RUI: Evaluating the Divergence-with-Gene-Flow Model in Natural Populations

热带雨林以其非凡的物种多样性而闻名。鸟类在这方面是突出的，因为热带雨林中有许多其他地方无法比拟的独特物种。然而，产生生物多样性的具体进化机制却知之甚少。在这个提议中，形态学和遗传学数据将被收集来测试一个关于雨林物种形成的新假设。这一假说假设过渡带，即存在于热带雨林中心以外草原上的小雨林碎片，是新适应和新物种出现的栖息地，可以丰富热带雨林中心的生物多样性。本文将量化三种热带雨林鸟类交错带种群的自然选择，并估计它们与热带雨林中部种群在形态上的差异。尽管这项研究解决了基本的进化问题，但它对撒哈拉以南非洲也有重要的保护意义。位于中心的雨林地区目前是保护工作的主要重点，而过渡带地区由于过度放牧、燃烧和砍伐木材而迅速消失，而对其保护的努力很少或根本没有。群落交错区区域被认为是不太重要,因为他们是纯粹的马赛克可能含有更少的物种和栖息地类型更小、更不稳定的人群。然而，这些介于森林和稀树草原之间的过渡区域可能是促进雨林生物多样性的进化新颖性的重要来源。\ \ Clm-06 \ \ SMITH425 debpop \ POPBIO \抽象。腹肌

Smith 9726425 Tropical rainforests are renowned for their extraordinary diversity of species. Birds are prominent in this regard, as tropical rainforests contain a spectacular array of unique species having no parallel elsewhere. However, the specific evolutionary mechanisms that generate biodiversity are poorly understood. In this proposal, morphologic and genetic data will be gathered to test a new hypothesis for rainforest speciation. This hypothesis postulates that ecotones, small rainforest fragments that exist in the grasslands outside the central rainforest, are habitats in which new adaptations and new species appear that can enrich the biodiversity of central rainforests. Natural selection in ecotone populations of three rainforest bird species will be quantified and the morphologic divergence between them and central rainforest populations will be estimated. Although this study addresses fundamental evolutionary questions, it also has important conservation implications for sub-Saharan Africa. Centrally located rainforest areas are presently the main focus of conservation efforts, whereas ecotone regions are rapidly being lost due to overgrazing, burning and wood harvesting with little or no effort toward their conservation. Such ecotone regions are assumed to be less important because they are mosaics of pure habitat types that may contain fewer species and smaller, more unstable populations. However, it is possible that these transition areas between forest and savanna are important sources of evolutionary novelty that contribute to rainforest biodiversity. \\Clm-06\debpop\POPBIO\ABSTRACT\SMITH425.ABS