Social brains and behaviour in cooperative insect societies

社会脑假说认为，生活在大的、以个人为基础的社会群体中的认知需求选择了大的大脑尺寸和增强的认知能力。这一假说得到了哺乳动物和鸟类的比较研究的支持，但很少有实验研究的假设。我们将进行实验，以测试社会性和大脑的进化和发展之间的因果关系，使用一个纸黄蜂在西班牙南部的野生种群。原始的真社会性昆虫，不像真社会性昆虫不表现出形态或任务专业化，表现出广泛的变化，在群体大小和社会的复杂性。群体成员形成基于个体的统治等级，表现出个体识别（例如基于Polistes纸黄蜂的面部模式），并形成对个体身份和力量的长期社会记忆。在物种内部，社会主导的雌性，以及那些在多个雌性群体中而不是单独筑巢的雌性，被发现比从属或孤独的雌性拥有更大的蘑菇体（MB）。蘑菇体是昆虫大脑的一个区域，被认为在学习和记忆中起着重要作用。这些研究共同支持了一个假设，即生活在社会丰富或社会要求生活中的个体拥有或发展的大脑在形态上不同于同种。然而，以前的研究是相关的，因此这种关系的因果性质是未知的。本项目将通过结合创新的野外实验、生物成像和理论建模来解决知识的不足。实验研究了真社会性昆虫-通过实验验证社会攻击行为对大脑发育和认知能力的影响.开发新的理论模型来解释社会侵略，社会记忆和紧急的社会结构在动物society.MethodsThe项目将使用一个既定的研究人口的纸黄蜂Polistes dominulus在西班牙南部的变化。小组成员将被单独标记和录像。社会地位将通过暂时去除占主导地位或从属地位的个人来操纵。攻击性会被人工合成的荷尔蒙控制。解剖黄蜂大脑的成像将在埃克塞特大学进行，显微CT图像将与自然历史博物馆合作获得。培训机会：成功的申请人将接受实验设计、行为测量、视频分析和生态数据收集方面的培训。S/他将展示如何定位巢，标记个人，设计和执行实验，视频巢，并处理在实地研究中固有的不可避免的不可预见的事件。这是一个发展可转移技能的绝佳机会，以便在未来建立新项目。成功的申请人将在自然历史博物馆接受解剖，样品制备和高分辨率微型CT扫描和成像的培训，由法拉艾哈迈德博士监督。最后，学生将接受行为的正式数学建模培训，包括进化博弈论，动态博弈和随机动态规划。要模拟的问题是明确界定的，在过去几年中出现了一些经济模型，这些模型处理的问题非常相似（在选举时间和军事/经济冲突的背景下）。成功的学生将有机会第一次将这些经济模型适应生物和进化背景。

The social brain hypothesis suggests that the cognitive demands of living in large, individually-based social groups selects for large brain size and enhanced cognitive abilities. This hypothesis has received some support from comparative studies of mammals and birds, but there have been very few experimental studies of the hypothesis. We will carry out experiments to test the causal relationship between sociality and brain evolution and development using a wild population of a paper wasps in southern Spain.Primitively eusocial insects, which unlike eusocial insects do not exhibit morphological or task specialisation, exhibit wide variation in group size and social complexity. Group members form individually-based dominance hierarchies, exhibit individual recognition (e.g. based on facial patterns in Polistes paper wasps) and form long-term social memories of individual identity and strength. Within species, socially dominant females, and those that found nests in multi-female groups rather than alone, have been found to  possess larger mushroom bodies (MBs) than subordinate or solitary-founding females. Mushroom bodies are a region of the insect brain thought to be important in learning and memory.Together these studies support the hypothesis that individuals living a socially rich or socially demanding life possess or develop brains that are morphologically distinct from conspecifics. However, previous studies have been correlational, and so the causal nature of this relationship is unknown. This project will address this shortfall in knowledge using a combination of innovative field experiments, bioimaging, and theoretical modelling.AimsThe specific aims of the project are1. To test experimentally the causal relationships between social status, group size and brain structure in a primitively eusocial insect, the paper wasp Polistes dominulus.2. To test experimentally how social aggression influences brain development and cognitive performance.3. To develop new theoretical models to explain variation in social aggression, social memory and emergent social structure in animal societies.MethodsThe project will use an established study population of paper wasps Polistes dominulus in southern Spain. Group members will be individually marked and videoed. Social status will be manipulated by temporary removal of dominant or subordinate individuals. Aggression will be manipulated using synthetic hormones. Imaging of dissected wasp brains will be carried out at the University of Exeter and micro CT images obtained in collaboration with the Natural History Museum. Training in mathematical modelling of behaviour will be provided.Training opportunities:The successful applicant will receive training in experimental design, measurement of behaviour, video analysis, and ecological data collection. S/he will be shown how to locate nests, mark individuals, design and execute experiments, video nests, and deal with inevitable unforeseen events that are inherent in field research. This is an excellent opportunity to develop the transferable skills to set up new projects in future.The successful applicant will receive training in dissection, sample preparation and high resolution micro-CT scanning and imaging at the Natural History Museum, under the supervision of Dr Farah Ahmed. Finally, the student will receive training in formal mathematical modelling of behaviour, including evolutionary game theory, dynamic games and stochastic dynamic programming. The problems to be modelled are well defined, and in the last few years a number of economic models have appeared which address problems that are strikingly similar (in the context of election timing and military/economic conflict). The successful student will be have an opportunity to adapt these economic models to a biological and evolutionary context for the first time.