Archean molecular fossils and the early rise of eukaryotes
Archean molecular fossils and the early rise of eukaryotes
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DOI：
10.1126/science.285.5430.1033
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发表时间：
1999-08-13
期刊：
影响因子：
56.9
通讯作者：
Summons, RE
中科院分区：
文献类型：
--
作者：
Brocks, JJ;Logan, GA;Summons, RE
生物脂类分子化石保存在澳大利亚皮尔巴拉克拉通2.7亿年前的板块中。相邻样品的连续提取表明，这些烃类生物标记物与太古宙页岩是原生的、同生的，极大地扩展了这类分子已知的地质范围。丰富的2 α -甲基藿烷的存在是蓝藻的特征，这表明在大气变得氧化之前，氧气光合作用就已经进化了。甾烷的存在，特别是胆甾烷及其28至30碳类似物，为真核生物的存在提供了有说服力的证据，比现存化石记录表明的谱系出现的时间早5亿至10亿年。
Molecular fossils of biological lipids are preserved in 2700-million-year-old shares from the Pilbara Craton, Australia. Sequential extraction of adjacent samples shows that these hydrocarbon biomarkers are indigenous and syngenetic to the Archean shales, greatly extending the known geological range of such molecules. The presence of abundant 2 alpha-methylhopanes, which are characteristic of cyanobacteria, indicates that oxygenic photosynthesis evolved well before the atmosphere became oxidizing. The presence of steranes, particularly cholestane and its 28- to 30-carbon analogs, provides persuasive evidence for the existence of eukaryotes 500 million to 1 billion years before the extant fossil record indicates that the lineage arose.