Talk:Geological history of oxygen

Inaccuracies

• This page has many inaccuracies. For example, what exactly does "Of course, in the absence of plants, photosynthesis was slower in the Precambrian" mean? Cyanobacteria produced vast quantities of oxygen via oxygenic photosynthesis prior to the evolution of plants. In addition the claim that there were no mass extinctions prior to the Cambrian. This is almost certainly wrong - the great oxidation wiped out the majority of life on Earth around 2.4Ga-1.8Ga, according to current understanding. I don't have time to review and edit the page at the moment, perhaps somebody would like to take a look at it? 20:35, 11 May 2011 User:139.222.200.73

Furter inaccurcies: it is stated 2% oxygen is needed for collagen production. Next section it states "40% of current levels" which would be about 8% for collagen production. Which is it?1812ahill (talk) 13:40, 17 July 2012 (UTC)

Many (not all) topics discussed in this article are still subject to continuing debate in the field, and this article should be updated to explain the controversy. Many of the article's more controversial claims with regards to animals and life (see discussion elsewhere on the page) come from a single scientist (Butterfield) and may not represent scientific consensus, in possible violation of WP:SCHOLARSHIP guidelines. Natural ironist (talk) 15:15, 9 October 2017 (UTC)

Source of Evolutionary Diversification

This page first suggests oxygenation was a driver for evolutionary diversification in the Cambrian period. Later, it says oxygenation is simply a prerequisite for the diversification. I think this just needs a little clarification. It seems oxygenation is more of a prerequisite. It brought about the opportunity for more complexity in a given speices, but the driving force for diversity seems to be coevolution. As more complex organisms began to appear, their interactions with each other required more adaptation. Kkennedy657 (talk) 21:53, 1 October 2014 (UTC)

Cyanobacteria

I feel some more info on the photosynthetic organisms would be helpful. The first photosynthetic organisms used sulfuric compounds with oxygen as the waste product. Cyanobacteria eventually developed photosynthesis that used water as fuel and while still expelling oxygen. The cyanobacteria had a new, more efficient way to photosynthesize. This made cyanobacteria the main producer of atmospheric oxygen. Kkennedy657 (talk) 22:32, 1 October 2014 (UTC)

Earth scientists consider the photosyntheic origin of O2 as "a junk"

There was a question in the Earth Science (duplicated here), asking about the difference between the ancient photosyntheis, which produced a lot of O2, and modern one, which does not seem to increase the O2 level in the atmosphere. It was trying to explain where goes the CH part and why cannot we burn it to reduce O2 back to zero. If we produce O2 by separating C and H from CO2 and H2O then there must be some depository of CH, where it is stored separately from the free O2 that we enjoy in the atmosphere. That question was relying on this article, particularly on the statement that atmospheric O2 was produced by the photosynthesis. It was closed however because it makes no sense for serious people. The serious scientists demand some evidence to support the "junk" about the photosynthetic origin of O2 and claim that its level in the atmosphere is dominated by the Earth rock, which contains much more O2 than any atmosphere. So, probably, we should remark about the crust origin of the O2 and put more emphasis into it than into CH separation from O2 by cianobacteria.--Javalenok (talk) 09:07, 9 July 2016 (UTC)

The statement in your header is false, it is in fact the scientific consensus. The "CH part", if it doesn't return directly to where it started from (as CO2 and H2O) goes into the fossil record as fossil fuels - peat, coal, oil, which modern industrial societies exploit to produce energy. The main difference between the "old photosynthesis" and the new is that in the Silurian the atmospheric CO2 concentration was many times higher than it is today, so plants produced huge amounts of biomass from this abundant CO2, increasing the O2 concentration by the Carboniferous to about 50% higher than it is today. The CH was buried as oil, peat and coal. What on earth makes you imagine the earth's rocks constitute a source of free gaseous oxygen that would be available to the atmosphere in the absence of photosynthesis. Have you ever attempted to extract oxygen from silica?? Before you troll this page again with statements about what "serious scientists demand", calling their hypotheses "junk" without justification, it might be worthwhile to take the trouble to read about and understand the facts. Plantsurfer 18:42, 10 July 2016 (UTC)

Thanks, Plant. I did not call it a junk. It was a quotation from the earthscience.stackexchange page that unanimously holds that opinion. The casted a shadow of doubt upon the quality of this article. Because they did it later, after this article was written, I took my right to think that they take more information into account and, thus, are more considerate. I could not believe that SE community could be hijacked by trolls. I am not one of them. Probably, calling people troll is their defense. Please do not apply their label to me. All what you say makes sense. I still have to figure out why cannot we cannot burn all that ancient peat, oil and coal to reduce atmospheric back O2 to 0, especially after majority of the oxygen was buried in the rock. But this article seems not to claim that we cannot. --Javalenok (talk) 09:51, 13 July 2016 (UTC)

OK, I retract my troll remark, but it was not clear whether the opinions expressed were yours or someone else's. A starting point for considering the problem you have raised is the idea that the atmosphere is not dominated by the inorganic chemistry that applies to other planets but is regulated by the chemistry of living organisms. I suggest you start by considering the gaia hypothesis article and the original paper by Lovelock and Margulis, 1974, and work forward towards more recent analysis of the idea. see http://web.gps.caltech.edu/classes/ge148c/pdf%20files/lovelock.pdf. Plantsurfer 10:23, 13 July 2016 (UTC)

The Golden Rule

So apparently this link exists "nitrogen crises" This article has left me rather confused. What does altruism and the rule of reciprocity have to do with nitrogen crisis? When was the last time this page was edited? — Preceding unsigned comment added by 14.2.189.32 (talk) 09:26, 30 March 2017 (UTC)

More precise Oxygen Levels in Atmosphere

I was reading last paragraph of Dinosaur: Extinction of major groups and after some more research, claims about oxygen levels in WikiPedia could be more precise. Traditionally it was believed that during Phanerozoic, levels of Oxygen in atmosphere very much higher than today (30%). But study of an international team of researchers led by Ralf Tappert, University of Innsbruck in Austria disproved this in 2013.

Those details could be added to this article too. I am no expert on this field so I don't think I have any right to edit this article. Someone with more experience can research this more and update the article.

Here is one good source, with two much better graphs.

• Encyclopedia of Evolutionary Biology Page 336-339

Here are few articles:

• uibk.ac.at Amber Provides New Insights Into the Evolution of the Earth's Atmosphere
• natureworldnews.com Dinosaurs Lived in a Low-oxygen World, Study Suggests
• abc.net.au Fossilised sap points to low oxygen past
• seeker.com Low Oxygen Dino Air Trapped in Amber
• softpedia.com Earth's Atmosphere Used to Be Much Poorer in Oxygen

Original article:

• Geochimica et Cosmochimica Acta Volume 121, 15 November 2013, Pages 240–262 Stable carbon isotopes of C3 plant resins and ambers record changes in atmospheric oxygen since the Triassic

SyncMaster192 (talk) 23:31, 10 May 2017 (UTC)

Article needs expansion

A few suggestions to start from

• Donald Canfield's book (2014): https://press.princeton.edu/titles/10089.html
• Canfield quotes this Kump's paper (2008) as an excellent mini-review: https://www.nature.com/articles/nature06587.pdf — Preceding unsigned comment added by 90.185.219.193 (talk) 08:29, 12 July 2018 (UTC)