Talk:Extinction event/Archive 1

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Archive 1


Vendian Extinction

What about the extinction that killed the Vendian (precambrian) biota? Should that be included? —Preceding unsigned comment added by Maurajbo (talkcontribs) 15:17, 11 May 2009 (UTC)

K-T Extinction

From the K-T extinction blurb: " including the dinosaurs." I personally feel that the evolutionary lineage of birds from dinosaurs is clear, so feel that this should be amended to say "including the non-avian dinosaurs." I realize that this may be contentious for some, so, before doing so, I wanted to hear what the community felt. Baryonyx 04:25, Sep 28, 2004 (UTC)

Electricity/Industrial Revolution

I didn't notice anyone mention the advent of electricity and the industrial revolution playing very real roles in the acceleroration of such a hypothetical instance as extinction occurring now. As with all else pertaining to the development of society, the advent of electricity and the industrial revolution has hastened the process.... in which ever directions a person chooses to recognize it as having proceded.

The Oxygen Revolution Extinctions

I remember having read about a (widely accepted?) theory that the second (or the first) mass extincting was caused by the development of photsynthesis in the evolution of life: The new organism capable of doing photosynthesis thrived and rapidly increases the abundance of oxygen in the atmosphere from only traces before to several tens of percents as now. As oxygen is highly corrosive (remember: there was no oxidation before) most organism died expect for those that developped protection against oxidation in time.

Does anybody know details? Is this correct? If so there should it go? -- sanders_muc

The original poster is talking about the idea that many of the original microbes of the Earth's early life evolved in the near complete abscene of oxygen in the atmosphere, and hence the oceans. The rise and expansion of the cyanobacteria would have posed a significant evolutionary pressure upon these organisms as oxygen began to increase in the oceans and in the atmosphere. It is believed that the Oxygen Revolution, as the buildup of oxygen during the Archean and Proterozoic is called, would have led to the extinction of organisms that could not cope with this oxygen-rich world, at least those that did not successfully move to anoxic areas or adapt. I have not seen it cited as counting as one of the Big Five, though. I would argue that it is an evolutionarily significant extinction: even if not Big Five material, it marks an important change in the history of life. As such, it probably merits mention.Baryonyx 04:25, Sep 28, 2004 (UTC)

The Sixth Mass Extinction?

Some people claim that we are living in the middle of another, man-made extinction event right now. However, humanity's effects are trivia compared with the extinction events shown in the fossil record.

Is that a fact? I've seen estimates on damage that are comparable to the smaller or intermediate sized mass extinctions, if nothing like the boundaries that end the Mesozoic and Palaeozoic eras.

If those are the same estimates that I've seen -- that something like 50,000 species a year are dying out -- they are not particularly reliable. The ones I've seen have all been created by organizations like the Sierra Club and people like Al Gore and Paul Ehrlich who have large, flaming political agenda that such figures are constructed to support. Over the past 500 years, almost 90 per cent of the forest along the Atlantic coast of Brazil has been cleared. However, no one has found a single known species that could be declared extinct. According to the "mass extinction" figures, about half the known species in that Brazilian forest should have been lost.
But if you can cite figures commonly accepted by paleontologists -- figures that, say, appeared in a peer-reviewed journal -- feel free to enter them! --The Epopt

Do a search for something like "current mass extinction" in google, and you will find a great number of hits, including articles in Nature and Science. It looks to me like the mass extinction view is closer to a consensus than to a minority of politically motivated views. At the very least there is enough here to remove the sentence from the article, which I'm doing.

We should move this discussion to Holocene extinction event anyway.
It should also be noted that some scientists have begun to refer to the period from 18th century forward as a new geological epoch, the Anthropocene, mainly because of the impact we are having on the planet. It is by no means in common use though, but wanted to note it.Baryonyx 04:25, Sep 28, 2004 (UTC)

So, do we actually have a common unbiased point of view that there is, in fact, another extinction event currently going on? If so, is there a wikipedia entry or other material we could link to? Because I, frankly, remain skeptical and would like to see more scientific evidence (on both sides of the argument). Cema 22:39, 12 Nov 2004 (UTC)

At present (Dec 2006) the "Holocene extinction" gets more space in this article than the P-Tr and K-T extinctions, which is ridiculous. A lot of the material about the debate and evidence should be moved to Holocene extinction event. My own inclination would be to qualify the "Holocene extinction" in this article as "suggested", because it appears from Holocene extinction event that a different method is being used to assess its severity (attempting to allow for undocumented extinctions) and that this method is likely to produce a higher extinction rate than the traditional fossil-counting method.Philcha 13:36, 8 December 2006 (UTC)

strongly disagree with philcha's comments. Holocene should not be watered down with words like "suggested". this is one article we ont need more weasel words. as for the coverage i think we need more coverage of Holocene in this article, not less. Anlace 15:08, 8 December 2006 (UTC)

Recently, removed this section:

Other scientists view this estimate as exaggerated, however. For example it can be noted that only 9 species of mammals have gone extinct in North America since Columbus' discovery. Of these, 7 are small rodents [1]. Compared to a background global extinction rate of roughly 2 mammal species per millenia, this is quite high, but probably not enough by itself to make dire predictions about. The most species rich environment on Earth are the rainforest, and their destruction could lead to major losses. However, though 12.5% of the amazon rainforest have been cleared, studies suggest that only a far smaller fraction of its diversity has been destroyed. Because animals and plants can frequently be found in many distant locales within the rainforest, it may be possible to preserve most of the rainforest's diversity in an area 1/3 to 1/2 its original size. Hence conservation efforts may be able to save a majority of these species.

and replaced it with:

A survey by the American Museum of Natural History in 1998 found that the vast majority of biologists agreed with Wilson's assessment, and numerous confirmatory studies in the years since then-- led by the IUCN's annual "Red List" of threatened species-- have now produced a scientific concensus on the subject.[2]

Obviously this is a change in perspective for that section of the article and not one I am entirely happy about. I don't doubt that there is a "mass extinction" ongoing in terms of humanity's reorganization of the environment and ensuing loss of diversity. However, from a paleontological perspective, the extinctions we have caused are no where near the scale of any of the major mass extinctions listed in the article. Maybe our impact could reach that level, but in my honest opinion, most of the near-term dire predictions are grossly overblown. In particular, they frequently apply the species-area relation in a context that has never been empirically verified. In doing so, they predict a number of extinctions based solely on the amount of habitat that was destroyed. However, I have never seen a single field study that concluded that the actual impact even approached the level predicted.

Frankly, this article has a problem in that it only talks about the truly major extinction events, which had profound effects even on global disperse and well-adapted taxa. While the Holocene extinctions might well qualify as a man-made event, to date, they simply aren't in the same category as the major mass extinctions. Perhaps we can discuss extinctions as having a gradiation between local/regional extinction events to those of global scale, and also discuss more of the minor/moderate mass extinctions that have occured in the past. In my opinion, the Holocene extinctions are basically minor so far. Whether they can graduate to major is obviously a matter of debate and should be portrayed as such.

Dragons flight 22:52, Dec 31, 2004 (UTC)

I'm the one ( who made the change you just described. Did you look at the reference link I provided?[3] The issue is not the extinctions that humans have caused so far-- it is the extinctions that are about to take place as a result of the staggering growth in human population and consumption over the past two centuries. It is this impending mass extinction that the world's biologists are warning about. And it certainly does rival the great mass extinctions of the past: the most recent estimate I heard at the California Academy of Sciences two weeks ago was that half of all species will be extinct in 50 years-- i.e., twice as fast as E.O. Wilson's estimate.

Check the list in the ref provided by our anonymous poster, it is quite impressive. I've upped the ante a bit by including the current or Holocene extinction event as #7. No doubt some skeptics will be unhappy and probably claim that its all some large, flaming political agenda as someone so eloquently put it earlier. So be it. Vsmith 03:17, 1 Jan 2005 (UTC)
Vsmith, you cited IUCN, without realizing that their own rate estimate of 2300 species extinctions a year predicts the extinction of only 1% of species in the next 50 years. (This compares with Wilson's 27000 - 100000 species extinctions a year, which is certainly on the high side of views held by scientists). Secondly, the 1998 AMNH study only showed that most biologists agreed that the current rate of extinction is historically very high, not that they endorsed Wilson's position. And they are right, a 1% turn over would be phenomenally high since 1% would be more typical of a million years. I don't disagree that the extinction rate is currently enormous. But I don't believe there exists a consensus that the current rate is high enough to lead to a MAJOR mass extinction in the near term.
Wilson holds an extreme position in a field where the scale of the problem is still being actively debated. I will provide more documentation for the more moderate position before updating this further. Dragons flight 03:58, Jan 1, 2005 (UTC)
Dragons flight (this is speaking!): The AMNH study said "The majority (70%) polled think that during the next thirty years as many as one-fifth of all species alive today will become extinct, and one third think that as many as half of all species on the Earth will die out in that time."[4] And the IUCN estimates that one in four mammals, one in three amphibians, and one in eight birds are now threatened with extinction.[5] I don't know where you got your figure for the IUCN estimating "2300 species extinctions a year." Can you give a reference? I don't recall the IUCN ever giving an estimate of the total number of species they believe are going extinct per year-- in fact, they seem to systematically avoid such global estimates, carefully limiting themselves to talking only about the groups of species (mammals, birds, and now amphibians) that they have fully evaluated.
Maybe what you're talking about is the increase of 3,300 threatened species between the 2003 and 2004 Red Lists (from 12,259 to 15,589). However, this figure of 3,300 is not even remotely the total number of species that the IUCN scientists think might be going extinct per year-- it is simply the increase between 2003 and 2004 in the number of species that the IUCN was able to fully evaluate and to conclude are threatened. But the number of species the IUCN has fully evaluated is only a microscopic fraction of the total number of species on earth. As the Executive Summary of the 2004 Red List says, "this figure (15,589) is an underestimate of the total number of threatened species as it is based on an assessment of less than 3% of the world’s 1.9 million described species"[6]-- and even the 1.9 million "described species" are only a small fraction (roughly 10%) of the total number of species on earth, which the IUCN estimates as being between 10 and 30 million.
A good example of how far the figure of 15,589 understates the magnitude of the extinction crisis is found in the fact that the 2004 Red List evaluated only 771 insect species out of the almost 1,000,000 insect species it says have been described[7] (by the way, of these 771 insect species, 559-- 73%-- were found to be threatened). And the 1,000,000 insect species that have been described are only a small fraction of the total number of insect species, which is now estimated at between 4 and 6 million[8]
So let's do the math (just a rough ballpark figure): the IUCN says 15,589 species are threatened, but it has evaluated only 3% of described species-- and described species are only about 10% of the total number of species on earth. So that means the IUCN has evaluated about .3% of the total number of species on earth, and has found that roughly 15,000 of those are threatened with extinction. So if we extrapolate to a ballpark figure, 15,000 X 300 = 4,500,000 species threatened with extinction. Granted that's just a ballpark figure, but the order of magnitude shows why the IUCN scientists and almost every other biologist in the world now think we're facing a mass extinction on the same scale as the other great extinction events in the earth's history.

New edit: Think of processes, of a graph with the numbers of species going down from 100% to 98% over millennia and then rapidly to about 95% in 2000. Then think of the momentum that such a 'system' posesses - to coast along to 90%, to 80%, to 50%, could be easy - do nothing new. The extinction debate should be about what counter forces can Humans begin to apply now so as not only to equal the forces driving extinctions, but to reverse the trend. Only then will the graph bottom out, and a painful, slow recovery begin.

I've made a small 'change of balance' edit and hope to do more. This first point is to reinstate the 'taxonomy' of the sixth extinction. The person who carefully, and I assume factually, records 1/, 2/ ... 6/ and 7/ mass extinction events, with 7/ being the sixth extinction should be - well the word is close to the tip of my tongue )- That person was being devious. I would be grateful to him for removing this confusion from the Article.

I've also removed a line that implied that someone (or more) had received a science research grant to search for a past total extinction! I hope he was alone when he earned his reward. Stanskis 04:10, 12 July 2005 (UTC)

      • I think there might be a Possible Link between unexplained events such as those experienced in a mass extinction in conjunction with where the sun and local planets lie within their travels across the galactic cycle. The Sun rotates around what we guess is a black hole, or a big bar of stars. we only preceve it as fixed because we have traveled such a short leg of this cycle since the age of scientific discovery. It could be that at points during its 65 million year cycle, that we come close to 'galactic clouds' or pulsars or whatnot, which may be the source of some random elements found in various layers of strata. —Preceding unsigned comment added by (talk) 01:30, 23 August 2008 (UTC)

Other Issues

Out of curiosity, is "extinction event" really the standard biological terminology here? Anyone know where the phrase originated? --Ryguasu 22:31 Dec 2, 2002 (UTC)

Yes "extinction event" is what biologists and geologists use. I don't think there is any special story behind the origin of the term since scientists often speak of "events." --mav

Although many life forms may become extinct, this does not necessarily imply that all life ceases to exist…

This seems like an awfully weak statement. If I'm not mistaken, no recorded or even theorized extinction event has ever implied that "all life cease[d] to exist". Sure, it could happen, but even a man-made nuclear winter or other catastrophic climate change would probably leave quite a bit of life, even if it destroyed all of our favorite genera. Surely this could be rephrased more meaningfully. -- Jeff Q 04:07, 19 May 2004 (UTC)

I'd vote for it to be removed. The summaries of the extinctions should make this pretty clear. If there really is a need to note this type of sentiment, it should be something more describing the sheer impossibility of wiping out all forms of life, because of life's resilience and the variability already shown on Earth. Remove oxygen... anoxic forms will take over. Nuclear winter? Bacteria, many arthropods, and probably a great deal of deep sea or chemical-processing organisms will be just fine. Hell... blow up the entire planet, and odds are most bacteria will adapt. This comment only begins to address the problem with viewing everything from a megafaunal PoV. Baryonyx 04:25, Sep 28, 2004 (UTC)

Remove verneshot paragraph

I removed the following questionable material. Verneshot is more untested hypothesis or wild speculation than theory. Google search brings up some bizzare sites. Don't think it belongs here.

An even more recent theory, which is still being evaluated, is that periodic large scale vulcanism along continental rifts may include eruption events named verneshots which launch gigatonnes of rock into sub-orbital trajectories. The consequent impacts are expected to have very similar effects to asteroid impacts. This theory explains the periodicity of extinction events as well as the apparently coincidental occurrence of large-scale impacts and vulcanism for at least three of the extinction events without relying on coincidence in the way that the asteroid impact theory does.

Vsmith 15:03, 31 Dec 2004 (UTC)

If this has a good Reference, use it, and the item can stay in place. It's a long-shot theory to help balance peoples' views against the inevitability of the processes that we take for granted as right an proper - CO2, and all that. Stanskis 04:16, 12 July 2005 (UTC)

We're missing one.

The Eocene Mass Extinction, about 36(?) million years ago. I don't know too many details, but I do know there was a drop in average temperature and a die-off of some mammal groups. Somebody who knows more could fill it in.--Rob117 03:48, 3 September 2005 (UTC)

Missing more than that (though the Eocene is minor on geological time scales). Raup and Sepkoski's Big 5 are End Ordovician, Late Devonian, End Permian, End Triassic, and End Cretaceous. To that one could easily add End Eocene, End Jurassic, End Middle Permian, End Silurian, Middle Carboniferous, Dresbachian (late Cambrian), and Botomanian (middle Cambrian). Depending on which author one chooses to cite there may be more than 20 discernable extinction "events" since the start of the Phanerozoic. Wiki's coverage of extinction events in general is just plain weak (not that I presently have the time to improve it). Dragons flight 05:13, September 3, 2005 (UTC)

Its weak...but you can't do anything about it. Thanks for stopping by. RealityCheck 06:23, 3 September 2005 (UTC)


I have seen various figures for how many years ago each event happened. There seems to be a rough margin of error of about 1 - 3%. And also, some events occured over a few million years, so I think there should be some way to clearly note this on the page. Phaldo December 12, 2005

Extinction events vs Mass extinctions

Geologic time periods and mass extinction events.

I agree with Phaldo that there should be a note in the article drawing attention to the margin of error for estimates of when extinction events occurred. In the External links section, The Sixth Extinction by Niles Eldredge (American Institute of Biological Sciences) puts the dates of the five previous mass extinctions at circa 65, 210, 245, 370 and 440 million years ago. The University of Hawaii's College of Natural Sciences says 65, 208, 245, 360 and 438 mya. A History of the Universe timeline on the University of California's website says 67, 205, 251, 370 and 440 mya. I've also seen a variety of alternative names for the most recent geologic periods. I think these discrepancies should be noted and explained. Non-specialist visitors might feel confused if the article seeks to establish one set of event dates and period/epoch names as difinitive when they've already seen alternative dates and names on other websites which they consider authoritative (universities, encyclopedias).

I found this article after a Google search for info on the five major mass extinctions. I was redirected from Wikipedia's superseded "Mass extinction" article. This article addresses Extinction events in general and includes a list of seven events. I feel there should be a specific section on the five major mass extinctions. I'm not well versed on the subject, which is why I resorted to Wikipedia for a quick summary. There are probably many non-scientists and highschool students who arrive at this article for the same reason.

I was trying to find reliable dates for the five major mass extinctions to include in a chart. I've included the current version of the chart, which I donated to Wikipedia. -- Bookish 12:40, 17 May 2006 (UTC)

Timeline graphic

I just removed Image:MassExtinctionTimeline.png from the article and restored the EasyTimeline version it had replaced. I figured I should elaborate on my reasoning. The EasyTimeline version is much easier to edit, the layout can be customized to different presentation formats (printed versions, for example, or link maps) with arbitrary resolution, and even as it currently stands it's more precice - the image version has a scale marked only at hundred million year intervals whereas the EasyTimeline is set to ten million year intervals. Bryan 07:24, 15 February 2006 (UTC)

Wilkes Land Crater

Added detail on recent report of putative P-T linked crater/mascon finding in Wilkes Land, Antarctica.

Extinction Theory Fallacy

The following text was inserted by (talk · contribs). It is not suitable for a scientific discussion of extinction, but it is cogent and might be suitable for some philosophical or metaphysical article, so I am preserving it here in case anyone knows a suitable place for it. Dragons flight 04:31, 27 June 2006 (UTC)

==Extinction Theory Fallacy==
Certain geotheorists and vitalistic philosophers (vide Buffon, Lamarck, de Luc, Pareto, Sorel, Deleuze, et al) have elaborated theories of eternal life-sustainability or infinite life-resilience in the process of constructing a philosophical problematics of life on earth (vide geosophy). Many of these theories maintain a common speculative or propositional assertion or claim of faith that life in all its manifestations, stages, and permutations is a "permanent integer," an inexpugnable factor in the quanta that envelope, permeate, embody, and constitute all energy. All of these theories contend that all theories of species (as opposed to population) extinction constitute non-malicious fallacies based on the dependence in the biological sciences on empirical proofs of presence or being. These theorists contend that life in its individual instance leaves an eternel, inerradicable, energetic presence-print or residue on the dimensions of time and space, one which grants each cell and thus each creature eternal presence in time and space– essentially eternal life. Such a presence or life would of course not be entirely equatable or identical to the life of, for example, new-born animals, for the simple reason that new-born animals would not have passed through the psychic, systemic, and energetic "trauma" of physical disintegration known as death, but it would nevertheless constitute a continuation of individual presence, not to mention an envolving state of energetic existence, another phase of life. The process of energy utilization would be different in both cases, and this difference would result in post-thanatic (vide thanatos) life being largely removed from and invisible to pre-thanatic life, although it would leave the possibility, if perhaps not the probability, of pre-thanatic life's detection of post-thanatic beings.
A related theory holds that all animals (and one assumes plants) that ever existed from the earliest unicellular life form, to the dinosaurs, to the latest mutant strain of avian flu, continue to exist in some zone or area of the planet and will continue to do so (although perhaps in greatly diminished numbers) until the earth itself ceases to exist. This theory contends that once life assumes a certain form through the processes of evolutionary change that form will eternally abide as an inerradicable part of the biological diversity of the earth through the organism's own undefeatable processes of preservation either as cellular or mitochondrial memory in the body of another organism or by actually finding the most impenetrable enviromental niches permitting its continued survival as a living relic, in certain cases with a relic population consisting of two individuals, or simply a pregnant female or even just a hermaphroditic specimen.

List of doomsday scenarios

Could use votes to save this article, thanks MapleTree 22:26, 28 September 2006 (UTC)

Need to restructure set of pages about mass extinctions

I think the set of pages about mass extinctions needs to be restructured, and in particular detailed discussion of particular extinctions should be removed from the general "mass extinction" page:

  • Before I recently edited it, the general "mass extinction page" presented just 1 theory for the P/T and K/T extinctions. i.e. it was not objective.
  • Adding further theories about P/T and K/T has made the page too long but the analysis of causes is still superficial and not very objective.
  • Meanwhile the page is unbalanced because there's no mention of causes of other extinctions.
  • The length of the page and the space taken up by the causes pf particular extinctions squeezes out disussion of other topics and makes it difficult to add other mass extinctions.

Topics that should be added to the general "mass extinction page" include:

  • The role of mass extinctions in evolution - competitive displacement of dominant groups appears to be rare and mass extinctions create openings for new or previously obscure groups of organisms. The P/T and K/t extinctions are spectacular examples of this.
  • The role of extinctions in evolutionary theory - supporters of punctuated equilibrium place more emphasis on mass extinctions than gradualists do.
  • The distinction between mass extinctions that change ecosystems and mass extinctions that simply kill a lot of species. I remember seeing a web page where a researcher argued that the late Devonian extinction(s) did not change the ecosystem. On the other hand the P/T and K/T extinctions did, even more in the seas than on land - before P/T 67% of known marine organisms were sessile, during the Mesozoic 50% were sessile, after K/T only 33% are sessile.
  • The related concept of key species (I can't remember if that's the right term) - if a lot of key species die the ecosystem changes, otherwise there's a temporary reduction in species but the ecosystem remains much the same.
  • The fact that the background extinction rate appears to have declined over time. Is this real or is it an artefact of e.g. fossilisation or how fossils are discovered?
  • The difficulty of deciding whether an extinction was abrupt or gradual because of the Signor-Lipps effect. This is a large feature of debates about the K/T extinction.
  • A list of all the proposed mass extinctions, including those whose status is under debate. This provides an opportunity to link to pages about each one, and to invite contributions for those which have no detail pages. One good example is the late Pre-Cambrian extinction which killed off the Ediacaran biota (this one is important for both the history and the theory of evolution - see for example Gould's Wonderful Life).
  • A list of hypothetical mass extinctions, i.e. those where we can see adequate causes but have little / no paleontological evidence. For example the O2 extinction and the extinction(s) likely to have been caused by the supercontinent Rodinia.

I also suggest that the "Marine genus diversity" diagram should be reversed - I've seen many presentations with time runing left to right and no other ones with time running right to left, and I think Wikipedia runs the risk of confusing readers if it remains the odd one out. Philcha 07:50, 6 October 2006 (UTC)

I agree, the text you added is much too long and the detail should appear in the specific articles, not here. I do think however, that is there is a leading cause (or causes) then it should be mentioned here, but all the details about what effect it would have or argument about different explanations should be at the subpage not here. Dragons flight 18:27, 6 October 2006 (UTC)

Discussion on end of civilization

Editors input would be appreciated at Talk:End_of_civilization. There seems to be some disagreement what the end of civilization actually means. nirvana2013 17:44, 10 November 2006 (UTC)

Need to include mid-Cambrian (Botomian) extinction

I've seen articles that say this had a major-league extinction percentage, and the "marine biodiversity" diagram agrees with this. It might also be important in terms of biodiversity and ecosystems - I'd have to check how many of the Cambrian explosion's "weird wonders" became extinct.Philcha 14:11, 14 January 2007 (UTC)

Update: Signor thinks a greater % of genera died out than in the end-Permian catastrophe [9], but the main victims appear to have been the small shelly fauna and the archaeocyathids.Philcha 16:44, 21 August 2007 (UTC)

Remove "Magnitude and rate of loss for current extinction"?

This section is in the wrong place within the the article and is as long as all the summaries of past mass extinctions put together. It also looks more like a "talk" item than a contribution to an article, especially the 2 references to Vreugdenhil's blog.

I therefore suggest that the person who added it ([[User:Stevenmitchell | Stevenmitchell) if I've read the history correctly) should move it either to the Holocene extinction event article to to the talk page about that article. That's better than someone else doing it because then the relevant history would show the real author's name.Philcha 17:44, 9 March 2007 (UTC)

I've moved it to Holocene extinction event. Philcha 00:37, 20 April 2007 (UTC)

Well, I won't waste my time again trying to write a serious contribution and then seeing it being completely deleted by knowbetters. I have real work to do to actually try and prevent as much as possible . I thought that it would interest people what the current expectations could be on the basis of a never contested biological curve. I only mentioned a blog because wikipedia asks for references. over and out, Daan Vreugdenhil —Preceding unsigned comment added by Dr. Daan Vreugdenhil (talkcontribs) 11:39, 1 March 2008 (UTC)

Most widely-supported explanations: Sustained global cooling

Section "Most widely-supported explanations: Sustained global cooling" says, "The glaciation cycles of the current ice age are believed to have had only a very mild impact on biodiversity ...". I've tried to find citations to support this and the first relevant material I found ([10]) contradicted it, saying that the long cooling beginning 3.2MYA in the run-up to the glaciations caused marine and terrestrial extinctions all over the world. Can any one supply citations (a) to support what the article currently says; and / or (b) to contradict it, as the one I found does. Philcha 13:58, 20 April 2007 (UTC)

Cosmic radiation

There's another interesting hypothesis for a 62 million year extinction cycle based on Cosmic Radiation effects when the Sun travels out of the Milky Way plane along the (northern) leading edge of the galaxy's collective motion.[11] It sounds at least somewhat plausible. — RJH (talk) 20:41, 20 April 2007 (UTC)

The Timeline...

Is upside down. Negative numbers need to be used: I'd fix it myself if I had time...

I've been thinking of whipping up an SVG version of it anyway, I'll fix it when I do that. Bryan Derksen 02:41, 14 July 2007 (UTC)
There, how's that? Bryan Derksen 03:16, 14 July 2007 (UTC)
Much better! Thanks! The only down side with using a graphic is that it is harder for people to update. That said, extinction events are now precisely enough dated that this oughtn't to be in issue. Cheers, Verisimilus T 13:44, 14 July 2007 (UTC)
On the other hand if people do update it there will be many more options than there would be with EasyTimeline. It's a tradeoff, and the old EasyTimeline code is still in the article history so we can always dig it up again if need be. Bryan Derksen 17:41, 14 July 2007 (UTC)
Incidentally, could I ask what program you used to create the SVG? I've tried a few but can't find anything satisfactory... Verisimilus T
I used Inkscape. Sorry, neglected to mark that on the Commons page. Bryan Derksen 17:41, 14 July 2007 (UTC)
Just a quibble, but being unconventional isn't the same as wrong. It never really bothered me to show it the way it was, though I'm fine with the current one too. Dragons flight 17:50, 14 July 2007 (UTC)
Conventions do exist for a reason - once you're used to time going upwards, anything else can be disorienting (for me, at least)! Verisimilus T 19:20, 14 July 2007 (UTC)
The things I don't like about this orientation is that now the text list goes in the opposite direction from the graphical timeline (easily fixable by reordering the text list) and the order of the period names is opposite from how they're used in the article (Tertiary-Cretaceous vs. Cretaceous-Tertiary). But if there's a convention to have timelines run a particular way I don't feel strongly enough about it to go against that. Unless perhaps a horizontal timeline would work better? Bryan Derksen 05:57, 15 July 2007 (UTC)
In terms of a horizontal timeline, the diversity chart already fulfils this role in a perhaps more informative way... You're right though, I hadn't picked up on those weaknesses with the right-way-up timeline. Hmm... Verisimilus T 09:13, 15 July 2007 (UTC)

Evolutionary importance of mass extinctions

Someone has inserted extraneous material into the 1st para of this section. I propose to remove the extraneous material, leaving only the 1st and last sentences.

Someone has added a "POV" tag to to the 2nd para, which represents AFAIK the current consesus and whose purpose is simply to provide a well-known example of how extinctions can open the door for evolution. I propose to remove the "POV" tag.Philcha 09:27, 19 July 2007 (UTC)

I've now removed the extraneous material and "POV" tag.Philcha 00:53, 3 August 2007 (UTC)

Implication of the title

I wonder if the article should also give some material or reference to events which could cause complete extinction of all life on earth, say an impact by a large asteroid which would destroy all life on earth including bacteria. The article seems to emphasise 'extinction' more than 'event'. AshLin 15:31, 19 July 2007 (UTC)

OMG, now an electrical engineers is becoming interested in extinctions!!!! You know, this is interesting. Last night, while eating dinner, I watched a program on Discovery Channel HD about a massive extinction event. Though probably very low probability now, because it would require an almost planet to planet collision, researchers believe that bacteria would survive in some very isolated deep earth pockets. If all life were destroyed, I would suggest that that would be it. Abiogenesis is an extraordinarily rare event--I personally believe that life outside of earth, if it does exist, is so rare that there is probably no chance for us to find it. My next project is touching up the Permian-Triassic extinction article, then keep going back. I think a total extinction event is either speculative (so not sure how we can create an article) or happened so far in the past that we may not have sufficient fossil evidence. Each extinction event going further back in time, becomes more and more difficult to analyze.Orangemarlin 17:02, 19 July 2007 (UTC)

Indeed, as bacteria live and multiply in rocks several kilometers below the surface, it would take an almost-complete destruction of the planet to remove all life from Earth. Tim Vickers 17:37, 19 July 2007 (UTC)

Thats really interesting. Do we have a wiki on such bacteria? I was under the impression that a 200km dia comet would be enough to wipe out all life. Shades of Deep Impact with its reference to 'Ellie'!
BTW, this electrical engineer started Wikipedia:WikiProject Lepidoptera and has an ambitious project of tackling 1000 Indian butterflies and 10,000 moths besides about 400 odd snakes! ;-) Nope, not a single edit about my electrical engineering - my craft or trade and just one GA review on soldiering my chosen profession. Hobbies rule on Wikipedia!AshLin 18:17, 19 July 2007 (UTC)
Atomic powered bacteria 2.8 km down. [12]. What would we call such an event? Meggar 18:29, 19 July 2007 (UTC)
Thanks for the url, very interesting!AshLin 14:00, 21 July 2007 (UTC)
We'd call it, We're Up The Creek without a Paddle Extinction Event. I could simplify that title, but I might offend someone.  :) Orangemarlin 20:06, 19 July 2007 (UTC)
BTW, Mr. Electrical Engineer, actually bacteria can survive some very harsh conditions. On the program that resurrected some Permian (I'm not sure if that's what he said, but I swear it was) bacteria locked in pockets of water within salt crystals. I'm not sure how wise it is to resurrect Permian bacteria (life on earth has no resistance to such an ancient microbe), but that wasn't he point. 200 million year old bacterial spores is quite impressive. Also, bacteria survive in some very hot locations (look at thermal hot springs, for example). The program stated that even a planet to planet collision would not cause heat to be equally distributed across the planet. Some deep earth locations (2000-5000 m below the surface) would be cool enough to allow bacteria to survive. But cockroaches would definitely not.  :) Orangemarlin 20:06, 19 July 2007 (UTC)
I'd say, fine. But such an event which extinguishes all (including cockroaches) but may leave some life behind also needs a paragraph to tell it like it is. More people have seen Deep Impact and had the words 'ELE' impacted on their memories and believe it to be completely true than ever looked at this article in Wikipedia. But some will definitely come this way. As the major article on extinction events, such large, though low-probability events deserve to be dealt with - NPOV and all that jazz.AshLin 13:40, 21 July 2007 (UTC)
I may have an overactive imagination but do all WP Extinction articles suggest feminine names, fitrst Katie now Ellie, ;-).AshLin 13:40, 21 July 2007 (UTC)


Isn't the loss of Ediacarian life a mass extinction? (talk) 08:48, 14 March 2008 (UTC)

Find a reliable source that classes it as such, and we can add it. --Anticipation of a New Lover's Arrival, The 14:04, 1 April 2008 (UTC)

Best known claim?

The line, "the best-known of these claims is the 26M to 30M year viral cycle in extinctions proposed by Raup and Sepkoski (1986)," made me somewhat suspicious. I hadn't heard of this claim, and yet I'd heard of some of the others. So, I followed the citations to see if it backed up this claim, and there was noting in that paper that made any claims to breadth of familiarity. -Miskaton (talk) 22:28, 2 April 2008 (UTC)

Gamma Ray Bursts

The article says that a burst within 8000 light years of Earth would destroy organisms and the O-Zone layer. While the article on GRB's agrees on the first point, that a burst within 6000 light years would cause a mass extinction, it differs on the latter, in that the burst wouldn't destroy the ozone layer, but rather that it would destroy half of the O-Zone layer, because the other side would be in the 'shadow' of the burst, and basic physics agrees with that, because any GR's that hit the Earth would be stopped by the Earth itself, in the same way that a tennis ball wouls stop the light from a flashlight. Also it would take a birst of at least 10 seconds for it to do that much damage, so its not like a quarter second burst would wipe out the world as we know it. Perhaps a re-wording of the article is needed to make it clear that there would be some O-Zone left and also to make it a little clearer that it would only be a mass extinction, not a total one, which is what I thought it said the first time I read it. (talk) 19:57, 10 April 2008 (UTC)

Ozone is destroyed by the nitrous oxides and other reactive chemicals in the atmosphere created by the burst, so it consumes the ozone on the other side too. Dragons flight (talk) 21:16, 10 April 2008 (UTC)

Image:Phanerozoic Biodiversity.svg

This could be useful for explaining the difference between "extiction" and "change in diversity". I've asked the image's author if he can turn the image round so that time runs left to right and if he can remove thetext so it can be added via Template:Annotated image -- Philcha (talk) 12:54, 13 September 2008 (UTC)

Wouldn't have to turn the image, if people had left "Extinction event" in the orientation it was published in to begin with. Dragons flight (talk) 15:12, 13 September 2008 (UTC)
Left-to-right time is a bit more intuitive, at least for laypeople. -- Beland (talk) 07:39, 15 September 2008 (UTC)


Consider that:

  • Image:Extinction Intensity.png lists both major and minor events, but can't link to articles because it is a flat graphic.
  • {{Annotated image/Extinction}} has links to articles, but only the major ones because it would be cumbersome to add in-graphic links to all the minor events.
  • {{ExtEvent nav}} has serious layout problems, doesn't show the "extinction intensity", and doesn't include many of the minor events.

I think it would be useful to have a new graphic that would show all the minor events on a vertical axis (putting the oldest events at the bottom, to match the period-to-period navigation convention). It could have the columns: Mya, Period, Event name/link, Extinction intensity (bar graph). Does that sound like the best approach? -- Beland (talk) 07:52, 15 September 2008 (UTC)

Or a table with the same info. I'd include all the known events, so users don't have to scroll around and then merge the info in their heads. I think we could still make the backgrounds of the "period" cells match the standard colours, although I'm not keen on that since the period names don't stand out so well as they are usually wikilinked. OTOH we might use the period colours as bg but give the labels white bg, if that doesn't make it look like measles.
Biggest problem would be the 3-pulse Late Devonian extinction - AFAIK no single pulse was huge but the cumulative effect was severe. P-Tr might also be tricky: elevated rate througout 2nd half of P, then 2 pulses - but we could summarise the total of the 2 final pulses, as they were close together. -- Philcha (talk) 10:23, 15 September 2008 (UTC)

Proposed merger of The Big Five

It has been proposed that The Big Five be merged into this article.

  • qualified support The Big Five duplicates content in this article, which should be merged with this article. However it also contains more detail about some of "The Big Five" than is appropriate for this overview article. The more detailed content should be merged into the articles on the specific extinctions. -- Philcha (talk) 10:29, 15 September 2008 (UTC)
Even though I am the one who created the The Big Fivearticle, I must agree--Dale S. Satre 22:08, 17 September 2008 (UTC) —Preceding unsigned comment added by Dale S. Satre (talkcontribs)

I implemented the proposed mergers, though some post-merge cleaning up of the target articles may be in order. -- Beland (talk) 20:50, 30 September 2008 (UTC)

Set of extinctions described

We need to sort out how this article lists extinctions:

  • The "Marine extinction intensity through time" diagram highlights the Big Five, although others are visible and the end-Botomian and end-Dresbachian have % scores higher than some of the Big Five. Perhaps we should note the Big Five for historical reasons, but otherwise de-emphasise the term as obsolescent.
  • Section "Major extinction events" lists 7. Those not highlighted in the "Marine extinction intensity through time" diagram are Tr-J and Holocene. I'm happy about including Tr-J as it may have been the dinos' lucky break, see Superiority, Competition, and Opportunism in the Evolutionary Radiation of Dinosaurs. The Holocene extinction is tricky: there's a fair amount of WP:RS literature about it; but its method of counting / estimating differs significantly from that used in the earlier ones. I'd move the sentence "Some paleontologists, however, question whether the available data support a comparison with mass extinctions in the past" to 2nd sentence so readers can see up front that theres' a difference.
  • A recently-added section "Minor events" sprawls far too much and the only cited source is "Partial list from Image:Extinction_Intensity.png". I think this is clearly WP:OR. The list is also a real mixed bag. For example the end-Botomian and end-Dresbachian have % scores higher than some of the Big Five and I already know a source or 2 for end-Botomian; but Ireviken event cites only one locality, so at present that article offers no evidence that it was wide-spread.

Since known significant extinctions are likely to increase as paleo knowledge increases, I propose a "List of extinction events" artilce to summarise all known extinctions. I suggest its main content should be a table: date (range); name; impact; notes, which can cover how wide-spread, severity, very brief description with internal link to further details in same article if necessary.

That leaves the question of which event should be mentioned specifically in Extinction event. I suggest:

  • Holocene, but possibly with stronger qualifications about difference in counting.
  • The Big Five.
  • Tr-J
  • end-Botomian and end-Dresbachian. High % extinction rate. One (can't remember which) has been described as a significant change in composition of Cambrian fauna.

That list has some implicit criteria - an extinction should be included if it satisfies one of:

  • wide-spread and % extinction rate at least 70% of Big Five - 70% is a rough guess, we may have to adjust to avoid having too many borderline cases; a "list of" article will help in showing the frequency distribution of % extinction rate.
  • significant change in ecosystems. It's hard to define "significant" up front, and we may need tohandle this case by case.

-- Philcha (talk) 11:16, 15 September 2008 (UTC)

List split?

So it's been proposed to create List of extinction events, but we already have Timeline of extinctions. But that only covers historical extinctions on a per-species basis, whereas here we cover both historic and pre-historic extinctions en masse. Should we have Timeline of extinction events with links to "event" articles from a big long table, as proposed above, or something else? -- Beland (talk) 21:04, 30 September 2008 (UTC)

As you point out, the timescale and extinction scale are totally different. A full list of paleo mass extinctions would still be a good idea, I think. -- Philcha (talk) 22:05, 30 September 2008 (UTC)
But where does one draw the line when deciding what qualifies as a mass extinction? Don't Template:Extinction events and The big five fulfil the role already? Martin (Smith609 – Talk) 03:20, 1 October 2008 (UTC)
All genera
"Well-defined" genera
Trend line
"Big Five" mass extinctions
Other mass extinctions
Million years ago
Thousands of genera
Phanerozoic biodiversity as shown by the fossil record
Benton M.J. and Harper.D.A.T "Basic Palaeontology" (1997; Addison Wesley Longman) allegedly defines "mass extinction" as "the loss of 10% or more of families, and 40% or more of species, in a short time"
A timeline diagram gives some perspective to the dates and period names, but that's all, and runs out of space quickly. For example Template:Extinction events graphical timeline would need considerable rearrangement to accommodate the PETM extinction or the apparently three Cambrian extinctions, which have an apparent % loss in the Big Five range, although the decline in total recorded biodiversity was apparently small and the end-Botomian extinction may have been an artefact due to the sharp decline of phosphatic preservation - which is the kind of info that could go in a "notes" column in a table. -- Philcha (talk) 07:05, 1 October 2008 (UTC)

Oxygen catastrophe?

Why is the oxygen catastrophe of ~2.7 bya and its associated massive extinctions not included? Vultur (talk) 23:35, 1 December 2008 (UTC)

These were 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) 08:51, 2 December 2008 (UTC)
To paraphrase Butterfield 2007, pre-Phanerozoic communities were stable and didn't really undergo "mass extinctions". I agree that this should be noted in the article, though! Martin (Smith609 – Talk) 22:53, 2 December 2008 (UTC)

Holocene extinction

I undid this edit because:

  • Paleontologists' "Big Five" does not include the Holocene extinction and AFAIK the O-S extinction is still rated the 2nd largest in % terms (after P-Tr).
  • The estimating methods for the "Big Five" and the Holocene extinction are different - for the "Big Five" it's taxa in the fossil record before and after the extinction, and Holocene extinction event is unclear about how extinction rates for the Holocene extinction are estimated. Note the statement (with citation) "Some paleontologists, however, question whether the available data support a comparison with mass extinctions in the past."
  • Any further statments that claim that the Holocene extinction is comparable with the "Big Five" will need citations that define the estimating metohds clearly, otherwise this article will wind up comparing apples and oranges. --Philcha (talk) 14:11, 27 December 2008 (UTC)

Period of Sun's orbit around the galaxy wrong?

In the section titled "Passage through galactic spiral arms" a value of 700 million years is given for the orbital period of the Sun around the galaxy. There are a number of sources that place this value closer to 200-250 million years. One is the Wikipedia enter titled Milky Way. "It takes the Solar System about 225–250 million years to complete one orbit of the galaxy (a galactic year),[37] " Amazedbyitall (talk) 06:33, 29 January 2009 (UTC)

The Earth orbits the center of mass of the galaxy every 225 Myr, give or take, but the spiral arms are also orbiting, albeit at a different rate. The time required to pass through all of the spiral arms is thus determined by the difference in these two rates of rotation and consequently much longer. Dragons flight (talk) 06:38, 29 January 2009 (UTC)

Reference needs to be added

Are periodic mass extinctions driven by a distant solar companion? Whitmire, D. P.; Jackson, A. A. Nature (ISSN 0028-0836), vol. 308, April 19, 1984, p. 713-715. (Nature Homepage) 04/1984 --aajacksoniv 19:30, 27 April 2009 (UTC) —Preceding unsigned comment added by Aajacksoniv (talkcontribs)


incorrect reference #52 Error--Page not Found —Preceding unsigned comment added by (talk) 17:14, 13 March 2010 (UTC)

gnome work

the major and minor timescales go in opposite directions. Needs fixing Andrewjlockley (talk) 01:29, 11 August 2009 (UTC)


Is a major Impact event triggering the the volcainsm ? as both are often associated with a mass extinction ? Photnart 04:24, 20 November 2009 (UTC)

Sea-level falls – Clarification

The article mentions:

"But sea-level falls are very probably the result of other events, such as sustained global cooling or the sinking of the mid-ocean ridges."

When one discusses the mid-ocean ridges, the first question that pops into my mind is where is it going?

The way I'm thinking about it is a shift in mass from the ocean seabed to the continents, or processes that would make the continents smaller and taller would tend to cause the sea level to fall. This would include the sequestration of water in the form of ice

Processes that transfer mass from on the continents to the sea such as erosion or melting of ice would tend to make the sea level rise.

So, if a force such as subduction moved mass from under the seabed to depositing the material in with the Cascade Mountain Volcanoes, then that would be equivalent to removing the equivalent amount of mass displaced by the mountains from the ocean.

If, on the other hand, India collides with Asia, the Himalayan mountains are pushed up, and essentially the continental area is decreased and the oceans levels could fall.

Anyway, it seems as if the concept of transferring matter from the ocean to the continents needs clarification.--Keelec (talk) 19:05, 21 February 2010 (UTC)

Graphic Kvetching

It would be nice if the graph at the top of the page had its X/y axes labeled.

Basesurge (talk) —Preceding undated comment added 08:28, 7 April 2010 (UTC).

97% huh?

The intro overboldly states:

Over 97% of species that ever lived are now extinct

How the heavens can such a precise number be determined?? My questions are: 1. Do we know the current number of species by a precision better than 1:10? 2. Do we know the general life time of a species? 3. Do we actually know the extinction rates of former extinction events, counting all species (f.ex. archaean species)? 4. The sentence, in current form, also implies that a. all precambrian is accounted for, b. extraterrestial species are accounted for. 97% is overly absurd in the context of "species that ever lived". Rursus dixit. (mbork3!) 11:17, 11 April 2010 (UTC)

If I understood it right, it is an estimate based on Mollusc/ Marine fossils. Sepkoski, J.J. (1996), "Patterns of Phanerozoic extinction: a perspective from global data bases", in O.H. Walliser, Global Events and Event Stratigraphy, Berlin: Springer, pp. 35–51  . Sepkoski's Global Genus Database of Marine Animals. Rohde, R.A. & Muller, R.A. (2005). "Cycles in fossil diversity". Nature. 434: 209–210.  Supplementary Material. --Chris.urs-o (talk) 11:42, 11 April 2010 (UTC)

Quote: "With kill rates for species estimated to have been as high as 77% and 96% for the largest extinctions." (Raup, David. M., 1979; Valentine et al., 1978). Raup, David M. and Sepkoski, J. John, Jr. (Feb. 1984). "Periodicity of extinctions in the geologic past." (PDF). Proc Natl Acad Sci U S A. 81 (3): 801–805. Retrieved 14-04-2010.  Check date values in: |access-date=, |date= (help) , (Raup, D.M. 12 October 1979. Size of the Permo-Triassic Bottleneck and Its Evolutionary Implications. Science. 206 (4415), 217-218, DOI: 10.1126/science.206.4415.217.) (Quote: "Rarefaction analysis of extinctions in the Late Permian indicates that as many as 96 percent of all marine species may have died out, thus forcing the marine biosphere to pass through a small bottleneck." [13]), (J. W. Valentine, T. C. Foin, and D. Peart; January 1978; A provincial model of Phanerozoic marine diversity; Paleobiology; 4 (1); p. 55-66.). If I'm right: 4% survivors (96% kill rate) times 23% kill rate and others, equals less than 0.9% survivors (more than 99.1% kill rate) for the marine species, it seems ok for me... If the marine environment is bad, the terrestrial environment must be even worse. My personal opinion: species give a lil bit the wrong picture, genera would be better. Ok Philcha, I was just trying to prove that a kill rate of more than 97% is ok, although not in this formulation. --Chris.urs-o (talk) 08:28, 14 April 2010 (UTC)

Hi, Chris.urs-o, thanks for the refs. But I don't think there's a need for additional arithmetic – Raup's Size of the Permo-Triassic Bottleneck and Its Evolutionary Implications says marine 96% kill rate at P-Tr. The deaths of 96% of marine species at the P-Tr is often quoted, so I think it would be WP:OR to omit it. And I can see why a species figure could be significant (my OR :-D) – species reproduction. As for land: IMO fixing the P-Tr boundary on land was difficult (I've not looked at this for a while), but for a few Myr almost the only land vebretrate fossil was Lystrosaurus, which was cosmospolitan. --Philcha (talk) 13:05, 14 April 2010 (UTC)

Magnetic field

In Bill Bryson's "A Short History of Nearly Everything", he mentions that the changes in Earth's magnetic field can also lead to devastation. Such as when the field diminishes while in the process of flipping, cosmic rays would shred living beings' DNA to pieces. Is this a legitimate probability in any of the events? Rgrds. (talk) 10:28, 13 May 2010 (UTC)

Earth's magnetic field#Magnetic field reversals occur all 300 ka, the last one occurred 780 ka. Regular events of a cycle are expected by nature and so the event alone do not cause an extinction event, but could worsen one. --Chris.urs-o (talk) 19:24, 13 May 2010 (UTC)

Automate archiving?

Does anyone object to me setting up automatic archiving for this page using MiszaBot? Unless otherwise agreed, I would set it to archive threads that have been inactive for 30 days and keep ten threads.--Oneiros (talk) 13:40, 14 May 2010 (UTC)

Yes check.svg Done--Oneiros (talk) 19:30, 18 May 2010 (UTC)

Mass Extinction Events – poor values for comparison

While the percentage of total families and total genera wiped out by each of the major five extinction events is given, the comparability falls short on the count of species as well as on dividing genera or species between land and sea. For the Late Devonian and Cretaceous-Tertiary events, the total percentage of species wiped out is given; however, for the Permian-Triassic event the percentages of land and marine species wiped out are given separately. Without knowing what percentage of the total species were marine-based and what percentage were land-based, it is not possible using this information to make an accurate comparison between the scale of the Permian-Triassic event and either of the other two aforementioned events in terms of species wiped out. Furthermore, the Triassic-Jurassic and Ordovician-Silurian events make no mention at all of the percentage of species wiped out, though I can understand if that data is simply not available (particularly for the latter event).

My point here is that tweaking the section to increase consistency in the stats given would be beneficial for people wishing to do a quick comparison of the various events. Granted they can still compare by genera or families; however, this strikes me as a less accurate and perhaps less useful comparison.

Thoughts on the matter? Celtic Minstrel (talkcontribs) 04:54, 9 June 2010 (UTC)

It's ideal, but we need verifiability. We can't do original research on the Sepkoski's Database, we need references. We could just use the data on Shells of Mollusca. Maybe it is better to concentrate on the graph based on Rohde & Muller (2005, Supplementary Material). (Rohde, R.A. & Muller, R.A. (2005). "Cycles in fossil diversity". Nature. 434: 209–210. doi:10.1038/nature03339. It is well known that the diversity of life appears to fluctuate during the course of the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0–542 million years ago). Here we show, using Sepkoski's compendium of the first and last stratigraphic appearances of 36,380 marine genera, a strong 62 ± 3-million-year cycle, which is particularly evident in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance we also consider the contributions of environmental factors, and possible causes.  ) --Chris.urs-o (talk) 05:37, 9 June 2010 (UTC)
How is event defined? The early-mid-Maastrichtian marked the end of the large-Dinosaur stratum. The avian Dinosaur genera obviously made it through the KT-event. The mammal genera found it's way through the event. Five major extinctions are defined, but what citeria is used to classify these as event transitions versus million year gradients? —Preceding unsigned comment added by Morbas Morbas (talk) 13:16, 17 June 2010 (UTC)
Seems signals over a baseline. --Chris.urs-o (talk) 12:05, 17 June 2010 (UTC)

Quote: "The data itself is taken from Rohde & Muller (2005, Supplementary Material), and are based on the Sepkoski's Compendium of Marine Fossil Animal Genera (2002). Note that these data do not represent all genera that have ever lived, but rather only a selection of marine genera whose qualities are such that they are easily preserved as fossils".

These are intensity signal over base line. Event relates to specific causality of bollide, or erruption, or physical events? So this article is premised on event causals. And, if so, I somehow object to inclusion outside of the Bollide events.Morbas (talk) 13:25, 17 June 2010 (UTC)
I do not know, if I undertood u right. As I understand, this is Sepkoski's Database, Rohde & Muller (2005). The fossils disappear each time period. There is a baseline, there are signals, these are facts. The causes are a matter of dispute, the discussion is not settled yet, these are speculations. --Chris.urs-o (talk) 13:50, 17 June 2010 (UTC)
I will not challenge a data base, other than peer controversy (if any) surrounding that datum. What I was relating to (perhaps a symmatic) is event definition. The Cretaceous bollide 65Ma ago was a physical event. Cracatoa was an event. Interpolating genera levels by themselves, does not indicate an event without a peer controversial tail. So, in a Genera level context, can you differemtiate an extinction event from a gradual (Ma) change of dominant species? Must be a criteria published somewhere.Morbas (talk) 19:07, 19 June 2010 (UTC)
As I understand, there is a background extinction level of genera (baseline). There is an uncertainty (noise). There are spikes (signals), major (6: Cambrian–Ordovician extinction events, Ordovician–Silurian extinction event, Late Devonian extinction, Permian–Triassic extinction event, Triassic–Jurassic extinction event (ETE), Cretaceous–Tertiary extinction event (K/T)) and minor extinction events (5: End-Ediacaran extinction, Lau event, Toarcian turnover, Aptian extinction, Middle Miocene disruption). In the German Wikipedia, they talk about mainly Mollusca shells fossils. So simple are both graphs. That's it... Just these show themselves... --Chris.urs-o (talk) 06:25, 19 June 2010 (UTC)
This might help you: Carpenter, P.A.; Bishop, P.C. (December 2009). "A review of previous mass extinctions and historic catastrophic events". Futures. 41 (10): 676–682. doi:10.1016/j.futures.2009.07.012.  --Chris.urs-o (talk) 08:03, 20 June 2010 (UTC)

Guessing the definition is signal over base line, a visual graphic rule. Chris I read only the overview, are you suggesting a better defintion is in the full article? Morbas (talk) 00:47, 21 June 2010 (UTC)

I just suggested it, because it is 2009, up to date, haven't read it either. The disapperance of your big terrestrial dinos and the disapperance of mainly marine Mollusca fossils shells are two different things. --Chris.urs-o (talk) 05:39, 21 June 2010 (UTC)
Bruce S. Lieberman and Adrian L. Melott (2007 August 22). "Considering the Case for Biodiversity Cycles: Re-Examining the Evidence for Periodicity in the Fossil Record". PLoS ONE. 2 (8): e759. doi:10.1371/journal.pone.0000759. PMC PMC1945088free to read Check |pmc= value (help).  Check date values in: |date= (help) and Andrew B. Smith and Alistair J. McGowna (2007). "The Shape of The Phanerozoic Marine Palaeodiversity Curve: How Much Can be Predicted from the Sedimentary Rock Record of Western Europe?" (PDF). Palaeontology. The Palaeontological Association. 50 (Part 4): 1–10.  are cheaper. --Chris.urs-o (talk) 10:44, 21 June 2010 (UTC)

Thanks Chris, It appears the analysis is targeting a nominal Galactic z-axis period of 62 Ma. Several big programs have been used to uncover periodicity based on interpretations of biodiverisity and even differential of genera types. I think arguments like this get published for reasons other an accuracy such as technical discipline(s) [not saying that technical discipline was done incorrectly]. You differentiated 'big terrestrial dinos' from 'Mollusca fossils shells', both Cretaceous I presume. Just marveling how ingenious we are at not finding the fundamental zero deviation 417 Ma year embedded the ICS ISC chronology.Morbas (talk) 02:51, 25 June 2010 (UTC) Morbas (talk) 02:52, 25 June 2010 (UTC)

Ok, ... --Chris.urs-o (talk) 03:59, 25 June 2010 (UTC)
The ICS International Stratigraphic Chart (ISC) is an organized geologic structure. The Extinction Event organizes events per this structure. Without presuming content, can we devise a Wiki article to organize this structure, sort of the top tree index. The branches (cross links) providing a informative organization. From my pernicious perspective, we would have perspective of the highest level patterns. The encyclopedia (of life) would be organized based on a hierarchical perspective...I apologize for crossing the discussion guidelines.Morbas (talk) 14:06, 25 June 2010 (UTC)
I'd not change the major and minor extinctions events. They are well referenced. The data is actually still scarce. --Chris.urs-o (talk) 04:32, 26 June 2010 (UTC)

Lesser extinctions

Definiton circa: about: used before an approximate date. The geologic dates, while in the past, and certainly changing with geologic methodology, are not circa dates. I think context is way out of scope for this preposition...just use 'Ma-ago'.Morbas (talk) 20:39, 18 July 2010 (UTC)

Could you please clarify what you're trying to say. --Philcha (talk) 23:10, 18 July 2010 (UTC)
I have not seen circa used in a geologic paper. Assuming you mean these dates are approximated, what is the tolerance you have references on?
P-Tr 251Ma-ago(0.4) meaning a confidence of +/-0.4M year [1]ICS International Stratographic Chart 2008.Morbas (talk) 03:37, 7 August 2010 (UTC)

Galactic Extinction Cycle

Extinction cycles are linked to two sets end Ordovician, end Permian, end Cretaceous and start Cambrian, end Devonian, end Triassic zones pointing to a 703.8 (+/-3) Myr four arm cycle. The theory includes presumed superchrons (geomagnetic reversals) and arm speed, and indicates a repetition at the mid arm points. Dependence of a meteorite impact pattern with a threshold of 20Km diameter is indicates a pattern extending to 2Ba ago. The coherent pattern indicates a galactic causal mechanism.

[1] Gillman and Erlener, Galactic Cycle of Extinction, International Journal of Astrobiology 7 (1) : 17–26 (2008) Morbas (talk) 11:51, 20 October 2010 (UTC)

I do not know the peer status of this article. Wiki Geomagnetic reversal discounts extinction superchron association.

Morbas (talk) 11:51, 20 October 2010 (UTC)

Alroy (2008) discounted any cyclicity in extinction events. Martin (Smith609 – Talk) 13:29, 20 October 2010 (UTC)
Now we have two published papers in conflict. To be unslanted, both must be presented. I asked for the peer status of Gillman/Erlener Galactic Cycle of Extinction. Would it be posted in the International Journal of Astrobiology, and do you have copy or open source to any critique? Morbas (talk) 14:56, 20 October 2010 (UTC)
Gillman & Erlener have also been criticised and roundly refuted by:
You may also note that Gillman & Erlener are already referenced in the article. You are right to point out that there is not enough criticism to present an unslanted view, so I've added the other two references that I found. Martin (Smith609 – Talk) 15:10, 20 October 2010 (UTC)
Incidentally, your first cite supports the existence of a 62 Myr that is interesting and worthy of further study. It cites the works of Melott and Liebermann that also support the statistical inference that this feature is significant, though it does also cite works that raise a variety of questions about the relevant conclusions. Both papers you cited argue that the proposed astrophysical models are probably wrong, but that's not the same as saying the cycle doesn't exist. Dragons flight (talk) 21:33, 20 October 2010 (UTC)
Well, published and peer reviewed astrophysic models...not giving up on that yet...Where these fail IMHO is failing to define the major geologic divisions and not telling us something more of causality.Morbas (talk) 23:23, 20 October 2010 (UTC)
Dragons Flight and Smith609,
The 417Myr table is WIP on my page, addressing the Smith609 slant issue. It is interesting to see that the Cambrian start date has been replaced by the Varangian.Ediacaran start date in the ICS 1998 chart. I view that the PreCambrian as largely unconstrained. I may further change the table with the 1998 datum. Please review, and discuss any remaining slants.Morbas (talk) 04:51, 21 October 2010 (UTC)

The ICS delta's (commutating intervals) are derived by an eliptical SOL Galactic Orbit, if the arms and central bar are causal to Periods and PER. The PTr PER point is at apoapsis and the Oligocene and OS is at periapsis. Gilman-Erlener 704M period then is close to 714M, but no cigar (2.5% error)? I wrote to these guys, yet to hear from them tho..IMHO a Havana is deserved...

The ICS period data shows near zero 417Ma Period sets, upon which ride the Big 6,5,4..1 extinctions. These are shown in Wikipedia Extinction Event-Physical Driver section. Taken separately, extinctions and Periods have poor statistical periodic regularity, but extracting the Kevet PER (which appears to be 417/2 Ma itself) the ICS physical boundaries have 417Ma pairings, and further have a commutative pattern. This pattern shows an PER apsis axis, indicative of Galactic Arm and slight SOL Galactic ellipsis interception points.

Morbas (talk) 17:43, 19 December 2010 (UTC)

Patterns in Frequency

This section is principally a refute of itself ! Logically it is better suited as an inclusion in Most widely supported explanations section. It is not about patterns in frequency, rather presents an opinion that no pattern exits. It needs work, like all the theories it seems to discuss.

To whomever wrote this...please overwright this disussion critique with your objectives and the frame you are striving for.

Comments please ! Morbas (talk) 16:30, 20 December 2010 (UTC) |}

Geologic Chronology

The International Commission on Stratigraphy International Stratigraphic Chart Period dating includes a interleaved sixth period 417Ma interval between HoloceneSilurian (0-416), OligoceneOrdovician (28-444), start* Maastrichtian [4] – Cambrian (71*-488), and Jurassic – Vendian Ediacaran-Varangian(146-563) unconstrained date. The Carboniferous 417Ma interval pair (703Ma-ago) extends further into Precambrian eons. Carboniferous 286Ma-ago date is circa 1961 thru 1982 [1] geologic dating and is within the Karoo Ice Age. The Cryogenian (or Sturtian-Varangian) Ice Age 800 to 600 million years ago is equivalently constrained at 417 M-years earlier. The Phanerozoic pattern includes the Planetary Equidistant Rupture [2] extending across the Proterozoic, through the Archaean and into Hadean starting at the 4.5Ba ago Moon-forming impact. Hyperthermophile life spawned upward from that event and frequent ocean boiling stages 4.3Ba-ago. The physical environment bounded life on Earth. Starting with CO2-dominated biosphere into the present and Pre-Cambrian global oxygenic Eukaryote plant life photosynthesis[3]. The ISC documents evolution of Eucarya, a unintended compendium of PER and 417Ma Period intervals. 'Physical perturbations break incumbancies, removing dominant life forms, opening opportunities for previous minor groups' [ref 3, p240]. Understandably, major extinction events are common to Period transitions, that represent an environmental biotic evolution process.

Reference: [1] Snelling 1985 Chronology of the Geologic Record; Boston, Blackwell Scientific Publications. ISBN 0-632-01285-4.

[2] 1991 Kevet, Radan 1991 Complete Periodical Geological Time Table, GeoJournal 24.4 417-420 Kluwer Academic Press.

[3] Rothschild, Adrian 2003, Evolution on Planet Earth, The Impact of the Physical Environment. Academic Press ISBN 0-12-598655-6.

[4] Barrera, Eniqueta, Geology, vol. 22, Issue 10, p.877, Global environmental changes preceding the Cretaceous-Tertiary boundary: Early-late Maastrichtian transition.(unstable temperature 4 to 7Ma before the KT event).

Morbas (talk) 05:38, 14 October 2010 (UTC)

See WP:SPS. You'd need some good sources, see the RS parts of WP:V. --Philcha (talk) 15:19, 26 June 2010 (UTC)

Comment period begins....Morbas (talk) 13:02, 16 August 2010 (UTC)

References added...and section posted in the main body.Morbas (talk) 18:23, 11 September 2010 (UTC)

Period Terminus Dates Interval 6th Interval ISC (Ma ago) PER [2]
-58 Ma ago
Borgzoic 57 Ma (Projected)
-1 Ma ago
Paleogene_Neogene 79-7 Ma 28.4(+/-0.1) <--Oligocene.Rupelian
72Ma ago 66(+/-0.3)
Cretaceous 75 Ma
146 Ma ago 145(+/-4.0)
Jurassic 54 Ma
200 Ma ago 201.3(+/-0.6)
Permian_Triassic 79+7 Ma 251(+/-0.4) <--PTr
~286 Ma ago 298.9(+/-0.8)
Carboniferous 73 Ma
359 Ma ago (417)Ma 358.9(+/-2.5)
Devonian 57 Ma
416 Ma ago 417 Ma 419.2(+/-2.8)
Ordovician_Silurian 79-7 Ma 417Ma--> 443.7(+/-1.5) <--OSi
488 Ma ago 417 Ma 485.4(+/-1.7)
Cambrian 75 Ma
~563 Ma ago 417 Ma ~541(+/-1.0)
Varangian.Ediacaran 54 Ma
~617 Ma ago 417 Ma ~635
period_period indicates a group.
period_period underscore shows a PER point.
~period indicates poorly constrained dates.
Borgzoic projection not included in the article.:)

Reviewer I editied the PER to a underscore and clarify. Morbas (talk) 02:52, 11 October 2010 (UTC)

Ok, whom ever deleted the posting in the main article, please open a discussion below. I will wait 24 hours....Morbas (talk) 02:39, 14 September 2010 (UTC)

I don't understand what this section means, nor its relevance to the article. You need to re-write this so that it is comprehensible, and ideally to adapt its style to match the existing article, before it can be incorporated. Martin (Smith609 – Talk) 14:23, 14 September 2010 (UTC)
The extinction article is restricted to the Phanerozoic, and needs to expand back to Earth's formation for a holistic view. The existing paragraphs structure push a perception, not the statistics; I always paraphrase 'pernicious perception' to make that point H.Poincare 'because they conceal laws'. Geologic Chronology has a real periodicity in an interleaved manner. What the article shows is a different approach to measuring periodicity using the covariance statisitc process. That although the major five periods are not regular, the period boundaries they appear on do have a tight 417Ma periodicity in there own domain. I do not purport to present anything but the raw data in the correct manner. This paragraph should stand out for these differences, and it does.
My counter question to you is what do you mean by comprehensible? Now that you have a table presented to you, are you convinced of a strong 417Ma pattern.

Morbas (talk) 02:14, 15 September 2010 (UTC)

"Comprehensible" means that it is possible to understand from the text what the text means. As I understand it, you are presenting original research that is in contradiction to the statements of published, peer-reviewed research (see Alroy 2008, referenced in the article). This content is therefore fundamentally unsuitable to Wikipedia. If you have really found a pattern, I suggest that you publish this information in a peer-reviewed journal. Martin (Smith609 – Talk) 14:49, 15 September 2010 (UTC)
You are avoiding the 2cd question and framing what you don't understand. The 417Ma pattern is published ICS data. Can you help me ?Morbas (talk) 13:45, 16 September 2010 (UTC)
When you use the correct data (I've taken the liberty of inserting the correct dates into your table per the current international commission on stratigraphy framework, although I've not edited the differences) the "pattern" disappears. A quick Google for "borgzoic" indicates that there is utterly no scientific support for your theory. Martin (Smith609 – Talk) 14:55, 16 September 2010 (UTC)
P.S. there were no pre-Proterozoic mass extinctions, see Butterfield 2007 (Palaeontology). Martin (Smith609 – Talk) 14:56, 16 September 2010 (UTC)
Never indicated "pre-Proterozoic mass extinctions", only possible pre-proterozoic subject was PER. I would only presume major ice changes distorted the globe, causing increased plate techtonic activity. And although moon formation would have sterilized Earth, no evidence exists to support "pre-Proterozoic mass extinctions". Morbas (talk) 16:45, 17 January 2011 (UTC)

I have taken the liberty to correct Martin Smith's changes, and move those into a separate column. Smith please double check your entries next time. Based on these official dates, the variance of my table is small. You may want to alter your critic accordingly. I will add the Oligocene 28.4Ma and the Ordovician 443.7 for another 417Ma pair this Sunday. The P-Tr, Ordovican-Silurian, and the Oligocene are PER points.Morbas (talk) 09:25, 17 September 2010 (UTC)

You do not show that your pattern is statistically significant; Alroy (2008) demonstrates that there is no statistically significant trend in mass extinction. You cannot arbritarily select a handful of extinctions that fit your pattern, then assign them arbritary dates, then pretend that there is a self-evident pattern. If there really is a pattern, go publish; then once you have a peer-reviewed confirmation of its statistical significance let's include it. Until then, that's all I have to say. Martin (Smith609 – Talk) 14:07, 17 September 2010 (UTC)
Whoa ! I did not propose any extinction periodicity. Association with the 417Ma is already in the extinction event article... "The classical "Big Five" mass extinction's identified by Jack Sepkoski and David M. Raup in their 1982 paper are widely agreed upon as some of the most significant: End Cretaceous, End Triassic, End Permian, Late Devonian, and End Ordovician,[2][3]". You have defaced my table with errant data. I have gracefully recovered it, and it shows existing ICS dates support the pattern. And...I have a personal.pdf record. I seek your assurance that you will not further extend an edit war when I place this back into the article. At minimum an apology is called for.Morbas (talk) 17:10, 17 September 2010 (UTC)
No. This is Original research. Do not place it in the article without providing a source directly supporting the 417Ma date, or you will be in volition of Wikipedia policy. In addition, the content contradicts published research (see Alroy 2008, referenced in article). Martin (Smith609 – Talk) 17:57, 17 September 2010 (UTC)
  1. Resolution Request. Opinion needed about Original Research claim. This is ICS data. This is GeoChronology data dating circa 1980. References are posted in the Geo Chronology entry. Trivial math is used to show sixth interval time differences.Morbas (talk) 04:57, 19 September 2010 (UTC)
The following paragraph is research...and is due diligence...
The end Cretaceous is officially aligned with a Meteorite impact. I have taken all officialy core sampled impacts, using energy calculations as amplitude then analyzed the frequency domain. With special broadband filtering I extracted only an insignificant 70Ma peak. Let me further clarify that result. It was discernable as a visual pattern, but statistically at the noise floor. I read a paper on this and essentially confirmed the published conclusion. Let us digress, the Maastrichtian is the biotic stage of Dinosaur decline. The big beasts did not make it across that stage, and no evidence to date has been found that the beasts made it to the Yucatan event. Since meteorites are random events, the ICS Cretaceous date is suspect and excludable from 417Ma interval.Morbas (talk) 03:19, 27 September 2010 (UTC)
Me thinks you are weeding data that is contrary to a favored theory. The Geologic Chronology article is presented by reference, and is framed to life on earth, extending into pre-Phanerozoic Eons. The PER spans this as a 'Complete Periodical Geological Time Table'. You wanted a reference to 417My interval, the PER indicates Oligocene, P-Tr and Ordovician are periodic dates. And the ICS chart shows the Oligocene and Ordovician are 417Ma apart. The 1991 Kevet published article pegs it at 440Ma. In 1991 the data was less bounded than today. As you see by my due diligence paragraph, I perform due diligence in presenting references. I framed it completely with published papers, the conclusion sentence is paraphrased reference text.Morbas (talk) 19:59, 19 September 2010 (UTC)

More due diligence. This is not part of the contention. Oligocene and Ordovician cold periods: "The early part of the Hirnantian was characterized by cold temperatures, major glaciation, and a severe drop in sea level." The Hirnatian was of short duration, lasting about 1.9 million years 445.6 ± 1.5 to 443.7 ± 1.5 Ma (million years ago), characterized by a drop in sea level then return to warmer climate. "The Oligocene climate change was a global [4] increase in ice volume and a 55m decrease in sea level (35.7-33.5Ma) with a closely related (25.5-32.5Ma) temperature depression." These are equivalent events separated by 417Ma. The Hirnantian dating is less constrained, as expected for such a time distant event.

Summary for dispuite resolver: Morbas uses incorrect dates to support his personal theory, and ignores extinction events that do not fit his pattern. A statistical analysis would be necessary to verify that the 417Ma period was not due to chance alone, and a recently published statistical analysis of extinction events refuted the concept of any periodicity (See Alroy 2008, reference in article). His observations have no scientific merit and should not be included in the article. Martin (Smith609 – Talk) 16:18, 20 September 2010 (UTC)
Counter for dispuite resolver The bold text is important. I did not say Extinction Events have periodicity. I did not propose a theory, just established data. I did cover the entire Eons of life on earth using established references. The data is unbiased, perhaps suggestive, but certainly self evident. Grey area? I will respect your evaluation. morbas Morbas (talk) 01:11, 22 September 2010 (UTC)
One possible solution has sprung to mind; perhaps the information would be better displayed in a graphic than a table. This would then be able to illustrate extinction intensity as well as timing, and avoids the bias implicit in including some events in a table but excluding others. Martin (Smith609 – Talk) 14:18, 20 October 2010 (UTC)
Presupposing 'intensity' defines the extinction domain...perhaps too restrictive. The physical characteristics should be undefined. Let me talk 417Ma interval pairing, the physical environment pairs appear to have equivalence(s); albeit also a 'pernicious perspective' to have. Also referencing just the ICS Periods is an error, as other divisions have simular physical properties, however with enough points we can make any pattern we please to make. Perhaps (still in the 417Myr domain) the open physical environment can be classified by intensity, association, and supportable observation. Morbas (talk) 09:07, 22 October 2010 (UTC)

Smith609, Looking at my user talk page Morbas, you will see a replication of the table. You asked earlier for a proof about 417Myr interval. Check the delta column entries and you will see a set of delta numbers that repeat, the law of Commutativity says the sum is invariant to the order they are summed.Morbas (talk) 15:49, 22 October 2010 (UTC)

Smith609, I am prepared to insert mypage Morbas into the main section.Morbas (talk) 14:30, 23 October 2010 (UTC)

Physical Geologic Driver

Morbas (talk) 16:33, 8 January 2011 (UTC)

For article in question please see Morbas.

What are you talking about? Can you explain? And why the strange pattern of out-of-sequence comments? This may make it harder for other people to understand what you're saying. bobrayner (talk) 14:13, 1 January 2011 (UTC)
Bobrayner, I've restored your comments that got deleted - Morbas please reply to Bobrayner rather than just editing his and your earlier comments, it makes it virtually impossible to understand what is going on. Mikenorton (talk) 16:18, 1 January 2011 (UTC)
Mike, BobR personnaly requested a rfc reboot. As part of that process I removed his associated comments. This discussion is long and involved...
Morbas (talk) 18:12, 1 January 2011 (UTC)
I did not request a reboot. I asked what you are talking about; it is still not clear. If you could clarify this thing about "The 417Ma has meaning only in repetition, arithmetic pattern and CALC. It meets Wiki rules. The Physical meaning is not indicated, but is apparent to the readership. So is an apparent physical linkage (in the readers mind) sufficient for exclusion" then maybe we could work together to improve the article. Please don't delete or misrepresent other people's comments. bobrayner (talk) 19:36, 1 January 2011 (UTC)
Oh...Aplogies it was from... "Hi. I see you started an RfC on the issue, however, you start the RfC off by telling people to go to "your page" (whatever that means) and to skip down somewhere. That's not an efficient way of requesting outside opinion. You may want to reboot the RfC, ask the question, and provide a space for response. Simple, no-nonsense works best." Viriditas
That puts a whole new light on things...your comments were about the article?
The 417Ma interval is the mathematical difference of multiple Period sets in the ICS Geologic Time Scale. All numbers are from mathematical Ma differences (see the table for details). All follow on supositions have listed citations.I have modified the section per discussions with VSmith and MikeNorton. Issues are discussed in the following discussion...and have reached an impass over interpretation of CALC and UNDUE (IMHO). Please continue....Morbas (talk) 20:43, 1 January 2011 (UTC)
Morbas, I seem to recall discussing this with you some time ago. I am told that you have deleted our discussion without archiving it. It is unacceptable to delete discussions that you don't agree with and then behave as if they never happened.
You were unable to defend the selection and validity of the dates in your table, or to demonstrate then that your work was not original research, and were told that your idea DID contradict published research. I gave you several reasons why the inclusion of this section contravened Wikipedia policy, and yet you appear to have ignored this and done it anyway. I am not aware that any editor besides yourself has ever suggested that your section should be included in the article. Martin (Smith609 – Talk) 15:35, 2 January 2011 (UTC)
I've restored the Geologic Chronology section so that other editors can understand what's going on and so that it is archived properly. Mikenorton (talk) 17:14, 2 January 2011 (UTC)
Bravo. Now to keep the discussion current, I recommend including the present version found at Morbas. Or one may simply mouse click on Morbas to see it.Morbas (talk) 21:43, 2 January 2011 (UTC)

Smith, Funny I didnot see IMHO in your paragraph. My understanding is that number ONE, Wiki has an auto archive system. And TWO a Wiki Bot automatically erases talk sections with no activity for over 30 days. And THREE, IMHO your implied preceptions introduce foreign conflict, the apparent objective to reject the article. Now you imply, that I selected the data to generate the 417Ma differences. Please note, all of the Phanerozoic Period Boundaries were used. Please also note that there are tolerances to these dates, and there are conflicts to whit I have included professional citation. IMHO the arguments you presented were cherry picked sentences within wiki paragraphs, that appear to be out of context to the intent of the rule discussion; and you have a perception issue with the meaning of should and shall. The first is a recommendation, expectation or probability; the second a requirement, determination or obligation. Morbas (talk) 05:08, 3 January 2011 (UTC)

If you concur, we have a rule to follow; do you concur? Morbas (talk) 05:08, 3 January 2011 (UTC)

Mr. Smith, given that enlightenment, I contend compliance with wiki policy. Impasse remains....Morbas (talk) 04:32, 3 January 2011 (UTC)

Mr Smith, I have worked with you on select improvements you have suggested...and will continue to try to do so. Morbas (talk) 16:59, 2 January 2011 (UTC)

A bit more enlightened... The time differences CALC of the ICS periods produce a commutative set having a summation of 417Ma. The commutative set has an alternating +/-3.5Ma time interval at the Oligene, O-S and P-Tr dates. This is a mathematical expression of the (Kepler) Conic Ellipse apsis.

Thus we have a mathematical expression from an associated single datum base, and that qualifies under wiki rules. Human interpolation is excluded from number base association, and cannot be OR. Morbas (talk) 15:26, 3 January 2011 (UTC)

No reason to include. First, making your own calculations and including them for anything but trivial matters (i.e., changing units, etc.) is against WP:WEIGHT: it is not included in the literature. Second, implying causality from correlation is against WP:OR. Third, the paper that you reference (Kvet) is an ignored paper in a humanities and social sciences journal. Your attempts to include this will go nowhere on Wikipedia, because it is neither appropriate nor notable to include. Continued argument will just continue to waste everyone's time. Try to get a paper published if you're that convinced about it, and then come back.
I propose that this RfC be closed. Awickert (talk) 07:52, 18 January 2011 (UTC)
WP:WEIGHT uses 'should' and not 'shall'. 'should' is a recommendation, 'shall' is a hard requirement. I contest you interpretation of WP:WEIGHT for the contested sentence as it's purpose is visual connection of time spans, and is not anything else. It must be mentioned because of the rules.
WP:OR is strictly interpreted by wiki. Even association of mathematical constructs is WP:OR by WIKI staff. I only object to this as it means Einstein could not write in WIKI; WP:OR needs to change. You must admit that I did not make any association with any physical processes, except to associate known WIKI mathematical constructs.
I propose that this RfC be closed. Morbas (talk) 19:16, 18 January 2011 (UTC)
The purpose of Wikipedia is that Einstein would need to go through the peer review process first. As we are unable in any official capacity to differentiate good work from bad, WP:OR must exist in this fashing.
I must admit nothing; you are suggesting that real extinction events are associated with some kind of galactic cyclicity, which goes beyond a mathematical construct.
I have no idea what the contested sentence that you're talking about is, but if it connects some cyclicity to these time scales in a way that suggests causality, it is definitely unacceptable.
Since we both agree to close this, I think that's a definite consensus. Awickert (talk) 21:26, 18 January 2011 (UTC)
I have highlighted and with Italic text indicating I have made no WP:OR with physical processes. That was made by the published and peer reviewed Honorable Kvet, Radan Czechoslovak Academy of Sciences paper. The line in question is "The apsis group is a subset of elevated tectonic intervals identified by Radon & Kevet 1990 which extends out of the Phanerozoic, across the Proterozoic, through the Archaean and into Hadean to the 4.5 Ba ago Moon-forming impact." I believe the paper was introduced correctly and footnoted properly. At no point was Galaxy indicated, as that was with your interpretation. If that is a discriminator, wiki should be restricted to defining the pin assignments of RS232 connectors, not how they are used.Morbas (talk) 01:33, 20 January 2011 (UTC)
Ah, OK. I have not seen any reference to this paper; could you give a link? At the moment, I am not sure how the inclusion of the line that you mention is useful or relevant. Awickert (talk) 04:46, 20 January 2011 (UTC)

Physical Geologic Driver

Need some help with the templates.

Reference Link Complete Periodical Geological Time Table

Evolution on Planet Earth

Morbas (talk) 03:09, 20 November 2010 (UTC)

I've added an expert tag as I'm not really sure what this section is trying to say - it is so poorly written. Definitely not written for the general reader. Either someone needs to rewrite for clarity and to explain it to dummies like me - or delete the section. Vsmith (talk) 23:34, 20 December 2010 (UTC)
Comment from a test general reader was that is very well written. What is your expertise so I may frame my reply correctly.Morbas (talk) 04:15, 21 December 2010 (UTC)
My "expertise" is irrelevant. The section is full of jargon and undefined technical phrases/acronyms. Example: Planetary Equidistant Rupture - what the ...., planets exploding? - and then the acronyms for undefined jargon. The table is even worse, presumably trying to show some 417 mya repeating planet clobbering something? Needs jargon cleanup and sourcing, WP:OR? The sentence Mid ocean-ridge volcanism of a (merged) Earth core regulates Ocean depth. is dropped in with no context?? And on and on... Vsmith (talk) 15:12, 21 December 2010 (UTC)
All these sentences are summaries of references.
The Kvet 'Complete Periodical Geologic Time Table' paper indicates a Planetary Equidistant Rupture (PER) as intervals of increased tectonic activity. These are associated in the Phanerozoic at the Oligocene, P-Tr and OS and extends back to Earths Moon Formation. Phrase planets exploding is a phrase not found in the article.
All sentences have references. The table is made from wikipedia sourced ICS dates. Which is the citation you need. What is shown is trivial math, and this strings to other wikipedia articles for ellipsis and commutation definition.
Mid ocean-ridge volcanism regulates Ocean Depth is referenced to Rothschild, and I will string that to the original paper...this should be done. It defines ocean formation, and is relevant to physical earth.
The frame of the article starts in present down to Moon Creation discussing Geologic Chronologic patterns, and returns to the present discussing major global environmenta up to (eukarya) atmospherics in chronologic order. This Physical treatment is not found in any of the wikipedia geologic articles.

Morbas (talk) 16:21, 21 December 2010 (UTC)

Then why not say intervals of increased tectonic activity rather than the jargon PER (which sounds to me like planets rupturing or exploding). Also, for example: expand the OS acronym to Ordovician-Silurian as "OS" is a meaningless acronym jargon.
Table needs a reference for the source information, else it is WP:OR or WP:SYN.
Mid ocean-ridge volcanism regulates Ocean Depth may define "ocean formation", but needs expansion beyond that one sentence and relevance tie in to the topic.
Also a google search of the section title returns nothing besides Wikipedia mirrors or copiers. So the section may need retitling to reflect usage by sources
If the main thrust is that extinctions relate to periods of orogeny then state that and re-title the section. If impact events are required due to position in galactic orbit or whatever the peri/apoapsis bit is implying then that requires explanation. Or are you saying the orogenic episodes are somehow orbit controlled?.
Vsmith (talk) 16:54, 21 December 2010 (UTC)
OS changed to O-S in text, table was correct. O-S is found in Wikipedia Morbas (talk) 18:47, 21 December 2010 (UTC)
intervals of increased tectonic activity added Morbas (talk) 18:43, 21 December 2010 (UTC)
The table is the ICS data, and is wiki linked to end of periods. It is not a synthesis of multiple sources, but elementary math using this golden source. The fact is 417Ma is the difference for sets of period transistions. The fact is the pairs are offset by a commutative pattern. The fact is that the commutative pattern cycles at apsis. Now I would like to reference orbital mechanics, but my interpretation is that that crosses the wiki synthesis line. I will not indicate that in the article, only in the discussion and on my page.
You may further divide the commutative set into three numbers, and thus calculate the entire Phanerozoic Period Transistions at a 2Ma deviation. Now this is useful information for students.
Further discussion on these perceived philisophical boundaries will impact every wiki pedia article. That is because they are synthesized from multiple sources.Morbas (talk) 19:05, 21 December 2010 (UTC)
One point is that there appears to be cherry-picking going on with some of the dates. For some reason the Cretaceous-Tertiary event is given an age of 71 Ma rather than the accepted 65.5 Ma and the end Carboniferous is given as 286 Ma rather than the currently accepted 299 Ma. Secondly, the Planetary Equidistant Rupture idea from Kvet has not been picked up by anybody else - his papers are barely cited and the concept does not appear elsewhere, so why should it be in this article? Mikenorton (talk) 21:07, 21 December 2010 (UTC)
Valid Points. By the numbers...

1) The current Cretacous-Tertiary event is a random meteorite event. No large dinosaur remains are found at that event point. Meteorites are random, thus dismissable as a pattern causal. The K-T dinosaur linkage is controversial among experts, as shown by Rothschild and others. Being controversial means it cannot be a cherry-picking criteria. 1a) According to NOVA "Arctic Dinosaurs" the big pile of dinosaur fossile is dated at 70Ma-ago in AK. The Dinosaur bone structure indicates a warm blooded taxa, residing in Arctic and Antarctic: counters the Meteorite global cooling causal. The Dinosaurs thrived above the artic circles (4x closer to the poles than the present AK fossil locations). Morbas (talk) 17:54, 28 December 2010 (UTC)

2) The Carboniferous is covered in the text. The 286 date is circa 1986 dating and resides about mid point at the Karoo Ice age. The ICS dating is taxia biased and not physical, and the circa 1986 is linked to physical strata. If you paruse the web, 286 is used frequently, and this on the Canadian Museum page too. This is a controversial issue and included in the text. FN3 links to ICS variations in the Pre-Cambrian dating, to which the golden table asserts a very small +/-1Ma uncertainty. 3) The Kvet Complete Geologic Time Table is circa 1991 Geo-Journal 24.1 417-420 kluwer Academic Publisher having first publish in 1990 Russia. Until otherwise shown, I respectively assume a scholar peer level review. I have emailed Kvet years ago, no response... Morbas (talk) 23:30, 21 December 2010 (UTC)Morbas (talk) 16:07, 30 December 2010 (UTC)

If it is based on an obscure? 1991 paper that has been ignored, then out with it. Did a google search and found Springer paywalls and a number of links to discussions on WP talk pages...hmm. We aren't supposed to promote fringe/ignored stuff. Unless more recent WP:RS sources can be found, this confused hodge-podge of a section should be cut. Maybe some of it could be merged with the previous section, but the Planetary Equidistant Rupture stuff should be removed.
The title of the section "Physical geologic driver" implies some geologic force causing extinctions and the text mentions orogenic cycles, but also implies that it is "driven" by something to do with the galactic orbit peri- and apoapsis pattern with no clarification of why. Has anyone other than Kvet made a case for or an explanation of this supposed correlation? Vsmith (talk) 23:44, 21 December 2010 (UTC)

I did not mention extinction in any of the text. The table has been ammended with the Big-5 and Big-ICE for information only. I make no claims about extinction cycles. Please refrain from that form of piracy.

Again, apsis axis is a mathematical function. I did not introduce Galaxy in any of the text or the table. Stop the Piracy please oh please.... Morbas (talk) 00:07, 22 December 2010 (UTC)

"Piracy"? er... maybe read WP:NPA. The article is about extinction, so if the section isn't about extinction events then why is it here? So you are talking about an abstract "mathematical function" rather than something physical connected to orbital position. If not galactic - then what? Vsmith (talk) 00:21, 22 December 2010 (UTC)

Is a referee needed? Are you qualified to review Kvet? (talk) 01:21, 22 December 2010 (UTC)

Referee?? I'm not reviewing Kvet, I'm discussing a problematic section in a Wikipedia article. Who are you? Vsmith (talk) 01:43, 22 December 2010 (UTC)

I am signing off...Answer to VSmiths question, if not glactic what? Have a nice night...Morbas (talk) 01:52, 22 December 2010 (UTC)

Section has been removed as undue weight and apparent "self-promotion" by the contributor of work promoted, posted or published elsewhere. See: [14], [15] and other websites discussing a Galactic Geologic Interval Theory. Vsmith (talk) 03:03, 22 December 2010 (UTC)

Also see: [16]. Vsmith (talk) 04:24, 22 December 2010 (UTC)
Having discussed this with other scientists is due diligence.Morbas (talk) 13:55, 30 December 2010 (UTC)

Section reinstated. This is a discussion still in progress. VSmith has inserted his own ideas (piracy) to justify removal. He removed this after I signed off for the night to expore PER replacement. The Kvet reference appears to be his last hurdle. This is not origianl research, galactic has not been used. Morbas (talk) 03:52, 22 December 2010 (UTC)

I don't see much discussion going on and throwing around accusations of piracy (whatever that's supposed to mean in this context) is not helping. If an article section is proving contentious it is perfectly normal to remove it. You have been given a lot of time to come up with a version that adds something to this article but that no longer seems likely. I have removed the section again. Mikenorton (talk) 07:32, 22 December 2010 (UTC)
And you took less than one session to assert....Vandalism Alert sinbot where are you?17:57, 22 December 2010 (UTC) — Preceding unsigned comment added by Morbas (talkcontribs)

Editing break - Physical Geologic Driver

This is a discussion still in progress.

Geologic Periods are defined by a biostratigraphy process statifying sedimentary rocks, and fossile floral and assemblages. Geologic Periods are a biostratigraphic fossil histogram classificiation. An Eon is a histogram of Periods, where Eons represent the highest biotic type class divisions. Period and Eon boundaries both represent fossil class-type biolevel changes. A histogram of the Eons and Periods outlines a biotic extinction process.

The Physical environment limits the range of biotic processes... Morbas (talk) 16:47, 23 December 2010 (UTC)

The article is about finished, per your instructions. Would you like review my page before I paste into the main article. Morbas (talk) 19:00, 26 December 2010 (UTC)

There were no 'instructions', just some observations. Regarding the 'new' version
  • Reference required for 'Geologic Periods are a form of biostratigraphy fossil histogram classificiation' and 'An Eon is a histogram of Periods, where Eons represent the highest physical-biotic taxa'.
First paragph shortened, objection resolved.Morbas (talk) 23:47, 27 December 2010 (UTC)
  • The 'compendium of 417 Ma covariant Period interval sets' also needs a source, otherwise it remains OR
I object to an OR classification of arithmetic operations on a single source. Single source material is not defined in wiki:SYN criteria. It is a fact that the Phanerozoic consists of period pairs of 417Ma intervals. This is instead CALC allowed in wikipedia. Morbas (talk) 23:57, 27 December 2010 (UTC)
If no one has noted the 417 Ma pattern or published any significance regarding the "pattern", then it is OR to try to make or derive significance from a simple arithmetic pattern or ascribe something like a "physical geologic driver" (whatever that is supposed to mean) from that observation. If this pattern is from Kvet, then as noted WP:Undue applies. Vsmith (talk) 00:07, 28 December 2010 (UTC)
CALC-"This policy allows routine mathematical calculations, such as adding numbers, converting units, or calculating a person's age, provided editors agree that the arithmetic and its application correctly reflect the sources." Does the arithmetic and it's application correctly reflect the source? (Yes/No) No restriction is made to how many times it is performed.
Awaiting an up/down answer....Morbas (talk) 13:55, 30 December 2010 (UTC)
"If no one has noted the 417 Ma pattern or published any significance regarding the "pattern", then it is OR to try to make or derive significance from a simple arithmetic pattern..."
arithmetic pattern? So the Kepler conic ellipse function mathematical is allowed...and apsis axis is allowed. I have written the article without any conclusive arguments something my test readers have noted. HS Grad level subject indicated that he could derive the unfamiliar terminology because this was written well. First test subject was a ISO expert and a Masters level Mathematician, he told me this is a well written subject and delved immediately in conclusive arguments. I propose to you this is an encyclopedic presentation. Morbas (talk) 13:58, 30 December 2010 (UTC)
One more time - if no investigator has published an analysis of or derived conclusions from the subject arithmetic or mathematical patterns: the "417 Ma repeat", a "Kepler conic ellipse function" or "apsis axis", then such a presentation is WP:OR. So the question is: who has published these mathematical patterns and analyses/conclusions regarding them? Vsmith (talk) 21:56, 28 December 2010 (UTC)
Again please, this is allowed under WP:CALC rules. These are simple arithmetic operations. These are time differences between Periods from a single wikipedia golden source.Morbas (talk) 00:40, 29 December 2010 (UTC)
Math may be allowed by CALC, but ascribing meaning, interpretation and/or physical significance to the calculations requires a reliable source. Without that meaning/significance the simple arithmetic is useless. Vsmith (talk) 03:11, 29 December 2010 (UTC)
"the arithmetic and it's application correctly reflect the source" is all I assert.Morbas (talk) 05:27, 2 January 2011 (UTC)
417Ma This is not from Kvet. Morbas (talk) 03:05, 28 December 2010 (UTC)
  • All reference to PER is undue, as in earlier discussions the PER of Kvet and his co-authors appear to be a minority view, held by almost no-one else, so it shouldn't be in the article
WIP Question. Is it improper to include minority views a) as nonbinding, or 2) a Iron Curtain source...
To quote from WP:UNDUE, "Generally, the views of tiny minorities should not be included at all" and Kvet is in a minority of only slightly greater than one, hence his views should not be included. Mikenorton (talk) 18:05, 28 December 2010 (UTC)
WP:UNDUE: "Neutrality requires that each article or other page in the mainspace fairly represents all significant viewpoints that have been published by reliable sources, in proportion to the prominence of each viewpoint. Giving due weight and avoiding giving undue weight means that articles should not give minority views as much of or as detailed a description as more widely held views. Generally, the views of tiny minorities should not be included at all. For example, the article on the Earth does not directly mention modern support for the Flat Earth concept, the view of a distinct minority; to do so would give "undue weight" to the Flat Earth belief."

Just wanted a complete paragraph. The difference here is that Kvet is not contrary and has incidental support properties. It is presented in the incidental manner and it's weight is referenced in the foot note section. If this was not clear to you, perhaps you could edit the single sentence in question. Be kind tho and present it separately here so I can maintain my records. And Kvet is published in a Czechoslovak Acadamy of Sciences, Institute of Geopgraphy journal which likely has a peer reviewed submission board.Morbas (talk) 21:20, 28 December 2010 (UTC)

  • The chart isn't helpful and I see no reason to include it
WIP: The wiki table (formating) is oversized. But it shows much of the data, the arithmetic results, the ICS dates, the major extinctions and major ICE. Would you suggest this should be split into several tables? It is here because in the OR talk, the response was to include it. Morbas (talk) 21:51, 28 December 2010 (UTC)
  • Anything else should be added to the existing text. Mikenorton (talk) 20:42, 26 December 2010 (UTC)
WIP and it is too bad tables cannot be copyrighted Morbas (talk) 23:47, 27 December 2010 (UTC)


(duplicate rfc tag removed) Article in question see Morbas. The 417Ma has meaning only in repetition, arithmetic pattern and CALC. It meets Wiki rules. The Physical meaning is not indicated, but is apparent to the readership. So is an apparent physical linkage (in the readers mind) sufficient for exclusion. Morbas (talk) 15:59, 1 January 2011 (UTC)

I've removed the duplicate rfc tag - don't need two on one talk page. The rfc discussion was moved by User:Morbas to the top of this section. Vsmith (talk) 20:46, 1 January 2011 (UTC)

The rfc tag you removed concerned wiki policy rules, different from the Science Technology at the top....but you were correct to do so.... However, IMHO your objections to this article may require policy redefinition, so I reserve the right to involk such a rfc tag.Morbas (talk) 05:30, 2 January 2011 (UTC) Morbas (talk) 16:48, 8 January 2011 (UTC) Morbas (talk) 16:51, 8 January 2011 (UTC)
I am not sure I can delete all the above entries. The more bold have my permission...Morbas (talk) 18:00, 3 March 2011 (UTC)

Recent times

Is there a name for the extinction event of the last few millenia owing to the dominance of Homo sapiens? ciphergoth (talk) 11:43, 24 December 2010 (UTC)

The Holocene extinction. Mikenorton (talk) 13:09, 24 December 2010 (UTC)

Morbas (talk) 14:05, 30 December 2010 (UTC)

Morbas, I don't need to provide citations when answering a query like that, this is not an article - holocene extinction has some issues but it does not lack citations. Mikenorton (talk) 16:40, 30 December 2010 (UTC)
Mikenorton, Your response was incomplete, and as such supported a supposition "owing to the dominance of Homo sapiens?" You should have noted that, unless you provide a citation. I signed along with you with a reservation. Morbas (talk) 15:36, 31 December 2010 (UTC)
If you felt a better/more complete answer was needed, the simply provide one rather than adding an absurd citation request tag. That tag is for article space not talk pages. Vsmith (talk) 16:46, 1 January 2011 (UTC)

Continental drift and plate tectonics

I think that the "Continental drift" and "plate tectonics" sections overlap, and could be merged. Comments / suggestions / complaints? bobrayner (talk) 21:48, 1 January 2011 (UTC)

Agree and renamed the Continental drift section to Plate tectonics as continental drift has been subsumed by plate tectonics. Deleted the previous plate tectonics section stub which really had no content. Vsmith (talk) 22:01, 1 January 2011 (UTC)

Science News resource, Permian–Triassic extinction event and Holocene extinction related

Acidifying oceans helped fuel mass extinction; Great die-off 250 million years ago could trace in part to waters' change in pH by Alexandra Witze October 8th, 2011; Vol.180 #8 (p. 10) Science News (talk) 00:54, 10 October 2011 (UTC)

Didn't plants cause a mass extinction by putting O2 in the atmosphere?

This theory is explored at "Theory 13 The dinosaurs may have been killed by their own metabolism system. Flowering plants are very effective at producing oxygen and during the tropical Cretaceous period (the last period of the dinosaurs) many new flowering plants appeared. More oxygen in the atmosphere increases the rate of metabolism in animals, particularly large ones, which meant they may not have been able to eat enough food to support their bodies to survive." I would anticipate this to be a fairly slow process and may not explain the fairly rapid and periodic nature of extinction events. Conversely, a pulse of CO2 initiated by an asteroid impact with the ocean could theoretically lead to suffocating levels of CO2 in the atmosphere for a short period before being reabsorbed back into the ocean. The spike in CO2 concentration may only last a few days or weeks, but sufficiently long to eliminate large quantities of air breathing fauna. Robert Beatty (talk) 07:03, 24 January 2013 (UTC)
I think this could also refer to the Great oxygenation event which caused a mass extinction in anaerobic life. --Tobias1984 (talk) 07:20, 24 January 2013 (UTC)

Most nonavian dinosaurs?

I noticed in the summary of the K-Pg Extinction event that it said most nonavian dinosaurs went extinct. As far as I know though-which is admitably not much-all nonavian dinosaurs went extinct at the K-Pg event. Is there some evidence that a nonaavian dinosaur survived a little past the K-Pg event?-- (talk) 04:27, 15 January 2012 (UTC)

Without any supporting evidence for non avian dinosaur fossils dating close to or after the K-Pg boloid event, please change...'The majority of non-avian dinosaurs became extinct during that time.' to... 'The majority of non-avian dinosaurs became extinct during the Maastrichtian Stage leading up to the K-Pg event.'Morbas (talk) 23:15, 23 September 2012 (UTC)

Missing the cause of the only observable extinction event

The only extinction event that we have observed is the one that is currently happening, yet the cause, while well known and well documented, is not listed. Who is to say that this is not the cause of some earlier events? I am of course referring to the altering of the biosphere by intelligent life. It has caused 100% of observable, documented extinction events. — Preceding unsigned comment added by (talk) 14:42, 25 June 2013 (UTC)

Graphic doesnt jive

" In the past 540 million years there have been five major events when over 50% of animal species died"

This is not reflected in the graphic. None show above or close to 50%. (talk) 11:22, 4 March 2012 (UTC)

You're quite right, but the diagram doesn't show all animal species. The description says Note that these data do not represent all genera that have ever lived, but rather only a selection of marine genera whose qualities are such that they are easily preserved as fossils. So I guess this is the reason for the conflict you have found.Nwhit (talk) 11:58, 4 March 2012 (UTC)

Other hypotheses

"Many other hypotheses have been proposed, such as the spread of a new disease, or simple out-competition following an especially successful biological innovation. But all have been rejected, usually for one of the following reasons: they require events or processes for which there is no evidence; they assume mechanisms which are contrary to the available evidence; they are based on other theories which have been rejected or superseded."

Isn't that supposition? Which one would, say, disease fall under? It's not a process with no evidence, it doesn't assume mechanism contrary to the evidence, and it certainly hasn't been rejected/superseded by other theories. --Stevehim (talk) 01:47, 25 June 2013 (UTC)

Extinction Event - Definition

I have a problem with the definition of an extinction event in the introduction. Extinction needs to be clearly distinguished from an extinction event. Extinction is the disappearance/death of a species (or larger taxonomic group). (One can make an argument that it also includes sub-populations). Extinction has no correlation with biomass, afaik. The "amount" of life on Earth can be measured in a number of ways, most general would be (imho) metabolic energy conversion, most specific the number of cells or the mass of organisms present. The article does a very bad job of trying to explain why counts of species are used as a measure of the "amount" or "abundance" of life. It has NO business, imho to attempt the redefinition of the word "amount". Number of species is not the "amount of life". Species is not life. An extinction process may involve evolutionary changes, elimination by a competitor, or destruction of a habitat, and of course often includes all three. This article confuses these possibly separate processes. (talk) 23:22, 16 August 2013 (UTC)

K-T effect on marine species and genera

The article says of the K-T extinction that "In the seas it reduced the percentage of sessile animals to about 33%" This makes no sense. Does it mean reduced sessile marine species by 33%, or 67%, or does it mean it made sessile animals a smaller percentage of all marine animals than they had been? Anyway it would be good if someone can add an estimate of the effect on marine genera and species as given for the other events. Colin McLarty (talk) 02:37, 17 April 2014 (UTC)

Holocene Extinction

I see some reference in this Talk page to the latest (6th) Mass Extinction Event, but do not see any response in the article to suggest that it be included in this article.

This is an article on the subject of extinction events, and imho no such article would be complete without at least a mention of this: there is certainly ample evidence and citations regarding the reality of the "Holocene" Extinction, starting around 10,000 BCE to merit it being included in the article. Note too that there is a Wikipedia article on the Holocene Extinction (, that should be linked this one. Tony (talk) 16:56, 21 April 2014 (UTC) (talk) 20:22, 15 January 2013 (UTC)

Is "Extinction Level Event" really an appropriate alternate name?

I believe the term "Extinction Level Event [ELE]" is a fictional jargon invented by the 1998 movie Deep Impact. I've never seen it used in anything scholarly, and Google Books turns up no references to it before 1998. Most of the results Google turns up are blogs trying to sound scientific (and one music group), which I'd bet anything were all inspired by the movie.

Graph of usage in books over time:

In the movie, a search for "E.L.E." turns up tons of research—but in the movie, Earth is also hit by a meteor. Neither one is real, and I don't think either one is appropriate to mention as fact in an article on this scientific subject. It's possible that after it was invented by the movie, it entered popular use and is now established enough to warrant mention, but I doubt it. I'm removing it from the lede, but if anyone disagrees, feel free to change it back. —MillingMachine (talk) 14:35, 23 February 2013 (UTC)

Terminology used in a movie, television programme or popular press sometimes does become part of scientific terminology. A good example is supervolcano, which started mainly from a BBC television programme in 2000 [17] and compare GoogleScholar hits for 2000-2004 [18] with those for 2005-2008 [19] and 2009-2013 [20]. A search on GoogleScholar] for ELE, does produce quite a few relevant results. It may not be appropriate to give this as an alternative at the moment, but I wouldn't bet on it staying that way. Mikenorton (talk) 09:05, 24 February 2013 (UTC)
I agree that it sometimes does, but as I said, I don't think it's happened in this case.—MillingMachine (talk) 08:04, 21 March 2014 (UTC)
It has indeed not happened in this case. As one piece of data, a Google search for "extinction level event" gets 250,000 results. When you include -busta, -armageddon, -conspiracy that number is cut in half (that is, look for pages not about Busta Rhymes's music or about conspiracy theories). And even then the only two results on the first page that are not about musicians are this article, plus an Amazon page announcing "an exciting new zombie apocalypse series called Extinction Level Event." This is not a scientific term. Colin McLarty (talk) 13:54, 2 November 2014 (UTC)

Suggest changing heading "Lesser extinctions" to "List of extinctions"

I suggest changing the heading "less extinctions" to "list of extinctions". This would mean incorporating the five big extinctions into the table in their appropriate chronological place. Right now, for a complete list, you have to refer to two totally different sections. It is more helpful to readers to have all of them in the same place. If no one objects, I'll do it myself in a couple weeks or so. Oiyarbepsy (talk) 20:28, 29 October 2014 (UTC)

Yes check.svg Done Oiyarbepsy (talk) 21:39, 4 January 2015 (UTC)


I plan on editing the section.

I have a cropped image of the Sepkoski Curve from the Milwaukee Public Museum that I plan on adding. However, for the sake of clarity of comparing the list VRS. the image, it would help if I could reverse the numbering of the list, from 1-2-3-4-5, to instead be 5-4-3-2-1 (aka David Letterman's "Top Ten" list).

Does anyone have advice as to how to do it?

LP-mn (talk) 05:57, 5 January 2015 (UTC)