Showing results 101 to 120 of 184
  Patterns of diversification in early eukaryotesJavaux, Emmanuelle  in Steemans, Philippe; Javaux, Emmanuelle (Eds.) Recent advances in palynology (2007) Detailed reference viewed: 8 (0 ULg) Deciphering the record of early life in Precambrian oceans using combined microscopy and microchemistry of organic-walled microfossils.Javaux, Emmanuelle ; in Geochimica et Cosmochimica Acta (2007), 71(15), 442 Detailed reference viewed: 9 (1 ULg)Microfossils in siliciclastics : a window into Proterozoic and Archean lifeJavaux, Emmanuelle Conference (2007) Detailed reference viewed: 6 (0 ULg)Evolution des eucaryotes au précambrienJavaux, Emmanuelle Conference (2007) Detailed reference viewed: 9 (0 ULg)Evolution of early Earth biosphere and implications for astrobiologyJavaux, Emmanuelle Scientific conference (2007) Detailed reference viewed: 6 (3 ULg)Evolution de la biosphère au précambrien et implications pour l’astrobiologieJavaux, Emmanuelle Conference (2007) Detailed reference viewed: 4 (0 ULg)Paléontologie, partim micropaléontologieJavaux, Emmanuelle Learning material (2007) powerpoint sur MyULg Detailed reference viewed: 7 (0 ULg)origine, évolution et distribution de la vie dans l’universJavaux, Emmanuelle Conference given outside the academic context (2007) Detailed reference viewed: 3 (0 ULg)La vie dans le système solaireJavaux, Emmanuelle ; Gérard, Jean-Claude Conference given outside the academic context (2007) Detailed reference viewed: 15 (1 ULg)L’origine de la vie dans l’universJavaux, Emmanuelle Conference given outside the academic context (2007) Detailed reference viewed: 2 (0 ULg)La vie : extrêmement vieille, extrêmement résistante, extrêmement loin ?Javaux, Emmanuelle Conference given outside the academic context (2007) Detailed reference viewed: 3 (0 ULg)The early eukaryotic fossa recordJavaux, Emmanuelle in Advances in Experimental Medicine and Biology (2007), 607 The Precambrian era records the evolution of the domain Eucarya. Although the taxonomy of fossils is often impossible to resolve beyond the level of domain, their morphology and chemistry indicate the ... [more ▼] The Precambrian era records the evolution of the domain Eucarya. Although the taxonomy of fossils is often impossible to resolve beyond the level of domain, their morphology and chemistry indicate the evolution of major biological innovations. The late Archean record for eukaryotes is limited to trace amounts of biomarkers. Morphological evidence appears in late Paleoproterozoic and early Mesoproterozoic (1800-1300 Ma) rocks. The moderate diversity of preservable eukaryotic organisms includes cell walls without surface ornament (but with complex ultrastructure), with regularly distributed surface ornamentation, and with irregularly or regularly arranged processes. Collectively, these fossils suggest that eukaryotes with flexible membranes and cytoskeletons existed in mid-Proterozoic oceans. The late Mesoproterozoic-early Neoproterozoic (1300-750 Ma) is a time of diversification and evolution when direct evidence for important biological innovations occurs in the fossil record such as multicellularity, sex, photosynthesis, biomineralization, predation, and heterotrophy. Members of extant clades can be recognized and include bangiophyte red algae, xanthophyte algae, cladophorale green algae, euglyphid, lobose, and filose amoebae and possible fungi. In the late Neoproterozoic, besides more diversification of ornamented fossils, florideophyte red algae and brown algae diversify, and animals take the stage. The record of biological innovations documented by the fossils shows that eukaryotes had evolved most cytological and molecular complexities very early in the Proterozoic but environmental conditions delayed their diversification within clades until oxygen level and predation pressure increased significantly. [less ▲] Detailed reference viewed: 22 (0 ULg)Astrobiology : origin, evolution and distribution of life in the universe.Javaux, Emmanuelle in CAPAS comptes-rendus (2007) Detailed reference viewed: 4 (3 ULg)Evolution de la biosphère au précambrien et implications pour l’astrobiologieJavaux, Emmanuelle Conference (2006, September) Detailed reference viewed: 3 (0 ULg)Astrobiology and Habitability workshop, Abstracts and Program, June 13th 2006 Brussels SCKCEN headquartersJavaux, Emmanuelle ; ; Book (2006) Astrobiology and Habitability workshop, Abstracts and Program, June 13th 2006 Brussels SCKCEN headquarters Detailed reference viewed: 5 (0 ULg)Early life evolution, habitats and biosignatures. Astrobiology and Habitability workshopJavaux, Emmanuelle ; Conference (2006, June) Detailed reference viewed: 6 (0 ULg)Criteria for biogenicity of morphological signaturesJavaux, Emmanuelle Conference (2006, April) Detailed reference viewed: 1 (0 ULg)The astrobiology primer: An outline of general knowledge - Version 1, 2006; ; et al in Astrobiology (2006), 6(5), 735-813 Detailed reference viewed: 20 (2 ULg)A new approach in deciphering early protist paleobiology and evolution: Combined microscopy and microchemistry of single Proterozoic acritarchsJavaux, Emmanuelle ; in Review of Palaeobotany and Palynology (2006), 139(1-4), 1-15 Beside a few cases, the biological affinities of Proterozoic and Paleozoic acritarchs remain, by definition, largely unknown. However, these fossils record crucial steps in the early evolution of ... [more ▼] Beside a few cases, the biological affinities of Proterozoic and Paleozoic acritarchs remain, by definition, largely unknown. However, these fossils record crucial steps in the early evolution of microorganisms and diversification of complex ecosystems. We present how combining microscopy (light microscopy, scanning and transmitted electron microscopy) with microchemical analyses of individual microfossils may offer further insights into the paleobiology and evolution of early microorganisms. We use our ongoing work on early Mesoproterozoic and Neoproterozoic assemblages, as well as other published work, as examples to illustrate how this approach may clarify the evolution of early microorganisms and we underline how useful this approach could be for palynologists working on younger material. Such a multidisciplinary approach offers new possibilities to investigate the biological affinities of acritarchs and the record of early life on Earth and beyond. (c) 2006 Elsevier B.V. All rights reserved. [less ▲] Detailed reference viewed: 17 (0 ULg)Biological innovations and diversification of early eukaryotesJavaux, Emmanuelle Conference (2006) Detailed reference viewed: 2 (0 ULg) |
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