Genetic Structure in Cooperative Societies

了解社会行为的演变，特别是 明显的合作，需要遗传相关性的知识， 在个体之间。 进化论证明了 族群亲属结构对传播的潜在影响 像合作和互惠这样的社会特征已经很好地 开发 有人提出，即使是明显的利他行为， (like帮助他人抚养后代而不是繁殖后代 （1）对捐赠者有利。 这种解释成立 当这种行为的潜在好处（增强 实际育种者的繁殖， （合作者对接受者）超过平衡成本 （可以在独立繁殖中生产的年轻人） 尝试）。 这一分析取决于对以下方面的准确评估： 合作者和年轻生产者之间的遗传相关性， 而这又取决于对谁生了谁的确切了解。 十年来，首席研究员研究了几个 弗伦斯（Campylorhynchus nuchalis，C.griseus， C. Fasciatus）在南方进行这种合作育种的做法 美国参考 这些鸟生活在大家庭中， 永久的公共领土，这是一种普遍存在的习惯， 热带鸟类 这些物种是一个特别有启发性的测试 上述进化思想的情况下，合作如此有效 增加了可以繁殖的幼仔数量。 家系 在多达11个繁殖季节， 涉及弗伦斯个体共计1600余只 可识别的个体。 育种合作提高了 繁殖成功五倍，作为独立的繁殖对几乎 总是失败。 幼鸟通常留在自己的帮助， 纳塔尔地，这意味着他们通常帮助他们的 假定的父母产生兄弟姐妹。 基于这一假设， 合作对这些帮助者有利。 我们对这项工作的扩展有两个目标。 使用新的- 开发DNA指纹技术，PI将建立 假定的繁殖者是否是唯一的鸟类繁殖， 这些家庭群体，以及假定的非繁殖助手是否 帮助抚养兄弟姐妹 这项测试将基于 来自遗传物质本身的决定性证据，而不是 基于行为观察的易犯错误的推论 的 在群体内部和群体之间共有亲子关系的程度 将被记录，分析模型和计算机 模拟将量化亲子关系的潜在重要性 在社会群体中除了主要的一对之外还有其他的。 项目 将继续进行实地实验， 生产性育种阵地竞争与群防群治 对掠食者，怀疑机制的优势， 在群体中繁殖。

Understanding the evolution of social behavior, especially apparent cooperation, requires knowledge of genetic relatedness among individuals. Evolutionary theory demonstrating the potential effects of kin-structure in populations on the spread od social traits like cooperation and reciprocity has been well developed. It is proposed that even apparently altruistic acts (like helping others to rear young rather than reproducing oneself) can be beneficial to the donor. This explanation holds when the potential benefits of such behavior (the enhancement of reproduction of the actual breeders weighted by the relatedness of the cooperator to recipients) more than balance the costs (young that could have produced in an independent breeding attempt). This analysis depends on accurate assessment of genetic relatedness between cooperator and young produced, which in turn depends on precise knowledge of exactly who begat whom. For ten years the principal investigator have studied several populations of wrens (Campylorhynchus nuchalis, C.griseus, and C. fasciatus) the practice such cooperative breeding in South America. These birds live in extended family groups on permanaent communal territories, a habit that is widespread among tropical birds. These species are an especially revealing test case of the above evolutionary ideas cooperation so effectively increases the number of young that can be produced. Pedigrees are available for as many as 11 breeding seasons in groups of wrens involving a total of more than 1600 individually recognizable individuals. Cooperation in breeding enhances reproductive success five-fold, as unaided breeding pairs almost always fail. Young birds usually remain as helpers on their natal territories, meaning they are usually helping their presumed parents produce siblings. Based on this assumption, cooperation benefits these helpers. Our extension of this work has two aims. Using newly- developed DNA fingerprinting techniques, the PIs will establish whether the presumed breeders are the only birds reproducing in these family groups, and whether putative nonbreeding helpers are aiding in rearing siblings. This test will now be based on conclusive evidence from the genetic material itself rather than on fallible inferences based on behavioral observation. The extent to which parentage is shared within and between groups will be documented, and analytical models and computer simulations will quantify the potential importance of parentage shared beyond a principal pair in social groups. The project will continue field experiments examining the processes of competition for productive breeding positions and group defense against predators, the suspected mechanism of the advantage of breeding in a group.