CAREER: Tracking the evolution of grasses and grasslands: using phytoliths to explore evolution-ecology links in deep time

职业：追踪草和草原的进化：利用植硅体探索深层进化与生态学的联系

• 批准号: 1253713
• 负责人: Caroline Stromberg
• 金额: $ 52.5万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2020-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1253713&HistoricalAwards=false
• 关键词: CAREER; Tracking; evolution; grasses; grasslands

CAREER: Tracking the evolution of grasses and grasslands: using phytoliths to explore evolution-ecology links in deep timeCaroline Stromberg, University of WashingtonGrasslands cover 40% of Earth's land surface today, provide habitats for over a billion animals including humans, and greatly influence global climate and the carbon and silica cycles. Understanding the history of the grassland biome is essential for disentangling its complex controls and predicting how natural grasslands and crop plants will respond to ongoing human induced climate change. In recent years, analysis of fossilized plant silica (phytoliths) has shed much needed light on evolutionary and ecological events during the establishment of grasslands. However, gaining further knowledge depends critically on refined methods for identifying specific grass lineages in the fossil record. This CAREER research has two main goals. First, the project will enhance the use of phytoliths for robust taxonomic (the naming of species) and ecological interpretations through the first comprehensive and detailed mapping of grass phytolith shapes in an evolutionary framework, coupled with mapping of other, functionally relevant traits (e.g., photosynthetic pathway) and environmental preferences. Second, project will use this "key" to fossil grass types and ecology to tackle two outstanding questions in grass evolution: (1) When and in what environments did grasses originate and diversify?; and (2) What drove the ecological expansion of grasses with C4 photosynthesis? To address the first question, the project will study Cretaceous-Paleogene (145-23 million years ago) phytolith assemblages from Argentina to determine the evolutionary relationships between the grasses present, and use this information to determine when the lineage split occurred. Phytolith assemblage analysis and other paleobotanical evidence will help determine what early grass habitats were like. To address the second question, the project will analyze Miocene-Pliocene (23-2.6 million years ago) phytolith assemblages from Kansas to document the ecological expansion of C4 grasses in the Great Plains. The project will infer major C4 grass lineages present, and reconstruct changes in vegetation structure. Direct comparison with stable isotopic data from the section will permit testing of which factors influenced the rise to dominance of C4 grasses. The results of this research program will transform the study of ecosystem change during the last ~70 million years, specifically the assembly of grasslands, and allow evaluation of what processes control grassland evolution, in the past and in the future. It will also contribute fundamentally to archaeology, where phytoliths have long been a principal tool for tracking domestication of crop plants and land use. The integrated themes explored in this research program--evolution, ecology, and environmental change--will be incorporated into formal and informal education at the middle-school- to graduate-school-level and public outreach. This educational component will be accomplished through (1) inquiry-based labs and activities in my undergraduate courses at University of Washington, (2) research mentoring of one postdoctoral researcher, one graduate student, and at least 7 undergraduates in the lab and field, (3) design of new exhibits at the Burke Museum demonstrating evolution research in action, and (4) an after-school program aiming to engage middle-school girls, which remain minorities in STEM, in evolution-ecology science. The joint research and educational activities proposed here aim to inspire a greater appreciation for the processes that shaped and continue to shape our world, and more broadly, a better understanding of the practice of science and critical thinking in students of all ages.

职业：跟踪草和草地的演变：使用植物石探索深层时期的timecaroline Stromberg的进化生物学联系，当今华盛顿大学占地40％的地球地面，为包括人类在内的十亿个动物提供了栖息地，并极大地影响了全球气候和碳和碳和碳和碳碳和碳纤维和西里卡。了解草原生物群落的历史对于解开其复杂控制并预测天然草原和作物植物将如何应对持续的人类诱发的气候变化至关重要。近年来，对化石植物二氧化硅（Phytoliths）的分析已经阐明了草原建立期间的进化和生态事件。但是，获得进一步的知识取决于精致的方法来识别化石记录中特定的草谱系。这项职业研究有两个主要目标。首先，该项目将通过在进化框架中对草植物植物形状的首次全面而详细的映射进行植物学分类（物种命名）和生态解释的使用，并与其他功能相关的特征（例如，Photosynththeththththeththethetical parway和Envorymental and Remotiensal and Remotiences）和环境相关性。其次，项目将使用此“关键”来化石草类型和生态学，以解决草的进化中的两个杰出问题：（1）草何时和在哪种环境中产生和多样化？ （2）是什么促进了C4光合作用的草的生态扩张？为了解决第一个问题，该项目将研究来自阿根廷的植物岩组合（145-2300万年前），以确定存在的草之间的进化关系，并使用此信息来确定谱系何时发生。 Phytolith的组合分析和其他古生物证据将有助于确定早期草栖息地的样子。为了解决第二个问题，该项目将分析堪萨斯州的中新世 - 白典（23-260万年前）的植物组合，以记录大平原上C4草的生态扩张。该项目将推断存在主要的C4草谱系，并重建植被结构的变化。与本节中稳定的同位素数据的直接比较将允许测试哪些因素影响C4草的优势升高。该研究计划的结果将改变过去约7000万年的生态系统变化的研究，特别是草原的组装，并允许评估过去和将来的过程控制草原进化的过程。它也将从根本上为考古学做出贡献，在那里，植物石长期以来一直是跟踪农作物植物和土地利用的主要工具。在该研究计划中探讨的综合主题 - 进化，生态和环境变化 - 将被纳入中学和研究生学院和公众外展的正规和非正式教育中。该教育组成部分将通过（1）在我在华盛顿大学的本科课程中的基于询问的实验室和活动来实现，（2）研究指导一名博士后研究员，一名研究生，一名研究生，以及在实验室和领域中至少7个本科生（3）在Burke的新展览中，在Burke的新展览中，在Burke severs of Sirder in Drognum in Action and School sectum in Action school sectorial of Croment of Criends of School of School sector of Sector of School of School of School（4）又（4）又（4）又是4）又（4）又有（4）又是4）。在STEM中，在进化生物科学中。这里提出的联合研究和教育活动旨在激发人们对塑造和继续塑造我们世界的过程的更加欣赏，更广泛地了解各个年龄段的学生的科学和批判性思维实践。