导读Bioon.net ：本期Nature封面所示为用显微断层摄影成像方式所显示出的一个大化石（macrofossil）标本的结构。研究发现该多细胞生物起源于21亿年前。
一支由法国等多国科学家组成的研究小组在最新一期英国《自然》杂志上报告说，他们对化石的最新研究发现，多细胞生物起源于21亿年前，而不是此前人们认为的6亿年前。
据研究人员介绍，地球上最早的生命迹象出现于35亿年前，主要以原核生物形式存在。在距今约6亿年前的寒武纪，各种生物以爆炸性的速度涌现。不过生命的多样化过程实际上发生于距今35亿年到6亿年前的元古代，在此期间诞生了真核生物，它们与原核生物的最大不同就是拥有了细胞核。然而，此前科学界发现的中元古代（距今16亿年至10亿年前）之前的多细胞生物证据很少。
提示：生物谷启用新域名 www.bioon.net
来自法国等国的科学家于2008年在加蓬的弗朗斯维尔意外发现了大批保存完好的生物化石。根据对其周围沉积物进行的测算，这些化石已有21亿年的历史。这些罕见的古老生物化石长度在10厘米到12厘米之间，堪称“大化石”。科学家分析认为，它们既不可能是原核生物，也不可能是单细胞真核生物。
在进一步的分析中，研究人员利用离子探测器对化石中硫同位素的成分进行了测定，并借助特殊设备绘制了标本的3D图像。结果显示，该生物化石正是多种组织的结合体，它也是迄今为止发现的最古老的多细胞真核生物。(生物谷Bioon.net)
生物谷推荐原文出处：
Nature doi:10.1038/nature09166
Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago
Abderrazak El Albani,Stefan Bengtson,Donald E. Canfield,Andrey Bekker,Roberto Macchiarelli,Arnaud Mazurier,Emma U. Hammarlund,Philippe Boulvais,Jean-Jacques Dupuy,Claude Fontaine,Franz T. Fürsich,Fran?ois Gauthier-Lafaye,Philippe Janvier,Emmanuelle Javaux,Frantz Ossa Ossa,Anne-Catherine Pierson-Wickmann,Armelle Riboulleau,Paul Sardini,Daniel Vachard,Martin Whitehouse& Alain Meunier
The evidence for macroscopic life during the Palaeoproterozoic era (2.5–1.6?Gyr ago) is controversial1, 2, 3, 4, 5. Except for the nearly 2-Gyr–old coil-shaped fossil Grypania spiralis6, 7, which may have been eukaryotic, evidence for morphological and taxonomic biodiversification of macroorganisms only occurs towards the beginning of the Mesoproterozoic era (1.6–1.0?Gyr)8. Here we report the discovery of centimetre-sized structures from the 2.1-Gyr-old black shales of the Palaeoproterozoic Francevillian B Formation in Gabon, which we interpret as highly organized and spatially discrete populations of colonial organisms. The structures are up to 12?cm in size and have characteristic shapes, with a simple but distinct ground pattern of flexible sheets and, usually, a permeating radial fabric. Geochemical analyses suggest that the sediments were deposited under an oxygenated water column. Carbon and sulphur isotopic data indicate that the structures were distinct biogenic objects, fossilized by pyritization early in the formation of the rock. The growth patterns deduced from the fossil morphologies suggest that the organisms showed cell-to-cell signalling and coordinated responses, as is commonly associated with multicellular organization9. The Gabon fossils, occurring after the 2.45–2.32-Gyr increase in atmospheric oxygen concentration10, may be seen as ancient representatives of multicellular life, which expanded so rapidly 1.5?Gyr later, in the Cambrian explosion.
