Talk:Great Oxidation Event

Geology Start‑class Mid‑importance

	Geology portal Talk:Great Oxidation Event is part of WikiProject Geology, an attempt at creating a standardized, informative, comprehensive and easy-to-use geology resource. If you would like to participate, you can choose to edit this article, or visit the project page for more information.GeologyWikipedia:WikiProject GeologyTemplate:WikiProject GeologyGeology articles
Start	This article has been rated as Start-class on Wikipedia's content assessment scale.
Mid	This article has been rated as Mid-importance on the project's importance scale.

Too Technical, Missing Points?

I have an MSc in Physics and I think this page is way too technical, or unfortunately is written in a way that makes it much less interesting. (no offence to the hard working souls who created it). There is a huge middle section that goes off on a technical tangent about a time lag, and only near the end do we get to the explanation of what actually happened. It also seems that there is no mention at all of the Snowball Earth or how the snowball earth was eventually broken by more microbes that evolved to consume oxygen and create carbon dioxide. I found the DamnInteresting page on this event to be much more readable. It follows events chronologically and explains cause and effect in less technical language, as opposed to explaining one or two technical points in verbose detail. (http://www.damninteresting.com/?p=673#more-673) 69.156.113.62 04:35, 3 December 2006 (UTC)[reply]

The Snowball Earth was several billion years later, so I don't see that it's directly relevant to the Oxygen Catastrophe. But yes, this article could certainly do with some work, I'll try a rewrite if I have time. -- Danny Yee 08:09, 3 December 2006 (UTC)[reply]

Also, the story on the DamnInteresting page is highly speculative. It goes into details that are certainly not known but simply guessed at. -- Danny Yee 08:10, 3 December 2006 (UTC)[reply]

Cyanobacteria

It would be useful to mention that the cause of the oxygen build up was the evolution of photosynthesising cyanobacteria from earlier photosynthesising sulphur bacteria. Photosynthesising sulphur bacteria use sunlight to split Hydrogen Sulphide (H2S) molecules to produce sulphur, but cyanobacteria modified this process to split water (H20)molecules to produce oxygen. RV 4 March 2007

The oxygenation of the atmosphere and oceans

This 2006 paper by Heinrich Holland lucidly reviews the subjects covered in this article. Professor Holland has kindly released figure 10 from his article under GFDL, for us to be able to use it in Wikipedia. These graphs illustrate the estimated evolution of atmospheric $\ P_{O_{2}}$ and the concentration of O₂ in the shallow and deep oceans. Your assistance is now needed to adapt these graphs for use in Wikipedia, and update our articles with the information provided in the said paper. Regards, Lior 17:03, 11 June 2007 (UTC)[reply]

The presentation of information D.I. End of Life here, deleted as "blogspam" [sic] might prove useful in improving the presentation in this Wikipedia article. --Wetman 17:14, 18 June 2007 (UTC)[reply]

When did ozone layer appear?

I thought that ozone layer appeared 500 millions years ago, when land became habitable (see Timeline of evolution). However this article relates its appearance with the much earlier Oxygen Catastrophe. Is it a real discrepancy, or are we talking about two different phases in its forming (i.e. for a stable 21% oxygen atmosphere one needs a much thinner ozone layer compared to the one needed for the land to become habitable)? Dan Gluck 09:41, 17 September 2007 (UTC)[reply]

Capitalization

The use of capitals in phrases like "Oxygen catastrophe" is unwarranted. --Wetman 18:56, 7 October 2007 (UTC)[reply]
I'm proposing moving the page to the non-capitalized version (which redirects here). - tameeria (talk) 20:09, 30 December 2007 (UTC)[reply]
There was only one oxgen catastrophe, so the expression may as well have capitals as a proper name of a specific event. Anthony Appleyard (talk) 21:10, 30 December 2007 (UTC)[reply]

I agree that it was a specific event that can have this title.

IceDragon64 (talk) 20:22, 2 February 2009 (UTC)[reply]

Image caption

What does 'A', 'B', and 'C' in the image caption refer to? There are no such labels in the image itself. —Preceding unsigned comment added by 85.228.39.223 (talk) 08:28, 16 November 2007 (UTC)[reply]

The source paper of the diagram does not seem to suggest these time frames either (PDF available here). Strangely, the phases A, B,C are in addition to the stages 1-5, which are not linear in time. Linear time scale is indicated at the bottom of illustration. --83.76.186.14 (talk) 21:08, 9 December 2007 (UTC)[reply]

The image caption refers to the old image (see right) that was replaced apparently without updating the image caption as well. - tameeria (talk) 20:00, 30 December 2007 (UTC)[reply]

Requested Move

Oxygen Catastrophe to oxygen catastrophe

Oppose as it refers to a specific and not a generic event. 70.51.11.191 (talk) 00:48, 2 January 2008 (UTC)[reply]
Oppose, probably. The stuff I can find usully doesnt have a capital 'C', but if we dont write it like that people will think its about a general phenomenon, not a specific event. Callmederek (talk) 19:18, 4 January 2008 (UTC)[reply]
Oppose per comments above; specific event --Lox (t,c) 12:55, 5 January 2008 (UTC)[reply]
Looks like the consensus is not to move the page, so I'm removing the move tag. - tameeria (talk) 16:33, 5 January 2008 (UTC)[reply]

What exactly was the "catastrophe" ?

I didn't find anything that actually explained what was so catastrophic to justify the title. What/how much actually happened ? Did existing lifeforms disappear, move underground, evolve ? Anaerobic organisms still exist. The availability of O2 seems more like a great opportunity than a catastrophe.Rcbutcher (talk) 02:53, 18 January 2008 (UTC)[reply]

The rising oxygen levels wiped out a huge portion of Earth's inhabitants at the time. From their perspective it was a catastrophe. Cyanobacteria were essentially responsible for probably the largest extinction event in Earth's history. Eris Discord | Talk 02:35, 29 February 2008 (UTC)[reply]

Eris, do you have any source for that statement? If so, exactly what would have killed off the previous species? What were the previous species? --Mlewan (talk) 15:34, 11 March 2010 (UTC)[reply]

Now that's exactly what should be in the article! ;) BenJury (talk) 13:15, 10 September 2008 (UTC)[reply]

The catastrophe was only ever hypothetical, there is no actual evidence of mass extinctions after the oxgen content of the atmosphere started rising. A recent paper (Energy metabolism among eukaryotic anaerobes in light of Proterozoic ocean chemistry, Royal Society, 2008) summarises current ideas about the issue. The idea of an oxygen catastrophe is based on ideas about the evolution of the biosphere that originated in the 1970s. Evidence found by microbiologists and geochemists since the 1990s paints a different picture, although the oxygen catastrophe hypothesis is still widely written about by scientists who are not specialists in these fields (Google Scholar give tons of hits for "oxygen catastrophe" but only a few for "oxygen catastrophe" evidence). The biological evidence consists of the existence of non-aerobic eucaryotes throughout the eucaryote family tree, not just in a few "primitive" groups - some plants and fungi are obligate (full-time) anerobes, and some plants, fungi and animals are facultative anerobes (can live without oxygen if circumstances require it). The geochemical evidence indicates that until about 600 million years ago the oceans remained anoxic and sulphidic, except possibly in the top 100-200 meters where there was enough light to support photosynthesis. (end of summary of paper). IMO it's very likely that oxygenation had effects on life from the start, but these were nowhere near as massive and abrupt as the phrase "oxygen catastrophe" implies. --Philcha (talk) 12:03, 2 December 2008 (UTC)[reply]

That link doesn't work for me, BTW. --Michael C. Price ^talk 08:28, 4 February 2010 (UTC)[reply]

'Catastrophe' doesn't refer to mass extinction but to the abrupt rise in oxygen levels (compare ultraviolet catastrophe; the reference is to how the graph looks, not to disastrous events speifically). 165.91.174.196 (talk) 07:31, 4 February 2010 (UTC)[reply]

Not quite. The UV catastrophe refers to the diaster implied by the shape of the graph. Similarly the reference here is to the associated mass extinction (real or imaginary) of the anerobes. --Michael C. Price ^talk 08:24, 4 February 2010 (UTC)[reply]

Sources

Recent publications suggest we need to re-examine the whole idea of an "oxygen catastrophe". I'm going to start collecting sources here, with brief notes. If we get enough, it may be necessary to re-organise the list into sub-sections. Please contribute, using a similar format. If you wish to discuss any of these items, please do so in separate sections, so that this remains a simple list.--Philcha (talk) 12:14, 2 December 2008 (UTC)[reply]

Energy metabolism among eukaryotic anaerobes in light of Proterozoic ocean chemistry (Mentel & Martin; Phil. Trans. Royal Society, 2008) - The existence of non-aerobic eucaryotes throughout the eucaryote family tree, not just in a few "primitive" groups, and the very narrow range of energy-producing chemical paths eucaryotes possess, suggest that eucaryotes acquired mitochondria / hydrogenosomes / mitosomes in a single endosymbiosis event that happened in an anerobic environment. Geochemical evidence suggests the oceans remained anoxic and probably sulphidic until about 600 million years ago, except for the photic zone in the top 100-200 metres.
Dating the rise of atmospheric oxygen (Bekker, Holland, Wang et al; Nature, 2004) - Oxygenation of atmosphere started about 2,450 million years ago and reached 10^-5 PAL (present atmospheric level), enough to become significant, by 2,320 million years ago.
The oxygenation of the atmosphere and oceans (Holland; Philos Trans R Soc Lond B Biol Sci., 2006) - Stages: 3,850 to 2,450 million years ago atmosphere and oceans anoxic, except possibly "oxygen oases" in shallow oceans; 2,450 to 1,850 million years ago atmospheric oxygen levels rose to between 0.02 and 0.04 PAL, shallow oceans became mildly oxygenated, deep oceans remained anoxic; 1,850 to 850 million years ago (the "boring billion") little change in atmospheric oxygen levels, surface and deep oceans mildly oxygenated, anoxic or euxinic deep oceans not inevitable; 850 to 540 million years ago atmospheric oxygen rose to about 0.2 atm, shallow oceans oxygenated, deep oceans anoxic at least some of the time(three major Neoproterozoic glaciations); 540 million years ago to present show atmospheric oxygen rising to 30% in Carboniferous ("wood crisis") then declining to present level (about 18%), shallow oceans were oxygenated, oxygen levels in deep oceans fluctuated, possibly sharply at times.
The loss of mass-independent fractionation in sulfur due to a Palaeoproterozoic collapse of atmospheric methane (Zahnle, Claire, Catling; Geobiology 2006) - Collapse of atmos methane level a prerequisite for oxygenation; collapse of methane greenhouse enabled Proterozioc glaciations; stable oxygen level restored methane greenhouseby protecting it from UV with ozone layer.
Did the Proterozoic ‘Canfield Ocean’ cause a laughing gas greenhouse? (Buick; Geobiology 2007) - not sure how serious, but start and finish are amusing (deliberately).
Oxygen and life in the Precambrian (Catling, Buick; Geobiology 2006) - Summarise all the other Geobiology 2006 papers.
Bistability of atmospheric oxygen and the Great Oxidation (Goldblatt, Lenton & Watson; Nature, 2006) - Oxygenic photosynthesis evolved about 2,700 million years ago but the "Great Oxidation" was about 2,400 million years ago; man yexplanation so fthis lag have been proposed. Possible explanation - atmospheric oxygen level is bistable: below 10^-5 PAL there is too little O2 to form an ozone layer, and UV drive oxidisation of methane; above 10^-5 PAL, ozone form and blocks UV, so O2 and methane levels rise again. This model predicts a sharp fall inmethane levels during the transtion, setting the scene for glaciations.
The Emerging Aerobic Earth System through Archaean-Palaeoproterozoic Transition: Problems and Perspectives (Melezhik, Fallick, et al; Geophysical Research Abstracts, 2006) - some puzzles, including first appearance of petroleum about 2,000 million years ago}.
The rise of atmospheric oxygen (Kump; Nature, 2008) - A failed oxygenation event about 3,200 million years ago ago?

--Philcha (talk) 14:24, 2 December 2008 (UTC)[reply]

Article title

Atmospheric oxygenation event is free, what about a move to a less dramatic title? Tim Vickers (talk) 21:10, 15 January 2009 (UTC)[reply]

That's better, but I'm not sure "event" is right for a 16,00M yr process. How about Atmospheric oxygenation? That leaves the options open, whichever way the geochemists jump.--Philcha (talk) 21:41, 15 January 2009 (UTC)[reply]

No, that might be an ambiguous title that could also refer to the oxygen cycle. This is something that happened once, within defined boundaries (however long these were), so I think "event" is technically accurate. Tim Vickers (talk) 21:56, 15 January 2009 (UTC)[reply]

Good point about the oxygen cycle. Re "event", the boundaries are not so well defined. In fact there's a series of events, see File:Oxygenation-atm.svg and the cited article. How about History of atmospheric oxygenation? --Philcha (talk) 22:28, 15 January 2009 (UTC)[reply]

Sounds good, but you'd then have to expand the article a bit to include later fluctuations after the initial reducing/oxidising switch, since that title covers a broader subject area. I'd be happy with that as a solution though. I wonder if anybody else watching this page will comment? Tim Vickers (talk) 22:53, 15 January 2009 (UTC)[reply]

I think that if we can settle that there was not a Catastrophe, then the bulk of the article, describing what actually happened, should move to Atmospheric oxygenation event. It doesn't really matter whether anyone has used it before or anything, so long as it establishes the truth as accurately as we know. I think that a small article should remain here about the original idea, that it was "The biggest extinction in history" or whatever, and showing any key research which discredits this- linked to a main article over there. I have been bold and created the page, in brief, wikidragon fashion.

IceDragon64 (talk) 20:34, 2 February 2009 (UTC)[reply]

I don't think we can (or should) settle that there wasn't a catastrophe.

BTW, there is an interesting take in New Scientist on it - claims that the GOE triggered a much earlier snowball Earth episode. See First breath: Earth's billion-year struggle for oxygen. A rare high quality article from NS. --Michael C. Price ^talk 17:32, 7 February 2010 (UTC)[reply]

Graph Lines?

Am I missing something? There are two different coloured lines on the graph and only one atmostpheric constituant discussed, so what does the other line mean and which is which?

IceDragon64 (talk) 21:03, 2 February 2009 (UTC)[reply]

One of them is O2 pressure, the other is O2 concentration in ocean surface waters. But which is which? 131.111.85.79 (talk) 15:19, 16 March 2009 (UTC)[reply]

Drake Equation

This is intended as a stub until either I or anyone else can fully illustrate the significance of this portion.

By many accounts, the [Drake Equation] is roughly 13 to 14 [orders of magnitude] higher than we are experiencing, taken even for when the anecdotially reported myriad forms of intelligent extraterrestrial life are accounted, totalling roughly more than one, perhaps 10, and far fewer than 100 distinctly differeing species.

It is my hypothesis that this hypothetical Great Oxygenation Event, which seems to have formed the [Ozone Layer], atmospheric and oceanic oxygen, and many useful minerals for life on Earth, could happen only rarely, and could perhaps wholly account for the 1/10,000,000,000,000 (1 in 10 quadrillion) chance that life evolved here and not everywhere else.

One other part of this entire hypothesis is that it appears to me that the entirety of the [Canadian Shield], including [Greenland], seems to be formed from a giant [impactor] which formed the crater now known as most of the [Hudson Bay] area. I would like it if more research was done to confirm or deny whether or not the [Hudson Bay area] in general, and the [Canadian Shield] at large is the result of a rather large and early (c.2,000M-3,400M years ago) [impactor] against the surface and early atmosphere of the Earth.

This is all posted as a postualtive, and not under copyright, although attribution would be appreciated under Creative Commons License.

IllegalKnowledge (talk) 14:02, 2 June 2010 (UTC)Michael Oatman (IllegalKnowledge@gmail.com)[reply]