Importance of cooperation and affiliation in the evolution of primate sociality

The idea that competition and aggression are central to an understanding of the origins of group‐living and sociality among human and nonhuman primates is the dominant theory in primatology today. Using this paradigm, researchers have focused their attention on competitive and aggressive behaviors, and have tended to overlook the importance of cooperative and affiliative behaviors. However, cooperative and affiliative behaviors are considerably more common than agonistic behaviors in all primate species. The current paradigm often fails to explain the context, function, and social tactics underlying affiliative and agonistic behavior. Here, we present data on a basic question of primate sociality: how much time do diurnal, group‐living primates spend in social behavior, and how much of this time is affiliative and agonistic? These data are derived from a survey of 81 studies, including 28 genera and 60 species. We find that group‐living prosimians, New World monkeys, Old World monkeys, and apes usually devote less than 10% of their activity budget to active social interactions. Further, rates of agonistic behaviors are extremely low, normally less than 1% of the activity budget. If the cost to the actors of affiliative behavior is low even if the rewards are low or extremely variable, we should expect affiliation and cooperation to be frequent. This is especially true under conditions in which individuals benefit from the collective environment of living in stable social groups. Am J Phys Anthropol 128:84–97, 2005. © 2005 Wiley‐Liss, Inc.     

Social effects on fruit fly courtship song

Courtship behavior in Drosophila has often been described as a classic innate behavioral repertoire, but more recently extensive plasticity has been described. In particular, prior exposure to acoustic signals of con‐ or heterspecific males can change courtship traits in both sexes that are liable to be important in reproductive isolation. However, it is unknown whether male courtship song itself is socially plastic. We examined courtship song plasticity of two species in the Drosophila melanogaster subgroup. Sexual isolation between the species is influenced by two male song traits, the interpulse interval (IPI) and sinesong frequency (SSF). Neither of these showed plasticity when males had prior experience of con‐ and heterospecific social partners. However, males of both species produced longer bursts of song during courtship when they were exposed to social partners (either con‐ or heterospecific) than when they were reared in isolation. D. melanogaster carrying mutations affecting short‐ or medium‐term memory showed a similar response to the social environment, not supporting a role for learning. Our results demonstrate that the amount of song a male produces during courtship is plastic depending on the social environment, which might reflect the advantage of being able to respond to variation in intrasexual competition, but that song structure itself is relatively inflexible, perhaps due to strong selection against hybridization.     

Tris not only controls the pH in microalgal cultures,but also feeds bacteria

Tris (Tris(hydroxymethyl)amino methane), a compound often used as a buffer in microalgal culture media, sustains active bacterial growth in non-axenic microalgal cultures when sodium phosphate is present. The low pH levels caused by bacterial growth and probably the depletion of phosphorus in the medium caused the collapse ofPhaeodactylum tricornutum cultures resulting in a reduction of microalgal growth from 32 x 10⁶ to 1.1 x 10⁶ cells ml^–1. This emphasizes the need for care when interpreting the results of non-axenic microalgae cultures in which Tris or other organic buffer is added.     

Differences in Titi Monkey (Callicebus cupreus) Social Bonds Affect Arousal,Affiliation, and Response to Reward

Titi monkeys (Callicebus cupreus) are a monogamous, New World primate. Adult pair‐mates form a bidirectional social bond and offspring form a selective unidirectional bond to their father. Some of the neurobiology involved in social bonds and maternal behavior is similar to the neural circuitry involved in nonsocial reward. Due to these overlapping mechanisms, social states may affect responses to external rewarding stimuli. We sought to determine whether having a social attachment, and/or being in the presence of that attachment figure, can affect an individual's response to a rewarding stimulus. In addition, we compared affiliative bonds between pair‐mates to those between offspring and fathers. Eighteen adult male titi monkeys were either living alone (Lone), with a female pair‐mate (Paired), or with the natal group (Natal; N = 6/condition). Each individual went through eight 30‐min preference tests for a sweet substance, Tang. For Paired and Natal males, half of the test sessions were with their attachment figure and half were alone. Lone males were always tested alone. Preference scores for Tang, time spent drinking, affiliative, and arousal behaviors were measured. Paired and Natal males emitted significantly more isolation peeps and locomoted more when tested alone compared to when tested with their attachment figure, and paired males engaged in more affiliative behavior than Natal males. Lone males engaged in significantly more behaviors indicative of behavioral arousal such as locomotion and piloerection compared to Paired and Natal males. Finally, Paired males drank significantly more Tang and had a significantly greater preference for Tang compared to Lone and Natal males. These results indicate that offspring undergo a behavioral separation response upon separation from their father that persists into adulthood, Lone males are more behaviorally reactive, and that living with an attachment figure and the type of attachment relationship result in different responses to a rewarding sweet stimulus. Am. J. Primatol. 74:758‐769, 2012. © 2012 Wiley Periodicals, Inc.     

Physiology as a caste-defining feature

Division of labour is a key factor in the ecological success of social insects. Groups of individuals specializing on a particular behaviour are known as castes and are usually distinguished by morphology or age. Physiology plays a key role in both these types of caste, in either the developmental physiology which determines morphology, or the temporal changes in physiology over an insect’s life. Physiological correlates of morphological or temporal caste include differences in gland structure, secretory products, leanness, neuroanatomy and neurochemistry. However, purely physiological castes could also occur. Physiological castes are discrete groups of same-age same-size individuals with particular physiological competencies, or groups of individuals with similar physiology crossing age or size groups. A stable physiological caste occurs in the monomorphic Pharaoh’s ant, where some ants can detect old pheromone trails and retain this specialization over time. These ants differ physiologically from other workers, and the differences arise before eclosion. More temporary physiological castes occur in the ant Ectatomma where brood care specialists have more developed ovarioles than other same-aged workers, and in the honeybee where nurses, wax-workers and soldiers all differ physiologically from same-aged nestmates. Physiology is an important aspect of caste, not only in its contribution to age-related and morphological castes, but also in its own right as a caste grouping factor. While age and morphological differences make caste structures accessible for study, more cryptic physiological castes may play just as important a role in division of labour. Received 19 December 2007; revised 24 July and 18 September 2008; accepted 19 September 2008.     

Leveraging remote learning during the Covid‐19 pandemic to enhance student understanding of biodiversity

We evaluated whether individual nature‐based ecological (NBE) study used in tandem with group collaboration enhanced undergraduate student understanding of ecological concepts and pro‐environmental perceptions. In response to the Covid‐19 pandemic, we developed a multiweek unit on the latitude diversity gradient (LDG) for fully online instruction that leveraged the unique situation of students learning in disparate geographic locations. Student understanding of the LDG and pro‐environmental perceptions were assessed with surveys administered both pre‐ and post‐activity in an introductory‐level biology laboratory course. Student understanding of the geographic location where biodiversity is the highest was high prior to the start of the laboratory unit and exhibited only a small improvement after the unit. In contrast, students’ higher order thinking around the LDG was enhanced by the lab activity. Student environmental perceptions shifted toward ecocentric views and away from anthropocentric views after the laboratory unit. The greatest gains in ecological understanding and shifts toward ecocentric viewpoints occurred in the group of students who visited their field sites most often. Our results provide further evidence as to the value of NBE for the introductory biology laboratory, even in an online learning setting. The lab unit described in this study provides a potential approach to teaching ecology in an online format that could easily be adapted to fit the needs of a particular curriculum.     

Behavioural phenotype affects social interactions in an animal network

Animal social networks can be extremely complex and are characterized by highly non-random interactions between group members. However, very little is known about the underlying factors affecting interaction preferences, and hence network structure. One possibility is that behavioural differences between individuals, such as how bold or shy they are, can affect the frequency and distribution of their interactions within a network. We tested this using individually marked three-spined sticklebacks (Gasterosteus aculeatus), and found that bold individuals had fewer overall interactions than shy fish, but tended to distribute their interactions more evenly across all group members. Shy fish, on the other hand, tended to associate preferentially with a small number of other group members, leading to a highly skewed distribution of interactions. This was mediated by the reduced tendency of shy fish to move to a new location within the tank when they were interacting with another individual; bold fish showed no such tendency and were equally likely to move irrespective of whether they were interacting or not. The results show that animal social network structure can be affected by the behavioural composition of group members and have important implications for understanding the spread of information and disease in social groups.     

Effect of process parameters on the production and drying of Leuconostoc mesenteroides cultures

Leuconostoc mesenteroides BLAC was grown on MRS broth or on a carrot juice medium, and the effects of sugar concentration, type of pH control, aeration and fermentor size on viable counts were examined. The effect on viability of the type of centrifuge used to concentrate the bacterial culture was also examined. When the MRS broth had the traditional 110 mM glucose, pH control did not increase the final population. However, using a zone pH control mode, increasing the glucose content of MRS both from 110 to 220 mM almost doubled the population. In MRS broth, the amount of acetic acid produced was the same for all treatments, and was proportional to the amount of citrate consumed. There was a significantly lower cell yield in the carrot juice medium when the pH was not regulated. In the carrot juice medium, pH had a more pronounced effect on the final population level than did aeration, even though the quantity of viable cells was greater when the culture was aerated. In MRS broth, glucose was completely consumed during fermentation, but this was not the case in carrot juice medium. Aeration resulted in increased acetic acid content of the fermented medium. Viable counts were not affected by scaling the volume of the fermentation from 2 to 15 l ,or by the type of centrifuge used to concentrate the cells. Cells were concentrated by a factor of 10, but in both centrifuge types, viable counts showed only an eightfold average increase. However, freeze-dried powders obtained from the continuous pilot-plant-centrifuged cultures had, on the average, 33% lower populations than those obtained from the laboratory unit. Journal of Industrial Microbiology & Biotechnology (2002) 28, 291–296 DOI: 10.1038/sj/jim/7000245 Received 09 July 2001/ Accepted in revised form 25 January 2002     

Conformist learning in nine-spined sticklebacks' foraging decisions

Theoretical analyses have reported that in most circumstances where natural selection favours reliance on social learning, conformity (positive frequency-dependent social learning) is also favoured. These findings suggest that much animal social learning should involve a copy-the-majority strategy, yet there is currently surprisingly little evidence for conformist learning among animals. Here, we investigate this possibility in the nine-spined stickleback (Pungitius pungitius) by manipulating the number of demonstrator fish at two feeders, one rich and one poor, during a demonstration phase and evaluating how this affects the likelihood that the focal fish copy the demonstrators'' apparent choices. As predicted, we observed a significantly increased level of copying with increasing numbers of demonstrators at the richer of the two feeders, with copying increasing disproportionately, rather than linearly, with the proportion of demonstrators at the rich foraging patch. Control conditions with non-feeding demonstrators showed that this was not simply the result of a preference for shoaling with larger groups, implying that nine-spined sticklebacks copy in a conformist manner.     

Complicaciones de la otitis media con parálisis del sexto par craneal contralateral en pediatría

Otitis media is a frequent infection during childhood. Complications may be present in up to 4 of 100 children including serious neurological complications, particularly in developing countries.We report the case of a 9-year-old girl with no disease history who presented with otitis media, otorrhea, intracranial hypertension syndrome, and paralysis of the VI cranial nerve contralateral to the lesion. A computed tomography scan of the skull and a brain magnetic resonance imaging revealed chronic otomastoiditis, petrous apicitis, and thrombosis of the transverse and sigmoid sinus, the jugular bulb, and the right internal jugular vein. She received antibiotics and surgical treatment.This case shows the spectrum of intra and extracranial complications associated with acute otitis media in the antibiotic era. The physical examination allows early identification of intracranial hypertension with signs such as papilledema and sixth contralateral nerve palsy as an unusual finding.