to heatwaves over several generations. Furthermore, we demonstrate that these mortality costs of sexual selection are gradually compensated over successive generations, which could be a result of a more effective purging of inbreeding depression. Thus, while the additive effect of sexual selection and heatwaves on survival may increase demographic risks for bottlenecked populations in the short term, sexual selection may increase resilience of populations to prolonged bottlenecks.
... This article is focussed exclusively on basic reproduction traits as primary elements behind the evolution of human sexual behaviour. However, many other, certainly closely related substantial differences between traits of humans and apes are beyond this paper's scope and are intentionally ignored, such as the roles of tools and garments, of language and eye contact, of penis shape and loss of baculum, of brain size and width of the female birth canal, of limb asymmetry and endurance running, of meat consumption and use of fire, of music and dance, of childhood and learning, of consciousness and mental models, of arts and ornaments, or of social structures of cooperation and competition (Darwin 1879;Leakey and Lewin 1977;Klix 1980;Graham 1981;Reichholf 1990;Dixson 1998;Gopnik et al. 1999;Facchini 2006;Pika 2008 ...
... With respect to reproduction behaviour, beauty (Darwin 1879, Reichholf 2011, Prum 2017Kull 2022) is a visual symbol assessed by mental prediction models for male decision-making (Feistel 2023a,b) with respect to sexual activity. "Possibly, human aesthetics emerged from sexual selection as an independent part, while the aesthetic taste developed as a part of female choice" (Miller 2000). ...
In this paper, the term childhood denotes the ontogenetic developmental stage of weaned mammal infants who are still helpless and need to be nurtured and protected for survival. Human infants have a pronounced childhood phase in contrast to great apes. For a hominin model scenario proposed here, it will be argued that upright bipedal locomotion facilitated early weaning and, as a consequence, the emergence of childhood. To raise their infants to healthy maturity by preventing early pregnancy after weaning, females exploited a succession of contraceptive traits, from concealed oestrus and adipose breasts to menopause. In turn, to ensure a sufficient reproduction rate of their own genes, males developed several related counter measures, from sexual objectification of female bodies as permanent mating targets, to altered male mental filters, then recognising young mature females as being beautiful and sexually attractive.
... Ecclesiastes 3: [19][20] No honest human is free of self-doubt about the validity his or her convictions, and the manner in which one deals with self-doubt expresses a degree of personal integrity. Fortunately for the theory of evolution, Charles Darwin (1859) was no exception from this rule, and it is not surprising that he started to doubt the universal applicability of natural selection-a concept he defined-a mere year after publishing The Origin of Species. In a letter to a friend, he stated, "[T]he sight of a peacock's train whenever I gaze at it makes me sick" (Darwin [1882(Darwin [ ] 1993. ...
... Fortunately for the theory of evolution, Charles Darwin (1859) was no exception from this rule, and it is not surprising that he started to doubt the universal applicability of natural selection-a concept he defined-a mere year after publishing The Origin of Species. In a letter to a friend, he stated, "[T]he sight of a peacock's train whenever I gaze at it makes me sick" (Darwin [1882(Darwin [ ] 1993. What was making him sick was the doubt and not the sight itself, because he found peacocks' tails to be pretty. ...
Biological evolution is an indisputable reality of life, regardless of our ability to conceptualize it. Life of a species cannot exist without death of individuals and birth of new ones. As long as this cycle exists, biological evolution is inevitable, with new speciation as its eventual outcome. The theory of evolution was formulated by Charles Darwin, but understanding of what life is and how it functions owes equally as much to Matthias Jakob Schleiden’s and Theodore Schwann’s cell theory. These three naturalists from the nineteenth century gave us the basis for biology as it is today, and yet cells and evolution are still only partially understood. Life remains mysterious. Death remains a focus of most world religions. This article gives a tremendously abbreviated current understanding of the history of life until this moment in an effort to motivate us to think about life on Earth as it really is—with all extant and lost living beings of Earth related through a common ancestor and made of water and dust.
... Physical attractiveness is an important factor in sexual selection (Clarkson et al., 2020;Rosenthal and Ryan, 2022;DuVal et al., 2023). Sexual selection is driven by two distinct forces, namely, intrasexual selection (i.e., sexual competition between individuals of the same sex) and intersexual selection (i.e., mate choice; Darwin, 1871). Darwin's original description of sexual selection stated that it is driven by male competition over access to females. ...
... This suggests gender differences in the hierarchy of gait attractiveness and femininity evaluation processes. Two distinct forces impact sexual selection among animals, including humans, namely, intrasexual selection (i.e., sexual struggle between members of the same sex) and intersexual selection (i.e., mate choice; Darwin, 1871). Moreover, physical attractiveness is a crucial factor affecting the dynamics of sexual selection (Clarkson et al., 2020;Rosenthal and Ryan, 2022;DuVal et al., 2023). ...
Introduction
Physical attractiveness plays a crucial role in building interpersonal relationships and in daily communication. Attractiveness is perceived through nonverbal information regarding one’s morphological features, posture, movement, and behavior. Selective pressures throughout our species’ evolutionary history have shaped sex differences in the evaluation of physical attractiveness. However, research on the process of body attractiveness perception has been limited to static information involving body images. Therefore, a better understanding of the attractiveness perception process in the real world requires an appreciation of the attractiveness perception mechanism of physical movement.
Methods
This study examined the attractiveness perception of 30-s walking animations, as well as gender differences in gaze behavior and statistical models of attractiveness evaluation. We recruited 16 men and 17 women and made gender comparisons of fixation ratio to each gaze area (head, trunk, hip, leg, and others). Furthermore, the standardized estimates of the statistical models were qualitatively compared between male and female observers.
Results
Male observers were highly fixated on the walkers’ trunk, whereas female observers tended to shift their attention from the trunk to the legs, especially when observing high-preference animations. The statistical model for attractiveness evaluation, which used gait parameters for each gender, showed the tendency that when assessing attractiveness, male observers placed greater weight on the walkers’ trunk silhouette, whereas female observers prioritized parameters requiring whole-body observation.
Discussion
Gender differences in gaze behavior were observed in the assessment and perception of human movement attractiveness; such differences may reflect the evaluation model for each gender. The results suggest that men assess female gait attractiveness based on observations of the reproductive regions of the female body. In contrast, women perceive other women as potential competitors and assess female gait attractiveness based on beauty standards, which are shaped by sociocultural environments and the walker’s psychological state. Our findings are the first step toward understanding the process of perceiving the attractiveness of physical movement and are expected to help generate attractive biological motions.
... However, the most influential nineteenth century work on emotional expression came in the work of Darwin. In Descent of Man (Darwin, 1871), Darwin aimed to show evolutionary continuity between human and animal behavior (Griffiths and Walsh, 2015). Darwin's Expression of the Emotions in Man and Animals (Darwin, 1872) aimed to further this aim by comparing the facial expressions of humans and animals. ...
The past few decades have brought rapid advancements in emotion recognition technologies (ERTs) that attempt to infer and monitor a user’s emotional state. One controversial class of ERTs attempts to infer emotional state by detecting coordinated changes in facial musculature (known as automated facial expression analysis or AFEA). Much discussion about appropriate usage and regulation of AFEA has occurred in isolation from scientific debate about what information facial expressions provide and whether emotional states can be inferred from them. In addition, scientific debate about the relationship between facial expressions and emotions does not engage with, and yet would likely benefit from, engagement with recent work in the philosophy of science on the relationship between models and target systems, and, in particular, cases where models introduce idealisations that approximate (but do not correspond to) real-world phenomena. This article brings both bodies of research to bear on the question of what AFEA can and cannot infer about a person’s feelings and intentions. It then advocates for more robust explainability for new and emerging ERTs and other ‘high-risk’ systems.
... Sexual selection is one of the main factors acting on the evolution of animal signals' (Darwin, 1871) diversity (Schaefer & Ruxton, 2015) and composition (Schwark et al. 2022). In birds, the role of sexual selection on the evolution of song diversity has been extensively documented in both wild and laboratory studies (Byers & Kroodsma, 2009). ...
Birdsong is a complex signal shaped by multiple factors and has been explored most widely through the lens of sexual selection, but with mixed results. Here, we focus on the evolution of two song parameters: diversity, which is widely studied, and composition, which is poorly understood. We assessed the potential role of mating system as a proxy for sexual selection, but in addition, investigated whether colony size, a proxy for sociality, and phylogenetic history influence the evolution of these parameters in weaverbirds family (Aves: Ploceidae). Using comparative and path analyses we find that, as expected, species living in larger colonies present greater song diversity and had similar song composition. However, contrary to expectations, polygamous species do not present higher song diversity, nor more similar acoustic composition than monogamous species. A relatively high effect of phylogeny was detected on both song variables. Our results thus suggest that, in this family, sociality is a stronger driver of song diversity and composition than sexual selection. These findings highlight the importance of testing multiple factors when studying bird song evolution and the relevance of sociality.
... houver resultado, ou se a prole for infértil com outras produzidas da mesma forma, elas são verdadeiras espécies fisiológicas (Huxley, 1860, p. 552-53). Darwin (1871) Ao determinar se duas ou mais formas próximas devem ser classificadas como espécies ou variedades, naturalistas são praticamente guiados pelas seguintes considerações; isto é, a quantidade de diferença entre elas, e se tais diferenças se relacionam com poucos ou muitos pontos de estrutura, e se eles são de importância fisiológica; mas mais especialmente se eles são constantes. A constância de característica é o que é principalmente valorizado e buscado pelos naturalistas (Darwin, 1871, p. 93). ...
Este artigo investiga o conceito darwiniano de espécie e suas consequências para a classificação dos seres vivos. Em sua formulação da teoria evolutiva, Darwin (1872) introduz o conceito de espécie enquanto segmentos de linhagens populacionais. Nessa perspectiva, a seleção natural atua de forma gradual e produz ligeiras variações nos indivíduos através do tempo. O autor vincula o componente evolutivo com a ideia de que a espécie consiste numa classificação taxonômica, na qual variações bem demarcadas são o critério central para classificar as linhagens descendentes. Formulações posteriores do evolucionismo mantiveram tais componentes, mas buscaram substituir o critério de classificação por bases mais objetivas. O resultado foi uma proliferação de definições e consequente controvérsia sobre o tema. Argumentar-se-á que inadequações históricas sobre a definição de Darwin contribuíram para o surgimento dessa discussão. Em conclusão, será desenvolvido um argumento a favor do princípio de seleção natural com base na discussão entre fisiologia e morfologia enquanto mecanismos para o surgimento de novas espécies.
... Darwin's theory of sexual selection was developed to explain the evolution of such conspicuous characteristics, as he recognized that such traits appear to be costly to an organism without conferring any obvious benefits to its survival. Instead, Darwin hypothesized that such traits could evolve through social mechanisms related to reproduction, with the sex competing more intensely for mates evolving elaborate ornaments or weapons functioning in mate acquisition (Darwin, 1859(Darwin, , 1871). ...
... Sexual size dimorphism (SSD) is common in birds, with males being typically larger than females, giving them an advantage in competing for mates and resources. Darwin suggested that natural selection favored larger and stronger males, enabling them to outcompete rivals during mating and territorial disputes [6]. ...
Sexual dimorphism in bill morphology influences foraging strategies and bird competitive interactions. This study uses geometric morphometric analyses to examine sex-based differences in the bill shape and size of Ciconia ciconia, a large wading bird. Standardized dorsal and lateral photographs of 45 white storks (24 females and 21 males) were analyzed. The mean centroid size (CS) confirmed that males have significantly larger bills than females, yet principal component analysis revealed no reliable shape-based sex differentiation. Allometric analyses indicated that larger individuals exhibit more pronounced shape variations, likely tied to functional adaptations, though these were insufficient for sex determination. While bill size correlates with sex, shape variation does not serve as a reliable criterion for sexing C. ciconia. This study contributes to the understanding of sexual dimorphism in Ciconia ciconia by quantifying bill size differences using geometric morphometrics.
... Other authors argue that although speech and music share overlapping brain areas, distinct areas can be found that are only activated in one or the other tasks, which is further supported by studies on patients with brain damages or developmental disorders affecting specific areas (see Leongómez et al., 2021 for a review and discussion). Darwin (1871) proposed that musicality and language may be based on the ability to imitate and modify sounds in nature, or sounds produced by con-or heterospecifics. This reinforces the role of vocal learning in human music and language evolution and has since been reframed as the musical protolanguage hypothesis (Fitch, 2013). ...
Isochrony, or the regular timing of sounds, is a prominent rhythmic feature of human music and can also be found in the vocalisations of non-human animals. In the evolution of music and language, the capacity for vocal learning is hypothesised to have played a key role, with vocal learning species thought to have more advanced rhythmic capabilities. However, studies show that vocal isochrony is also present in vocal non-learners, indicating that it is perhaps a highly conserved property providing adaptive benefits across taxa. As mechanisms that are shared across multiple species are likely to have been the bedrocks of our current abilities, comparative research into vocal isochrony can give clues on how rhythms in human music and language might have evolved, even though modern speech is not typically isochronous. This review summarises possible adaptive functions of vocal isochrony by describing its presence across different species and call types found in recent research. Thus, it represents a narrative synthesis of the adaptive functions of vocal isochrony. Here, we highlight three major possible functions of vocal isochrony: firstly, isochrony could improve communication by enhancing signal transmission from one individual and auditory detection by others and possibly function in conveying meaning. Secondly, vocal isochrony could inform others about mate quality, indicating a role in sexual selection. Lastly, isochrony could facilitate vocal coordination between two or more individuals, as the predictability of isochrony can help individuals to adjust the timing of their vocalisations to each other more readily. These functions seem to be highly intercorrelated, which might provide clues for the evolution of human music and speech.
... By including one, we found, "So much is 'wasted' in conflict… The more produced, the more there is to steal and so the greater the pay-off to theft and to defense against it" (Hawkes, Rogers, et al. 1995, 663-664). "Wasteful conflict" should have recalled Darwin's (1859Darwin's ( , 1871 insights about sexual selection. Also, directly pertinent but not cited there, are Geoff Parker's (1974Parker's ( , 1979 distinctions between two kinds of mating competition, guarding or seeking another paternity elsewhere. ...
Compared to our closest living cousins, the great apes, humans can live longer with a distinctive postmenopausal lifespan; our development is slower, yet our babies are weaned earlier. Continued investigation since 2003 shows our grandmother hypothesis is a robust explanation for those differences and many other distinctive human features: When ecological changes in ancient Africa spread profitable foraging targets for ancestral adults that infants and small juveniles couldn't handle, reliable foraging by females near the end of their own fertility could subsidize dependent grandchildren and shorten their daughters' time to next conception. Coevolution of shorter birth intervals with slower aging expanded the pool of older still‐fertile males. With more competitors, guarding a mate wins more paternities, linking pair bonds to our mid‐life menopause. Mate guarding plus older males' advantage in reputation building explains many aspects of human patriarchy. In addition, final brain size in placental mammals depends on the duration of development. As increasing longevity slowed development and expanded brain size, earlier weaning of still physically helpless ancestral infants prioritized their attention and capacities to engage carers. Resulting socially precocious infancies wire us with lifelong appetites for cooperation.
... However strong the assertion of human rights, their force can be diminished to an infinitesimal level in any given situation simply by numerically overwhelming natural persons by juridical persons, and this possibility is already extensively exploited. 40 It is closely related to the possibility of the unlimited creation of money via credit [51], one consequence of which is that corporations can typically access vastly greater financial resources than individuals in judicial proceedings. A practical limit is imposed by the requirement for companies to have human directors, but already some people hold dozens of directorships, and AI will greatly increase this limit, a trend doubtless welcomed by techno-libertarians, whose ideal is a technology-driven world free from all government constraints, as embodied, for example, by the city of Próspera in Honduras. ...
... These ideas formed the basis of Spencer's "speech theory" of the origins of music. Darwin's evolutionary theory of music 29 posited the reverse progression, claiming that speech evolved from a primitive form of hominin singing. However, Darwin's conception of singing was not well-speci ed in his writings, and included very nonscaled vocalizations like the territorial calls of gibbon apes. ...
Music is well-known to be based on sets of discrete pitches that are combined to form musical melodies. In contrast, there is no evidence that speech is organized into stable tonal structures analogous to musical scales. In the current study, we developed a new computational method for measuring what we call the “scaledness” of an acoustic sample and applied it to three cross-cultural ethnographic corpora of speech, song, and/or instrumental music (n=1,696 samples). The results confirmed the established notion that music is significantly more scaled than speech, but they also revealed some novel findings. First, highly prosodic speech – such as a mother talking to a baby – was no more scaled than regular speech, which contradicts intuitive notions that prosodic speech is more “tonal” than regular speech. Second, instrumental music was far more scaled than vocal music, in keeping with the observation that the voice is highly imprecise at pitch production. Finally, singing style had a significant impact on the scaledness of song, creating a spectrum from chanted styles to more melodious styles. Overall, the results reveal that speech shows minimal scaledness no matter how it is uttered, and that music’s scaledness varies widely depending on its manner of production.
... Indirect evidence from each of these fields may be combined to tell a story that can begin to explain the relatively rapid leap in human cognitive capacity that gave rise to advanced abilities such as the creation of sophisticated tools, intricate art and complex language. How and when this revolution took place is a matter of great debate [1][2][3][4][5][6][7][8][9][10][11][12][13]. ...
Primates have been evolving for over 50 million years. At some point, humans made an unusually large evolutionary leap, giving rise to abilities like the creation of tools, intricate art and complex language. The neuronal synapse, a key player in information processing and brain plasticity, has largely been ignored as a potential factor in this process. Here we used the genomic databases of ancestral hominins to compare the expression levels of 995 genes expressed in the human nervous system among archaic (6 Neanderthal, 2 Denisovan) and modern humans (62 African Modern Human). We searched in the 95th top p-value for variants whose derived alleles had a frequency >90% in modern and <10% in archaic humans. We then used the STRING database to perform protein-protein interaction networks on the 95th top p-value for the variants. We identified genetic variants in 15 genes, and in two (STX16 and UBASH3B), the allele frequency was significantly higher in modern versus archaic humans. These genes have previously been associated with critical cellular (proliferation, differentiation, migration, survival) and synaptic (exocytosis, synaptic vesicle fusion) processes, supporting the idea that changes in synaptic structure and function may have played a key role in the development of human cognition.
... Neanderthals became the first archaic humans to be recognized by science. In The Descent of Man, Charles Darwin argued that humans are like other animals in being the products of evolution (Darwin 1871). Although Darwin himself did not recognize their significance, Neanderthals were eventually recognized to be from a population more closely related to modern humans than to living apes, providing evidence for Darwin's theory that such populations must have existed in the past. ...
This article seeks to provide some genetic perspectives on the question “Just How Special Are Humans—Really?” It begins with an introduction to how genetic variation can provide information about the past. It continues by discussing two ways in which genetic analyses has, on multiple occasions, shown that humans are less unique than we thought we are. We have a cognitive bias to toward thinking we are special. Our species has colonized an ecological niche not exploited by any other species on our earth, but how much of our adaptation to that niche is cultural rather than genetic?
... People are curious creatures, interested in exploring novel experiences, practices and customs (Darwin, 1871;Krippendorf, 1986). When politics allow, people from countries relatively closed to the outside world, as China was before the economic reforms, welcome such novelty and the benefits it brings, facilitating the acceptance of, in this case, Western MNEs and their products, technologies, values and practices. ...
In this paper, we replicate and expand Littrell et al.’s (in Cross Cultural Management: An International Journal, 19(3), 315–335 2012) study examining variations in employee preferences for explicit managerial leader behaviors in mainland China. Drawing on Hofstede´s model of culture, culturally contingent leadership theory and theory of cultural dynamism, and using a wider array of data including that on societal cultural values, we found that, unlike the original study, these values and preferences have homogenized across the country. They have reverted towards traditional Chinese societal-cultural values and distanced from the “Western influx” occurring from the 1970-ies. We argue that recent environmental shock, the Covid-19 pandemic, may have induced the phenomenon of relapse towards traditional societal cultural values and, thus, preferences for leader behaviors. On these bases, we elaborate on our contributions, identify practical implications, and suggest future research directions to examine the global scale and magnitude of the phenomenon.
... Female-biased SSD occurs in other geckos from southern New Zealand (Cree & Hare 2016a;Knox et al. 2019) and lizards from high-latitude sites elsewhere (Fernández et al. 2015;Tarr et al. 2019;Valdecantos et al. 2019). This pattern is presumed to have evolved to maximize fecundity (Darwin 1874). We speculate that it may enable larger Cascade gecko females to produce larger offspring with increased survival in cool climates. ...
... This era led to two strong, yet illogical, belief that women are inferior in the traits and capacities in comparison to man. Two historical men who led this belief about women were Darwin (1871) [5] and Freud (1905Freud ( , 1931 [8,9] . Since 1850s we can see that the scientist and psychologist had opposed this prevailing notion about the women. ...
... Aggression, particularly between conspeci cs, is often bene cial for acquisition of resources such as territory, food, and/or mating opportunities that are necessary to survive and reproduce. In animals, aggression takes the form of various agonistic behaviors, from threat displays to physical combat (Darwin 1888;Lorenz 1966;Archer 1988; Kravitz and Huber 2003;Huntingford 2013). However, aggression is also costly, as engaging in aggressive behavior expends energy and time that could be devoted to other activities such as foraging or mating (Briffa and Sneddon 2007). ...
Aggression is a key behavior for acquiring resources necessary for survival and reproduction, but it is both energetically costly and risky. Theory predicts that aggression should reflect a balance between an individual’s resource-holding potential (RHP) and motivation, yet predicting aggression under conditions of resource scarcity is challenging. Nutritional status is particularly important, as food deprivation reduces RHP but may simultaneously increase motivation to fight. Here, we examined how the duration of food deprivation affects male–male aggression in the broad-horned flour beetle, Gnatocerus cornutus , a species where combat is primarily used to secure mating opportunities rather than food. We paired size-matched males that were either fed ad libitum or starved for up to 11 days and recorded their aggressive behaviors during 20-minute trials. Our results show that short-term food deprivation reduces aggression, consistent with reduced RHP. However, as the duration of food deprivation lengthened, aggression in starved males gradually increased, resembling the “hangry” response described in other animals. In contrast, aggression levels in fed males remained stable across time. Importantly, these patterns were not explained by differences in general activity levels. These findings highlight a dynamic interaction between RHP and motivation, showing that severe resource limitation can override poor condition to elevate aggression. This work contributes to understanding behavioral plasticity under resource scarcity and demonstrates that aggression responses to food deprivation are complex and context-dependent.
... Sexual selection is one of the main factors acting on the evolution of animal signals' 99 (Darwin, 1871) diversity (Schaefer & Ruxton, 2015) and composition (Schwark et al. 2022). 100 In birds, the role of sexual selection on the evolution of song diversity has been extensively 101 documented in both wild and laboratory studies (Byers & Kroodsma, 2009). ...
... It suggests that early life adversity (eg, VP or VLBW) indicating a higher mortality risk 20 may orient individuals toward a fast LH strategy (ie, to reproduce early to reduce the risk of not reproducing at all). Darwin's theory of sexual selection [21][22][23] conceptualizes reproductive success via the processes of intrasexual competition and intersexual selection. Individuals born VP or with VLBW more often than term-born individuals experience a range of impairments in childhood 24 and lower education and wealth by adulthood. ...
... The inquiry into the significance of coloration and color vision in animal communication and plant-animal interactions has stood as a central inquiry within the field of evolutionary biology for numerous decades [1][2][3][4][5][6][7][8][9] . ...
The reflection in natural objects mediates an important fraction of the light reaching animal photoreceptors. Knowledge of the spectral properties of natural objects is increasingly valuable for different research fields. Measured datasets of natural objects’ reflectance can offer insights into fundamental and applied research questions, contributing to investigations from coloration and color vision to color analysis and representation. Thus, datasets of natural objects’ reflectance across different locations are crucial to assessing the universality and variability of physical visual inputs in diverse environments. However, the Southern Hemisphere is notably underrepresented in publicly available datasets of natural objects. To address this gap, we present a spectral dataset of natural objects’ reflectance from the Southern cone of South America, specifically Northwestern Argentina. Our dataset encompasses 532 samples representing diverse natural objects such as barks, flowers, fruits, leaves, plant fruits, stones, and animal specimens, including birds, beetles, and butterflies. By openly sharing this dataset, as a publicly available online resource, we aim to facilitate research across various disciplines, from evolutionary biology to industrial applications.
... Some resemble similarities to Sexual Selection and Mate Choice although some are not explicitly described as such. Sexual Selection, also pioneered by Darwin (Darwin, 1859(Darwin, , 1981, can be described as a parallel force to Natural Selection, which has the potential to shape evolutionary paths and establish differences between organisms of the same species (Alonzo & Servedio, 2019;Clutton-Brock, 2007;Gayon, 2010;Ralls & Mesnick, 2009). Mainly divided into two categories, we can observe the influence of Sexual Selection via competition for mates or by conveying evolutionary advantage to some traits critical to be accepted as a mate (i.e., Mate Choice) (Jones & Ratterman, 2009). ...
Several mating restriction techniques have been implemented in Evolutionary Algorithms to promote diversity. From similarity-based selection to niche preservation, the general goal is to avoid premature convergence by not having fitness pressure as the single evolutionary force. In a way, such methods can resemble the mechanisms involved in Sexual Selection, although generally assuming a simplified approach. Recently, a selection method called mating Preferences as Ideal Mating Partners (PIMP) has been applied to GP, providing promising results both in performance and diversity maintenance. The method mimics Mate Choice through the unbounded evolution of personal preferences rather than having a single set of rules to shape parent selection. As such, PIMP allows ideal mate representations to evolve freely, thus potentially taking advantage of Sexual Selection as a dynamic secondary force to fitness pressure. However, it is still unclear how mating preferences affect the overall population and how dependent they are on set-up choices. In this work, we tracked the evolution of individual preferences through different mutation types, searching for patterns and evidence of self-reinforcement. Results suggest that mating preferences do not stand on their own, relying on subtree mutation to avoid convergence to single-node trees. Nevertheless, they consistently promote smaller and more balanced solutions depth-wise than a standard tournament selection, reducing the impact of bloat. Furthermore, when coupled with subtree mutation it also results in more solution diversity with statistically significant results.
... For example, in many representatives of Dytiscidae, elytra showing a sexual dimorphism are impressed with primary and secondary reticulation in females. These reticulation patterns have taxonomical significance (Drotz et al. 2010) and in the past, were assumed to aid males during mating (Darwin 1871). Further studies suggested that these elytra sculptures reduce male adhesion and are therefore a sexually antagonistic trait associated with sexual conflict (Miller 2003;Karlsson Green et al. 2013;Bilton et al. 2016). ...
This study investigates the coevolution of male attachment devices and female elytral morphology in coccinellid beetles, focusing on the sexual dimorphism of claws and adhesive pads. We analyzed 11 species from different tribes with different feeding regime, examining the structure of male and female attachment organs (claws and hairy pads) in relation to the surface structure of female elytra. Our findings show that disco‐setae, which enhance adhesion during mating, are present only in males of some species and are localized on the hairy pads of their legs. These setae exhibit morphological adaptations based on the surface structure of female elytra, with larger discoid setal tips in species with smooth elytra and smaller tips in those with hairy elytra. Additionally, male beetles with hairy elytra possess dimorphic claws, which enhance attachment efficiency compared to species with smooth elytra, where claw dimorphism is less pronounced. Our results reveal that sexual dimorphism in hairy pads is more pronounced in larger species, where claw dimorphism is absent, while in smaller species, claw dimorphism alone suffices for effective attachment. These findings contribute to a deeper understanding of the evolutionary dynamics shaping attachment adaptations in Coccinellidae, with implications for reproductive strategies, pest management, and ecological interactions in this diverse beetle family.
... One common limitation of evolutionary theories of music is their lack of explanation regarding the incredible sonic variation in what we observe in contemporary cultures-an issue because this variation is arguably one of the most interesting and defining features of musical behaviour. Evolutionary accounts propose adaptive solutions for functions such as coalition signalling [1][2][3][4], parent-offspring communication [5], social bonding [6], predator deterrence [7,8], sexual signalling [9,10] and more, but these factors cannot explain in any detail how and why you get a Bach chorale, a South African drum circle, or a dissonant noise drone in the times and places they appear. An important part of the puzzle is missing. ...
Music traditions worldwide are subject to remarkable diversity but the origins of this variation are not well understood. Musical behaviour is the product of a multicomponent collection of abilities, some possibly evolved for music but most derived from traits serving nonmusical functions. Cultural evolution has stitched together these systems, generating variable normative practices across cultures and musical genres. Here, we describe the cultural evolution of musical distortion, a noisy manipulation of instrumental and vocal timbre that emulates nonlinear phenomena (NLP) present in the vocal signals of many animals. We suggest that listeners’ sensitivity to NLP has facilitated technological developments for altering musical instruments and singing with distortion, which continues to evolve culturally via the need for groups to both coordinate internally and differentiate themselves from other groups. To support this idea, we present an agent-based model of norm evolution illustrating possible dynamics of continuous traits such as timbral distortion in music, dependent on (i) a functional optimum, (ii) intra-group cohesion and inter-group differentiation and (iii) groupishness for assortment and social learning. This account illustrates how cultural transmission dynamics can lead to diversity in musical sounds and genres, and also provides a more general explanation for the emergence of subgroup-differentiating norms.
This article is part of the theme issue ‘Nonlinear phenomena in vertebrate vocalizations: mechanisms and communicative functions’.
... Still, some form of selective pressure likely also acted on the structure of males' vocal units. Therefore, our second hypothesis involves sexual selection, the primary evolutionary cause of sex difference [65]. Indris live in a female-dominated society where female mate choice and intra-sexual male selection are likely to take place [66]. ...
Animal vocalizations contain a varying degree of nonlinear phenomena (NLP) caused by irregular or chaotic vocal organ dynamics. Several hypotheses have been proposed to explain NLP presence, from unintentional by-products of poor vocal technique to having a functional communicative role. We aimed to disentangle the role of sex, age and physiological constraints in the occurrence of NLP in the songs of the lemur Indri indri, which are complex harmonic vocal displays organized in phrases. Age and sex affected the presence and type of NLP in songs. In particular, the proportion of the phenomena considered decreased with age, except for subharmonics. Subharmonics potentially mediate the perception of lower pitch, making signallers appear larger. Subharmonics and frequency jumps occurred in lower-pitched notes than regular units, while chaos and sidebands occurred in higher-pitched units. This suggests that different types of NLP can be associated with different vocal constraints. Finally, indris might present short-term vocal fatigue, with units occurring in the last position of a phrase having the highest probability of containing NLP. The presence of NLP in indris might result from proximate causes, such as physiological constraints, and ultimate causes, such as evolutionary pressures, which shaped the communicative role of NLP.
This article is part of the theme issue ‘Nonlinear phenomena in vertebrate vocalizations: mechanisms and communicative functions’.
... Body Image perception could also be an adaptation of intrasexual competition (ISC), which is an evolutionary theory proposed by Darwin [10]. He defines ISC as the rivalry among individuals of the same sex for access to mates. ...
This literature review explores the impact of evolutionary factors on body image perceptions across different cultures, focusing specifically on the comparative analysis between Chinese and American contexts. It examines the debate between evolutionary adaptations and cultural evolution byproducts in shaping body image ideals. Drawing on key studies, the review highlights the role of evolutionary psychology in explaining universal beauty cues, such as waist-to-hip ratio and facial symmetry, and how these traits influence mating preferences across cultures. It also discusses the influence of intrasexual competition on body image concerns, particularly the drive for thinness among women and height competition among men. Additionally, the review addresses the cultural evolution of body image preferences in China and the United States, tracing historical shifts and current trends influenced by media, social norms, and gender roles. Finally, the review identifies gaps in the existing literature, particularly the need for more research on male intrasexual competition and cross-cultural comparisons of body image preferences, and outlines a proposed study to further investigate these dynamics.
... Altogether, pre-existing ecological conditions and their associated perceptual biases, as well as the role of drift in the Fisher process, can all be seen to contribute to the contingencies of an organism's evolutionary history. While most comparative and experimental research has focused on relatively simple sexual ornaments, the interaction between the deterministic process of sexual selection, historical contingency, and biological constraints also applies to the most elaborate courtship phenotypes, such as those seen in polygynous bird clades, which were a key inspiration in the initial formulation of sexual selection theory (Darwin 1871). Birds moreover represent a particularly relevant vertebrate example since they are often hailed for their exceptional diversity of courtship displays that appear to have evolved in a relatively unconstrained manner. ...
Natural selection is broadly considered to be a deterministic process, though the roles of historical contingency and constraint are increasingly being recognised as key factors shaping the diversity of life on earth. Sexual selection through mate choice is similarly deterministic and there is increasing evidence that processes such as sensory drive may produce predictable evolutionary outcomes in the design features of sexual signals. However, much variation amid the extraordinary diversity of courtship phenotypes among animals is left unexplained by purely deterministic processes. Since evolution acts without foresight, the elaboration of phenotypes—including those involved in sexual signalling—is analogous to a tinkering process, meaning that nuanced historical contingencies in an organism’s phylogenetic history set the stage for unique constraints in the future. Even in famously diverse ‘ornamental’ radiations, such as the birds of paradise—which feature numerous unique courtship traits or evolutionary “one-offs”—they also exhibit exceptional convergence in signalling traits despite strikingly diverse signal production mechanisms. While comparative research often focuses on signaller phenotypes, a clear distinction between signal production mechanisms (i.e., the mechanical or physiological basis of display) and their perceptual effects for signal receivers (i.e., signal design features) is critical to understand the deterministic processes shaping signal evolution. Furthermore, while there may be disparate evolutionary trajectories to similar elaborate signalling phenotypes, the resulting unique mechanisms of display can impose equally unique constraints on signalling phenotypes. These and other findings suggest that, to understand the evolution of elaborate courtship phenotypes, comparative research should address the interacting effects of deterministic processes, historical contingencies, and biological constraints.
... Florence Nightingale believed that good nurses were individuals who deliberately developed specific good traits in their character, one of which was compassion. An earliest perspective on compassion as stated by Darwin [1] was "those communities which included the greatest number of the most sympathetic members would flourish best, and rear the greatest number of offspring." Compassion is central to the belief systems of the majority of the world's religious traditions. ...
Compassion is an essential aspect of the provision of nursing care. However, the concept of compassion is complex as multiple elements are involved in it and the perspectives of nurses as well as patients help us to unveil the complex concept. To summarize the various elements of compassion from the perspective of patients and nurses. A systematic review based on preferred reporting items for systematic review and meta-analysis was conducted to explore compassionate care in nursing. The review protocol was registered in PROSPERO (an international database of prospectively registered systematic reviews) with the CRD number CRD42022336220. Multiple medical subject headings keywords across databases were used to retrieve the qualitative studies on compassion. A total of 18 qualitative papers were included in the review after the quality assessment with critical appraisal skill program checklist. The meta-synthesis was carried out using Noblit and Hare's seven-step approach. The perspectives of 485 participants were synthesized for the meta-synthesis. Two major themes with multiple subthemes were derived from the meta-synthesis. Major themes include the construct of compassion and the attributes of compassion. The construct of compassion had various subthemes such as similarity with other constructs or negative perceptions of compassion and measures to improve compassion or inhibitors or outcomes of compassion. Similarly, the attributes of compassion had personal, caring, and relationship attributes. The knowledge, skills, and attitudes of nursing staff were reported as predominant attributes. Further, establishing a trusting relationship with the patient by using verbal and nonverbal communication skills conveyed compassion to a greater extent. Compassionate care involves a multitude of components. A thorough understanding of the components by aspiring nursing students and novice clinical nurses is highly warranted in the current era to provide high-quality nursing care.
... Within the context of sexual selection theory, males have typically garnered attention across taxa as the more aggressive and socially dominant sex, both intrasexually and intersexually [1,2]; however, there has been mounting evidence that the females of certain species are the more competitive sex [3]. Female aggression is most often studied in the context of maternal or defensive aggression [4][5][6], whereas female competitive agonism and its neuroendocrine underpinnings are not well covered. ...
Aggression and its neurochemical modulators are typically studied in males, leaving the mechanisms of female competitive aggression or dominance largely unexplored. To better understand how competitive aggression is regulated in the primate brain, we used receptor autoradiography to compare the neural distributions of oxytocin and vasopressin receptors in male and female members of female-dominant versus egalitarian/codominant species within the Eulemur genus, wherein dominance structure is a reliable proxy of aggression in both sexes. We found that oxytocin receptor binding in the central amygdala (CeA) was predicted by dominance structure, with the members of three codominant species showing more oxytocin receptor binding in this region than their peers in four female-dominant species. Thus, both sexes in female-dominant Eulemur show a pattern consistent with the regulation of aggression in male rodents. We suggest that derived pacifism in Eulemur stems from selective suppression of ancestral female aggression over evolutionary time via a mechanism of increased oxytocin receptor binding in the CeA, rather than from augmented male aggression. This interpretation implies fitness costs to female aggression and/or benefits to its inhibition. These data establish Eulemur as a robust model for examining neural correlates of male and female competitive aggression, potentially providing novel insights into female dominance.
... Consequently, mandrills also occupy some of the largest total home ranges documented in any wild primate (118 km 2 , 46 km 2 of forest) (White et al. 2010) and may travel up to 10 km per day (White 2007;Hongo et al. 2022). These socioecological traits are coupled with the most extreme size dimorphism seen in primates and extravagant facial adornments on male animals (Darwin 1871;Setchell 2016). Furthermore, the geographic range of mandrills overlaps with those of numerous other primate species and high biomass frugivores, such as forest elephants (Loxodonta cyclotis) and red river hogs (Potamochoerus porcus) . ...
Understanding primate dietary plasticity provides insights into trait evolution and resilience to environmental change. Here, we investigate the feeding ecology of mandrills ( Mandrillus sphinx ), a species that forms groups of close to 1000 individuals, which presumably impacts feeding ecology by creating exceptionally high feeding competition. Mandrills are also threatened by habitat loss and climate change, and a full understanding of their dietary plasticity is essential to ongoing conservation efforts. Evidence suggests that mandrills are generalist feeders and consume a wide variety of resources to compensate for shortfalls in fruit availability. However, a lack of long‐term data on fruit production within the mandrill geographic range means that it is unknown whether the flexible feeding strategies observed previously are stable over multiple years. We combined two rare data sets comprising 8 years of fecal collection and fruit availability to assess the dietary flexibility of mandrills in Lopé National Park, Gabon. We found fruit to be the most frequently consumed resource and fruit consumption covaried positively with fruit availability, peaking during periods of fruit abundance. Mandrill dietary diversity increased during periods of fruit scarcity, through greater consumption of animal prey, leaves, seeds, and other plant fibers. These results demonstrate that mandrills are primarily frugivorous, but that they are also highly flexible feeders, able to respond to temporal variation in fruit production over several annual cycles. In addition, we found that mandrills varied in the extent to which they preferred different fruit taxa. Lipid‐rich oil palm ( Elaeis guineensis ) fruits were by far the most frequently consumed resource and may constitute a staple resource for mandrills in the study site. Our multiyear study provides robust evidence for generalist feeding behavior by mandrills, which may be driven by extreme group sizes or past environmental fluctuations and provide resilience to future environmental change.
The main objective of this work is to show how evolutionary ethics manages to overcome the empirical and conceptual challenges that are imposed on it. Contemporary evolutionary ethics endorses a methodological naturalist perspective, and can be characterized as a theoretical project that seeks to explain human morality from considerations of the theory of evolution. However, for this project to be carried out satisfactorily, it is necessary to overcome the challenges that have traditionally been posed to it, namely, the problem of altruism and the challenges of the naturalistic fallacy and Hume's law. In a first moment, it will be shown that the problem of altruism can be minimized from the theories of reciprocal altruism and kin selection. In a second moment, it will be shown that conceptual problems are minimized from the descriptivist character of evolutionary ethics. Finally, we will argue that, although pertinent challenges have been raised, evolutionary ethics manages to offer strong answers and consolidate itself as an important theoretical alternative and as a scientifically informed philosophical project.
Este estudo analisou interações discursivas que emergiram durante uma intervenção didática realizada com licenciandos de biologia sobre processos de alterização na ciência, utilizando cenas do anime Fullmetal Alchemist: Brotherhood. O objetivo foi avaliar o uso do anime para mobilizar especificamentea história do racismo científico e a Educação das Relações Étnico-raciais (ERER). Com base na Análise Crítica do Discurso, os resultados forneceram indícios de que o anime contribuiu para mobilizar ideias relacionados à ERER e compreensões sobre teorias raciais, processos de alterização, alterocídio e alterofobia, apesar de algumas limitações encontradas. Os licenciandos avaliaram o anime como um recurso interessante para o ensino de evolução e ERER. Assim, consideramos o anime um recurso potencial para abordagem da temática.
Brain characteristics play an important role for vocal learning in birds. Although some characteristics, such as cell density, have always been considered important for song memorization, other traits, such as astrocyte morphology, have been neglected or poorly studied. We studied the relationship between cell density in the High Vocal Centre (HVC), astrocyte morphology (intersections and length), and vocal learning capabilities in a tropical songbird. Individual birds were recorded, and different brain characteristics were analysed using whole-brain imaging, cellular density analysis, and confocal microscopy. Our findings suggest that song innovation relies on both a higher HVC cell density and more complex astrocytic structures, likely reflecting enhanced song complexity and innovation. In contrast, repertoire size appears to be primarily constrained by astrocyte morphology, emphasizing its role in memory and motor control. This study highlights the neural trade-offs required for song complexity, linking vocal behaviours to developmental conditions and sexual selection. By elucidating the interplay between astrocyte architecture and birdsong in tropical songbirds, we provide insights into the evolution of vocal learning and innovation. These results underscore the importance of astrocytes in shaping behavioural complexity and offer a framework for understanding the neural basis of acoustic communication.
This coursebook offers an expansive exploration of bioethics, an interdisciplinary field examining ethical, social, and legal dilemmas in medicine, life sciences, and beyond. It challenges conventional boundaries, embracing Van Rensselaer Potter’s vision of bioethics as a global, holistic ethics of life—integrating human health, environmental considerations, and transdisciplinary insights.
Through engaging discussions, thought experiments, and case studies, the book empowers students to critically reflect on ethical questions without dictating rigid answers. Topics range from the historical roots of ethical thought to cutting-edge debates in molecular biology, such as epigenetics and exposomics, demonstrating how interconnected human, animal, and environmental health truly are.
Central themes include the limits of scientific knowledge, the biases shaping research, and the evolving interplay between moral philosophy and empirical science.
Students will encounter key philosophical frameworks—ontology, epistemology, and ethics—woven into practical bioethical applications. Feminist philosophy, experimental bioethics, and embedded ethics enrich this perspective, urging readers to question assumptions, embrace diverse viewpoints, and connect ethical principles with real-world science.
Targeted at students in philosophy, biology, biomedical sciences, and bioengineering, this book is a toolkit for future thinkers, fostering a nuanced understanding of how ethical science advances humanity in a complex, ever-changing world.
This coursebook offers an expansive exploration of bioethics, an interdisciplinary field examining ethical, social, and legal dilemmas in medicine, life sciences, and beyond. It challenges conventional boundaries, embracing Van Rensselaer Potter’s vision of bioethics as a global, holistic ethics of life—integrating human health, environmental considerations, and transdisciplinary insights.
Through engaging discussions, thought experiments, and case studies, the book empowers students to critically reflect on ethical questions without dictating rigid answers. Topics range from the historical roots of ethical thought to cutting-edge debates in molecular biology, such as epigenetics and exposomics, demonstrating how interconnected human, animal, and environmental health truly are.
Central themes include the limits of scientific knowledge, the biases shaping research, and the evolving interplay between moral philosophy and empirical science.
Students will encounter key philosophical frameworks—ontology, epistemology, and ethics—woven into practical bioethical applications. Feminist philosophy, experimental bioethics, and embedded ethics enrich this perspective, urging readers to question assumptions, embrace diverse viewpoints, and connect ethical principles with real-world science.
Targeted at students in philosophy, biology, biomedical sciences, and bioengineering, this book is a toolkit for future thinkers, fostering a nuanced understanding of how ethical science advances humanity in a complex, ever-changing world.
Nigerian writer Chimamanda Ngozi Adichie’s 2009 TedTalk, “The Danger of a Single Story,” highlighted “one-story” thinking, wherein the first story people hear about others becomes their unshakeable baseline understanding. In illustration, the chapter traces forward the European One Story of Headless Monsters started by Herodotus, as its damage moved from Africa to the Americas, through permutations in Aeschylus, Virgil, Diodorus Siculus, Pliny the Elder, Iohn Lok, Walter Raleigh, Carolus Linnaeus, John Smith, Shakespeare, Lafitau, and Darwin.
In 1655, La Peyrère was the first to substantially argue for and popularize polygenism—the view that God created multiple original human mating pairs in separate acts of creation with numerous pairs created before Adam. Positing or rejecting polygenism has been central to modern theorizing about human types and origins. Prominent recent interpreters have maintained that La Peyrère’s polygenism does not imply a hierarchy of human types. This paper reconstructs La Peyrère’s account and, in opposition to the dominant view, argues that his polygenism produces a human species hierarchy. The Adamite species is superior to the pre-Adamite species in virtue of its material composition, mode of creation, and form. The upshot is that La Peyrère’s theological system posits a protoracialist conception of human types.
The free will–determinism discussion is centuries old, with numerous stances taken by philosophers and scientists alike. The debate has clear implications for interpreting causal relations in scientific systems and predicting and influencing the behavior of living organisms, particularly humans. Advances in quantum physics and neuroscience have recently revitalized the debate over free will versus determinism, as depicted in recent books by Robert Sapolsky and Kevin Mitchell. In this article we review and critique Determined: A Science of Life Without Free Will (Sapolsky, 2023) and Free Agents: How Evolution Gave Us Free Will (Mitchell, 2023), which differ in their conclusions regarding how contemporary research findings in genetics, neuroscience, and quantum mechanics support or countervail the notion that people possess free will. Drawing on Killeen et al. (2024) recent analysis of agency, we attempt to reconcile the authors’ perspectives on the premise that the laws of physics, including quantum mechanics, imply hard determinism in terms of past events but can offer only broad, global predictions about a person’s future behavioral outcomes, because people entertain a range of considerations while deciding between available response options.. We suggest probabilistic determinism as a conceptualization of agency that accommodates this past–future distinction in determinism. We invite readers to consider that although behavior is determined, people nonetheless have opportunities to make choices and exercise autonomy.
A scientific answer to suicidology’s central question, “Why do people kill themselves?” can take two forms, and they are complementary, not competing. A proximate explanation addresses mechanistic causation—psychological experiences, interactions of risk factors, and suchlike. An ultimate explanation speaks to the behaviour’s evolution in the human species. A coherent understanding of suicide requires integration of the two levels of analysis. However, suicidology has traditionally focussed on the proximate and neglected the ultimate, thereby missing half the explanatory story and hobbling the research effort. This chapter encourages a healthy rebalancing of priorities. The publication of this chapter marks a breakthrough in that it indicates an emerging rapprochement between suicidology and human evolutionary science. The two fields need each other. “Why do people kill themselves?” is a key question for evolutionists too: how could natural selection, powered by the Darwinian “Struggle for Existence”, have produced an animal that wilfully and voluntarily deselects itself from the struggle? Seeking to resolve the paradox are more than a score of evolutionary hypotheses, advanced from diverse disciplines. The chapter outlines, critiques, and organises the various ideas into a conceptual map, intended to mark out the most promising throughways. The hypotheses are set out in five sections reflecting different genres of theory: non-reproductivity theories, kin and group selection theories, pathology theories, communication theories, and escape theories. The authors find the last of these most promising: “escape”-type evolutionary theories broadly align with several existing proximate theories in suicidology, but they raise important new questions for researchers. The primary obstacle to an evolutionary suicidology may be more psychological than technical, because an evolutionary view may require suicide to be understood as a universal feature of our species: there is potentially a suicidal person in us all.
The evolution of music, speech, and sociality have been debated since before Darwin. The social bonding hypothesis proposes that these phenomena may be interlinked: musicality may have facilitated the evolution of social bonding beyond the possibilities of spoken language. Although dozens of experimental studies have argued that synchronised rhythms can promote bonding, methodological issues including publication bias, sample bias, experimenter effects, and appropriateness of experimental controls make it unclear whether synchronous singing reliably and generally enhances bonding relative to speaking. Here, we propose a Registered Report to overcome these issues through a global experiment in diverse languages aiming to collect data from 1800 participants across 60 sites. The social bonding hypothesis predicts that bonding will increase more after synchronous singing than after spoken (sequential) conversation or (simultaneous) recitation, while alternative hypotheses predict that song will not increase bonding relative to speech. Regardless of outcome, these results will provide an unprecedented understanding of cross-cultural relationships between music, speech, and sociality.
This article explores the intersections of Victorian medicine and literature by examining medical treatises on hereditary psychosis and criminal instincts and Wilkie Collins’ The Legacy of Cain (1888). It first considers the ideas of Prosper Lucas, Bénédict A. Morel, and Henry Maudsley, focusing on the supposed role of women in perpetuating the phenomenon of human degeneration, as claimed by many Victorian physicians. Second, it analyses The Legacy of Cain as a fascinating example of the reciprocal relationship between literature and medicine. Through clinical rhetoric, the novel critiques theories of hereditary degeneration and infectious motherhood, challenging prevailing beliefs about biological determinism.
This paper aims to determine whether Darwin’s theory of evolution was influenced by German Naturphilosophie. I start with a brief presentation of Naturphilosophie, a scientific and aesthetic approach that emphasizes the holistic understanding of the natural system and the interrelation of its parts. As I show, Naturphilosophen acknowledges the existence of a specific relation of reciprocal causality between
various parts of nature, and recognize the valuable causal agency of life in the natural system. Moving forward, I analyze Darwin’s theory of evolution and identify the fundamental hypotheses of his conceptual framework. Since Naturphilosophen endorse a holistic conception of nature, and highlight the presence of reciprocal causality between its parts, I examine whether Darwin adopts any of these assumptions about the natural system. I turn to his understanding of the struggle for survival – a phenomenon that captures various relations between organisms and their environment. My analysis shows that Darwin recognizes the causal activity of the natural environment, but neglects the ability of organisms to modify their habitat for the sake of survival. Thus, he establishes the causal asymmetry between these two fundamental parts of his worldview. If that is the case, then Darwin’s theory does not represent a (fully) holistic worldview of nature, and the influence of Naturphilosophen on the formulation of his evolutionary theory is only partial.
Humans engage with music for various reasons that range from emotional regulation and relaxation to social bonding. While there are large inter-individual differences in how much humans enjoy music, little is known about the origins of those differences. Here, we disentangle the genetic factors underlying such variation. We collect data on several facets of music reward sensitivity, as measured by the Barcelona Music Reward Questionnaire, plus music perceptual abilities and general reward sensitivity from a large sample of Swedish twins (N = 9169; 2305 complete pairs). We estimate that genetic effects contribute up to 54% of the variability in music reward sensitivity, with 70% of these effects being independent of music perceptual abilities and general reward sensitivity. Furthermore, multivariate analyses show that genetic and environmental influences on the different facets of music reward sensitivity are partly distinct, uncovering distinct pathways to music enjoyment and different patterns of genetic associations with objectively assessed music perceptual abilities. These results paint a complex picture in which partially distinct sources of variation contribute to different aspects of musical enjoyment.
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