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Journal ArticleDOI

Precambrian micro‐organisms and evolutionary events prior to the origin of vascular plants

J. William Schopf
- 01 Aug 1970 - 
- Vol. 45, Iss: 3, pp 319-352
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TLDR
The nature of the early Palaeozoic life was a fertile subject for speculation as mentioned in this paper, however, evidence of this development remained largely undeciphered ; the nature of Precambrian life was also fertile subject to speculation.
Abstract
The nature of the Precambrian biota-its antiquity. composition and evolutionand the well-known faunal discontinuity near the beginning of the Palaeozoic. have long been recognized as particularly puzzling problems in palaeontology . The evolutionary continuum well-documented in Phanerozoic sediments and the diversity and complexity of the early Palaeozoic biota augur well for a substantial period of Precambrian evolutionary development . Until recently. however. evidence of this development remained largely undeciphered ; the nature of Precambrian life was a fertile subject for speculation. essentially unfettered by the poorly known fossil record . The past few years have witnessed a renewed interest in these classic problems and a marked proliferation of available data; this increased activity has resulted in the

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Citations
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Journal ArticleDOI

Thermodynamics of heterogeneous iron—Carbon systems: Implications for the terrestrial primitive reducing atmosphere

TL;DR: In this paper, it was shown that the primary source of carbon for biochemical genesis on the early earth was CO 2 and the fundamental chemical process was reduction by ferrous ion in the primitive ocean, for which radiation was required as an initiator but not as a source of free energy.
Journal ArticleDOI

Alkyl substituted cyclic ethers in 2,300 M yr old Transvaal algal stromatolite

TL;DR: Two cyclic ethers have been identified from insoluble polymer-like kerogen in a Precambrian rock by ozonolysis, gas chromatography, and mass spectrometry.
Journal ArticleDOI

Environmental parameters for the origin of life

TL;DR: It is suggested that the carbonaceous chondrites represent relics of such a protoplanetary phase and record five successive environments with a generally decreasing but fluctuating temperature range as mentioned in this paper.
Book ChapterDOI

Hydromedusan Photophysiology: An Evolutionary Perspective

TL;DR: For many groups of simple invertebrates, and particularly cnidarians, there has been insufficient information to begin to examine the correlation between the degree of structural complexity and photoreceptor function, revealed either by its photophysiology or by the behavior of the animal.
Book ChapterDOI

Modes and Tempos of Mitochondrial and Chloroplast Genome Evolution in Chlamydomonas : A Comparative Analysis

TL;DR: The level of ribosomal RNA gene sequence divergence in both mitochondrial and chloroplast genomes is higher in the Chlamydomonas lineage than in land plants and is most likely due to higher rates of nucleotide substitution in ChlamYDomonas organellar DNAs.
References
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Journal ArticleDOI

Carbon isotope fractionation during photosynthesis

TL;DR: In this paper, a study was made of the reasons for isotopic fractionation in photosynthesis and various factors controlling it, and the effects of high light intensities on the fractionation factors of photosynthesis were studied.
Journal Article

Microflora of the Bitter Springs Formation, late Precambrian, central Australia

TL;DR: In this article, 30 new species, representing 24 new genera, of green algae, blue-green algae, colonial bacteria, fungus-like filaments, and possible pyrrophytes, are described from the bedded carbonaceous cherts of the late Precambrian Bitter Springs formation, Ross river area, central Australia.
Journal ArticleDOI

Metabolic fractionation of C13 & C12 in plants

TL;DR: Analysis of chemical fractions from several plant phyla show that in all cases the lipid fraction is enriched in C/sup 12/ compared to the whole plant, which may be explained if selective preservation of plant lipids occurred during the sedimentation process.
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