Terminal proterozoic reorganization of biogeochemical cycles
Article Abstract:
Biogeochemical cycles were reorganized in the late Proterozoic according to an analysis of hydrocarbons from Proterozoic sediments around the globe, indicating an unusually efficient biodegradation mechanism fro algal products. The organic matter floated slowly to the ocean depths and oxygen was largely removed, probably by sulphate-reducing bacteria. The production of fecal matter by newly evolved Cambrian creatures caused rapid sinking of organic matter, allowing oxygen to reach the ocean depths and therefore allowing for the development of sea floor creatures.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
User Contributions:
Comment about this article or add new information about this topic:
Biomarker evidence for green and purple sulphur bacteria in a stratified palaeoproterozoic sea
Article Abstract:
Hydrocarbon biomarkers from a 1.64-Gyr-old basin in northern Australia that reveals the ecological structure of mid-Proterozoic marine communities are presented. Phototrophic purple sulphur bacteria are detected in the geological record based on the new carotenoid biomarker okenane, and they seem to have co-existed with communities of green sulphur bacteria.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2005
User Contributions:
Comment about this article or add new information about this topic:
2-Methylhopanoids as biomarkers for cyanobacterial oxygenic photosynthesis
Article Abstract:
2-methyl-bacteriohopanepolyols are found to occur in a high proportion of cultured cyanobacteria and cyanobacterial mats. The 2-methylhopane hydrocarbon derivatives are rice in organic-rich sediments as old as 2,500 Myr. Such biomarkers provide constraints for the age of the oldest cyanobacteria and the emergence of oxygenic photosynthesis.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1999
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Germline transmission of genetically modified primordial germ cells. Somatic control of germline sexual development is mediated by the JAK/STAT pathway
- Abstracts: Chemistry claim provokes strong reaction. The molecular wake-up call. Hopping fences
- Abstracts: 14-3-3[sigma] controls mitotic translation to facilitate cytokinesis. Regulation of cap-dependent translation by eIF4E inhibitory proteins
- Abstracts: Tropical to mid-latitude snow and ice accumulation, flow and glaciation on Mars. Recent and episodic volcanic and glacial activity on Mars revealed by the High Resolution Stereo Camera
- Abstracts: Clock coordination. Coherent signal amplification in bistable nanomechanical oscillators by stochastic resonance