The Peacock Fallacy: Art as a Veblenian Signal

The fact that world-over people seem inexplicably motivated to allocate time and effort to apparently useless cultural practices, like the arts, has led several evolutionary scholars to suggest that these might be costly Zahavian signals correlated with genetic fitness, such as the infamous peacock’s tail. In this paper, I review the fundamental arguments of the hypothesis that art evolved and serves as a costly Zahavian signal. First, I look into the hypothesis that humans exert mate choice for indirect benefits and argue that the data supports mate choice for direct benefits instead. Second, I argue that art practice may well be a costly signal, however not necessarily related to good genes. Third, I suggest that Thorstein Veblen’s original concept of conspicuous signals as social tools to obtain and convey prestige provides a better account than the Zahavian model for the evolution and function of art in society. As a Veblenian signal, art could still have many of the effects suggested for visual art as a Zahavian signal, except not for the indirect benefits of optimal offspring, but for the direct benefits of acquiring and conveying social status.

Fitness and Power: The Contribution of Genetics to the History of Differential Reproduction

Textual evidence from pre-modern societies supports the prediction that status differences among men translate to variance in reproductive success. In recent years, analysis of genetic data has opened up new ways of studying this relationship. By investigating cases that range over several millennia, these analyses repeatedly document the replacement of local men by newcomers and reveal instances of exceptional reproductive success of specific male lineages. These findings suggest that violent population transfers and conquests could generate considerable reproductive advantages for male dominants. At the same time, this does not always seem to have been the case. Moreover, it is difficult to link such outcomes to particular historical characters or events, or to identify status-biased reproductive inequalities within dominant groups. The proximate factors that mediated implied imbalances in reproductive success often remain unclear. A better understanding of the complex interplay between social power and genetic fitness will only arise from sustained transdisciplinary engagement.

The far-reaching ecological effects of genetic fitness in a keystone predator species, grey wolves

Although loss of genetic fitness is known to be severely detrimental to the viability of populations, little is known about how changes in the genetic fitness of keystone species can impact the functioning of communities and ecosystems. Here we assessed how changes in the genetic fitness of a keystone predator, grey wolves, impacted the ecosystem of Isle Royale National Park over 2-decades. The decline and subsequent resurgence of inbreeding in the wolf population led to a rise and then fall in predation rates on moose, the primary prey of wolves and dominant mammalian herbivore in this system. Those changes in predation rate led to large fluctuations in moose abundance which in turn impacted browse rates on balsam fir, the dominant forage for moose during winter and an important species in the forest. Thus, forest dynamics can be traced back to changes in the genetic health of a predator population.

Agent-based modeling of DFNB1A prevalence with regard to intensity of selection pressure in isolated human population: will cochlear implantation increase the cases of hereditary deafness?

It was evidenced, that the increase in the prevalence of autosomal recessive deafness 1A (DFNB1A) in populations of European descent was promoted by assortative marriages among deaf people. Assortative marriages become possible with a widespread introduction of sign language resulting in increased the genetic fitness of deaf individuals, thus relaxing selection against deafness. Currently, cochlear implantation is becoming a common method of rehabilitation for deaf patients, restoring their hearing ability and promoting the acquirement of spoken language. Whether the mass cochlear implantation could affect the spread of hereditary deafness is unknown. We have developed an agent-based computer model for analysis of the spread of DFNB1A. Using the model, we tested impact of different intensity of selection pressure on an isolated human population for 400 years. The modeling of the "purifying" selection pressure on deafness resulted in decrease of the proportion of deaf individuals and the pathogenic allele frequency. The modeling of relaxed selection resulted in increase of the proportion of deaf individuals and the decrease of the pathogenic allele frequency. The results of neutral selection pressure modeling showed no significant changes in both the proportion of deaf individuals and the pathogenic allele frequency after 400 years. Thus, initially low genetic fitness of deaf people can be significantly increased in the presence of assortative mating by deafness, resulting in a higher prevalence of DFNB1A. Contrary, frequency of pathogenic allele and the incidence of hereditary hearing loss will not increase in a population where all deaf individuals undergo cochlear implantation.

Contextualizing Disability

The interconnection of language and societal context is demonstrated through the Library of Congress Subject Headings surrounding disability. This study examines and compares how language encapsulates contemporary understandings of disability in the second edition (1919) and eighth edition (1975). Created and published during the so-called “Progressive Era,” the second edition emphasizes Victorian beliefs in the correspondence of morality with participation in the labour force and genetic fitness (i.e., conformity to physical and psychological norms). The language of this context further marginalized persons with disabilities. In contrast, the eighth edition marks the growing respect for and autonomy of people with disabilities, with language related to the civil rights movement, medical advances, and the replacement of ableist terms such as “Deaf and dumb” with neutral terms or self-definitions, such as “Deaf.” This evolution demonstrates the positive effects when we as librarians accept our social responsibility to eschew marginalizing language and instead use language that affirms minority identities.

Attractiveness and distinctiveness in voices and faces of young adults

Facial attractiveness has been linked to the averageness (or typicality) of a face. More tentatively, it has also been linked to a speaker’s vocal attractiveness, via the “honest signal” hypothesis, holding that attractiveness signals good genes. In four experiments, we assessed ratings for attractiveness and two common measures of distinctiveness (“distinctiveness-in-thecrowd”- DITC and “deviation-based distinctiveness”-DEV) for faces and voices (vowels or sentences) from 64 young adult speakers (32 female). Consistent and strong negative correlations between attractiveness and DEV generally supported the averageness account of attractiveness for both voices and faces. By contrast, indicating that both measures of distinctiveness reflect different constructs, correlations between attractiveness and DITC were numerically positive for faces (though small and non-significant), and significant for voices in sentence stimuli. As the only exception, voice ratings based on vowels exhibited a moderate but significant negative correlation between attractiveness and DITC. Between faces and voices, distinctiveness ratings were uncorrelated. Remarkably, and at variance with the honest signal hypothesis, vocal and facial attractiveness were uncorrelated, with the exception of a moderatepositive correlation for vowels. Overall, while our findings strongly support an averageness account of attractiveness for both domains, they provide little evidence for an honest signal account of facial and vocal attractiveness in complex naturalistic speech. Although our findings for vowels do not rule out the tentative notion that more primitive vocalizations can provide relevant clues to genetic fitness, researchers should carefully consider the nature of voice samples, and the degree to which these are representative of human vocal communication.