Effect of soil hardness on aggression in the solitary wasp Mellinus arvensis

1. Two alternative nesting strategies are exhibited by soil‐nesting Mellinus arvensis females, digging a new nest (diggers) and searching for an old unoccupied burrow (searchers). Wasps appear unable to distinguish between occupied and unoccupied nests, and aggressive interactions between searchers and nest owners at nest entrances are frequent. 2. In aggressive encounters, there is an advantage in size and residency status. 3. The costs associated with the two nesting strategies vary across geographically separated populations: nest digging incurs costs in terms of time, and these vary according to the hardness of the soil substrate; nest searching is variably costly in terms of risk of injury in aggressive encounters with nest‐owning females. 4. Individual female wasps can switch between nesting strategies, and thus soil hardness, by affecting the cost of nest construction, affects the relative frequencies of the two nesting strategies within a population, favouring an increase in the searching strategy. This, in turn, affects the frequency and intensity of aggression between females at a nesting aggregation. 5. Female body size is correlated with soil hardness. As aggressive encounters are more frequent in sites with hard soil substrates, there is increased selective advantage in having large body size at these sites. 6. Body size is determined primarily by the availability of food resources during larval development, which is, to a degree, a function of the size of the adult female. There is a trade‐off between provisioning a few cells with many provisions in each, leading to the development of few but large adults, as opposed to many cells with few provisions, leading to many small offspring. The relative advantage of these two provisioning strategies is, at least in part, a function of the hardness of the soil substrate.     

Phosphoproteome Analysis

Protein phosphorylation is directly or indirectly involved in all important cellular events. The understanding of its regulatory role requires the discovery of the proteins involved in these processes and how, where and when protein phosphorylation takes place. Investigation of the phosphoproteome of a cell is becoming feasible today although it still represents a very difficult task especially if quantitative comparisons have to be made. Several different experimental strategies can be employed to explore phosphoproteomes and this review will cover the most important ones such as incorporation of radiolabeled phosphate into proteins, application of specific antibodies against phosphorylated residues and direct staining of phosphorylated proteins in polyacrylamide gels. Moreover, methods to enrich phosphorylated proteins such as affinity chromatography (IMAC) and immunoprecipitation as well as mass spectrometry for identification of phosphorylated peptides and phosphorylation sites are also described.     

Behavioural differences between individuals and two populations of stickleback (Gasterosteus aculeatus)

Behavioural syndromes are correlations between behaviours in different functional contexts. Behavioural syndromes are attracting the attention of evolutionary biologists because they mean that different behaviours might not be free to evolve independently of one another. In a landmark study, Huntingford (1976) showed that individual stickleback which were bold toward predators were also aggressive toward conspecifics and active in an unfamiliar environment. Here, I revisited the activity-aggression-boldness syndrome in stickleback and tested the hypothesis that correlations between behaviours might act as evolutionary constraints. I measured a suite of behaviours on wild-caught individuals and their offspring from two different populations and calculated heritabilities and genetic correlations between the different behaviours. I found that these behaviours were phenotypically and genetically correlated in one population but not another. On average, boldness and aggression were negatively related to each other across the populations. These results suggest that behavioural syndromes don't always act as evolutionary constraints.     

Single-family versus multi-family introductions

The early success of plant introduction as a function of source material and habitat quality was tested in Arnica montana to determine whether different introduction strategies could affect plant viability of the introduced population. Plants originating from related (single-family introductions) and unrelated (multi-family introductions) individuals were introduced into undisturbed sites and into sites which were limed, turf cut, or both turf cut and limed. For four consecutive years, we analysed plant performance by measuring survival time, growth, and reproductive capacity. Introduction success was found to be strongly affected by habitat quality. Turf cutting in combination with additional liming significantly increased reproductive capacity and stimulated early flowering. To restore eutrophic and acidified soil conditions, turf cutting with additional liming prior to introduction is recommended. Furthermore, a significant effect of multi-family introductions was observed. Multi-family introductions showed higher introduction success compared to single-family introductions. Although the long-term effects of multi-family introductions will emerge after several generations, the preliminary results suggest multi-family introductions as the most successful introduction strategy.     

Genetic mating patterns studied in pools with manipulated nest site availability in two populations of Pomatoschistus minutus

Pomatoschistus minutus show paternal care in a resource defence mating system. We investigated the effect of nest-site availability on parasitic spawning. Each experimental pool contained four potentially nest-building males, four females and nests-sites in shortage (2) or excess (6). Both treatments were conducted in two populations; one with natural nest-sites in excess, one with a nest-site shortage. Microsatellite-DNA revealed that all nest-holders had fertilized most of the eggs they tended. Yet, 35% of the nests contained eggs fertilized by another male and 14.4% of the males had performed parasitic spawning. There was no site or treatment effect. Several females spawned in two nests, which coincided with parasitic spawnings, suggesting a cost to the nest-holder in terms of lost mating success. Nest-holders with and without eggs and non-nesting males all spawned parasitically, generating a significantly lower opportunity for sexual selection compared to if there had been no parasitic spawning.     

论自我效能感对学生学习活动的影响及培养策略

自我效能感是Bandura自我效能理论的核心概念,是指个体对自己是否能够成功地进行某一成就行为的主观判断。文章介绍了自我效能感的概念、形成因素及对学生学习活动的影响,在此基础上,探讨了对学生学习自我效能感的培养策略。     

Birds adjust acoustic directionality to beam their antipredator calls to predators and conspecifics

Animals in many vertebrate species vocalize in response to predators, but it is often unclear whether these antipredator calls function to communicate with predators, conspecifics or both. We evaluated the function of antipredator calls in 10 species of passerines by measuring the acoustic directionality of these calls in response to experimental presentations of a model predator. Acoustic directionality quantifies the radiation pattern of vocalizations and may provide evidence about the receiver of these calls. We predicted that antipredator calls would have a lower directionality if they function to communicate with surrounding conspecifics, and a higher directionality and aimed at the receiver if they function to communicate with the predator. Our results support both of these functions. Overall, the birds produce antipredator calls that have a relatively low directionality, suggesting that the calls radiate in many directions to alert conspecifics. However, birds in some species increase the directionality of their calls when facing the predator. They can even direct their calls towards the predator when facing lateral to it—effectively vocalizing sideways towards the predator. These results suggest that antipredator calls in some species are used to communicate both to conspecifics and to predators, and that birds adjust the directionality of their calls with remarkable sophistication according to the context in which they are used.     

Personality and the emergence of the pace-of-life syndrome concept at the population level

The pace-of-life syndrome (POLS) hypothesis specifies that closely related species or populations experiencing different ecological conditions should differ in a suite of metabolic, hormonal and immunity traits that have coevolved with the life-history particularities related to these conditions. Surprisingly, two important dimensions of the POLS concept have been neglected: (i) despite increasing evidence for numerous connections between behavioural, physiological and life-history traits, behaviours have rarely been considered in the POLS yet; (ii) the POLS could easily be applied to the study of covariation among traits between individuals within a population. In this paper, we propose that consistent behavioural differences among individuals, or personality, covary with life history and physiological differences at the within-population, interpopulation and interspecific levels. We discuss how the POLS provides a heuristic framework in which personality studies can be integrated to address how variation in personality traits is maintained within populations.     

Giving offspring a head start in life: field and experimental evidence for selection on maternal basking behaviour in lizards

The timing of birth is often correlated with offspring fitness in animals, but experimental studies that disentangle direct effects of parturition date and indirect effects mediated via variation in female traits are rare. In viviparous ectotherms, parturition date is largely driven by female thermal conditions, particularly maternal basking strategies. Our field and laboratory studies of a viviparous lizard (Niveoscincus ocellatus) show that earlier‐born offspring are more likely to survive through their first winter and are larger following that winter, than are later‐born conspecifics. Thus, the association between parturition date and offspring fitness is causal, rather than reflecting an underlying correlation between parturition date and maternal attributes. Survival selection on offspring confers a significant advantage for increased maternal basking in this species, mediated through fitness advantages of earlier parturition. We discuss the roles of environmentally imposed constraints and parent–offspring conflict in the evolution of maternal effects on parturition date.     

MATERNAL ADJUSTMENT OF EGG SIZE ORGANIZES ALTERNATIVE ESCAPE BEHAVIORS,PROMOTING ADAPTIVE PHENOTYPIC INTEGRATION

Numerous integrated traits contribute to any aspect of organismal performance, but favorable trait combinations are difficult to maintain in the face of genetic recombination. We investigated the role of maternal effects in promoting integration of alternative reproductive strategies (～throat colors) with antipredator traits (escape behaviors and dorsal patterns) in the side‐blotched lizard (Uta stansburiana). Previously, we reported that maternally derived estradiol adaptively pairs dorsal patterns with progeny throat colors. Here we show adaptive maternal effects on escape behaviors within each throat color morph. Specifically, yellow‐throated females and all females mated to yellow‐throated sires lay larger eggs. Larger eggs produce stockier offspring, who remain stockier throughout life. Stockiness promotes evasive escape behaviors (e.g., reversals), which are adaptive in barred, yellow‐throated offspring. Orange‐throated females lay smaller eggs, producing leaner hatchlings who perform vertical escape behaviors (e.g., jumping). Vertical behaviors enhance survival in striped, orange‐throated progeny. Escape behavior was not heritable, but was organized by natural or experimental egg size variation. Maternal effects on adaptive phenotypic integration are likely common in polymorphic species, because recombination otherwise breaks apart beneficial trait combinations. Furthermore, our results provide insight into the role of body shape in organizing (and constraining) evolution of integrated reproductive and antipredator strategies.