DISSERTATION RESEARCH: The Maintenance of Cooperative Nest Construction in Sociable Weavers (Philetairus Socius)

虽然自然选择的进化常常被描述为倾向于无情、自私的行为，但合作实际上在自然界中广泛存在。因此，合作行为的进化已成为生物学的核心问题。本研究考察了一种特殊合作形式的进化，即非洲鸟类的合作筑巢。公共巢穴代表了一种公共物品困境：每个个体都直接从公共巢穴中受益，但如果它可以避免为筑巢做出贡献，只要其他人继续维护巢穴，它就会受益更多。这种公共产品困境在人类社会中很常见，但很少在非人类动物中进行探索。本研究将调查一种纳米比亚的群居织布鸟的合作筑巢行为。对自然界中筑巢的观察将检验性别和个体的相对贡献，以检验这种情况下的合作是否可以通过亲缘选择来解释。简单地说，亲缘选择是一种有利于遗传亲属的自然选择。我们将使用一个基于智能体的模型来进一步探索通过亲缘选择来维持合作筑巢的可能性。用于实现该模型的计算机代码将提供给其他科学家，从而促进未来在社会进化方面的建模工作。此外，实验将测试放弃合作筑巢的个体是否会受到其他个体的惩罚；这种惩罚是人类社会对公共产品做出贡献的常见解释。因此，本研究将检验解释人类社会对公共产品贡献的理论是否解释了该模型系统中的合作。该项目还将有助于培养下一代科学家和工程师。该项目包括对本科生进行遗传分析和行为观察方面的指导和培训，从而为下一代美国科学家提供有用的研究经验。

Although evolution by natural selection has often been depicted as favoring ruthless, selfish behavior, cooperation is actually widespread in nature. Consequently, the evolution of cooperative behavior has become a central problem in biology. The present research examines the evolution of a particular form of cooperation, cooperative nest building in an African bird. Communal nests represent a public goods dilemma: each individual benefits directly from the communal nest, but would benefit more if it could refrain from contributing to nest-building as long as others continued to maintain the nest. Such public goods dilemmas are common in human societies but have rarely been explored in non-human animals. This research will investigate cooperative nest construction behavior of a Namibian bird, the sociable weaver. Observations of nest construction in nature will examine relative contributions of the sexes and of individuals to test whether cooperation in this instance can be explained via kin selection. Simply, kin selection is a type of natural selection favoring aid to genetic relatives. An agent-based model will be used to further explore the possibility that cooperative nest building can be sustained through kin selection. The computer code used to implement the model will be made available to other scientists, thus facilitating future modeling efforts in social evolution.In addition, an experiment will test whether individuals that forego cooperative nest construction are punished by others; such punishment is a common explanation for contribution to public goods in human societies. Thus the research will test whether theories explaining contribution to public goods in human societies explain cooperation in this model system. The project will also contribute to the development of the next generation of scientists and engineers. The project includes undergraduate mentoring and training in genetic analyses and behavioral observation, thus providing useful research experience for the next generation of American scientists.