Comparative Social Biology of Sponge-Dwelling Snapping Shrimp (Synalpheus)

海绵体食虾的比较社会生物学。“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”“”根据汉密尔顿的规则，社会行为可以被理解为通过互动者的遗传关系介导的环境所施加的挑战的解决方案。因此，对社会进化的全面理解需要对群体成员之间的遗传关系、种群的基本生态约束以及评估它们相互作用的进化后果的一些方法进行核算。本研究采用互补的遗传、行为和比较方法来评估亲缘结构与社会生物学之间的相互作用，以及它的一些宏观进化结果，以促进物种丰富和社会多样化的海绵虾（Synalpheus）的社会进化，这是一种罕见的动物群体，在密切相关的物种之间反复出现社会性。本项目有两个主要目标：(1)评估繁殖系统及其种群遗传结构对两种独立进化且种群分布不同的真社会性虾类帝王对虾（Synalpheus regalis）和沙虾（s chacei）的行为动态和极端繁殖偏态维持的影响。这将通过在8个微卫星位点上对每个物种野外采集的菌落进行基因分型，并在实验室中通过实验评估圈养菌落中个体之间的冲突和合作水平来实现。本研究将描述群体内个体之间的亲缘关系、侵略性优势、交配成功率和亲缘关系的分布，以及群体内与群体间的亲缘关系。(2)这些社会动态的长期进化结果将在最近完成的海绵栖进化枝的系统发育重建的基础上，通过利用Synalpheus物种之间的社会多样性，在一个比较框架内进行探讨。系统发育上独立的对比将检验由理论和社会昆虫的实证研究预测的群体大小、繁殖歪斜和种姓分化之间的联系。本研究将为非昆虫无脊椎动物独特的社会性多样性进化分支的起源、适应意义和宏观进化结果提供一个新的窗口，并将有助于在广泛的分类水平上评估基于社会性昆虫数据的先进动物社会进化理论的普遍性。

COMPARATIVE SOCIOBIOLOGY OF SPONGE-DWELLING SNAPPING SHRIMPSJ. Emmett DuffySchool of Marine ScienceThe College of William and Mary Eusociality, characterized by cooperative colonies in which most members sacrifice individual reproduction, has long presented a fundamental paradox for behavioral and evolutionary ecology. According to Hamilton's rule, social behaviors can be understood as solutions to challenges imposed by the environment mediated through the genetic relatedness of interactants. A full understanding of social evolution thus entails an accounting of the genetic relationships among group members, the basic ecological constraints on populations, and some means of assessing the evolutionary consequences of their interplay. This proposal employs complementary genetic, behavioral, and comparative approaches to assess the interplay between kin structure and social biology, and some of its macroevolutionary consequences, in fostering social evolution in the species-rich and socially diverse sponge-dwelling shrimps (Synalpheus), one of the rare animal groups in which eusociality has arisen repeatedly among closely related species. The project has two principal objectives:(1) Assess the influence of breeding system, and consequent genetic structure of colonies, on behavioral dynamics and the maintenance of extreme reproductive skew in two independently evolved, and demographically divergent, eusocial shrimp species Synalpheus regalis and S. chacei. This will be accomplished by genotyping individuals from field-collected colonies of each species at eight microsatellite loci, and experimentally assessing levels of conflict and cooperation among individuals in captive colonies in the laboratory. This research will characterize the distributions of relatedness, aggressive dominance, mating success, and parentage among individuals within colonies, and of relatedness within vs. among colonies. (2) The longer-term evolutionary consequences of these social dynamics will be approached in a comparative framework by exploiting the social diversity among species of Synalpheus, building on the recently completed phylogenetic reconstruction of the sponge-dwelling clade. Phylogenetically independent contrasts will test the association, predicted by theory and empirical studies of social insects, among colony size, reproductive skew, and caste differentiation. This research will provide a new window on the origin, adaptive significance, and macroevolutionary consequences of eusociality in a unique, socially diverse clade of non-insect invertebrates, and will contribute to evaluating the generality at a broad taxonomic level of theories for the evolution of advanced animal societies based primarily on data from social insects.