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

俄亥俄大学的Gar Rothwell博士和Alexandru Tomescu先生获得了一项拨款，用于研究形成已知最早陆地地被物的有机体。受赠者在北美东部(弗吉尼亚州、宾夕法尼亚州)4.45亿-4.35亿年前的岩石中收集的这些生物的化石是海洋领域以外大陆上生命的最古老的明确证据。他们项目的目标是描述这些早期陆地生物的结构，并阐明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，进行准备，并使用光学和电子显微镜研究其结构。然后，他们将把化石有机体与活着的群体进行比较，以阐明它们之间的生物学和进化关系。尽管4.5亿多年前陆地上的生命起源一直是大量研究和猜测的主题，但最早的陆地生物的性质仍然是现代生命科学中最关键的悬而未决的问题之一。通过调查新发现的最早陆地生物的化石，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说。通过确定最早在大陆上定居的生物群，这项工作将为早期陆地殖民者的祖先以及陆地上生物进化和多样化的最初模式提供亟需的直接证据。确定第一批丰富的陆地生物的特征对于在全球范围内解释陆地地被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也具有重要意义。

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.