Pobre Darwin, vida multicelular há mais de 2 bilhões de anos atrás

quarta-feira, junho 30, 2010

Nature 466, 100-104 (1 July 2010) | doi:10.1038/nature09166; Received 29 March 2010; Accepted 4 May 2010

Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago

Abderrazak El Albani1, Stefan Bengtson2, Donald E. Canfield3, Andrey Bekker4, Roberto Macchiarelli5,6, Arnaud Mazurier7, Emma U. Hammarlund2,3,8, Philippe Boulvais9, Jean-Jacques Dupuy10, Claude Fontaine1, Franz T. Fürsich11, François Gauthier-Lafaye12, Philippe Janvier13, Emmanuelle Javaux14, Frantz Ossa Ossa1, Anne-Catherine Pierson-Wickmann9, Armelle Riboulleau15, Paul Sardini1, Daniel Vachard15, Martin Whitehouse16 & Alain Meunier1

Laboratoire HYDRASA, UMR 6269 CNRS-INSU, Université de Poitiers, 86022 Poitiers, France
Department of Palaeozoology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden
Nordic Center for Earth Evolution, DK-5230 Odense M, Denmark
Department of Geological Sciences, University of Manitoba, Manitoba, R3T 2N2 Canada
Département Géosciences, Centre de Microtomographie, Université de Poitiers, 86022 Poitiers, France
Département de Préhistoire, UMR 7194 CNRS, Muséum National d’Histoire Naturelle, Paris, 75005, France
Société Etudes Recherches Matériaux, CRI Biopole, 86000 Poitiers, France
Department of Geological Sciences, Stockholm University, SE-106 91 Stockholm, Sweden
Département Géosciences, UMR 6118, Université de Rennes, 35042 Rennes, France
Bureau de Recherches Géologiques et Minières, 45060 Orléans, France
GeoZentrum Nordbayern, Universität Erlangen, Fachgruppe Paläoumwelt, D 91054 Erlangen, Germany
Laboratoire d'Hydrologie et de Géochimie de Strasbourg, UMR 7517 CNRS, 67084 Strasbourg, France
Département Histoire de la Terre, UMR 7207 CNRS, Muséum National d’Histoire Naturelle, Paris, 75005, France
Département de Géologie, Unité de Recherche Paléobotanique-Paléopalynologie-Micropaléontologie, Université de Liège, Sart-Tilman Liège 4000, Belgium
Laboratoire Géosystèmes, FRE 3298 CNRS, Université Lille 1, 59655 Villeneuve d'Ascq, France
Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden

Correspondence to: Abderrazak El Albani1 Email: abder.albani@univ-poitiers.fr


Reconstruction of a specimen from Gabon showing the peripheral radial fabric
and inner structural organization - Image: A. El Albani

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.

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NOTA CAUSTICANTE DESTE BLOGGER:

Pobre, pobrecito Darwin. Se a explosão Cambriana já era um pé no saco teórico de Darwin, imaginem vida multicelular há 2 bilhões de anos atrás. Possíveis reações da Nomenklatura científica: Nós não esperávamos encontrar tanta complexidade neste período. Isso vai lançar luz na origem e evolução da vida multicelular, talvez não a preconizada pelo gradualismo darwiniano, mas Darwin já tinha preconizado essa possibilidade, y otras cositas mais.

Gente, o que precisa ser encontrado são os quintilhões de quintilhões de elos transicionais para corroborar o fato, Fato, FATO da evolução, mas isso o registro fóssil se recusa em fornecer. O que temos não é ciência, mas retórica vazia para a manutenção do dogma darwiniano. E ai de quem mijar fora do caco de Down...

Fui, nem sei por que, pensando que o registro fóssil tem fósseis que a razão darwiniana teima desconhecer intencionalmente como uma grave anomalia que a teoria não responde com a robustez exigida pelo contexto de justificação teórica.

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