MOLECULAR PHYLOGENY OF EUKARYOTES

最古老的真核生物是单细胞生物， 可能与原生生物的某些成员相似。 的 真核生物的进化起源以及 特定的原生生物群体，产生了真菌，植物， 动物学仍然不清楚。 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 巨大的细胞学和生化多样性。 在过去 两年来，定量分子生物学研究 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，真核生物代表了一种 古老的血统，可能与古细菌一样古老， 真细菌的血统，以及“更高”的真核生物部门 几乎同时出现在一个时期， 形式的多样化。 由于数量有限， 我们的研究中包括的生物， 可能描绘祖先的关系，引起了 真菌，植物和动物王国，也不太可能是完整的 真核生物多样性的程度在我们的系统发育中得到了体现。 树结构。 这项提案的目的是继续我们对遗传学的分析， 真核生物王国内的多样性， 小亚基核糖体RNA基因序列， 原生动物，因此，构建一个一致的定量 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.