NSF Postdoctoral Fellowship in Biology: Was there a Tropical Forest in North America after the end-Cretaceous Extinction?

这一行动资助了NSF 2023财年生物学博士后研究奖学金，扩大了生物学中代表性不足的群体的参与。该研究金支持一项针对该研究员的研究和培训计划，该计划将增加生物学中代表性不足的群体的参与。该项目将研究来自美国科罗拉多州城堡岩的一个6380万年前的植物化石沉积物，它之前被确认为上一次导致恐龙死亡的大规模灭绝后的第一个热带雨林。这位研究员将通过分析现有的植物谱系及其繁殖方法来确定城堡岩植物区系是否应该被归类为真正的热带雨林或温带森林。这项研究将促进有关开花植物如何进化，森林如何在上一次大灭绝后恢复的科学知识，导致今天生活的著名植物科的出现。了解现代热带雨林的起源具有重要意义，因为类似的现代栖息地正受到由于当今气候变化和人类影响而灭绝的威胁。该项目还将扩大参与，培训研究员实施双语科学交流和公共宣传，并指导不同背景的高中生和本科生。研究将涉及对保存完好的城堡岩化石叶子和生殖遗骸的深入研究，以确定植物区系的组成、其生物地理和结构类似物，以及水果和种子的传播策略。这位研究员将分析丹佛自然科学博物馆现有大量藏品(n=~5000)中的化石叶子结构和角质层，以及菲尔德博物馆标本馆的全面热带收藏品，以进行分类鉴定。最近亲属的分布和现存的雨林参考地块数据将被用来更好地确定哪个生物地理区域是现代类似城堡岩石森林的区域，即生活在低纬旧大陆或新热带热带雨林或更类似于东亚和北美东部的暖温带雨林。将使用CT扫描和与现代雨林和其他化石森林的比较来评估化石生殖结构的形态和扩散类型，以评估植物的适应性。培训目标将包括学习被子植物系统学、角质层准备和生殖形态方面的额外技能。该研究员还将培训和指导STEM中代表性不足群体的其他学生。这项工作的结果将与博物馆参观者分享，远程分享到服务不足的学校，并通过双语YouTube视频在全球范围内分享。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。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Broadening Participation of Groups Underrepresented in Biology. The Fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. The project will examine a 63.8 million year old fossil plant deposit from Castle Rock, Colorado, USA, which was previously identified as the first tropical rainforest after the last mass extinction that killed the dinosaurs. The Fellow will determine whether the Castle Rock flora should be classified as an actual tropical rainforest or a temperate forest by analyzing the plant lineages present and their reproductive methods. The research will advance scientific knowledge of how flowering plants evolved and forests recovered after the last mass extinction, leading to the emergence of the prominent plant families living today. Understanding the origins of modern rainforests is significant because comparable modern habitats are threatened by extinction due to present-day climate change and human impacts. This project will also broaden participation with the training of the Fellow to implement bilingual science communication and public outreach and mentor high school and undergraduate students of diverse backgrounds.The research will involve an in-depth study of well-preserved fossil leaves and reproductive remains from Castle Rock to determine the composition of the flora, its biogeographic and structural analogs, and fruit and seed dispersal strategies. The Fellow will analyze fossil leaf architecture and cuticles from extensive existing collections (n=~5000) at the Denver Museum of Nature & Science alongside comprehensive tropical collections at the Field Museum Herbarium to make taxonomic identifications. The distribution of nearest living relatives and extant rainforest reference plot data will be used to better determine what biogeographic region is the modern analog for the Castle Rock forest, i.e., living low-latitude Old World or Neotropical rainforests or warm-temperate rainforests more similar to those in East Asia and eastern North America. The morphology and dispersal types of fossil reproductive structures will be evaluated using CT scans and comparisons to modern rainforests and other fossil forests to assess plant adaptations. Training objectives will involve learning additional skills in angiosperm systematics, cuticle preparation, and reproductive morphology. The Fellow will also train and mentor other students from underrepresented groups in STEM. The results of the work will be shared with museum visitors, remotely to underserved schools, and globally with a bilingual YouTube video.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.