The Blake Johnson Files Part 1: Hope
Hypotheses for ancient microbial growth rates vary between short-term diurnal cycles based on modern cyanobacterial motility Doemel and Brock, ; Golubic and Focke, , and slower growth over many months or years Chivas et al. Evidence from LHC suggests that elements of both ideas are at work in modern mats. Patterns of LHC mat communities and carbonate growth suggest that cyanobacterial motility does separate modern mats into upper organic-rich and lower carbonate-rich zones, but on slower timescales than thought by previous hypotheses. At observed precipitation rates, a minimum of 23 years is required for a hypothetical LHC mat starting with no carbonate present to fully lithify, all things being equal.
However, if production rates of organic carbon consistently outpace carbonate precipitation rates in this mat, it is possible that the mats may never become fully lithified. It is possible to speculate that the paucity of microbialites versus the ubiquity of microbial mats in modern environments may reside in the balance between rates of organic carbon production versus carbonate precipitation, where times of abundant microbialite formation in the past may represent conditions where carbonate precipitation rates were equal to or greater than microbial growth rates.
Our study of 1-day growth rate experiments shows i Rates of autotrophic carbon fixation are not correlated with rates of biogenic carbonate precipitation within certain microbial mats. The uppermost layers of LHC mats have the highest carbon fixation rates as well as abundant autotrophic communities, but biogenic precipitation only occurred in Layers B, C, and D. This hypothesis is supported by recent research indicating higher rates of primary productivity in unlithified microbial mats than within recently formed stromatolites Schuler et al.
Abiogenic precipitation occurred in the uppermost LHC layer, and in concert with biogenic precipitation in the lower two layers. The uppermost LHC layer had the lowest percentage of carbonate Comparing differences in carbonate percentage and production rate can potentially provide growth histories of microbial mats. DW assisted with mat collection, field geochemistry, laboratory experiments, data analysis and interpretation, and wrote the initial manuscript draft. SG and MD assisted with mat collection, field geochemistry, laboratory experiments, data analysis and interpretation.
HJ and WB designed and ran laboratory analyses, and assisted with geochemical interpretation.
OP assisted with field geochemical sampling and saturation state calculation. FC co-directed and secured funding for the International Geobiology Course, and assisted with interpreting significance to modern and ancient lithified microbialites. JS co-directed and secured funding for the International Geobiology Course. All authors contributed in the writing and editing of the manuscript. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
A permit was granted to JS from the U. We thank Nick Rollins for analyzing and reducing data, and Julien Emile-Geay and Jeffrey Thompson for their assistance on statistical analyses. This work was supported in part through funding for the International Geobiology Course from the Agouron Institute. National Center for Biotechnology Information , U. Journal List Front Microbiol v. Front Microbiol. Published online Jul Dylan T. Johnson , 2 Blake W. Stamps , 3 William M. Berelson , 1 Bradley S. Stevenson , 4 Heather S. Nunn , 4 Sharon L.
Grim , 5 Megan L. Dillon , 6 Olivia Paradis , 1 Frank A. Corsetti , 1 and John R. Hope A. Blake W. William M. Bradley S. Heather S.
- The Lost Jupiter (Mauras Gate Book 3)!
- Wells Fargo Shootout, Part 1.
- Rekindling the Love Connect.
- Moving the world with images!
- Running: The Ultimate Runners Guide On How To Master The Art Of Running And Getting The Most Out Of Your Training (Running, Cardio, Fitness).
- Search form?
Sharon L. Megan L. Frank A. John R. Author information Article notes Copyright and License information Disclaimer. Wilmeth, moc. Spear, ude.
- Growing Up With Kip.
- Guest blog: Tyler Cowen is wrong about gold (By Blake Johnson) | The Market Monetarist.
- The Voice (American season 2) - Wikipedia.
- Hana-Kimi, Vol. 19: Raise the Bar!
This article was submitted to Aquatic Microbiology, a section of the journal Frontiers in Microbiology. Received Dec 1; Accepted Jun The use, distribution or reproduction in other forums is permitted, provided the original author s and the copyright owner s are credited and that the original publication in this journal is cited, in accordance with accepted academic practice.
No use, distribution or reproduction is permitted which does not comply with these terms. DOCX 28K. DOCX 22K. DOCX 20K. Abstract Microbial mats are found in a variety of modern environments, with evidence for their presence as old as the Archean. Keywords: microbial mat, carbonate precipitation, biomineralization, carbon fixation, hot spring. Introduction Microbial mats have been preserved within the rock record over 3.
Open in a separate window. Incubation Experiments The rates of biogenic carbonate precipitation and autotrophic production of organic carbon in each layer were determined using incubation experiments with 13 C-labeled HCO 3 -.
Upstream and Downstream locations are relative to the sampled mat. Precipitation Rates Compared With Microbialite Formation Precipitation rates from LHC mats not only provide valuable information about the dynamics of modern mat growth, but can also help constrain conditions for microbialite formation and preservation in deep time. Author Contributions DW assisted with mat collection, field geochemistry, laboratory experiments, data analysis and interpretation, and wrote the initial manuscript draft. Conflict of Interest Statement The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Acknowledgments A permit was granted to JS from the U.
Footnotes Funding. Click here for additional data file. References Aloisi G. Acta 72 — Deblur rapidly resolves single-nucleotide community sequence patterns.
Edge of Danger
Calcification in cyanobacterial biofilms of alkaline salt lakes. Photosynthesis-induced biofilm calcification and calcium concentrations in phanerozoic oceans. Science — Biofilm exopolymers control microbialite formation at thermal springs discharging into the alkaline Pyramid Lake, Nevada, USA. Proterozoic stromatolites: the first marine evolutionary biota. Sulfate reducing bacteria in microbial mats: Changing paradigms, new discoveries. UV B-induced vertical migrations of cyanobacteria in a microbial mat. Hot spring siliceous stromatolites from Yellowstone National Park: assessing growth rate and laminae formation.
Geobiology 9 — The Meaning of Stromatolites.
Guest blog: Tyler Cowen is wrong about gold (By Blake Johnson) | The Market Monetarist
Earth Planet. Morphological record of oxygenic photosynthesis in conical stromatolites. Carbonate-rich dendrolitic cones: insights into a modern analogue for incipient microbialite formation, Little Hot Creek, Long Valley Caldera, California. NPJ Biofilms Microbiomes 3 : Phage community dynamics in hot springs. Calcium carbonate precipitation by anoxygenic phototrophic bacteria. Cyanobacterial formation of intracellular Ca-carbonates in undersaturated solutions. Geobiology 16 49— QIIME allows analysis of high-throughput community sequencing data. Methods 7 — Earth Sci. Cyanobacterial calcification in modern microbialites at the submicrometer scale.
Biogeosciences 10 — Potential of unicellular cyanobacteria from saline environments as exopolysaccharide producers. Bacterial stromatolites: origin of laminations. Processes of carbonate precipitation in modern microbial mats. Microbial lithification in marine stromatolites and hypersaline mats.
Trends Microbiol. Microbe-mineral interactions: early carbonate precipitation in a hypersaline lake Eleuthera Island, Bahamas. They are the forces of supply and demand that seem to work pretty well in basically every other market. Lawrence H. To go over it here in detail would take far too much space. Second, commodity prices have not been increasing independent of monetary policy; the steady inflation over the last 30 years has had a significant effect on commodity prices. This is rather readily apparent if one looks at a graph of the real price of gold, which is extremely stable and even falling slightly until Nixon closes the Gold Window and ends the Bretton Woods system, at which point it begins fluctuating wildly.
Market forces stabilize the purchasing power of the medium of redemption in a commodity standard; this would be true for any commodity standard, it is not something special about gold in particular. As an aside, in response to Lars question, why gold and not some other commodity or basket of commodities, I would argue that without a low transaction cost medium of redemption the process of adverse clearings that ensures that money supply tends toward equilibrium becomes significantly less efficient.
I would gladly say that I believe there are many other commodities that a monetary standard could be based upon. A gold standard, by the way, is still compatible with plenty of state intervention.