Anticipating the species jump: surveillance for emerging viral threats.

Zoonotic disease surveillance is typically triggered after animal pathogens have already infected humans. Are there ways to identify high-risk viruses before they emerge in humans? If so, then how and where can identifications be made and by what methods? These were the fundamental questions driving a workshop to examine the future of predictive surveillance for viruses that might jump from animals to infect humans. Virologists, ecologists and computational biologists from academia, federal government and non-governmental organizations discussed opportunities as well as obstacles to the prediction of species jumps using genetic and ecological data from viruses and their hosts, vectors and reservoirs. This workshop marked an important first step towards envisioning both scientific and organizational frameworks for this future capability. Canine parvoviruses as well as seasonal H3N2 and pandemic H1N1 influenza viruses are discussed as exemplars that suggest what to look for in anticipating species jumps. To answer the question of where to look, prospects for discovering emerging viruses among wildlife, bats, rodents, arthropod vectors and occupationally exposed humans are discussed. Finally, opportunities and obstacles are identified and accompanied by suggestions for how to look for species jumps. Taken together, these findings constitute the beginnings of a conceptual framework for achieving a virus surveillance capability that could predict future species jumps

Oral contraception and romantic relationships - from the lab to the real world

We review recent evidence that suggests that oral contraceptives may influence the dynamics of sexual relationships and the human pair-bond. Hormonal birth control likely has positive effects on cementing the pair-bond by decoupling sex from conception. However, changes in women's evolved mate preferences associated with initiation or discontinuation of hormonal contraception may alter attraction to her partner, with potentially negative consequences for sexual satisfaction. We describe the evidence for such changes produced by laboratory studies, including prospective experimental designs, and how the consequences of such changes are being explored beyond the laboratory. In view of the growing prevalence of modern hormonal contraceptive methods across the globe, further study of such effects is urgently required

The impact of artificial fragrances on the assessment of mate quality cues in body odor

We investigated the impact of artificial fragrances on the accurate detection of biologically relevant information in human body odor. To do this, we examined cross-sensory consistency (across faces and odors) in the perception of masculinity and femininity in men and women, and how consistency is influenced by the use of artificial fragrance. Independent sets of same and opposite-sex participants rated odor samples (with and without a fragrance, N = 239 raters), and photographs (N = 130) of 20 men and 20 women. In female, but not male raters, judgments of masculinity/femininity of non-fragranced odor and faces were correlated. However, the correlation between female ratings of male facial and odor masculinity was not evident when assessing a body odor and fragrance blend. Further analysis also indicated that differences in ratings of male odor masculinity between men with very masculine or high and low levels of facial masculinity were removed by the addition of fragrance. This effect was absent in ratings of female odors by both female and male raters, suggesting sex-specificity in the effects of fragrance on odor perception. The widespread use of artificial fragrance in many modern populations raises questions about how this cultural practice influences ability to detect and utilize mate-choice relevant cues. Our findings suggest that women may be more sensitive to these cues, and therefore also to disruption of this information through fragrance use. We discuss our results using the framework of culture-gene coevolution

Hormonal contraception use during relationship formation and sexual desire during pregnancy

Women who are regularly cycling exhibit different partner preferences than those who use hormonal contraception. Preliminary evidence appears to suggest that during pregnancy women’s partner preferences also diverge from those prevalent while regularly cycling. This is consistent with the general assertion that women’s mate preferences are impacted by hormonal variation. During pregnancy, women’s preferences are thought to closely resemble those displayed by women who are using hormonal contraception. Here, based on this literature, we compared levels of sexual desire among pregnant women who met their partner while using hormonal contraception and pregnant women who met their partner while regularly cycling. We predicted that women who met their partner while using hormonal contraception would experience higher levels of in-pair sexual desire during pregnancy since these women will have partner preferences that more closely match those prevalent at the time of their partner choice. Our results provided support for the idea that previous contraceptive use/non-use may impact subsequent sexual desire for the partner during pregnancy. Pregnant women who met their partner while using hormonal contraception (N=37) were shown to have higher levels of in-pair sexual desire than those who met while regularly cycling (N=47). In contrast, levels of extra-pair desire were not related to previous use/non-use of hormonal contraception. These findings were robust when controlling for a number of relevant individual difference variables known to impact sexual desire. Our results contribute to our understanding of factors affecting relationship functioning during pregnancy

Partner choice, relationship satisfaction, and oral contraception: the congruency hypothesis

Hormonal fluctuation across the menstrual cycle explains temporal variation in women’s judgment of the attractiveness of members of the opposite sex. Use of hormonal contraceptives could therefore influence both initial partner choice and, if contraceptive use subsequently changes, intrapair dynamics. Associations between hormonal contraceptive use and relationship satisfaction may thus be best understood by considering whether current use is congruent with use when relationships formed, rather than by considering current use alone. In the study reported here, we tested this congruency hypothesis in a survey of 365 couples. Controlling for potential confounds (including relationship duration, age, parenthood, and income), we found that congruency in current and previous hormonal contraceptive use, but not current use alone, predicted women’s sexual satisfaction with their partners. Congruency was not associated with women’s nonsexual satisfaction or with the satisfaction of their male partners. Our results provide empirical support for the congruency hypothesis and suggest that women’s sexual satisfaction is influenced by changes in partner preference associated with change in hormonal contraceptive use

Greater precision, not parsimony, is the key to testing the peri-ovulation spandrel hypothesis: a response to comments on Havlíček et al. 2015

We welcome the wide range of comments provoked by the introduction of our alternative theoretical perspective on the peri-ovulation paradigm (Havlíček etal. 2015)—some positive and some very critical—and here we address briefly some of the key objection

The spandrels of Santa Barbara? A new perspective on the peri-ovulation paradigm

Numerous recent studies document peri-ovulatory increases in women’s physical attractiveness and in their preferences for certain male traits, which appear to be linked to cyclical fluctuation in levels of ovarian hormones. Changes in physical traits are subtle, leading to the widespread conclusion that cues of ovulation are adaptively concealed. It has been argued that concealment enables women to pursue a mixed-mating strategy characterized by pair-bonding with opportunistic extrapair copulation with high-quality mates when conception is possible. Men’s preferences for peri-ovulatory cues and women’s cyclical preference shifts are thus also argued to reflect distinct psychological adaptations. Here, we re-interpret the evidence for each of these putative adaptations and argue that cyclic changes need not result from incomplete concealment of ovulatory status. We also emphasize that ovarian hormone levels underpin between-individual differences in both women’s attractiveness and their mate preferences, which influence the sexes’ mate-choice decisions. We contrast the salience and efficiency of these within- and between-individual effects, and suggest that, although both effects have the potential to influence mating behavior, the between-individual effects are stronger and more robust. This introduces the possibility that both men’s increased attraction towards peri-ovulatory women and women’s cyclical shifts in preference for certain male traits may not constitute adaptations per se, but are, instead, inevitable by-products, or “perceptual spandrels,” of putative adaptations related to between-individual differences in reproductive potential. Our framework parsimoniously explains several observable phenomena and potentially could transform the way evolutionary researchers interpret changes in behavior associated with the menstrual cycle.&nbsp

Self-reported dominance in women: Associations with hormonal contraceptive use, relationship status, and testosterone

How to achieve dominance in a group is a recurrent challenge for individuals of many species, including humans. Previous research indicates that both relationship status and contraceptive use appear to moderate women’s testosterone levels. If testosterone contributes to dominance, this raises the possibility for group differences in dominance between single and partnered women, and between users and non-users of hormonal contraception. Here, we examine associations between relationship status and use/non-use of hormonal contraception and women’s self-reported social dominance. In a sample of 84 women, we replicate previous research documenting a significant positive correlation between women’s saliva testosterone levels and their self-reported dominance. Consistent with other literature, we also find that women using hormonal contraception have significantly lower testosterone than those who are regularly cycling and that partnered women have significantly lower testosterone than single women. Although we do not find a main effect of either relationship status or hormonal contraceptive use status on women’s reported levels of dominance, the interaction between these variables predicted reported dominance scores. This interaction remained significant when participant age and testosterone values were added to the model as covariates. We discuss these results in the context of the existing literature on testosterone and women’s dominance behaviour and with respect to the evolutionary benefits of social dominance in women

Analysis of symmetries in models of multi-strain infections

In mathematical studies of the dynamics of multi-strain diseases caused by antigenically diverse pathogens, there is a substantial interest in analytical insights. Using the example of a generic model of multi-strain diseases with cross-immunity between strains, we show that a significant understanding of the stability of steady states and possible dynamical behaviours can be achieved when the symmetry of interactions between strains is taken into account. Techniques of equivariant bifurcation theory allow one to identify the type of possible symmetry-breaking Hopf bifurcation, as well as to classify different periodic solutions in terms of their spatial and temporal symmetries. The approach is also illustrated on other models of multi-strain diseases, where the same methodology provides a systematic understanding of bifurcation scenarios and periodic behaviours. The results of the analysis are quite generic, and have wider implications for understanding the dynamics of a large class of models of multi-strain diseases

Investigate the origins of COVID-19

On 30 December 2019, the Program for Monitoring Emerging Diseases notified the world about a pneumonia of unknown cause in Wuhan, China. Since then, scientists have made remarkable progress in understanding the causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), its transmission, pathogenesis, and mitigation by vaccines, therapeutics, and non-pharmaceutical interventions. Yet more investigation is still needed to determine the origin of the pandemic. Theories of accidental release from a lab and zoonotic spillover both remain viable. Knowing how COVID-19 emerged is critical for informing global strategies to mitigate the risk of future outbreaks