Dissertation Research: Fossil History of the Saxifragaceae sensu stricto and their Woody Relatives, Cretaceous to Pleistocene

康奈尔大学的William Crepet博士和Elizabeth Hermsen女士获得了一笔赠款，用于审查被子植物（开花植物）虎耳草科（岩叶和其他植物）以及相关的茶藨子属（醋栗和醋栗）和伊泰亚属（弗吉尼亚杨柳）的化石历史。今天，这些植物主要分布在北方半球的温带、北极和高山地区。已发表的化石虎耳草的报告将重新评估和新的化石虎耳草从新泽西将被描述。其中一些化石具有花结构的细节，这将使它们能够使用分支系统学进行分析，这是一种确定进化关系的数学技术，具有重要意义，因为它可以比许多其他方法更精确地分析这些关系。这将有助于实现该项目的近期目标，即汇编虎耳草化石的准确记录。这些记录将用于研究虎耳草起源的时间和地点，它们何时多样化，它们的生殖生物学如何随着时间的推移而变化，以及它们如何实现目前的地理分布。这也将影响我们目前对虎耳草类关系的理解，特别是在最近的DNA证据表明真正的虎耳草类植物比以前认为的要少的情况下。现存最大的进化之谜之一是关于被子植物的起源、关系和成功。这一群体的重要性，通过其数量丰富及其经济，医学和生态意义来证明，使解决这个谜团成为一个重要的优先事项。这个项目在整体神秘的背景下是重要的，因为1）许多针对的过程可以概括为被子植物增殖和上升到优势的历史方面，2）因为虎耳草被一些早期的工作者认为是许多更先进的开花植物群体的祖先。

A grant has been awarded to Dr. William Crepet and Ms. Elizabeth Hermsen of Cornell University to review the fossil history of the angiosperm (flowering plant) family Saxifragaceae (rockfoils and other ornamentals) and the related genera Ribes (currants and gooseberries) and Itea (Virginia willow). Today, these plants occur primarily in temperate, arctic, and alpine zones of the Northern Hemisphere. Published reports of fossil saxifrages will be reevaluated and new fossil saxifrages from New Jersey will be described. Some of these fossils possess details of floral structure that will allow them to be analyzed using cladistics, a mathematical technique for determining evolutionary relationships, which is of great significance as it allows for more precise analysis of these relationships than many other methods. This will aid in the attainment of the immediate goal of this project, compilation of an accurate record of fossil saxifrages. This record will be used to study questions such as when and where saxifrages originated, when they diversified, how their reproductive biology has changed over time, and how they have acheived their current geographical distribution. It will also affect our present understanding of saxifragoid relationships, especially in light of recent DNA evidence that indicates fewer plants are true saxifrages than previously thought.One of the greatest remaining evolutionary mysteries concerns the origin, relationships, and success of the angiosperms. The vital importance of this group, demonstrated by their numerical abundance and their economic, medicinal, and ecological significance, makes solving this mystery a significant priority. This project is important in the context of the overall mystery because 1) many of the processes targeted within can be generalized to historical aspects of the angiosperm proliferation and rise to dominance and 2) because the saxifrages have been considered by some earlier workers as ancestral to many more advanced flowering plant groups.