DISSERTATION RESEARCH: Integrating genomic and paleobotanical data for phylogenetic and biogeographic reconstruction in the basal lamiid family Icacinaceae

众多的植物群？大约330个科60个属？分布模式横跨南美洲、非洲和大洋洲的热带地区。这些复杂的现代分布模式表明了热带生态系统的动态历史，包括地质历史上主要热带地区之间频繁的生物交换。对广泛分布的热带种群进行详细的进化研究，可以对形成热带生物和生态系统全球分布格局的历史因素提供相当大的启示。然而，这样的研究需要大量的化石证据来揭示多样化事件的时间和地点，而热带植物的化石记录是出了名的贫乏。Icacinaceae是泛热带开花植物科，包括大约140种木本藤本植物和乔木，在热带植物群中是独一无二的，因为它们有很好的化石记录，记录了广泛地理和地质范围内的属的多样性。这使得伊卡奇科成为推断热带植物扩张和多样化的更广泛的历史模式的极好模型。该项目将整合伊卡奇科广泛的化石记录和基于dna的科内物种间关系研究。结果将是一个全面的家庭画面？这对过去6500万年来热带植物在气候和地质变化下的多样化和传播提供了重要的更广泛的启示。此外，本研究将解决伊仙科在开花植物生命树中的精确进化位置，这在以往的研究中一直是模糊的。该项目将整合尖端的DNA测序技术与传统的形态学和古植物学方法，为研究生、本科生和高中生提供多样化的培训机会。本文采用的综合方法也将作为未来研究的方法论模型，旨在将DNA和化石证据结合起来，重建历史生物地理学。这项研究的结果将在会议和同行评议的出版物中传播，将引起热带生物学家和被子植物系统学家的兴趣，因为伊卡奇科对理解热带生物地理学和开花植物生命树的形态进化模式具有更广泛的重要性。

Numerous plant groups?approximately 330 families and 60 genera?have distribution patterns spanning the tropical regions of South America, Africa, and Australasia. These complex modern distribution patterns suggest a dynamic history for tropical ecosystems, involving frequent biotic exchange among major tropical regions over geologic history. Detailed evolutionary studies of widespread tropical groups can shed considerable light on the historical factors that have shaped the global distribution patterns of tropical organisms and ecosystems. However, such studies require extensive fossil evidence to reveal the timing and location of diversification events, and the fossil record of tropical plants is notoriously poor. The Icacinaceae, a pantropical family of flowering plants including approximately 140 species of woody vines and trees, are unique among tropical groups in that they have an excellent fossil record, documenting a diversity of genera across wide geographic and geologic ranges. This makes the Icacinaceae an excellent model for inferring broader historical patterns of tropical plant expansion and diversification across the tropics. This project will integrate the extensive fossil record of Icacinaceae with DNA-based studies of relationships among species in the family. The result will be a comprehensive picture of the family?s evolutionary history, offering important broader implications for tropical plant diversification and spread in response to climatic and geologic changes over the past ~65 million years. Additionally, this study will resolve the precise evolutionary placement of Icacinaceae in the flowering plant tree of life, which has been ambiguous in previous studies. This project will integrate cutting-edge DNA sequencing techniques with traditional morphological and paleobotanical approaches, providing a diversity of training opportunities for graduate, undergraduate, and high school students. The synthetic approach employed here will also serve as a methodological model for future studies aiming to combine DNA and fossil evidence for reconstructions of historical biogeography. The results of this research, which will be disseminated at meetings and in peer-reviewed publications, will be of interest to both tropical biologists and angiosperm systematists given the broader importance of Icacinaceae for understanding both tropical biogeography and patterns of morphological evolution across the flowering plant tree of life.