The evolution of despotic societies in mammals

哺乳动物专制社会的进化

• 批准号: 505297756
• 负责人: Dr. Oliver Höner
• 金额: --
• 依托单位: Leibniz-Institut für Zoo- und Wildtierforschung (IZW)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/505297756?language=en
• 关键词: evolution; despotic; societies; mammals

Social hierarchies limit conflicts between the members of a group by regulating their access to resources; as a result, the social rank in the hierarchy affects nearly every aspect of an individual’s Darwinian fitness. Much research has investigated the causes and consequences of an individual’s social rank in group-living species, but little is known about why some animal societies are more hierarchical than others, and specifically why social hierarchies vary in how strictly individuals are tied to their rank and how steep the differences between ranks are. This project aims at understanding the evolutionary origins of such variation in dominance style in group-living mammals, showing a gradient from egalitarian to despotic societies, across multiple scales (individuals, groups, populations and species). We will test three main hypotheses, respectively positing that individual differences in dominance style (i.e., the frequency and pattern with which an individual distributes aggression across the social hierarchy) represent stable, heritable behavioural syndromes (H1), flexible individual responses to changes in the ecological or social environment (H2), or socially-learned responses to changes in the cultural environment, resulting in ‘egalitarian’ or ‘despotic’ cultures (H3). Specifically, we will investigate variations in dominance style through 4 main objectives: 1. across individuals, to characterize individual differences in dominance style and test their stability and heritability (H1), using high-resolution behavioural data from three long-term studies on wild chacma baboons (Papio ursinus), mandrills (Mandrillus sphinx) and spotted hyenas (Crocuta crocuta); 2. within and across social groups, by linking individual dominance styles to the group dominance style to test if they reflect flexible responses of individual group members to changes in the ecological, social (H2) or cultural (H3) environment, using a combination of modelling and empirical data from the same populations. Individuals may for instance adjust their dominance style following a change in their own social rank or in the alpha position to strengthen their position in the new hierarchy, or they may socially learn and copy the style of new group members; 3. across populations and species, to provide a synthesis of the evolutionary history of dominance style in mammalian societies and test H1-3 using a broad comparative framework ; and 4. between the sexes by capitalizing on Objectives 1-3 and on the socio-ecological contrasts offered by our study populations to investigate why male and female dominance styles differ. Ultimately, this project will shed new light on the evolutionary origins of social inequality within and across animal societies.

社会等级制度通过控制群体成员对资源的访问来限制他们之间的冲突；因此，等级制度中的社会等级几乎影响到个人达尔文适合度的方方面面。许多研究已经调查了个体在群体生活物种中社会地位的原因和后果，但很少有人知道为什么一些动物社会比其他动物社会更有等级，特别是为什么社会等级在个人与其等级的严格联系以及等级之间的差异有多大方面存在差异。该项目旨在了解群居哺乳动物在统治方式上的这种差异的进化起源，显示出从平等主义社会到专制社会的梯度，跨越多个尺度(个人、群体、种群和物种)。我们将检验三个主要假说，分别假设个人在支配风格上的差异(即，个人在社会等级中分布攻击性的频率和模式)代表稳定的、可遗传的行为综合征(H1)、个人对生态或社会环境变化的灵活反应(H2)、或社会学习对文化环境变化的反应，从而导致“平等主义”或“专制”文化(H3)。具体地说，我们将通过四个主要目标来调查优势度风格的变化：1.跨个体，描述个体在优势度风格上的差异，并测试其稳定性和遗传性(H1)，使用来自三个长期研究的高分辨率行为数据，这些研究来自于野生长臂猿(Papio Ursinus)、山竹(Mandrillessphinx)和斑点鬣狗(Crocuta Crocuta)；2.在社会群体内部和跨社会群体，通过将个人优势度风格与群体优势度风格联系起来，测试它们是否反映了个体群体成员对生态、社会(H2)或文化(H3)环境变化的灵活反应。例如，个体可以在自己的社会等级或阿尔法位置发生变化后调整他们的优势风格，以加强他们在新等级中的地位，或者他们可能在社交上学习和复制新群体成员的风格；3.跨种群和物种，提供哺乳动物社会中优势风格的进化史的综合，并使用广泛的比较框架测试H1-3；以及4.通过利用目标1-3和我们的研究群体提供的社会生态对比来研究为什么男性和女性的优势风格不同，来调整他们的优势风格。最终，这个项目将为动物社会内部和跨动物社会的社会不平等的进化起源提供新的线索。