ABR: Phylogenetic Relationships of the Freshwater Genera ofthe Centric Diatom Family Thalassiosiraceae

费城自然科学院的 Edward Theriot 博士在对硅藻的开创性分支和形态测量研究的基于成就的更新中，将研究北半球的两大类淡水硅藻，研究化石和活体形式，以确定进化变化的模式。 诊断细胞壁特征的形态变异性将通过光学和电子显微镜结合统计分析进行检查。 硅藻物种的可靠识别将有助于基本分类学和地质沉积物的地层解释，从而使石油公司地质学家和古生物学家受益。 尽管硅藻体积很小，但它是世界上分布最广泛、对生态最重要的植物之一。 它们对湖泊和海洋的光合作用以及硅（细胞壁的组成部分）的地球化学循环做出了重大贡献。 这些硅质细胞壁堆积在致密的化石沉积物中，为评估主要植物谱系的进化起源和灭绝记录提供了独特的机会。 因此，Theriot 博士的工作提供了有关近代地球历史中气候事件与进化变化之间联系的见解。

In an Accomplishment-Based Renewal of his pioneering cladistic and morphometric studies of diatoms, Dr. Edward Theriot of Philadelphia's Academy of Natural Sciences will examine two major groups of freshwater diatoms of the northern hemisphere, studying both fossil and living forms to determine patterns of evolutionary change. Morphological variability in diagnostic cell-wall features will be examined by light- and electron- microscopy in conjunction with statistical analyses. Reliable identification of diatom species will facilitate both basic taxonomic classification as well as stratigraphic interpretation of geological sediments, thus benefitting oil company geologists and paleontologists. Diatoms are among the most widespread and ecologically important plants in the world, despite their small size. They contribute significantly to photosynthesis in lakes and oceans as well as to geochemical cycling of silicon, a constituent of their cell walls. These siliceous cell walls accumulate in dense fossil deposits, providing unique opportunities to assess the record of evolutionary origins and extinctions in a major lineage of plants. Dr. Theriot's work thus provides insight concerning the linkage between climatic events and evolutionary changes during recent Earth history.