Kin-selection versus costs of inbreeding in the transition from subsocial to social spiders

从亚社会性蜘蛛向社会性蜘蛛转变过程中的亲缘选择与近交成本

• 批准号: 20681626
• 负责人: Professorin Dr. Jutta M. Schneider
• 金额: --
• 依托单位: Abteilung Verhaltensbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/20681626?language=en
• 关键词: Kin; selection; versus; costs; inbreeding

Sociality has evolved about 12 times independently in spiders, however resulting in less than 25 social species. Social spiders differ markedly from the eusocial insects in several aspects, for example are social spiders always characterised by extreme inbreeding. Inbreeding does result in very high degrees of relatedness and the evolution of sociality requires kin-associations since related individuals are much more likely to cooperate. However, inbreeding is also associated with several disadvantages and is therefore usually avoided. Hence, inbreeding may on one side facilitate cooperation while the associated fitness costs will determine the level of tolerance towards inbreeding and ultimately influence the potential for social evolution. The aim of this study is to identify the selection pressures and preconditions that have led to the evolution of extreme inbreeding in social spiders. In particular, we will focus on kin selection and the specific role of sexual selection through female choice, polyandry and sexual conflict in favouring or disfavouring the likelihood of inbreeding. To assess the relevance of genetic diversity and genetic distance for the evolution of cooperation and group performance, we will conduct experiments that test specific predictions derived from the hypothesis that kin selection strongly favours inbreeding in the evolution of communal tasks such as foraging in these spiders. Using experiments and molecular genetics we will assess the role of multiple mating in natural populations and its consequences for individual female fitness. The genus Stegodyphus with three independently evolved social species is ideal to address these questions. The proposed research is based on previous studies of subsocial Stegodyphus lineatus spiders that found (1) a high tolerance towards inbreeding and (2) an advantage of relatedness for communal feeding and growth. An additional study suggested short-time disadvantages of multiple paternity for groups of young.

社会性在蜘蛛中独立进化了大约12次，但导致不到25个社会物种。社会性蜘蛛在几个方面与真社会性昆虫有明显的不同，例如社会性蜘蛛总是以极端的近亲繁殖为特征。近亲繁殖确实会导致高度的亲缘关系，而社会性的进化需要亲属关系，因为有亲缘关系的个体更有可能合作。然而，近亲繁殖也有一些缺点，因此通常要避免。因此，近亲繁殖一方面可以促进合作，而相关的健身成本将决定对近亲繁殖的容忍程度，并最终影响社会进化的潜力。本研究的目的是确定选择压力和先决条件，导致极端近亲繁殖的社会蜘蛛的进化。特别是，我们将集中在亲属选择和性选择的具体作用，通过女性的选择，一妻多夫制和性冲突，有利于或不利于近亲繁殖的可能性。为了评估遗传多样性和遗传距离的合作和群体绩效的进化的相关性，我们将进行实验，测试特定的预测来自假设，亲属选择强烈支持近亲繁殖的进化，如觅食在这些蜘蛛的公共任务。利用实验和分子遗传学，我们将评估自然种群中多次交配的作用及其对个体雌性适应度的影响。具有三个独立进化的社会物种的Stegodyphus属是解决这些问题的理想物种。这项拟议的研究是基于之前对亚社会性条纹剑水蚤蜘蛛的研究，这些研究发现（1）对近亲繁殖有很高的耐受性，（2）对于公共进食和生长具有相关性的优势。另一项研究表明，多个父亲对年轻群体的短期不利。