The eco-evolutionary landscape of power relationships between males and females

In animal societies, control over resources and reproduction is often biased towards one sex. Yet, the ecological and evolutionary underpinnings of male-female power asymmetries remain poorly understood. We outline a comprehensive framework to quantify and predict the dynamics of male-female power relationships within and across mammalian species. We show that male-female power relationships are more nuanced and flexible than previously acknowledged. We then propose that enhanced reproductive control over when and with whom to mate predicts social empowerment across ecological and evolutionary contexts. The framework explains distinct pathways to sex-biased power: coercion and male-biased dimorphism constitute a co-evolutionary highway to male power, whereas female power emerges through multiple physiological, morphological, behavioural, and socioecological pathways

From Parasite Encounter to Infection: Multiple-Scale Drivers of Parasite Richness in a Wild Social Primate Population

Host parasite diversity plays a fundamental role in ecological and evolutionary processes, yet the factors that drive it are still poorly understood. A variety of processes, operating across a range of spatial scales, are likely to influence both the probability of parasite encounter and subsequent infection. Here, we explored eight possible determinants of parasite richness, comprising rainfall and temperature at the population level, ranging behavior and home range productivity at the group level, and age, sex, body condition, and social rank at the individual level. We used a unique dataset describing gastrointestinal parasites in a terrestrial subtropical vertebrate (chacma baboons, Papio ursinus), comprising 662 faecal samples from 86 individuals representing all age-sex classes across two groups over two dry seasons in a desert population. Three mixed models were used to identify the most important factor at each of the three spatial scales (population, group, individual); these were then standardised and combined in a single, global, mixed model. Individual age had the strongest influence on parasite richness, in a convex relationship. Parasite richness was also higher in females and animals in poor condition, albeit at a lower order of magnitude than age. Finally, with a further halving of effect size, parasite richness was positively correlated to day range and temperature. These findings indicate that a range of factors influence host parasite richness through both encounter and infection probabilities, but that individual-level processes may be more important than those at the group or population level

On automatic class insertion with overloading

Also published in Proceedings of the 11th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (OOPSLA)International audienceSeveral algorithms [Cas92, MS89, Run92, DDHL94a, DDHL95, GMM95] have been proposed to automatically insert a class into an inheritance hierarchy. But actual hierarchies all include overriden and overloaded properties that these algorithms handle either very partially or not at all. Partially handled means handled provided there is a separate given function f able to compare overloaded properties [DDHL95, GMM95].In this paper, we describe a new version of our algorithm (named Ares) which handles automatic class insertion more efficiently using such a function f. Although impossible to fully define, this function can be computed for a number of well defined cases of overloading and overriding. We give a classification of such cases and describe the computation process for a well-defined set of nontrivial cases.The algorithm preserves these important properties:- preservation of the maximal factorization of properties- preservation of the underlying structure (Galois lattice) of the input hierarchy- conservation of relevant classes of the input hierarchy with their properties

Corrigendum: Editorial: Sex and gender effects on power, status, dominance, and leadership – an interdisciplinary look at human and other mammalian societies

In the published article, there was an error in Research investigating sex effects in non-human mammals, paragraph 5. We omitted a few words in two places of the same sentence. The sentence previously stated: “Several papers in this Research Topic investigated whether the degree of dominance of females over males depends on morphological, demographic or ecological factors such as relative body size, adult sex ratio, sexual maturity or mating season.” The corrected sentence appears below: “Several papers in this Research Topic investigated whether the degree of dominance of females over males depends on morphological, demographic, ecological or social factors such as relative body size, adult sex ratio, sexual maturity, mating season or social support.” In the published article, there was an error in Research investigating sex effects in non-human mammals, paragraph 7. We omitted a full sentence citing the results of one study of the Research Topic. This sentence previously stated: “Conversely, Koenig et al. show in wild gray langurs that male dominance appears inflexible across contexts, and that the rare events of female aggression toward males are aimed at infant protection, while most male aggression towards females occur in a feeding context. This work suggests that intersexual feeding competition may contribute to shaping male-female relationships.” The corrected sentence appears below: “Conversely, Koenig et al. show in wild gray langurs that male dominance appears inflexible across contexts, and that the rare events of female aggression toward males are aimed at infant protection, while most male aggression towards females occur in a feeding context. This work suggests that intersexual feeding competition may contribute to shaping male-female relationships. Moreover, McCormick et al. report support for the idea that sex differences in agonistic behavior as well as in social support both mediate female dominance over males in clans of spotted hyenas, even though adult females can often dominate immigrant males without any support.” In the published article, there was an error in Research investigating sex effects in non-human mammals, paragraph 8. A couple of words need to be changed to the following sentence to avoid repeats arising from the inserted sentence. This sentence previously stated: “Finally, in the female-dominated society of spotted hyenas, East et. al., show that male fitness is substantially affected by the loss of offspring due to infanticide by females.” The corrected sentence appears below: “Finally, also in spotted hyenas, East et al. show that male fitness is substantially affected by the loss of offspring due to infanticide by females.” The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.</p

Developmental transitions in body color in chacma baboon infants: Implications to estimate age and developmental pace

International audienc

Red Is Not a Proxy Signal for Female Genitalia in Humans

Red is a colour that induces physiological and psychological effects in humans, affecting competitive and sporting success, signalling and enhancing male social dominance. The colour is also associated with increased sexual attractiveness, such that women associated with red objects or contexts are regarded as more desirable. It has been proposed that human males have a biological predisposition towards the colour red such that it is ‘sexually salient’. This hypothesis argues that women use the colour red to announce impending ovulation and sexual proceptivity, with this functioning as a proxy signal for genital colour, and that men show increased attraction in consequence. In the first test of this hypothesis, we show that contrary to the hypothesis, heterosexual men did not prefer redder female genitalia and, by extension, that red is not a proxy signal for genital colour. We found a relative preference for pinker genital images with redder genitalia rated significantly less sexually attractive. This effect was independent of raters' prior sexual experience and variation in female genital morphology. Our results refute the hypothesis that men's attraction to red is linked to an implied relationship to genital colour and women's signalling of fertility and sexual proceptivity

Female house sparrows "count on" male genes: experimental evidence for MHC-dependent mate preference in birds

<p>Abstract</p> <p>Background</p> <p>Females can potentially assess the quality of potential mates using their secondary sexual traits, and obtain "good genes" that increase offspring fitness. Another potential indirect benefit from mating preferences is genetic compatibility, which does not require extravagant or viability indicator traits. Several studies with mammals and fish indicate that the genes of the major histocompatibility complex (MHC) influence olfactory cues and mating preferences, and such preferences confer genetic benefits to offspring. We investigated whether individual MHC diversity (class I) influences mating preferences in house sparrows (<it>Passer domesticus</it>).</p> <p>Results</p> <p>Overall, we found no evidence that females preferred males with high individual MHC diversity. Yet, when we considered individual MHC allelic diversity of the females, we found that females with a low number of alleles were most attracted to males carrying a high number of MHC alleles, which might reflect a mating-up preference by allele counting.</p> <p>Conclusions</p> <p>This is the first experimental evidence for MHC-dependent mating preferences in an avian species to our knowledge. Our findings raise questions about the underlying mechanisms through which birds discriminate individual MHC diversity among conspecifics, and they suggest a novel mechanism through which mating preferences might promote the evolution of MHC polymorphisms and generate positive selection for duplicated MHC loci.</p