The phylogenetic Biology of the Paleotropical Tree Genus Lithocarpus (Fagaceae)

杜克大学的保罗·马诺斯博士正在研究以古热带为主的石果属树木(约300个物种)，以更好地了解水果形态和DNA序列在不同景观中变化的生物学意义。常见的橡子状果实的修饰通常标志着该属内的亚群，但这样的变化似乎进化了不止一次。这项研究将探索新的量化方法来表征水果形状的变化，并将这些数据与DNA序列进行比较和结合，以测试某些水果类型是否具有多个起源。石果在亚洲大陆和整个马来亚群岛的广泛分布也为利用叶绿体DNA变异进行植物种群遗传学研究提供了极好的机会，叶绿体DNA变异是一种跟踪种子运动的母系遗传标记。通过对该属范围内的个体进行采样，这项研究将解决植物迁移与地质/古生态变化之间的关系。将使用各种方法来检验基于古生态数据的避难区和迁徙路线的明确假设。研究热带树种的生物多样性和分子进化需要一个建立在对自然历史、分类学、形态和系谱关系的透彻知识基础上的框架。橡树科的物种为研究植物迁移和基因流动的形式和模式的多样性提供了广泛的机会。热带木本植物在这方面的研究很少，在橡树的重要生态亲缘关系中，各种基本的生物学问题从未得到解决。考虑到这种树木群落为热带雨林提供的碳贮量、生态系统服务、生物多样性和物理结构，这项研究将是将几种强大的分子技术应用于重要的热带属的同类研究之一。

Dr. Paul Manos of Duke University is studying the predominantly paleotropical tree genus Lithocarpus (ca. 300 species) to better understand the biological significance of variation in fruit morphology and DNA sequences across a diverse landscape. Modifications of the common acorn-like fruit typically mark subgroups within the genus, but such changes appear to have evolved more than once. The study will explore new quantitative methods to characterize changes in fruit shape and compare and combine these data with DNA sequences to test whether certain fruit types have multiple origins. The widespread distribution of Lithocarpus on the continent of Asia and throughout the Malayan Archipelago also provides an excellent opportunity to pursue the genetics of plant demography using chloroplast DNA variation, a maternally inherited marker that tracks seed movement. By sampling individuals throughout the range of the genus, the study will address the relationship between plant migration and geological/paleoecological change. A variety of methods will be used to test explicit hypotheses of refugial areas and migration routes based on paleoecological data. Trees will be sampled to examine genealogical structure within populations through contrasting nuclear and cytoplasmic molecular markers with reference to taxonomy, geography, and differential patterns of genome evolution.The study of organismal diversity and molecular evolution in tropical tree species requires a framework built upon thorough knowledge of natural history, taxonomy, morphology, and genealogical relationships. Species in the oak family present a broad spectrum of opportunities to study diversity in form and patterns of plant migration and gene flow. Tropical woody plants are poorly studied in this regard and a variety of basic biological questions have never been addressed in the ecologically important relatives of the oaks. Given the amount of carbon storage, ecosystem services, biodiversity, and physical structure provided to the tropical rainforest by this tree community, this study would be one of first of its kind to apply several powerful molecular techniques to an important tropical genus.