Personality in the context of social networks

There is great interest in environmental effects on the development and evolution of animal personality traits. An important component of an individual's environment is its social environment. However, few studies look beyond dyadic relationships and try to place the personality of individuals in the context of a social network. Social network analysis provides us with many new metrics to characterize the social fine-structure of populations and, therefore, with an opportunity to gain an understanding of the role that different personalities play in groups, communities and populations regarding information or disease transmission or in terms of cooperation and policing of social conflicts. The network position of an individual is largely a consequence of its interactive strategies. However, the network position can also shape an individual's experiences (especially in the case of juveniles) and therefore can influence the way in which it interacts with others in future. Finally, over evolutionary time, the social fine-structure of animal populations (as quantified by social network analysis) can have important consequences for the evolution of personalities-an approach that goes beyond the conventional game-theoretic analyses that assumed random mixing of individuals in populations.     

Contest outcome in a territorial butterfly: the role of motivation

In many butterfly species, males compete over areas advantageous for encountering females. Rules for contest settlement are, however, largely unknown and neither morphological nor physiological traits can reliably predict the contest outcome. Here, we test the hypothesis that contests are settled in accordance with a motivation asymmetry. We staged contests between males of Pararge aegeria and after removing the resident, the non-resident was allowed (i) either to interact with a non-receptive female for 30 min (n = 30) or (ii) to spend 30 min alone in the cage (n = 30), after which the initial resident was reintroduced. The results show that males that had interacted with a female had a higher probability of becoming dominant and reversing contest outcome. Moreover, males that were faster to take over a vacant territory when the resident was removed were more likely to become dominant. Here, we show for the first time, to our knowledge, that frequent encounters with a mated female can increase male motivation to persist in a territorial contest in a butterfly. Further, we suggest that variation in intrinsic motivation reflects male eagerness to take over vacant territory. This study indicates that variation in resource value and motivational asymmetries are important for settling contests in butterflies.     

铁线莲属植物分类学及园艺学研究进展

从分类地位、引种育种、繁殖栽培和资源开发等方面,对铁线莲属植物的研究现状进行了较为系统的综述,并对其野生资源的合理利用和保护提出了一些建议,为今后进一步的研究工作提供参考。今后我国应在保护种质资源的基础上,加强铁线莲新品种的培育,尽快实现产业化生产。     

大杯香菇辐射选育新株系数量性状的因子分析

对20个大杯香菇品种和辐射选育新株系的数量性状进行因子分析.结果表明,20个大杯香菇品种和辐射选育新株系的18个数量性状,可提取为7个公因子,其累积方差贡献率达91.85 %,代表了所有性状绝大部分相关信息.按照主因子所包含的性状及其所反映的生物学、营养学和酶学含义,可把7个主因子命名并按方差贡献大小顺序排列为：促长因子1、CAT活性因子2、营养质量因子3、MDA因子7、化学评分因子4、氨基酸比值系数分因子5、粗壮因子6.从主因子出发进行大杯香菇辐射育种,可以加大目标性状的针对性的选择效率,比较容易获得综合数量性状优良的新品种.     

菊花分子育种研究进展

对菊花分子育种的研究起源于20世纪90年代初,导入外源基因的主要目的是改变菊花的株型、花色,提高抗虫性、抗病性,增强对寒冷、干旱、盐碱的耐性。近年来,选用不同类型的启动子构建新型载体的研究也为改善菊花育种工作提供了参考。这些都预示着菊花分子育种的研究逐渐走向全面和成熟。     

Altruistic self‐removal of health‐compromised honey bee workers from their hive

Social insect colonies represent distinct units of selection. Most individuals evolve by kin selection and forgo individual reproduction. Instead, they display altruistic food sharing, nest maintenance and self‐sacrificial colony defence. Recently, altruistic self‐removal of diseased worker ants from their colony was described as another important kin‐selected behaviour. Here, we report corroborating experimental evidence from honey bee foragers and theoretical analyses. We challenged honey bee foragers with prolonged CO₂ narcosis or by feeding with the cytostatic drug hydroxyurea. Both treatments resulted in increased mortality but also caused the surviving foragers to abandon their social function and remove themselves from their colony, resulting in altruistic suicide. A simple model suggests that altruistic self‐removal by sick social insect workers to prevent disease transmission is expected under most biologically plausible conditions. The combined theoretical and empirical support for altruistic self‐removal suggests that it may be another important kin‐selected behaviour and a potentially widespread mechanism of social immunity.     

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.     

Reproductive skew theory unified: The general bordered tug-of-war model

Reproductive skew has been identified as a major dimension along which animal societies vary. Two major kinds of reproductive skew models are transactional models, which explain the distribution of reproduction within animal societies as the result of reproductive payments exchanged among group members with differential leverage, and tug-of-war models, in which the reproductive shares are determined by costly ‘tugs-of-war’. These two models have recently been synthesized to yield the mutual-pay, bordered tug-of-war model. In this paper, we extend the latter, show its evolutionary stability, and demonstrate that the generalized model yields four sub-models, namely the mutual-pay, alpha-pay, beta-pay, and pure tug-of-war. The alpha-pay sub-model turns out to closely resemble the original “concessions” transactional skew model, and the beta-pay sub-model turns out to have properties similar to the “restraint” transactional skew model. Thus, the general model unifies the four major models of reproductive skew and is rich in its predictions, as each sub-model exhibits different qualitative and quantitative relationships between reproductive skew or intra-group conflict and the ecological and genetic factors that determine skew and conflict. The conditions favoring transitions among these sub-models also are precisely predicted by the general model. The general model accommodates data from acorn woodpeckers and primitively eusocial bees potentially can account for many of the highly varied empirical findings on reproductive skew. We suggest further research that focuses on (1) determining which model is suitable for certain species and (2) understanding why and how various social animals resolve their breeding conflict by different conflict resolution mechanisms.     

Effects of food deprivation on refuge use and dispersal in juvenile North Sea houting Coregonus oxyrinchus under experimental conditions

This study tested the influence of energetic state on refuge use and dispersal in juvenile North Sea houting Coregonus oxyrinchus in an artificial stream. Food-deprived fish spent more time outside refuges than well-fed fish; however, the well-fed fish initiated dispersal faster than the food-deprived fish. The results may indicate state-dependent refuge use and dispersal in C. oxyrinchus.