Agonistic Competition Research Articles

Transcriptional Profile of the Industrial Hybrid Saccharomyces pastorianus Reveals Temperature-Dependent Allele Expression Bias and Preferential Orthologous Protein Assemblies.

Saccharomyces pastorianus is a natural yeast evolved from different hybridization events between the mesophilic S. cerevisiae and the cold-tolerant S. eubayanus. This complex aneuploid hybrid carries multiple copies of the parental alleles alongside specific hybrid genes and encodes for multiple protein isoforms which impart novel phenotypes, such as the strong ability to ferment at low temperature. These characteristics lead to agonistic competition for substrates and a plethora of biochemical activities, resulting in a unique cellular metabolism. Here, we investigated the transcriptional signature of the different orthologous alleles in S. pastorianus during temperature shifts. We identified temperature-dependent media-independent genes and showed that 35% has their regulation dependent on extracellular leucine uptake, suggesting an interplay between leucine metabolism and temperature response. The analysis of the expression of ortholog parental alleles unveiled that the majority of the genes expresses preferentially one parental allele over the other and that S. eubayanus-like alleles are significantly over-represented among the genes involved in the cold acclimatization. The presence of functionally redundant parental alleles may impact on the nature of protein complexes established in the hybrid, where both parental alleles are competing. Our expression data indicate that the majority of the protein complexes investigated in the hybrid are likely to be either exclusively chimeric or unispecific and that the redundancy is discouraged, a scenario that fits well with the gene balance hypothesis. This study offers the first overview of the transcriptional pattern of S. pastorianus and provides a rationalization for its unique industrial traits at the expression level.

A review of Dendrocephalus (Dendrocephalinus) (Crustacea: Anostraca) with the first records of male-male anostracan aggressive competition

We present a review of Dendrocephalus (Dendrocephalinus) with an updated diagnosis for the subgenus and a key to all known species. We provide new records of Dendrocephalus alachua, which was previously supposed to be extinct, and we describe a new species, Dendrocephalus proeliator sp. nov., which is separated from all other species based on the form of the male frontal appendage. Dendrocephalus proeliator sp. nov. appears to be morphologically intermediate between D. alachua and D. lithaca. In addition, we provide conservation assessments for all four species in the subgenus, according to IUCN Red List standards. We also report for two species the first known examples of direct male-male agonistic behaviour and competition for access to areas frequented by receptive females.

Embodying Compassion: Disability Sport and the Mercy of God

ABSTRACTThe author offers a robustly theological account of compassion, highlighting its bodily nature. Divine mercy is presented as being conveyed through human bodies to remake and enliven both the human agent and recipient. Culminating in a story of a physically and mentally impaired runner, this account of mercy and compassion fleshes out God's mercy, which can be understood as flowing through human bodies in the context of sporting activities. A challenge is thus levied at modern secularized accounts of compassion and mercy, as well as many of the dominant values in contemporary sport—flawless athletic beauty, agonistic competition, and financial success—which have rendered simple acts of intercompetitive compassion and mercy nearly unintelligible.

Competition for shelter occupancy between a native freshwater crab and an invasive crayfish

Potamon potamios populations have decreased significantly due to the degradation of its habitat caused by human activities, mainly the use of insecticides. Today, P. potamios is protected by Cypriot law, but not much information is known regarding possible effects on the species from interactions with the introduced and invasive freshwater crayfish Procambarus clarkii. We tested the hypothesis that the invasive crayfish P. clarkii can cause negative effects on the populations of the only indigenous freshwater crab of Cyprus P. potamios, through agonistic competition for shelter. A laboratory experiment on the competition between P. potamios and P. clarkii for securing shelter has been performed. During the experiment, pairs of equal-sized individuals from each species were evaluated for aggressiveness, domination in fights and shelter occupation. Results showed that even though both species are similarly aggressive, the crayfish wins more fights and occupies shelter more efficiently than the crab. Even though at present there is no evidence that the two species are syntopic, these results are indicative of possible negative effects of the alien invasive crayfish on the indigenous crab where they may become syntopic in the future.

Glory, Passions and Money in Alberti’s Della famiglia: A Humanist Reflects on the Foundations of Society

The article examines Alberti’s dialogue Della famiglia (“On the Family”) as a reflection on the foundations of ethics and politics from the perspective of humanist discourse. The polyphonic work presents and critically examines several views. The authorial voice of the text rehearses the traditional philosophical view the humanists inherited, according to which humans are sociable by nature. However, some of the interlocutors reject this convenient view, implying that it cannot be squared with the humanist critique of the premises of mainstream classical and medieval philosophy. Another line of argumentation in the dialogue attempts to harness the key humanist notion of gloria as the basis of human association, according to which humans self-interestedly seek fame and glory but to gain them they must promote the common good. But also this position is contested in the dialogue, with some arguing that the agonistic competition for glory produces envy and resentment rather than a civic spirit and as such threatens social cohesion. Finally, Della famiglia also explores the implications of the radical possibility that men and women are asocial creatures, by casting them as selfish economic actors who are only interested in making material gains.

Egalitarian despots: hierarchy steepness, reciprocity and the grooming-trade model in wild chimpanzees, Pan troglodytes

Biological market theory models the action of natural selection as a marketplace in which animals are viewed as traders with commodities to offer and exchange. Studies of female Old World monkeys have suggested that grooming might be employed as a commodity to be reciprocated or traded for alternative services, yet previous tests of this grooming-trade model in wild adult male chimpanzees have yielded mixed results. Here we provide the strongest test of the model to date for male chimpanzees: we use data drawn from two social groups (communities) of chimpanzees from different populations and give explicit consideration to variation in dominance hierarchy steepness, as such variation results in differing conditions for biological markets. First, analysis of data from published accounts of other chimpanzee communities, together with our own data, showed that hierarchy steepness varied considerably within and across communities and that the number of adult males in a community aged 20-30 years predicted hierarchy steepness. The two communities in which we tested predictions of the grooming-trade model lay at opposite extremes of this distribution. Second, in accord with the grooming-trade model, we found evidence that male chimpanzees trade grooming for agonistic support where hierarchies are steep (despotic) and consequent effective support is a rank-related commodity, but not where hierarchies are shallow (egalitarian). However, we also found that grooming was reciprocated regardless of hierarchy steepness. Our findings also hint at the possibility of agonistic competition, or at least exclusion, in relation to grooming opportunities compromising the free market envisioned by biological market theory. Our results build on previous findings across chimpanzee communities to emphasize the importance of reciprocal grooming exchanges among adult male chimpanzees, which can be understood in a biological markets framework if grooming by or with particular individuals is a valuable commodity.

Cultural Differences in Victory Signals of Triumph

A recent study reported that winners in agonistic competition displayed a victory signal that might be related to power and dominance, but losers did not. We explored cultural differences in this victory expression by reanalyzing data from that study on the country level, examining the association between country means in Olympic judo players’ first expressions at the moment of winning or losing a medal and Hofstede’s Power Distance (PD) dimension. Country-level PD was correlated with winners’ victory signals but not with those of losers, even when country-level Individualism-Collectivism was controlled. These findings indicated that hierarchical and dominant cultures may endorse more expressivity of triumph in competitive contexts.

Agonistic competition for fruit among members of a titi monkey (<i>Callicebus coimbrai</i>) group during a severe drought

No abstract

Tracing the Olympiad's Chronological Arc

Modern purists prone to lament the tenuous links between the Olympic Games of antiquity and today's quadrennial extravaganzas often cite the four-year Olympic cycle as a symbol of continuity and permanence. Yet the Olympiad also evinces a striking historical paradox: this benchmark of ancient calendar reckoning has emerged, in our time-sensitive age, as a source of both chronological and semantic confusion, fragmenting into contextual strands bearing little relation to time cycles, the Olympic Games or sport. In revisiting these ancient--modern links, this article holds that the Olympiad's importance has traditionally been derivational and its precision relative rather than absolute. Multiple uncertainties persist over how the ancient festival was scheduled, affixed as a four-year cycle and retro-dated to 776 bce, reflecting wider struggles to forge a universal calendar standard in a fragmented Greek world. Such knowledge gaps, and the Olympiad's obsolescence as a recognised time frame, give new perspective to the definitional flaccidity and juridical half-life now associated with it. In its post-2000 switch from games-to-games to calendar-year reckoning, the IOC belatedly modernised the Olympiad cycle amidst a downgrading of its chronological significance. Alternative applications, however, evoke unexpected elements of continuity from antique notions of agonistic competition as a societal underpinning.

Quantifying Primate Food Distribution and Abundance for Socioecological Studies: An Objective Consumer-centered Method

Food abundance and distribution have played a central role in the conceptual theory of primate socioecology. This theory predicts that agonistic (contest) competition should occur when food is distributed in discrete, defensible patches; in contrast, when food sources are distributed uniformly or randomly, nonagonistic (scramble) competition is expected. Primatologists usually measure resource density and patchiness from a botanical perspective, without an explicit link to the biology of the animal being studied. Such an approach may be irrelevant to how the animals view the dispersion of resources. For studies related to feeding competition, we suggest the use of a method that provides a consumer-based index of food distribution. We then describe such an approach and apply it to understand agonistic behavior in white-faced capuchins (Cebus capucinus), at Lomas Barbudal. Instead of choosing sample plots at random, we use each actual feeding tree of a group as the center of a sample plot and we use the monkey species’ average group spread as the sampling area. This focal tree method allows us to evaluate the resource availability both within and outside of the feeding tree during a particular feeding bout. To summarize the spatial distribution of food at the level of a foraging group, we define and use an extension of Lloyd’s Dispersion Index, Lloyd’s Extended Index (LEI), designed to allow the inclusion of resources of diverse sizes and species in a single measure. We evaluate if LEI can be used to predict the frequency of aggression, if changing the area of the plot alters these results, and if calculating LEI based on fruit abundance or fruit biomass better predicts the frequency of aggression in this population of capuchins. In support of socioecological predictions, our results show that the frequency of agonism in a focal tree declines as LEI increases. This relationship is significant when LEI is calculated using a 20-m plot size and weighting tree size by fruit counts, but not when using larger plot sizes, unweighted tree counts, or weighting by fruit biomass. Our approach demonstrates the importance of carefully considering plot size and different measures of food availability when testing socioecological models relating resource distribution and quality to aggression in nonhuman primates.

Predicting the frequency of food‐related agonism in white‐faced capuchin monkeys (Cebus capucinus), using a novel focal‐tree method

Food abundance and distribution have played a central role in the conceptual theory of primate socioecology [Janson, Behaviour 105:53-76, 1988; Isbell, Behavioral Ecology 2:143-155, 1991; Sterck et al., Behavioral Ecology and Sociobiology 41:291-309, 1997; van Schaik, In: Standen V, Foley RA, editors, Comparative Socioecology. Oxford: Blackwell. p 195-218, 1989]. This theory predicts that agonistic ("contest") competition should occur when food is distributed in discrete, defensible patches; in contrast, when food sources are distributed uniformly or randomly, non-agonistic ("scramble") competition is expected. Primatologists usually measure resource density and patchiness from a botanical perspective, ignoring the biology of the animal being studied. Such an approach may be irrelevant in terms of how animals view the dispersion of resources. Using a novel focal-tree method that measures resource availability on a scale that is both spatially and temporally relevant to the animal under investigation, we take a cost-benefit approach to predict the frequency of food-related agonism in white-faced capuchin monkeys (Cebus capucinus) from 11 ecological and social variables. We retained four variables in the regression model: two representing the opportunity for aggression (i.e., feeding bout length and the number of feeding adult females), and two representing opportunity costs (i.e., fruit abundance and the number of potential feeding sites in the focal tree). The results of this study indicate that the amount of food-related aggression in white-faced capuchins can be predicted by variables representing the costs and benefits of contesting a food resource.

Social object play among young Japanese macaques (Macaca fuscata) in Arashiyama, Japan

Social object play (SOP), i.e., social play using portable object(s), among young Japanese macaques (Macaca fuscata; 0-4 years old) in the Arashiyama E troop was studied using a modified sequence sampling method from July to October 2000. SOP was a relatively common activity for most of the young macaques and often continued for long periods. Participants used many kinds of object, including edible natural objects and artificial objects, such as plastic bottles, but they never used provisioned food or wild fruit in SOP bouts. An analysis of long bouts (>/=0.5 min) revealed the following interactive SOP features: (1) at any given time, participants used only one object, and only one participant held the object; (2) during SOP play-chasing, the object holder was likely to be chased by others; (3) during long bouts, the object changed hands frequently; and (4) agonistic competition for an object among young macaques was rare. Combinations of sexes, ages, relative ranks, or matrilines of the object holder and non-holder did not affect the tendency that the holder was chased by non-holder(s) during play-chasing. Even when there was a change in object holders, the repetitiveness of this interactive pattern, i.e., that the holder would be chased during SOP bouts, distinguished the SOP structure from that of other types of social play without object(s). General proximate social play mechanisms, such as self-handicapping or role taking, were associated with SOP. Other mechanisms that affected SOP included the following: (1) young macaques treated an object as a target in play competition, and (2) 'being the holder of a target object' was associated with the 'role of the chasee.'

Proximate mechanisms of reproductive monopolization in male moustached tamarins (Saguinus mystax).

In moustached tamarin (Saguinus mystax) groups, the single breeding female mates polyandrously with most or all nonrelated adult males. Nonetheless, paternity is monopolized in many groups by a single male. No evidence for male endocrine suppression has been found in this species. The proximate mechanisms of monopolization thus remain poorly understood. The aim of this study was to investigate the possible impact of agonistic interactions and mate-guarding on the monopolization of paternity in male moustached tamarins. Furthermore, we evaluated the likely costs of these behaviors, and whether olfactory cues might be used for its timing. We used behavioral data on proximity, agonistic interactions, time budgets, and scent-marking behavior to answer these questions. While direct agonistic competition does not play a prominent role, fertile females were consorted in some periods by one male, the sire of the previous and next litter. Consorting was instigated nearly exclusively by the male. It probably occurred during the female's periods of highest fertility, and thus likely functions as mate-guarding. The timing of the consortship was probably guided by olfactory cues in the female's scent marks. While we did not obtain direct evidence for energy costs in terms of increased energy expenditure or decreased food intake, we found that consorting males are more conspicuous and therefore may be more vulnerable to predators.

Temporary Sequestration of Fingerling Channel Catfish in Cages as a Means to Improve Production of Multiple-Crop Ponds

Two studies were conducted to determine if temporary sequestration of fingerling channel catfish, Ictalurus punctatus, in cages improves production of multiple-crop ponds. In the first study, 0.04-ha ponds were stocked with 295 large (mean weight = 566 g) and 780 fingerling (mean weight = 21 g) catfish. Fingerlings were stocked into cages or open ponds. At 120 days after stocking, fish in cages were released. After an additional 40 days, ponds were clean-harvested to remove large (>500 g) and small (<500 g) fish. In the second study, ponds (0.08-ha) were stocked with 750 large (mean weight = 46 g) and 750 small (mean weight = 20 g) fingerling catfish. Small fingerlings were stocked into cages or open ponds. At 60 days after stocking, fish in cages were released. Market-ready fish were selectively harvested at five and nine months after stocking. Results from the first study indicated that individual weight, weight gain, and yield of both size classes of fish raised in sequestered ponds were significantly greater (P< 0.05) than that of fish raised in open ponds. In addition, total weight gain and yield of fish in sequestered ponds was significantly greater (P< 0.05) than those in non-sequestered ponds. Results from the second study indicated that a significantly greater (P< 0.05) number of market-ready fish were harvested from sequestered ponds than from non-sequestered ponds. Mean yield of sequestered ponds was 31% greater than that of non-sequestered ponds; however, differences were not significant (P> 0.05). Amount of feed fed to fish raised in sequestered ponds was significantly greater (P< 0.05) than amount of feed fed to fish raised in non-sequestered ponds in both studies. It is unclear which factor or factors were responsible for the enhanced production of sequestered ponds; however, temporary sequestration may reduce agonistic behavior and competition for feed between fish size groups.

Reproductive strategies of rhesus macaques

Reproductive strategies incorporate a multitude of mechanisms that have evolved to promote the reproductive success of individuals. Evolutionary perspectives tend to emphasize the advantages of male-male competition and female choice as mediators of differential reproduction. Male rhesus macaques have not been observed to fight for access to sexually receptive females, although they suffer more wounds during the mating season. An increased likelihood of attacks appears to coincide with male troop entry. Males who spend more time in consort and mate with more females tend to sire more offspring. Genetic analysis of paternity has pinpointed age and endurance rivalry, rather than agonistic competition, as key variables associated with variation in progeny production. Female rhesus macaques often copulate with multiple males during their ovulatory period, and tend to conceive on the first cycle of the mating season. Female reproductive success is more likely to be a function of offspring survivorship than the identity of particular male partners. The role of female choice as a direct mediator of male reproductive success is unresolved, but female mate selection seems to indirectly affect male reproductive success because female preference for mating with novel males seems to foster male dispersal. Evaluating whether mating preferences for particular male phenotypes affectsfemale reproductive success is a task for the future. A common denominator to the reproductive strategies of both female and male rhesus macaques is that feeding patterns affect body condition which influences reproductive output and regulates relative reproductive success.

Contexts and Patterns of Injuries in Free-Ranging Male Baboons (Papio Cynocephalus)

AbstractInjury in male baboons (Papio cynocephalus) was investigated as an indicator of damaging fights in order to provide a framework for analyses of conflict resolution and dynamics of agonistic competition in primates. The vast majority of wounds were canine slashes resulting from intraspecific face-to-face combat. Wounds were more common in males than females. In males they concentrated on the right side of anterior parts of the body, principally the head. Wounds took on average three weeks to heal. Aggressive conflicts represented 10% of all interactions between males. Less than 1% of aggressive contests led to injury. The individual rate of injury from fights with other males was on average once every 1.5 months. The winner of damaging fights was sometimes the wounded individual. The number of wounds per damaging fight was not related in a simple way to the presence of proceptive females or to recent immigration events. Four fights yielding the highest number of injuries, however, involved recent immigrations or attempts to immigrate by adult males in their prime. Contexts of male injury observed during infliction include challenges to the resident alpha male by newcomers, intertroop encounter, fights over proceptive females or unusual foods, redirected aggression, defense of a female and a fight unrelated to any obvious resource. This study and anecdotal reports from the literature point at various implications of injury to male baboons, including physical impairments which can constrain feeding efficiency, limit access to resting sites and safe retreats, cause a drop in dominance rank, jeopardize mating success and even result in death. Severely injured males typically reduce interaction rates, retreat to the periphery of the troop or emigrate temporarily. Although most wounds are small and heal well, the potentially high costs of injury probably exercise strong selection pressure on contestants for means of peaceful conflict resolution, given that during fights both baboons risk injury irrespective of their competitive abilities. The potential fitness consequences of inflicted injury can explain the evolution of the formidable canine weaponry of some male primates.

Competition, coalitions and canine size in primates

Explanations of the evolution of canine tooth size sexual dimorphism in primates implicitly assume that male canine size is the primary target of natural or sexual selection, even though there is substantial unexplained variation in female canine size. Here we demonstrate that the canines of both males and females are relatively larger in species where agonistic interactions are more likely to escalate. Hence, the canine teeth of both sexes are influenced by selection for the development of weaponry, though the nature of the selection (natural or sexual) favoring development of the canines as weapons depends on the objects of competition (mates vs. food, for example). However, we also suggest that where the outcome of fights is typically determined between coalitions of individuals, selection for weaponry is reduced, even though agonistic competition can be very intense. Coalitionary aggression between males occurs in only a handful of anthropoid primates, but it is common among female anthropoids, and helps explain, in part, the extreme sexual dimorphism in the canine teeth of a number of catarrhine species. This is the first demonstration that cooperation among animals may affect their morphology. The lack of sexual dimorphism in canine size among prosimian primates is also consistent with the model. This analysis demonstrates that a better understanding of the interspecific variation in sexual dimorphism among primates is gained by considering behavioral variation in both sexes.

BODY SIZE, SPERM COMPETITION, AND DETERMINANTS OF REPRODUCTIVE SUCCESS IN MALE SAVANNA BABOONS.

One component of sexual selection is sperm competition. It has been reasoned that the intensity of sperm competition may be reflected in the relative testicular sizes of animals. Among males residing in multimale breeding systems, testicular size is relatively larger than among males residing in unimale mating systems. Information on whether differences in testicular size within a species can account for differences in male reproductive success is unavailable for natural populations of primates. A population of six troops of savanna baboons in Kenya was surveyed for morphometric analysis, and one of these troops was the subject of extensive behavioral observations afterwards. Testicular weights could not be obtained, but measurements of linear dimensions were transformed into volumetric estimates. Male weight accounted for 30% of the variance in testicular volume. Neither body size nor testicular volume was associated with differences in male reproductive activity. The outcome of fights over access to females could not be related to male body size, and ejaculatory patterns of males were independent of testicle size. Both sperm competition and aggressive competition intensified during the four-day optimum conception period, but fights over access to consort females were infrequent. Among savanna baboons, the probability of an ejaculation resulting in a conception is fairly low, which may account for the infrequency of injurious fights. Although testicle size influences sperm production, it does not influence either the timing of mating or the fertilizing capacity of spermatozoa, and both of these factors probably account for a substantial fraction of the variance in male baboon paternity. Sperm competition is an adjunct to agonistic competition as a mechanism affecting male baboon reproductive success. It is concluded that male reproductive success in baboons is affected more by social factors than by morphological traits associated with size.

Status Interactions of Captive Female Lowland Gorillas

Agonistic interactions and incentive competition data were examined both under paired confrontations and during a 2-month group living situation. These preliminary data suggest the presence of interactions which may be operationally described as a quasilinear dominance structure for female gorillas. Particular rankings appear to be sensitive to the total social situation and change to readapt to modifications induced in the social environment. These findings are hypothesized to reflect the overall adaptation of this species in terms of spatial deployment, other signaling systems and the physical characteristics of the animals. Priority to incentives was found to be a valid measure of assertion and competitive success, and appears to be only indirectly related to other motivational states.