Sexual Conflict and Sexually Antagonistic Coevolution in an Annual Plant

Background

Sexual conflict theory predicts sexually antagonistic coevolution of reproductive traits driven by conflicting evolutionary interests of two reproducing individuals. Most studies of the evolutionary consequences of sexual conflicts have, however, to date collectively investigated only a few species. In this study we used the annual herb Collinsia heterophylla to experimentally test the existence and evolutionary consequences of a potential sexual conflict over onset of stigma receptivity.

Methodology/Principal Findings

We conducted crosses within and between four greenhouse-grown populations originating from two regions. Our experimental setup allowed us to investigate male-female interactions at three levels of geographic distances between interacting individuals. Both recipient and pollen donor identity affected onset of stigma receptivity within populations, confirming previous results that some pollen donors can induce stigma receptivity. We also found that donors were generally better at inducing stigma receptivity following pollen deposition on stigmas of recipients from another population than their own, especially within a region. On the other hand, we found that donors did worse at inducing stigma receptivity in crosses between regions. Interestingly, recipient costs in terms of lowered seed number after early fertilisation followed the same pattern: the cost was apparent only if the pollen donor belonged to the same region as the recipient.

Conclusion/Significance

Our results indicate that recipients are released from the cost of interacting with local pollen donors when crossed with donors from a more distant location, a pattern consistent with a history of sexually antagonistic coevolution within populations. Accordingly, sexual conflicts may have important evolutionary consequences also in plants.     

Rituals,Repetitiveness and Cognitive Load

A central hypothesis to account for the ubiquity of rituals across cultures is their supposed anxiolytic effects: rituals being maintained because they reduce existential anxiety and uncertainty. We aimed to test the anxiolytic effects of rituals by investigating two possible underlying mechanisms for it: cognitive load and repetitive movement. In our pre-registered experiment (osf.io/rsu9x), 180 undergraduates took part in either a stress or a control condition and were subsequently assigned to either control, cognitive load, undirected movement, a combination of undirected movement and cognitive load, or a ritualistic intervention. Using both repeated self-report measures and continuous physiological indicators of anxiety, we failed to find direct support for a cognitive suppression effect of anxiety through ritualistic behavior. Nevertheless, we found that induced stress increased participants’ subsequent repetitive behavior, which in turn reduced physiological arousal. This study provides novel evidence for plausible underlying effects of the proposed anxiolytic effect of rituals: repetitive behavior but not cognitive load may decrease physiological stress responses during ritual.     

Applying Signaling Theory to Traditional Cultural Rituals

The branch of evolutionary theory known as signaling theory attempts to explain various forms of communication. Social scientists have explained many traditional rituals as forms of communication that promote cooperative social relationships among participants. Both evolutionists and social scientists have realized the importance of trust for the formation and maintenance of cooperative social relationships. These factors have led to attempts to apply signaling theory to traditional cultural rituals in various ways. This paper uses the traditional ritual of mumming in small Newfoundland fishing villages to evaluate alternative hypotheses about the connection between rituals, communication, trust, and cooperation. Mumming is found to be most consistent with the hypothesis that it is a ritual of trust wherein participants take a specific type of risk: the risk of harm at the hands of other participants. Individuals who take this risk actively signal their trust. Conversely, individuals who restrain themselves from inflicting harm on other participants actively signal their trustworthiness.

毕摩,我们彝族的信仰和仪式

洪正勇(男子 28岁 雪花村):"剑川有两个老人去世已有两年和三年,是一对夫妻,请我去做祭祀,这是最后一次为他俩办后事、彝族的老人去世一共要做三次大的祭祀。其中一人去世做一次,第二人去世再做一次,二、三年后为他俩共同再做一次。"     

(Re)Creating Rituals through Contemporary Dance

After fieldwork on the ten-hour performance “Insomnia 2–In Memoriam” about rituals and death, the author asks how the deRothfils company makes life meaningful through audience interaction with this dance creation. She explores the notion of ritual for performance analysis, drawing on Catherine Bell’s framework. She examines four dimensions of the performance, each showing how various aspects of ritual are generated: reviving esthetic features, fulfilling social needs through collective encounters, experiencing strong affects, and offering a space for existential reflection. The article concludes with a more general question of how this artistic process produces knowledge.     

Cultural Rules, Rituals, and Behavior Regulation

While it is generally agreed that culture and biology are both relevant to an understanding of human behavior, there is little consensus about the appropriate use of reductionist procedures. Disagreement abounds concerning the nature of the interaction and the relative contribution of distal and proximal mechanisms. An understanding of such issues may emerge only with long study of the interaction of variables at different conceptual levels of organization that intervene between the genes and culture. It is toward this larger end that the limited efforts of this paper are directed. Two cultural phenomena are considered: Murdoch's "social laws of sexual choice," and aspects of human ritual behavior. Although these constitute a unique organization of cultural items, I attempt to show how they are influenced by underlying biopsychological processes. I specifically reject, however, the view that cultural phenomena are isomorphic with, or can be completely reduced to, such processes. Emergent novelty and multiple possibilities are always present at more inclusive levels of organization. I argue that the relationship between the different sets of system variables is based on homologous functions and not merely on analogies.
SEYMOUR PARKER is Professor, Department of Anthropology, University of Utah, Salt Lake City. UT 84112     

Conflict of interest

Sleep and Biological Rhythms -     

Religion against the Self: An Ethnography of Tamil Rituals.

Religion against the Self: An Ethnography of Tamil Rituals. Isabelle Nabokov. New York: Oxford University Press, 2000. 230 pp.     

Parent-Offspring Conflict

When parent-offspring relations in sexually reproducing speciesare viewed from the standpoint of the offspring as well as theparent, conflict is seen to be an expected feature of such relations.In particular, parent and offspring are expected to disagreeover how long the period of parental investment should last,over the amount of parental investment that should be given,and over the altruistic and egoistic tendencies of the offspringas these tendencies affect other relatives. In addition, undercertain conditions parents and offspring are expected to disagreeover the preferred sex of the potential offspring. In general,parent-offspring conflict is expected to increase during theperiod of parental care, and offspring are expected to employpsychological weapons in order to compete with their parents.Detailed data on mother-offspring relations in mammals are consistentwith the arguments presented. Conflict in some species, includingthe human species, is expected to extend to the adult reproductiverole of the offspring: under certain conditions parents areexpected to attempt to mold an offspring, against its betterinterests, into a permanent nonreproductive.     

Food as the Holographic Condensation of Life in Sri Lankan Rituals

This paper seeks to elaborate the dynamics through which food acquires potency in shaping human life and organisation as it takes shape in enacting ritual transformation. I argue that whereas life and various existential concerns get condensed from the fringes of the social order into ritual, food further holographically condenses the existential concerns of life with which it is entangled as an assemblage. As such, it turns into a centripetal force in ritual by constituting a means that enables ritual and somatic transformation to materialize in the matter of food and thus in helping to render ritual effective. To grasp this complex process we will look at the basic dynamic of holographic condensation throughout the different ways in which various foods ritually enact the regeneration of life in the astrological New Year and the Sātuwe anti-sorcery healing rite in a Sinhalese Buddhist village in the North-Western province of Sri Lanka.     

Whence Collective Rituals? A Cultural Selection Model of Ritualized Behavior

Ritualized behavior is a specific way of organizing the flow of action, characterized by stereotypy, rigidity in performance, a feeling of compulsion, and specific themes, in particular the potential danger from contamination, predation, and social hazard. We proposed elsewhere a neurocognitive model of ritualized behavior in human development and pathology, as based on the activation of a specific hazard-precaution system specialized in the detection of and response to potential threats. We show how certain features of collective rituals—by conveying information about potential danger and presenting appropriate reaction as a sequence of rigidly described precautionary measures—probably activate this neurocognitive system. This makes some collective ritual sequences highly attention-demanding and intuitively compelling and contributes to their transmission from place to place or generation to generation. The recurrence of ritualized behavior as a central feature of collective ceremonies may be explained as a consequence of this bias in selective transmission.     

Primate Rituals: The Function of Greetings between Male Guinea Baboons

The bond‐testing hypothesis suggests that social animals can obtain honest information about the quality of their dyadic relationships by exchanging costly, high‐risk signals (Zahavi & Zahavi 1997). We evaluated this hypothesis by investigating whether adult male baboons use intense greeting interactions to test the quality and strength of their social bonds. Intense greetings involve intimate and risky behaviors such as embracing and the diddling of the penis and/or scrotum. Data were collected on a colony of 40 Guinea baboons (Papio papio) at the Brookfield Zoo in Chicago. Fifteen adult male baboons were focally observed for 30‐min sessions over a 6‐mo period, resulting in 195 h of observation. We assessed the quality of male–male relationships using measures of affiliation, aggression, and social tolerance. As predicted by the bond‐testing hypothesis, dyads with strong social bonds exchanged a higher frequency of intense greetings than did pairs with poor relationships. We found no support for the competing hypotheses, that suggest that greetings have an aggressive or submissive function or are used as a form of post‐conflict reconciliatory behavior. Neither dominance relationships nor contextual variables were predictive of intense greeting patterns. We suggest that by imposing on his partner, a male baboon is able to obtain reliable information about this individual's current willingness to cooperate and invest in the relationship.