Morphological and ecological complexity in early eukaryotic ecosystems
Morphological and ecological complexity in early eukaryotic ecosystems
复制标题
DOI：
10.1038/35083562
复制
发表时间：
2001-07-05
期刊：
影响因子：
64.8
通讯作者：
Walter, MR
中科院分区：
文献类型：
--
作者：
Javaux, EJ;Knoll, AH;Walter, MR
分子生物学和地球化学表明，真核生物在地球历史的早期就已经分化。小亚基核糖体RNA基因的序列比较表明，真核生物和古生物在进化上存在很深的分歧（1）; 27亿年前的干酪根中C-27-C-29甾烷（来源于真核生物合成的甾醇）和C-13（产甲烷古生物的地球化学特征）的强烈耗竭独立地确定了这一分裂的最小年龄（2，3）。古元古代岩石中有甾烷、大的球状微化石和可能起源于真核生物的罕见的宏化石（4-6）。然而，到目前为止，该领域内形态和分类多样性的证据通常仅限于中元古代晚期和新元古代的继承（7）。在这里，我们表明，真核生物多样性的细胞骨架和生态先决条件已经建立在真核微生物中，这些真核微生物在北方澳大利亚中元古界早期罗珀群的页岩中生活了近15亿年。
Molecular phylogeny and biogeochemistry indicate that eukaryotes differentiated early in Earth history. Sequence comparisons of small-subunit ribosomal RNA genes suggest a deep evolutionary divergence of Eukarya and Archaea(1); C-27-C-29 steranes (derived from sterols synthesized by eukaryotes) and strong depletion of C-13 (a biogeochemical signature of methanogenic Archaea) in 2,700 Myr old kerogens independently place a minimum age on this split(2,3). Steranes, large spheroidal microfossils, and rare macrofossils of possible eukaryotic origin occur in Palaeoproterozoic rocks(4-6). Until now, however, evidence for morphological and taxonomic diversification within the domain has generally been restricted to very late Mesoproterozoic and Neoproterozoic successions(7). Here we show that the cytoskeletal and ecological prerequisites for eukaryotic diversification were already established in eukaryotic microorganisms fossilized nearly 1,500 Myr ago in shales of the early Mesoproterozoic Roper Group in northern Australia.