Ethnicity and factionalism in Zimbabwe nationalist politics 1957–79

Four explanations of xenophobia and racism will be reviewed by confronting them with the results of empirical studies. I try to show that xenophobic and racist views of the social world are not instrumental to a fight for scarce jobs or housing. Neither is it appropriate to interpret them as a result of a culture clash that is caused by migratory movements across countries and continents. They are not mere radicalizations of the discourse of exclusion and devaluation which political and administrative elites generate and institutionalize, for example, in immigration policies. Starting from the insights of this critical review, I shall develop the hypothesis that xenophobia and racism should be seen as appeals to the pact of solidarity into which state and society have entered in modern nation‐states and which in times of intensified social conflicts seems fragile in the eyes of downwardly mobile groups. The xenophobic discourse serves not only to reassure identity when nationalistic self‐images run into crisis but is an element of a political struggle about who has the right to be cared for by the state and society: a fight for the collective goods of the modern state.     

Female contributions to the peaceful nature of bonobo society

Although chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are closely related, females of the two species show surprisingly large differences in many behavioral aspects. While female chimpanzees tend to range alone or in small parties during non-estrous periods, female bonobos aggregate even more often than do males. Female chimpanzees do not have frequent social interactions with other females, whereas female bonobos maintain close social associations with one another. Although the ranging patterns of chimpanzee parties are generally led by males, female bonobos often take the initiative in ranging behavior. While female chimpanzees usually do not exhibit estrus during postpartum amenorrhea or pregnancy, female bonobos exhibit a prolonged pseudo-estrus during such non-conceptive periods. Studies of these two species have also shown great differences in agonistic behaviors performed by males. Male chimpanzees frequently fight with other males to compete for estrous females, but male bonobos seldom do so. While there are many records of infanticide by male chimpanzees, there is no confirmed record of such an event among bonobos. Several cases of within-group killing among adult male chimpanzees have been reported, but there is no such record for bonobos. While intergroup conflicts among chimpanzees sometimes involve killing members of the other group, intergroup conflicts among bonobos are considerably more moderate. In some cases, bonobos from two different groups may even range together for several days while engaging in various peaceful interactions. I will address two important questions that arise from these comparisons, exploring why females of such closely related species show such clear differences in behavior and whether or not the behavioral characteristics of female bonobos contribute to the peaceful nature of bonobo society.     

Overestimating resource value and its effects on fighting decisions

Much work in behavioral ecology has shown that animals fight over resources such as food, and that they make strategic decisions about when to engage in such fights. Here, we examine the evolution of one, heretofore unexamined, component of that strategic decision about whether to fight for a resource. We present the results of a computer simulation that examined the evolution of over- or underestimating the value of a resource (food) as a function of an individual's current hunger level. In our model, animals fought for food when they perceived their current food level to be below the mean for the environment. We considered seven strategies for estimating food value: 1) always underestimate food value, 2) always overestimate food value, 3) never over- or underestimate food value, 4) overestimate food value when hungry, 5) underestimate food value when hungry, 6) overestimate food value when relatively satiated, and 7) underestimate food value when relatively satiated. We first competed all seven strategies against each other when they began at approximately equal frequencies. In such a competition, two strategies--"always overestimate food value," and "overestimate food value when hungry"--were very successful. We next competed each of these strategies against the default strategy of "never over- or underestimate," when the default strategy was set at 99% of the population. Again, the strategies of "always overestimate food value" and "overestimate food value when hungry" fared well. Our results suggest that overestimating food value when deciding whether to fight should be favored by natural selection.     

Antimicrobial compounds from the excretions of surgical maggots, Lucilia sericata (Meigen) (Diptera, Calliphoridae)

Maggots of Lucilia sericata are widely used in the therapy of infected wounds and skin ulcers. Antimicrobial materials released by the insects during their feeding period in order to suppress microbial competitors and potential pathogens play the key role both in the maggots’ survival in their natural habitats (animal corpses) and their therapeutic efficacy. Although the antimicrobial activity of the maggots’ excretion was demonstrated about a hundred years ago, little is known about the nature of its active compounds. We studied the structural characteristics and antimicrobial activities of the compounds released by L. sericata maggots into the environment. To isolate the compounds, excretion was collected from the culture of actively feeding last instar larvae, active compounds were purified using a combination of liquid chromatography and antibacterial growth inhibition assay and characterized by mass spectrometry. Two groups of antibacterial compounds were isolated from the excretion: polypeptides with molecular masses ranging from 6466 to 9025 Da and small molecules with molecular masses ranging from 130 to 700 Da. The polypeptides characterized by the masses of 8882 and 9025 Da and showing selective activity against Gram-negative bacteria correspond well to diptericins, antimicrobial peptides previously found in the hemolymph of Calliphoridae maggots and known to be part of immune response to bacterial pathogens. Other high-molecular compounds with masses 6466, 6633, 5772, and 8631 Da have no clear analogs among antimicrobial peptides present in the hemolymph. The nature of small molecules present in the excretion awaits further study. Thus, the diversity of antimicrobial compounds discovered in Lucilia excretion demonstrates a sophisticated strategy that helps the maggots to fight bacteria and other microorganisms settling their environment. The strategy combines secretion of a set of antibacterial peptides involved in insect immune response as well as molecules which function outside the host organism.     

Mind, memory and history: How classifications are shaped by and through time, and some consequences

Understanding the history of systematics bears on contemporary issues such as the distinction between classifications and systems, the belief that ‘natural’ classifications reflect the progressive refinement of our ideas of relationships, and the dubious reputation acquired by systematics. Here I emphasize the extent to which ‘mind’ shapes classifications. I show that groups in biological classifications often have six or fewer members, in line with the number of things that humans can conveniently memorize together. Concerns about memorization are evident in the work of systematists like Tournefort, Linnaeus, and Antoine-Laurent de Jussieu, and the whole hierarchy of George Bentham's and J. D. Hooker's great Genera plantarum is structured by such concerns. An analytical element in Jussieu's work was emphasized by Cuvier and others, and the hierarchy of their classifications reflects more directly aspects of nature as they understood it, although concerns about memorisation remain evident. Linking an understanding of what classifications can represent to the ideas the makers of classifications had about nature makes it clear that classifications are rarely rigid class hierarchies, but are often more like systems. Historically, the synthetic approach, discussed here, tends to lead to systems, the analytical approach, to ‘classifications’. We must remember that systematists’ work is evaluated by other scientists, and by society at large. The confusion evident in systematics simply confirmed the negative perceptions that many people in the nineteenth century had of naturalists, botanists and zoologists, perceptions that persist today. Zoologica Scripta itself, and the Journal of Natural History, which under this title is about the same age, reflect part of this history. I conclude by emphasizing (1) if systems or classifications in the nineteenth century reflect ‘nature’, it is a nature very different from that we understand today, and (2) the extent and the persistence of the opposition between the synthetic and anaytical approaches.     

Inferring reputation promotes the evolution of cooperation in spatial social dilemma games

In realistic world individuals with high reputation are more likely to influence the collective behaviors. Due to the cost and error of information dissemination, however, it is unreasonable to assign each individual with a complete cognitive power, which means that not everyone can accurately realize others' reputation situation. Here we introduce the mechanism of inferring reputation into the selection of potential strategy sources to explore the evolution of cooperation. Before the game each player is assigned with a randomly distributed parameter p denoting his ability to infer the reputation of others. The parameter p of each individual is kept constant during the game. The value of p indicates that the neighbor possessing highest reputation is chosen with the probability p and randomly choosing an opponent is left with the probability 1-p. We find that this novel mechanism can be seen as an universally applicable promoter of cooperation, which works on various interaction networks and in different types of evolutionary game. Of particular interest is the fact that, in the early stages of evolutionary process, cooperators with high reputation who are easily regarded as the potential strategy donors can quickly lead to the formation of extremely robust clusters of cooperators that are impervious to defector attacks. These clusters eventually help cooperators reach their undisputed dominance, which transcends what can be warranted by the spatial reciprocity alone. Moreover, we provide complete phase diagrams to depict the impact of uncertainty in strategy adoptions and conclude that the effective interaction topology structure may be altered under such a mechanism. When the estimation of reputation is extended, we also show that the moderate value of evaluation factor enables cooperation to thrive best. We thus present a viable method of understanding the ubiquitous cooperative behaviors in nature and hope that it will inspire further studies to resolve social dilemmas.     

Conflicts of interest in health care: who guards the guardians?

Conflicts of interest are rife in all areas of human endeavor, including medicine. Dealing with them is often difficult, because various disclosure remedies are sometimes too weak, while explicit prohibitions against participation in certain forms of research could block the needed synergies between scientists who work in universities, government, and industry. The situation is made still more difficult, because any effort to control one set of conflicts will necessarily generate another in its stead, as is well captured in Juvenal's famous question, "Who will guard the guardians?" That problem is more acute today, because many of our social watchdogs are in fact complex organizations that are rife with their own internal conflicts of interest. The problem is acute for the FDA, for example, which so fears the release of harmful drugs that it often keeps beneficial ones off the market. The problem can also arise in connection with the review of medical research by major journals, which is well illustrated by the recent effort of the New England Journal of Medicine to attack a Vioxx study it published in order to protect its own reputation.     

Janus-faced race: Is race biological,social, or mythical?

As belief in the reality of race as a biological category among U.S. anthropologists has fallen, belief in the reality of race as a social category has risen in its place. The view that race simply does not exist—that it is a myth—is treated with suspicion. While racial classification is linked to many of the worst evils of recent history, it is now widely believed to be necessary to fight back against racism. In this article, I argue that race is indeed a biological fiction, but I critique the claim that race is socially real. I defend a form of anti-realist reconstructionism about race, which says that there are no races, only racialized groups—groups mistakenly believed to be races. I argue that this is the most attractive position about race from a metaphysical perspective, and that it is also the position most conductive to public understanding and social justice.     

Dimorphic Males Display Alternative Reproductive Strategies in the Marine Amphipod Jassa marmorata Holmes (Corophioidea: Ischyroceridae)

Discrete dimorphism of males within a species is often the result of selection for alternative reproductive strategies, and these strategies may be evolutionarily stable (ESS). An ESS may be either mixed (genetically fixed differences) or conditional (flexible differences related to varying environmental conditions) (PARKER 1984). Mature males of the marine amphipod Jassa marmorata are dimorphic. Large ‘major’ males have a greatly enlarged thumb (propodus) on their 2nd gnathopods, while small ‘minor’ males exhibit thumbs that are reduced, and CONIAN (1989) suggested that minors may exhibit a different mating strategy from majors. Ratios of males and females fluctuate seasonally (FRANZ 1989) and female body size is inversely correlated with temperature (FRANZ 1989) so male dimorphism could be a flexible response to varying environmental conditions. I sampled a natural population of J. marmorata over a 1-yr period, quantified major and minor morphology, and measured male behaviour and mating success in experimental arenas that contained varying proportions of male morphs and females. Morphology of the two morphs is discrete; female body size varies with season with significantly smaller individuals in summer and fall; body size predicts morph type; and ratios of majors, minors and females fluctuate seasonally. Finally I showed that majors and minors use different mating tactics to gain access to receptive females, and that these behaviours depend on the male's own morphology and on the environmental setting that it finds itself in. Major males fight, display and attempt to evict other males to mate with receptive females. Minors never fight with, display to or attempt to evict majors, but they infrequently display to and attempt to evict other minor males. Furthermore, mating success of the two morphs was not significantly different and may depend on whether males are with a majority or minority of their own type. These data support the conclusion that major and minor male J. marmorata display evolutionarily stable alternative reproductive strategics, but more work should address the nature of this ESS.     

Reputation,a universal currency for human social interactions

Decision rules of reciprocity include ‘I help those who helped me’ (direct reciprocity) and ‘I help those who have helped others’ (indirect reciprocity), i.e. I help those who have a reputation to care for others. A person''s reputation is a score that members of a social group update whenever they see the person interacting or hear at best multiple gossip about the person''s social interactions. Reputation is the current standing the person has gained from previous investments or refusal of investments in helping others. Is he a good guy, can I trust him or should I better avoid him as a social partner? A good reputation pays off by attracting help from others, even from strangers or members from another group, if the recipient''s reputation is known. Any costly investment in others, i.e. direct help, donations to charity, investment in averting climate change, etc. increases a person''s reputation. I shall argue and illustrate with examples that a person''s known reputation functions like money that can be used whenever the person needs help. Whenever possible I will present tests of predictions of evolutionary theory, i.e. fitness maximizing strategies, mostly by economic experiments with humans.     

Evolutionary stability of first-order-information indirect reciprocity in sizable groups

Indirect reciprocity is considered as a key mechanism for explaining the evolution of cooperation in situations where the same individuals interact only a few times. Under indirect reciprocity, an individual who helps others gets returns indirectly from others who know her good reputation. Recently, many studies have discussed the effect of reputation criteria based only on the former actions of the others (first-order information) and of those based also on the former reputation of opponents of the others (second-order information) on the evolution of indirect reciprocity. In this study, we investigate the evolutionary stability of the indirectly reciprocal strategy (discriminating strategy: DIS), which cooperates only with opponents who have good reputations, in -person games where more than two individuals take part in a single group (interaction). We show that in n-person games, DIS is an evolutionarily stable strategy (ESS) even under the image-scoring reputation criterion, which is based only on first-order information and where cooperations (defections) are judged to be good (bad). This result is in contrast to that of 2-person games where DIS is not an ESS under reputation criteria based only on first-order information.     

No Evidence for Audience Effects in Reciprocal Cooperation of Norway Rats

Norway rats (Rattus norvegicus) cooperate according to indirect reciprocity, which implies the involvement of a reputation mechanism. Here, we test whether the rats employ such mechanism in repeated cooperative interactions. Focal subjects were first trained individually to pull food towards a social partner. During the experiment, the focal rats were confronted with two types of trained social partners: one always cooperated and the other one always defected, either in the presence or in the absence of an audience. Based on the hypotheses that the rats possess a reputation mechanism involving image scoring, we predicted them to be more helpful in the presence of an audience, independently of the partner's cooperative behaviour. If, in contrast, reputation involved a standing strategy, we predicted the rats to distinguish more between cooperators and defectors in the presence of an audience than in its absence. The rats helped cooperative partners more than defectors, but against both predictions the presence or absence of an audience did not influence their helping propensity. This indicates that either reputation is not included in the decision of rats to help an individual that has helped others, or that reputation is neither involving image scoring nor a standing strategy. Although the rats have been shown to modulate their decision to help a social partner based on its helpful behaviour towards others, they do not seem to adjust their behaviour strategically to the presence of an audience.     

Sociobiology and the Comparative Approach: One Way to Study Ourselves

This paper is based on my lecture in a macroevolution course I team-teach with Profs. Daniel Brooks and David Evans at the University of Toronto. The lecture has undergone many revisions over the years as I grappled with problems discussing certain areas (e.g., rape as an adaptive strategy, gender “roles”). Eventually, I realized that the problem areas said more about my personal conflicts than they did about the science. This was one of those epiphany moments, a time when I recognized that I was less likely to accept hypotheses that contradicted the way I wanted the world to be and more likely to uncritically accept hypotheses that confirmed my world view. That epiphany, in turn, led me to realize that science is never separate from the personal biases/demons of its practitioners, especially when we are asking questions about the evolution of human behavior. That realization was not novel within the vast literature of sociology and philosophy. But it was novel for me. I was aware of discussions about personal biases clouding scientific interpretation; I just didn’t think it applied to me (I absorbed the philosophical discussions without making the connection to “my world”). So, on the heels of that epiphany, the following is a very personal take on the question of teaching sociobiology, based on where my journey, aided by my experience as an ethologist and phylogeneticist and colored by my own history, has taken me.     

Neural Correlates of Gender Differences in Reputation Building

Gender differences in cooperative choices and their neural correlates were investigated in a situation where reputation represented a crucial issue. Males and females were involved in an economic exchange (trust game) where economic and reputational payoffs had to be balanced in order to increase personal welfare. At the behavioral level, females showed a stronger reaction to negative reputation judgments that led to higher cooperation than males, measured by back transfers in the game. The neuroanatomical counterpart of this gender difference was found within the reward network (engaged in producing expectations of positive results) and reputation-related brain networks, such as the self-control network (engaged in strategically resisting the temptation to defect) and the mentalizing network (engaged in thinking about how one is viewed by others), in which the dorsolateral prefrontal cortex (DLPFC) and the medial (M)PFC respectively play a crucial role. Furthermore, both DLPFC and MPFC activity correlated with the amount of back transfer, as well as with the personality dimensions assessed with the Big-Five Questionnaire (BFQ-2). Males, according to their greater DLPFC recruitment and their higher level of the BFQ-2 subscale of Dominance, were more focused on implementing a profit-maximizing strategy, pursuing this target irrespectively of others'' judgments. On the contrary, females, according to their greater MPFC activity and their lower level of Dominance, were more focused on the reputation per se and not on the strategic component of reputation building. These findings shed light on the sexual dimorphism related to cooperative behavior and its neural correlates.     

Ergological viewpoint in real-life study

I think that real-life studies on human work must be done, if possible, not objectively, but subjectively from an ergological viewpoint. Essentially, I consider ergology as the biology of human living and work, along German biologist Haeckel's idea. He considered ergology a field of anthropology. The instinctive (genetic) element and the learned (environmental) element constitute human behavior. It is conceivable that the adaptation by human learnability has today brought about high-tech society, and genetic human attributes (human nature) have been adapted to the living environment of hunters and gatherers, which has been long-lasting in human history. Hunters-gatherers form a band consisting of about 50 (30-100) persons and move in a more or less vaguely defined territory (1,000-3,000 km2). The unsuitableness of human nature for modern scientific civilization has caused various problems. Always keeping human nature in mind when considering human living and work is the philosophical background of human ergology. Two real-life working conditions in agriculture, the packing of leeks and promoting a system for securing employees in strawberry production, are presented.     

Selfish altruism,fierce cooperation and the predator*

This paper suggests a new way to think about a famous question: what explains cooperation in nature and in particular in humans? I argue that, for an evolutionary biologist as well as a quantitative social scientist, the triangle of two ‘teammates’ in the presence of a predator (passing and shooting in two-on-one situations) is one of the fundamental conceptual building-blocks for understanding these phenomena because in such a situation the fact that life is packaged in many distinct enclosures (and not in one big monolithic blob) can unfold its comparative advantage. I show how, in the presence of a predator, cooperative equilibria emerge among entirely selfish teammates if we infinitesimally bias the lead player in the selfish direction or assign a computational burden on the predator due to the presence of a teammate. I argue that ‘predators’ are common in the biological jungle but also in everyday human settings. Intuitively, this paper builds on the simple idea – a familiar one to a biologist observing the natural world but perhaps less so to social scientists – that everybody has enemies.     

Conflict in Protected Areas: Who Says Co-Management Does Not Work?

Natural resource-related conflicts can be extremely destructive and undermine environmental protection. Since the 1990s co-management schemes, whereby the management of resources is shared by public and/or private sector stakeholders, have been a main strategy for reducing these conflicts worldwide. Despite initial high hopes, in recent years co-management has been perceived as falling short of expectations. However, systematic assessments of its role in conflict prevention or mitigation are non-existent. Interviews with 584 residents from ten protected areas in Colombia revealed that co-management can be successful in reducing conflict at grassroots level, as long as some critical enabling conditions, such as effective participation in the co-management process, are fulfilled not only on paper but also by praxis. We hope these findings will re-incentivize global efforts to make co-management work in protected areas and other common pool resource contexts, such as fisheries, agriculture, forestry and water management.     

Why do winners keep winning? Androgen mediation of winner but not loser effects in cichlid fish

Animal conflicts are influenced by social experience such that a previous winning experience increases the probability of winning the next agonistic interaction, whereas a previous losing experience has the opposite effect. Since androgens respond to social interactions, increasing in winners and decreasing in losers, we hypothesized that socially induced transient changes in androgen levels could be a causal mediator of winner/loser effects. To test this hypothesis, we staged fights between dyads of size-matched males of the Mozambique tilapia (Oreochromis mossambicus). After the first contest, winners were treated with the anti-androgen cyproterone acetate and losers were supplemented with 11-ketotestosterone. Two hours after the end of the first fight, two contests were staged simultaneously between the winner of the first fight and a naive male and between the loser of first fight and another naive male. The majority (88%) of control winners also won the second interaction, whereas the majority of control losers (87%) lost their second fight, thus confirming the presence of winner/loser effects in this species. As predicted, the success of anti-androgen-treated winners in the second fight decreased significantly to chance levels (44%), but the success of androgenized losers (19%) did not show a significant increase. In summary, the treatment with anti-androgen blocks the winner effect, whereas androgen administration fails to reverse the loser effect, suggesting an involvement of androgens on the winner but not on the loser effect.     

农户生计策略转型及对环境的影响研究综述

随着我国经济形势的不断变化,越来越多的农户从传统的"单一生计"转向"生计多样化"和"优势生计"的发展方向。农户作为农村地区最基本的社会经济单元和行为决策主体,处于人口、经济与资源环境矛盾的核心,其生计策略与生计活动的动态变化势必对所处的自然-社会-经济复合生态系统带来一定的影响。在回顾农户生计研究的历史与现状的基础上,分别从农户生计策略的内涵与类型、农户生计策略转型及其驱动因素、生计策略转型对环境的影响3个方面,系统梳理了国内外学者对农户生计策略转型及对环境的影响的研究进展,尝试性地构建了农户生计策略转型及对环境的影响的基本研究框架,提出未来研究应当体现生计问题本身的动态性和复杂性,并注重可持续生计策略的界定与实现。     

Temporal partitioning and aggression among foragers: modeling the effects of stochasticity and individual state

In many natural systems, individuals compete with conspecificsand heterospecifics for food and in some cases, individualshave been observed to partition their foraging times or fightover food. In this study, I investigated when it is optimalfor a consumer to partition time and be aggressive. I formulatedan individual-based model of foraging and used game theoryto find evolutionarily stable strategies (ESSs) that maximizethe probability that consumers survive each day and acquiretheir daily food requirements. Consumers choose when to forageand when to behave aggressively during confrontations overfood. Consumers are each associated with a state variable,representing the amount of food eaten, and a dominance ranking, which describes how likely they are to forage and fight forfood. The ESS is sensitive to food abundance, consumer state,and the dominance ranking. When food is abundant, temporalpartitioning is often an ESS where the dominant consumer foragesfirst; however, partitioning is unlikely to be an ESS when food abundance is low. Fights over food are typically avoidedbut may be part of an ESS when food abundance is low, bothconsumers are hungry, or the time available for foraging eachday is drawing to a close. Because the ESS is sensitive toconsumer state, the stochastic nature of finding food often results in considerable variation in observed foraging dynamicsfrom one day to the next, even when consumers adopt the samestate-dependent strategy each day. Results are compared withempirical observations, and I discuss implications for consumercoexistence.