Conflict, Cooperation and the Evolution of Conditional Social Behaviors in Colonial Marine Invertebrates

格罗斯伯格9906741冲突与合作之间的紧张关系推动了社会行为的演变，有时还会导致社会组织的永久性转变。然而，更常见的是，这种紧张导致了同种生物之间短暂的社会联系的演变，这些联系形成、瓦解和从一个地方到另一个地方、从一个地方到另一代人。在这些短暂的联想背后，隐藏着一系列的塑料行为--一些利他主义的，一些自私的--这些行为的表达取决于相互作用的同类行为所提供的社会环境。当前的社会进化理论建立在亲属选择的基本作用之上，同时承认社会环境的其他方面影响利他和自私行为的成本和收益，因此它们应该在什么条件下表达。在其他条件相同的情况下，个人应该引导利他(或合作)行为对待亲戚，引导自私行为远离亲戚。个体还应该根据当时的社会环境和自己的个体发育状态来调节利他主义和自私行为的表达。最后，不同物种所经历的社会环境的变化应该促进社会行为的多样化。尽管这些条件行为在调节涉及捕食者、竞争对手和配偶的生态相互作用中无处不在并具有理论上的重要性，但对于社会环境如何影响它们的表达和进化，特别是在海洋生物中，几乎一无所知。这项研究项目将使用一群群居的海洋线虫(水母类)来测试和扩展社会进化理论的基本预测，这些动物表现出戏剧性的、上下文相关的行为，包括基因间融合(和嵌合体形成)和攻击性，并经历了广泛的社会环境。通过从生态学、遗传学和系统发育的角度研究社会环境介导的选择如何影响这一行为和社会多样性的水生动物群体中融合和攻击性的表达和进化，本研究将为理解条件行为的演变、表达的线索及其在种群和社区水平上的广泛影响奠定一般基础。

Grosberg 9906741The tension between conflict and cooperation drives the evolution of social behavior, occasionally leading to permanent transitions in social organization. More commonly, however, the tension results in the evolution of transitory social liaisons among conspecifics that form, disintegrate and reform from place to place and generation to generation. Underlying many of these transient associations is a spectrum of plastic behaviors -some altruistic, some selfish - whose expression depends on the social environment provided by interacting conspecifics. Current theories of social evolution build on the fundamental role of kin selection, while acknowledging that other facets of the social environment influence the costs and benefits of altruistic and selfish behaviors, hence the conditions under which they should be expressed. All else being equal, individuals should direct altruistic (or cooperative) behaviors toward relatives, and selfish behaviors away from relatives. Individuals should also modulate the expression of altruistic and selfish behaviors according to the prevailing social environment and their own ontogenetic state. Finally, changes in the social environment experienced by different species should promote the diversification of social behavior.Despite the ubiquity and theoretical importance of these conditional behaviors in the regulation of ecological interactions involving predators, competitors, and mates, virtually nothing is known about how the social environment affects their expression and evolution, especially in marine organisms. This research project will test and extend the basic predictions of social evolutionary theory using a group of colonial marine cnidarians (the hydractiniids) that exhibit dramatic, context-dependent behaviors, including intergenotypic fusion (and chimera formation) and aggression, and that experience a broad range of social environments. By examining from ecological, genetic, and phylogenetic perspectives how selection mediated by the social environment influences the expression and evolution of fusion and aggression in this behaviorally and socially diverse group of hydrozoans, this research will build a general foundation for understanding the evolution of conditional behaviors, the cues underlying their expression, and their widespread effects at the level of the population and community.