DISSERTATION RESEARCH: Ecological Divergence and Reproductive Isolation in an Amazonian Tree Species: Protium subserratum (Burseraceae)

热带雨林拥有地球上最高的树木多样性，但很少有进化研究旨在了解热带树木物种形成过程中涉及的机制。这项研究将通过系统地检查一个物种开始分化成为两个物种时所涉及的因素，提高我们对进化的理解。亚马逊乔木Protium subserratum提供了一个理想的研究系统，因为在白沙生境和粘土生境上的种群具有不同的叶片特征，在野外很容易区分。遗传研究表明，专门在不同土壤类型上交配的种群比预期的要少，尽管它们的生殖结构相似，而且它们在同一时间开花。这些结果表明，在不同土壤类型上发现的种群正在分化，并正在形成一个新的物种。野外实验、种群遗传学和自然历史观察的结合将被用来确定哪些因素在推动热带环境中新树种的产生方面是最重要的。除了是首批明确研究树木生殖隔离机制作用的研究之一外，这项研究还将促进对本科生进行群体遗传技术培训，并支持与秘鲁学生的合作。这项研究的结果也将通过西班牙文出版物广泛传播。

Tropical rainforests harbor the highest tree diversity on earth, yet very few evolutionary studies are aimed at understanding the mechanisms involved in the process of speciation in tropical trees. This study will improve our understanding of evolution by systematically examining the factors involved when one species begins to diverge and become two species. The Amazonian tree, Protium subserratum provides an ideal study system because populations on white-sand habitats and clay habitats have different leaf characters and are easily distinguished in the field. Genetic studies show that populations that are specialized on different soil types mate with each other less frequently than would be expected despite the fact that their reproductive structures are similar and they flower at the same time. These results suggest that populations found on different soil types are diverging and in the process of forming a new species. A combination of field experiments, population genetics and natural history observations will be used to determine what factors are most important in driving the creation of new tree species in tropical environments.In addition to being among the first studies to explicitly examine the role of reproductive isolating mechanisms in trees, this research will foster the training of undergraduate students in population genetic techniques and support collaborations with Peruvian students. The results of this research will also be disseminated widely through publication in Spanish.