CAREER: Unearthing the conifer tree of death

随着气候的变化、生物群的变化以及大陆的形成和分裂，植物在陆地环境中生存了超过4亿年。我们对全球变化如何随着时间的推移影响植物进化史的理解仍然有限。该项目包括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体，包括今天最高的(红杉)和最长的(松树)生物，是如何在过去3亿年里进化的，以应对不断变化的地球。结果将帮助我们更好地了解现代植物群的起源，以及它们可能如何受到持续的全球变化的影响。为了推进这些科学目标，扩大对科学的参与，并促进植物生物学的知识，该项目包括一门新的植物结构研究课程，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开展览。PI和一个由本科生、研究生和博士后组成的团队将重建现存和灭绝针叶树的系统发育，研究随时间推移的多样性动态，并测试关于针叶树生殖结构进化和同源性的假说。这些分析将部分利用基于新课程的本科生对发育植物解剖学的研究经验产生的数据。将根据形态和分子数据，并使用各种系统发育方法来推断系统发育。分化时间将被估计为直接包含化石。进化速度(物种形成、灭绝和表型进化)将使用系统发育和基于化石出现的方法进行估计。还将调查进化速率变化的潜在环境和生物驱动因素。最后，比较解剖学和发育解剖学将被用来检验种子球果的同源性假说，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理解植物的系统发育，为深入了解多样性动态提供新的见解，解决植物形态中的一个长期存在的问题，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NSF的法定使命，并通过使用基金会的智力优势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.