MOLECULAR PHYLOGENY OF EUKARYOTES

最古老的真核生物是单细胞生物， 很可能与原始人的某些成员相似。这个 真核生物的进化起源及其鉴定 特定的原生生物群体，产生了Fungii，Plantae和 动物纲仍然鲜为人知。真核生物的准确历史 微生物进化是必要的，但努力构建一致的 原生生物的系统发育关系因其 巨大的细胞学和生物化学多样性。在过去 两年来，定量分子系统学研究已经 彻底改变了我们对真核生物进化的看法。比较 核糖体RNA序列表明，真核生物代表一种 古老的血统，可能和考古细菌和 真细菌的后代系，以及“更高”的真核细胞分裂 几乎同时出现在一个时期，特征是 形式的大规模多样化。鉴于数量有限， 已经包括在我们研究中的生物体，它还没有 有可能勾勒出祖先之间的关系 真菌、植物和动物王国也不太可能完全 真核生物多样性的程度体现在我们的系统发育中 树的构造。 这项提议的目标是继续我们对基因的分析 真核生物王国内的多样性比较完全 来自不同来源的小亚基核糖体RNA基因序列 原生动物，因此，构建一个一致的数量 真核生物的系统发育树。

The most ancient eukaryotes were unicellular organisms that probably resembled certain members of the Protista. The evolutionary origins of eukaryotes as well as the identification of specific protist groups that gave rise to the Fungii, Plantae, and Animalia remain obscure. An accurate history of eukaryotic microbial evolution is needed but efforts to construct consistent phylogenetic relationships for protists are frustrated by their enormous cytological and biochemical diversity. During the past two years, quantitative molecular phylogeny studies have revolutionized our views of eukaryotic evolution. Comparisons of ribosomal RNA sequences show that eukaryotes represent an ancient lineage that may be as old as the archaebacterial and eubacterial lines of descent, and the "higher" eukaryotic divisions arose nearly concurrently during a period characterized by a massive diversification of forms. Given the limited number of organisms that have been included in our studies, it is not yet possible to delineate ancestral relationships that gave rise to the fungal, plant, and animal kingdoms nor is it likely that the full extent of eukaryotic diversity is represented in our phylogenetic tree constructions. The goal of this proposal is to continue our analysis of genetic diversity within the eukaryotic kingdom by comparing complete small subunit ribosomal RNA gene sequences from a variety of protozoans, and, hence, to construct a consistent quantitative phylogenetic tree from the Eukaryota.