CAREER: Unearthing the conifer tree of death

4亿多年来，植物在陆地环境中繁衍生息，经历了气候的变化、生物群的变化以及大陆的形成和分裂。我们对全球变化如何影响植物进化史的理解仍然有限。这个项目包含了一个综合的研究和教育计划，将调查被称为针叶树的广泛而古老的植物群，其中包括今天最高的（红杉）和最长寿的（松树）生物，如何在过去的3亿年中进化以应对不断变化的地球。研究结果将帮助我们更好地了解现代植物群的起源，以及它们如何受到持续的全球变化的影响。为了推进这些科学目标，扩大科学参与，并促进植物生物学知识，该项目包括一个新的基于研究的植物结构课程，多个职业阶段的研究培训，以及在堪萨斯大学自然历史博物馆的永久公共展览。该项目将带领由本科生、研究生和博士后组成的团队，重建现存和已灭绝针叶树的系统发育，研究长时间的多样化动态，并检验关于针叶树生殖结构进化和同源性的假设。这些分析将利用部分来自基于发育植物解剖学的新课程的本科研究经验的数据。系统发育将根据形态和分子数据，并使用各种系统发育方法来推断。将直接结合化石来估计分化时间。进化速率（物种形成、灭绝和表型进化）将使用系统发育和基于化石发生的方法来估计。进化速率变化的潜在环境和生物驱动因素也将被研究。最后，比较和发育解剖学将用于测试种子球果的同源性假设，并阐明针叶树生殖进化的模式和过程。这项工作将有助于我们对植物系统发育的理解，为深入了解植物多样性动态提供新的见解，解决植物形态学中长期存在的问题，并在植物结构、进化和科学过程方面教育新一代科学家。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Plants have populated terrestrial environments for over 400 million years, through changing climates, shifting biotas, and the creation and breakup of continents. Our understanding of how global changes have impacted the evolutionary history of plants through time remains limited. This project encompasses an integrated research and education program that will investigate how the widespread and ancient group of plants known as conifers, which includes the tallest (redwoods) and longest-lived (pines) organisms today, evolved over the last 300 million years in response to a changing planet. Results will help us to better understand the origins of our modern floras and how they might be impacted by ongoing global change. To advance these scientific goals, broaden participation in science, and promote knowledge of plant biology, the project includes a new research-based course in plant structure, research training at multiple career stages, and a permanent public exhibit at the University of Kansas Natural History Museum.The PI and a team of undergraduates, graduate students, and postdocs will reconstruct the phylogeny of living and extinct conifers, investigate diversification dynamics through deep time, and test hypotheses on the evolution and homology of conifer reproductive structures. These analyses will utilize data generated in part from a new course-based undergraduate research experience on developmental plant anatomy. A phylogeny will be inferred based on both morphological and molecular data, and using a variety of phylogenetic methods. Divergence times will be estimated that directly incorporate fossils. Evolutionary rates (of speciation, extinction, and phenotypic evolution) will be estimated using both phylogenetic and fossil occurrence-based approaches. Potential environmental and biological drivers of evolutionary rate shifts will also be investigated. Finally, comparative and developmental anatomy will be used to test homology hypotheses of seed-bearing cones and to elucidate patterns and processes underlying reproductive evolution in conifers. This work will contribute to our understanding of plant phylogeny, provide new insights into diversification dynamics in deep time, address a longstanding problem in plant morphology, and educate a new generation of scientists in plant structure, evolution, and the scientific process.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.