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Proterozoic Ocean Chemistry and Evolution: A Bioinorganic Bridge?
Recent data imply that for much of the Proterozoic Eon (2500 to 543 million years ago), Earth's oceans were moderately oxic at the surface and sulfidic at depth. Under these conditions, biologicallyExpand
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Estimating the timing of early eukaryotic diversification with multigene molecular clocks
Although macroscopic plants, animals, and fungi are the most familiar eukaryotes, the bulk of eukaryotic diversity is microbial. Elucidating the timing of diversification among the more than 70Expand
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The Evolution of Modern Eukaryotic Phytoplankton
The community structure and ecological function of contemporary marine ecosystems are critically dependent on eukaryotic phytoplankton. Although numerically inferior to cyanobacteria, these organismsExpand
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Large Perturbations of the Carbon Cycle During Recovery from the End-Permian Extinction
High-resolution carbon isotope measurements of multiple stratigraphic sections in south China demonstrate that the pronounced carbon isotopic excursion at the Permian-Triassic boundary was not anExpand
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Eukaryotic organisms in Proterozoic oceans
The geological record of protists begins well before the Ediacaran and Cambrian diversification of animals, but the antiquity of that history, its reliability as a chronicle of evolution and theExpand
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Neoproterozoic variations in the C-isotopic composition of seawater: stratigraphic and biogeochemical implications.
The recent proliferation of stratigraphic studies of delta 13C variation in carbonates and organic C in later Neoproterozoic and basal Cambrian successions (approximately 850-530 Ma) indicates aExpand
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Stromatolites in Precambrian carbonates: evolutionary mileposts or environmental dipsticks?
Stromatolites are attached, lithified sedimentary growth structures, accretionary away from a point or limited surface of initiation. Though the accretion process is commonly regarded to result fromExpand
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Biomarker evidence for green and purple sulphur bacteria in a stratified Palaeoproterozoic sea
The disappearance of iron formations from the geological record ∼1.8 billion years (Gyr) ago was the consequence of rising oxygen levels in the atmosphere starting 2.45–2.32 Gyr ago. It marks the endExpand
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Morphological and ecological complexity in early eukaryotic ecosystems
Molecular phylogeny and biogeochemistry indicate that eukaryotes differentiated early in Earth history. Sequence comparisons of small-subunit ribosomal RNA genes suggest a deep evolutionaryExpand
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The early evolution of eukaryotes: a geological perspective.
  • A. Knoll
  • Biology, Medicine
  • Science
  • 1 May 1992
Molecular phylogenies of eukaryotic organisms imply patterns of biological and environmental history that can be tested against the geological record. As predicted by sequence comparisons,Expand
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