DISSERTATION RESEARCH: Structure and Systematics of the Earliest Terrestrial Ground Cover

俄亥俄大学的Gar Rothwell博士和Alexandru Tomescu先生获得了一笔资助，用于研究已知最早的陆地地被生物。这些生物的化石是由受资助者在北美东部（弗吉尼亚州，宾夕法尼亚州）的4.45 - 4.35亿年前的岩石中收集的，它们是最古老的明确证据，表明在海洋领域之外，大陆上有生命存在。他们项目的目标是描绘这些早期陆生生物的结构特征，并澄清它们之间的生物学关系。为了做到这一点，他们将从岩石中分离出化石，准备它们，并使用光学和电子显微镜研究它们的结构。然后，他们将化石生物与生活群体进行比较，以澄清它们的生物学和进化关系。尽管4.5亿年前陆地上生命的起源一直是大量研究和推测的主题，但最早陆生生物的性质仍然是现代生命科学中最关键的未解之谜之一。通过研究新发现的最早陆生生物化石，该项目可以解决这些问题，强烈影响进化生物学和地球科学的思维和工作假设。通过确定第一批殖民大陆的生物群体，这项工作将为早期陆地殖民者的祖先，以及陆地上生命进化和多样化的初始模式提供急需的直接证据。描述第一批丰富的陆地生物也对全球尺度解释由陆地地被物起源引起的风化过程变化以及这些变化对大陆-海洋化学循环的影响具有重要意义。

A grant has been awarded to Dr. Gar Rothwell and Mr. Alexandru Tomescu at Ohio University to study the organisms that formed the earliest known terrestrial groundcover. Fossils of these organisms collected by the grantees in 445-435 million year old rocks of eastern North America (Virginia, Pennsylvania) represent the oldest unequivocal evidence for life on continents, out of the marine realm. The goal of their project is to characterize the structure of these early terrestrial organisms, and to clarify their biological relationships. To do this, they will isolate fossils from the rocks, prepare them, and investigate their structure employing light- and electron microscopy. They will then compare the fossil organisms to living groups, to clarify their biological and evolutionary relationships. Although the origin of life on land over 450 million years ago has been the subject of considerable research and much speculation, the nature of the earliest terrestrial organisms still ranks among the most crucial unanswered questions in modern life sciences. By investigating newly found fossils of the earliest terrestrial organisms, this project can address these questions, strongly impacting thinking and working hypotheses in evolutionary biology and earth sciences. By identifying the groups of organisms that were the first to colonize the continents, this work will provide much-needed direct evidence for the ancestors of early terrestrial colonizers, and for the initial patterns of evolution and diversification of life on land. Characterizing the first abundant land organisms also has important implications for global-scale interpretations of weathering process changes that resulted from the origin of terrestrial groundcover, and for the impact of these changes on continent-ocean chemical cycles.