Talk:Toba catastrophe theory/Archive 1

Archive 1

Archive 2

earlier conversations

Removing a garbage page full of errors written by a non-scientist. Biology is NOT a matter if personal opinion. This goes way beyond NPOV. Frankly, it is against Wikipedia policy to create a parallel Wikipedia within Wikipedia. If Stevertigo rejects the facts described on the many article we already have on the origin and evolution of humans, then he should go to those talk pages, and describe what changes he believes should be made. But it is totally against Wikipedia protocol to try and subvert the communal consensus process and create a parallel set of Wikipedia articles. RK

I'm not sure whose views this article describes, but it could be a valid addition to Wikipedia if properly attributed (in the article title as well as the text) rather than stated as fact. Deleting without first asking the author to fix his contribution seems harsh. Mkweise 15:05 Feb 22, 2003 (UTC)

NO, Mkweise. Wikipedia is an encyclopedia, and not the appropriate place for Stevertigo to create his own mythical theories of human history and race. This is science based NPOV encyclopedia. Stevertigo's peculiar theories of races and human history have no currency in the scientific community. Further, it is a gross violation of Wikipedia policy to deceitfully make an end-pass by the communal review process of all our articles by setting up parallel articles on a given topic. Wikipedians have not allowed this violation of NPOV before, and we should not change our policy now. RK

Wikipedia is a general encyclopedia, not an encyclopedia of science. Alternative theories and minoriy beliefs, even verifiably incorrect ones, are a matter of interest. There is no violation of NPOV as long as beliefs and theories are represented as such, and not as fact. Mkweise 15:33 Feb 22, 2003 (UTC)

You are way off base here. Stevertigo is making explicitly scientific claims - and his claims are wrong. Worse, he is bypassing the Wikipedia peer-review process. Many scientists already have set their "Watchpages" to follow our Wikipedia articles on human evolution and history, and Stevertigo is doing an end-run around them. How can an honest person like you not have a problem with this? RK

Um, Im not seeing the problem here besides the fact that this article doesn't describe some competing "theories". What is here certainly isn't unencyclopediac, although I guess it would be more POV if we included the theory that aliens created all life about 10,000 years ago. Susan Mason

The problem is that this is an encyclopedia, and not a personal webpage. Again, we have an obligation for us to discuss science and history in accord with the highest levels of academic standards. If we don't all follow this rule, then we descend to the level of Stevertigo who has never shown an ability to distibguish between his own personal theories and actual science, and who actually revels in the belief that his personal views matter more than peer-reviewed science. RK

RK, take a Valium. STV is not Clutch and neither is Susan. I have some difficulties with the entry myself, but thus far it contains nothing to justify those wild accusations you make, nor your confrontational tone. Just calm down a little, OK? Tannin 15:19 Feb 22, 2003 (UTC)

Tannin, please take the time to actually read the comments I made. This is an encyclopedia, not a personal web page, and we have scientific and academic standards we are all obligated to adhere to. If Stevertigo is unwilling to work with us on our science articles, then he must go elsewhere. There are rules, even on Wikipedia. RK

I read them already. If you calm down and stop abusing other contributors, maybe I'll read them again, and if it seems useful, respond to them. When aiming to persuade people to a point of view, it is counterproductive to fill your text with emotive terms like "garbage page", "full of errors", "subvert", "mythical theories", and "deceitfully". If you can focus on the content instead of the personalities for a while, what exactly, are you objecting to? Where is the "racial theory" here? (For that, I take it, is your real objection.) Tannin 15:57 Feb 22, 2003 (UTC)

RK - respectfully - I'm with Tannin (and not just because our usernames are similar). Your points would be better received if you dialed back your rhetoric a bit. --Tannerpittman 17:11, 15 February 2007 (UTC)

---

I've moved the article to a title that more accurately reflects the article so far. Can we all live with leaving it here while giving the author a fair chance to respond? Mkweise 16:56 Feb 22, 2003 (UTC)

I don't have any problem with an article on Toba catastrophe theory. (Though I suspect that this limited topic was not the intent of the original article.) RK

Well, not being a psychic I have no way of knowing unexpressed intent. But any intent to convince - rather than inform - the reader is out of place in an encyclopedia anyway. Mkweise 17:49 Feb 22, 2003 (UTC)

I agree with RK. It's better placed here. Tannin 00:01 Feb 23, 2003 (UTC)

Not sure what you mean, as right now the article is still at Toba catastrophe theory, where I moved it to. But if you want to move it somewhere else, that's fine with me. I just moved it here as an alternative to RK's solution of deleting it entirely. And, it looks to me to have since evolved into a pretty good article on a subject that wasn't previously covered. Mkweise 00:09 Feb 23, 2003 (UTC)

Sorry, I was unclear. I meant that I agreed with RK agreeing with you - the current location at Toba catastrophe theory is good, and the entry is shaping up. Tannin

I didnt start anything, by tossing this particular stone in the water, did I? I does, after all, contradict Creationism. :] -'Vert

How does the genetic evidence work?

The catastrophe supposedly created a population bottleneck. How can you tell that something like that happened if there are no survivors of the extinct genetic lines (by definition) to analyze? I think the article implies noticably small genetic drift in current lines as proof; but isn't that indistinquishable from human genetics starting out with low diversity? Are there fossils with recoverable DNA that do not match any current genetic line? (I'm not an expert; can fossils have recoverable DNA?)

--69.37.220.12 21:47, 21 Oct 2004 (UTC)

As I remember it: If you begin with a single individual (mito-Eve) and extrapolate to the present day, the mutation rate, combined with migration effects would lead to expections of a lot of diversity in mtDNA. They found unepectedly low diversity. The major bifucations due to migration are there, sure enough, but it's as if most of the smaller branches and nearly all of the twigs have been blasted off the family tree. So, after much head-scratching, and some inter-disciplinary consultation, they came up with this theory. (I don't know if other animal species suffered in a comparable way or not). Personally, I see two items, needing to be addressed:- 1) Mito-DNA codes for the structure of the organelle itself and the enzymes for converting carbohydrates to useable energy, which basically keep the cell alive. The potential for a mutation scoring a direct hit on enzyme code, leading to cell death (esp. in egg or sperm) would appear to be higher here than for nuclear DNA. Therefore the expected mutation rate needs to be reduced by a factor to account for the proportion which would be fatal to the cell (and thus not inheritable anyway). 2) Allowances need to be made for the consequences of any cultural preference for male offspring (even if confined to recent history). An 'all-sons' family effectively terminates a maternal mtDNA line, decreasing variety. An 'N daughters to get one son' family certainly helps to keep the male/female ratio in the population close to 50-50 but means multiple copies of the same mtDNA propagate, also contributing to reduced variety.

Unfortunately, fossilisation of bone takes a lot longer than it takes for DNA to spontaneously disintegrate. DNA from the teeth of mummies and burials only 1600+ years old is already fragmentary. The smaller they get the harder it is to find their true place on the map and draw any worthwhile conclusions, compared to modern samples. The best-case preservation scenario are the ice mummies, since chemical reaction rates are halved for every 10 deg C drop in temperature.EatYerGreens 15:51, 21 February 2007 (UTC)

Using only mtDNA or Y-chromosome alone to trace population bottleneck leads to wrong conclusions (see population bottleneck, founder effect, Mitochondrial Eve and Most recent common ancestor). This Ambrose paper claims to base its genetics evidences on work by Harpending (which I am not familiar with). Even though the paper talks mostly about Mitochondrial Eve, it seems to indicate that Harpending et al have used many other genes to trace coalescence points. And the paper seems to imply that all genes coalesce at around 70,000 years ago. This is in stark contrast to current academic consensus that there is no population bottleneck, as different genes show wildly different coalescent points. Fred Hsu 04:16, 17 March 2007 (UTC)

The implied (in your opinion) "all genes coalesce..." is an extravagant claim for the paper to make, since it sounds like they're referring to the entire genome. Surely, if the paper was mostly about mito-DNA (and, perhaps, some parts about Y-chromosomal genes) then what they should have been implying was "all sex-linked genes coalesce..." - a specific sub-set. The whole point of the divergence-rate studies is that the genes concerned have that provenence (females-only; males only), from which they can extrapolate a number of individuals of either sex (eg "as few as 2000 females"), which becomes the headline-grabber. So I am curious about the academic 'concensus' to which you refer - is that referring to coalescence points for genes which are neither mitochondrial nor Y-chromosome? EatYerGreens (talk) 23:04, 13 June 2008 (UTC)

One problem with "genetic evidence" is it is hardly verifiable and not necessarily unbiased (eg. towards the pharmaceutical industry). Since it hinges on the god-creation concept it has also always been a subject of personal interpretation more then most. That genetic divergence is shaped through bottlenecks is hardly a question. You only have to think of darwins finks. Obviously one big question is : how relevant are these genetical data then. It would be worth having a wiki on that. As far as raw paleological data goes it is very interesting what the recent afar finds will represent, if i am not mistaken a factor of genetic isolation and experimentation in a very early culture (presumably a bottleneck). This and the indication that oral tradition had spanned a longer then 100ka period, put a few questionmarks at the coincedences-theories. Also the article on wich most of this is based does not reach a stronger conclusion really, then that survival rates in tropic refuges would be 300% higher, it does not mention if that correlates with the genetic build up, so i guesstimate that people vye for exclusivity a bit to much in general on these subjects (adams, eves, technology, replacement rates/superiority).77.251.179.188 11:19, 27 August 2007 (UTC)

Well, there are a lot of words (and some interesting bits) but I cannot work out what point it is that you are trying to make there. The genetic evidence was, indeed, lapped up by the creationists at one time (mito-Eve and Y-Adam seemed to serve a purpose for them) but the evidence is more frequently used to club them over the head, since "mito-Eve and Y-Adam never met", as the headline once put it (they lived in eras several thousand years apart). In no way do I see the gathering of this evidence as ever hinging on a god-concept - they set out to characterise human genetics first and foremost and stumbled across this unexpected lack of variety in mitochondrial and Y-chromosome DNA. This catastrophe theory is merely an adjunct to it - an attempt to explain away the anomaly. With more time and more thought, other theories may emerge as to the cause and the Toba thing may be reduced to a historical footnote. EatYerGreens (talk) 23:25, 13 June 2008 (UTC)

Possible Errata

"Some geological evidence and computed models support the plausibility of the Toba catastrophe theory, and genetic evidence suggests that all humans alive today, despite their apparent variety, are descended from a very small population (see mitochondrial Eve). Using the average rates of genetic mutation, some geneticists have estimated that this population lived at a time coinciding with the Toba event." At the end of the first sentence, the reference (see Mitochondrial Eve) should be edited to (see Y-chromosomal Adam). Under the Mitochondrial Eve article, Eve is believed to have lived about 150,000 years ago. That would predate the Toba catastrophe event by another 75,000 years. Whereas, in the case of Y-chromosomal Adam it is stated, he probably lived between 60,000 and 90,000 years ago. This time frame agrees more with the time of the Toba catastrophe. --Free Citizen 13:53, 29 Dec 2004 (UTC)

I agree with Free Citizen that the link should be changed to Y-chromosomal Adam and will do so in the article. The section below is not written by me and I'm not sure if the author was responding to Free Citizen.

--Finbar 01:33, 18 October 2005 (UTC)

I changed the link to Y-Chromosomal Adam to a link on Population bottleneck which is a better explaination.

-- Finbar 12:08, 18 October 2005 (UTC)

I wouldnt call the article garbage its based on genetic scientific facts,the mitochondrial eve theory is well documented as is the MRCA theory all genetic lines lead to a single person that lived 150000 years ago,there must be a reason for this why do you seem so convinced it a "myth"? I think the real myth is your own ability to think.

The problem is people who would use the Mitochondrial Eve theory to leap to the assumption that the Bible's version of things is correct. Otherwise, I at least see no problem with it. In fact, the article on the theory takes care of that difficulty I see by very carefully explaining that the theory doesn't mean that ME was the only woman alive in her time. So no worries there. Also, your criticism seemed reasonable right up until that last jab at his ability to think that you couldn't resist throwing in. -Andy

Obvious error: one (1) gigaton is not more than 3000x the amount of 350mt (Mt. St. Helens) - please check against the eruption of Mt. St. Helens. Was 1000gt meant? -mkb

1000gT was likely meant, as Crater Lake (Mt Mazama) exceeded 1 gT that I recall, much more recently.Mzmadmike 21:17, 10 April 2007 (UTC)

Also, are there reductions in other species to support this? It couldn't have affected only humans.Mzmadmike 21:18, 10 April 2007 (UTC)

I guess most other species are not so well studied.88.195.46.112 (talk) 07:53, 27 July 2008 (UTC)

Ice Age?

I am wondering, is this supposed to be describing the ice age man apparently went through a while ago, or would that be a different event? The drop in temperature seems to imply that... sort of like what the old dinosaurs went through but a bit less extreme? Tyciol 19:04, 28 February 2006 (UTC)

Lake Toba

Lake Toba linked to this article as the "main article" about the eruption. Since that's not what this article is about (directly), I've changed it so that the discussion of this theory links to this article, inline.[3] If anyone thinks that's a bad idea, and that the purpse of this article is really to discuss the eruption 75,000 years ago in general, then feel free to put it back and discuss your reasoning on the talk page. Thanks -Harmil 07:39, 6 October 2006 (UTC)

Migration pattern?

How is it possible to migrate from Africa to Australia without passing through the Middle East or fertile cresent? Surely we aren't suggesting a boat trip across the Indian Ocean? The only thing I can think of is that the article is suggesting humans passed through the FC but for some reason never settled there until after the migratory population had reached Australia. This seems implauisble to say the least.138.77.2.130

I was thinking the same thing. How would they move "...first to Arabia and India and onwards to Indochina and Australia, and later to the Fertile Crescent and the Middle East."? How can they move to India without passing through the Middle East? And isn't Arabia a part of the Middle East? Someone needs to clarify this. Parsecboy 00:48, 11 June 2007 (UTC)

Maybe there's a difference between a migratory settlement and a migratory route. They could have passed through the Fertile crescent en route to other countries, only settling there later than the longer migrations. Needs checking for sure. Julia Rossi 06:16, 19 August 2007 (UTC)

"Theory"?

Is it fair, really, to call this a theory? Should this perhaps be under "Toba catastrophe hypothesis"? DS 13:04, 6 June 2007 (UTC)

They shade into each other. What's the big deal? --Michael C. Price ^talk 20:03, 6 June 2007 (UTC)

The big deal is creationists who say "evolution's Just A Theory". DS 00:15, 7 June 2007 (UTC)

So? They're morons. --Michael C. Price ^talk 05:52, 7 June 2007 (UTC)

Granted, but we really shouldn't misuse the terminology. DS 13:28, 9 June 2007 (UTC)

But that's the irony of the situation: "theory" and "hypothesis" shade into each other. When a creationist says that evolution is "just a theory" they reveal their scientific incompetence. We don't have to be concerned with such idiots here, and we shouldn't allow them to drive the language, no matter how indirectly. --Michael C. Price ^talk 16:16, 9 June 2007 (UTC)

I do agree with you, but let's remain civil, ok? There's no need to call anyone a moron or an idiot, no matter how poorly educated they may be. Parsecboy 00:50, 11 June 2007 (UTC)

Point taken about civility. About the article -- "theory" is better than "hypothesis" since there is some evidence (genetics and archeology) to support it; "hypothesis" would suggest that it is "just an idea" without any data either to support or refute it. However if you wish to describe it as an hypothesis and a theory I wouldn't object.--Michael C. Price ^talk 13:48, 11 June 2007 (UTC)

I do agree that it should be labeled as a theory, not a hypothesis. There is, as you said, evidence to support it, so it's not just a hypothesis. Parsecboy 15:55, 11 June 2007 (UTC)

This statement needs revision: The analysis of louse genes confirmed that the population of Homo sapiens mushroomed after a small band of early humans left Africa sometime between 150,000 and 50,000 years ago

Considering the time frame that Humans have been on the earth, A 100,000 year window is absurd. —Preceding unsigned comment added by 96.239.19.215 (talk) 17:25, 6 April 2009 (UTC)

Again?

If we worked out that this was going to happen again, could we stop it? Or would we lose 99% of six billion? — Chameleon 12:52, 15 August 2007 (UTC)

You mean if a similar event was going to happen again, could we do anything? Well I'd say, yes and no. Firstly I don't think there's any known way of stopping or even postponing a volcanic eruption (and the bigger it is the less likely). So all we could really do is prepare, if we knew about it years in advance (which seems probable), then we could predict it and perhaps make it less devastating to the human population. I guess the main problem, would be massive crop failures for years on end, which would cause mass famine. One thing to do might be to store and preserve food in the years running up to the eruption and then attempt to disseminate it on a basis of strict rationing during the "lean" years. I guess it depends how severs the conditions are, but almost certainly millions would die, no matter what. If it was REALLY bad, what you'd have to do is build some giant underground bunker, to shelter as many people as possible, and store enough food and resources to survive there, for however long it takes for the environment to return to normal and then rebuild. I'm just putting out ideas off the top of my head here, I don't know, maybe it wouldn't be as bad as I'm imagining, or maybe it'd be worse. Anyway it's some interesting speculation, maybe they should make a movie out of it (if they haven't already). --Hibernian 01:11, 16 August 2007 (UTC)

See http://en.wikipedia.org/wiki/Year_without_a_summer --Frunobulax (talk) 20:08, 13 March 2008 (UTC)

Given that the modern human population boom has occurred over such a relatively short period of time, such an event resulting in billions of casualties is not unthinkable. Despite the fact that humans are large-bodied consumers, complete human extinction is an unlikely result due to their oft-celebrated behavioral adaptability, unless some unprecedent event devastates the first-order producers. The most interesting aspect of such a hypotheized catastrophe, in my opinion, is that the resulting isolation of the surviving human populations could catalyze speciation in the human lineage. --129.81.157.169 14:27, 24 October 2007 (UTC)

The Yellowstone Caldera is a good candidate for a Toba-like eruption, and it might be good if it did. If it erupts soon enough, it could reverse global warming, which is the biggest threat faced by life today. Negritos and other masters of Late Stone Age technology should be able to survive, though whatever stories they pass on would likely not be believed by future generations. But no matter--they won't find any easily accessible coal or oil to start it all over again. Alas, Peter Ward (paleontologist) in Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future (2007) ISBN 9780061137921 0061137928; says that climate change — the same global warming that occurs today — brought on four out of five major extinction events. (Reviewer Doug Brown goes a bit further, averring This Is How the World Ends.) Scientists at the Universities of York and Leeds also warn that the fossil record supports evidence of impending mass extinction, according to this Science Daily release of Oct. 24, 2007. On the Beach would only need up-dating to show life (and death) Under a Green Sky. Analog Science Fiction and Fact has already run stories of what life might be like trying for humans trying to survive in greenhouses as closed ecological systems that make the effort appear commendable, but futile. As did Biosphere 2 Pawyilee —Preceding comment was added at 15:29, 25 October 2007 (UTC)

Index gauge

Near the link for Volcanic Explosivity Index the copy says 8 is "mega-colossal" on this index. Following the link the graph shows "very large", so maybe "colossal" would be enough. Mega colossal sounds like an enthusiastic exaggeration in this context. If no-one objects I'll edit then. Julia Rossi 06:12, 19 August 2007 (UTC)

Name of the Late Pleistocene Toba eruption?

Does this eruption have any specific name? I mean like we don't say "Taupo eruption" but "Oruanui eruption" to point specificly on the eruption that occured 26,500 years ago. Does the Lake Toba eruption of 74,000 years ago have a similar kind of name? ––Bender235 14:44, 20 August 2007 (UTC)

Climate change

I moved the following addition by User:Pawyilee to article, to this talk page. Fred Hsu 12:26, 7 September 2007 (UTC)

Climate Change Spurred Human Evolution by Andrea Thompson, LiveScience Staff Writer, posted: 06 September 2007 12:13 pm ET; information that may have a bearing on this article, but has not yet been evaluated for inclusion.

See Also

http://www.andaman.org/BOOK/originals/Weber-Toba/ch5_bottleneck/textr5.htm http://www.andaman.org/BOOK/originals/Weber-Toba/textr.htm

Pawyilee 11:43, 9 September 2007 (UTC)

Migration

I may have jumped the gun in the citation I just added to Migration. The paragraph as presently written is better supported by the link (with map) that I just added to External links Out Of Africa -- Bacteria, As Well: Homo Sapiens And H. Pylori Jointly Spread Across The Globe. Pawyilee 15:49, 20 October 2007 (UTC)

New Research Confirms 'Out Of Africa' Theory Of Human Evolution ScienceDaily (May 10, 2007). This article includes a migratory map, a paragraph on Related Information: "Australia's archaeological record provides several apparent inconsistencies with the “Out Of Africa” theory..."; and also has links to other articles pertinent to this subject. Pawyilee 16:45, 20 October 2007 (UTC)

photo contrast

Does somebody want to adjust the contrast or brightness of the picture as I think it is very dark! Regards, 122.148.173.37 (talk) 23:32, 14 March 2008 (UTC)

Done. I will upload the image atop the existing one. - Arcayne (^{cast a spell}) 20:38, 19 March 2008 (UTC)

Er, actually, I've never uploaded an image via WikiCommons before, and would prefer not to bollix matter up. Can someone let me know on my talk page how to do so without clusterfucking things up? - Arcayne (^{cast a spell}) 20:44, 19 March 2008 (UTC)

=

On Nov. 20, 2008 the photo is totally black. Regards, BlueSkies999 00:16, 21 November 2008 (UTC)~ —Preceding unsigned comment added by BlueSkies999 (talk • contribs)

Modern humans survived unscathed?

I'm about to head back to the UK from the US so don't have time to work on this, but I've added a mention and 2 references.--Doug Weller (talk) 13:36, 20 April 2008 (UTC)

Compare it with the Nördlinger Ries meteorite impact

The strength of the meteorite impact at Nördlingen was roughly 10 times larger than the assumed Toba event (10 Gigatons TNT equivalent compared to only 1). However, there is neither evidence for a large scale extinction of species 14.5 million years ago in middle Europe nor 75.000 years ago in Asia. Why then should there be any influence of such explosions on the evolution of life at all? Most significantly, there is no correlation between mass extinction or even small scale extinction of species (the human gene pool bottleneck at that time is obviously wishful thinking, because even the endangered Neanderthal men and all other species did not notice it). Since the Toba explosion is supposed to be one of largest Supervolcano explosions like the big ones in the Yellowstone area without influence on life on earth, we have to conclude that the so-called supervolcano explosions are overestimated or do no take place in the way some geologists want us to believe. Finally, Calderas do not necessarilay originate from explosions, but may simply represent the collapse (downward movement) of geological structures. Pjotr Morgen 23:39, 21 July 2008 (UTC)

How powerful?

If Toba was 1 GT, and Mount St. Helens claims 350 MT, this is more like a factor of 3, not 3,000. So which figure is wrong? Mdwh 03:29, 17 March 2007 (UTC)

The article on 1980 eruption of Mount St. Helens quotes 24 MT, which comes from the US Geological Survey [4], making the Toba eruption approximately 40 times as powerful as that of Mount St. Helens. Please note that a simple arithmetic calculation does not constitute WP:OR. I will change the article accordingly. Silverchemist (talk) 17:36, 22 April 2009 (UTC)

Artist's conception removed

I've removed the image Image:Tobaeruption.png from the article. It has a few problems which I've also listed on the image talk page:

1. The entire image is horizontally flipped. Compare the shape of the depicted island with the shape of Sumatra; you can see that it's backwards.
2. The "compass rose" is an equilateral triangle, which makes no sense and doesn't help tell which way is north. In fact, given that the editor who added the rose obviously didn't consult a map of Sumatra (or else he'd have noticed the error above), I wonder whether the "compass rose" was even supposed to be correct to begin with.
3. I'm leery of the whole idea of including an "artist's conception" of the event in the article; after all, this is supposed to be a factual article about a real event, so we shouldn't be mixing in any fictionalized elements. I would prefer to see, let's say, a photograph of the present-day Lake Toba, rather than a computer-generated picture of some smoke.

Once the first two errors are corrected, I don't really mind if someone re-adds the image; but please keep in mind my third objection anyway. --Quuxplusone (talk) 19:09, 29 July 2008 (UTC)

I completely disagree with your third point. Should we remove pictures of dinosaurs, just because they are all conceptual (and they are)? But it wasn't a very good picture, so I don't care either way. --Michael C. Price ^talk 20:58, 29 July 2008 (UTC)

In regard to number 1, you can see that it's backwards. nooo, actually it's a view from suborbital height looking from the east. Here's a map of the area, the viewer would be over the South China Sea

On 2, It is indeed equilateral but is also 3d and had the important point highlighted with yellow. I've made this more apparent, in case anyone else has a hard time seeing it.

On 3, Michael C. Price is correct in that conceptual images are fine here. Check out Wikipedia:Image use policy#User-created images.

To Michael C. Price, what would you like to see changed? Anynobody(?) 03:24, 8 August 2008 (UTC)

Only Indian genetic diversity reduced by Toba?

In an interesting twist on the Toba story I saw an expect (I forget the name, alas) on a documentary stating that the effect of the Toba explosion was to reduce India's genetic diversity, but to leave the rest of humanity's diversity unaffected. He stated that the genetic diversity of humans reduces steadily as you follow their trail out of Africa, so that Africans have the highest diversity (which is well known), with Native Americans the having the lowest (which I didn't know, but seems plausible), since America was the last continent settled prehistorically. He said that Indians (presumably Dravidians, not the later IndoEuropean influx) are the exception to this due to Toba reducing their population severely. If he is correct it would mean that the out of Africa event took place before Toba did not have to be repeated again (although it might have been of course) after Toba (in contradiction to what the article says). --Michael C. Price ^talk 11:19, 5 January 2009 (UTC)

bottlenecks and coalescent time

The evidence section seems to assume that the coalescence of a genetic lineage (eg "mitochondrial eve") indicates a severe bottleneck in the breeding population at the time of coalescence (e g 140 000 years for the mitichondrial lineages). as far as I know, there is no direct link between coalescence dates and bottlenecks, especially not for the autosomes. As I am not a geneticist, I am not familiar enough with the subject to dare re-write the section myself, but I am quite sure that the passage in its present version is flawed. Hezarfen67 (talk) 17:04, 3 March 2009 (UTC)

The evidence section seems pretty unclear on what it is trying to say, it seems to me. But you're right, the extistence of ME or YA has no nearing in the Toba issue.--Michael C. Price ^talk 20:45, 3 March 2009 (UTC)

I, for one, am wondering where all the millions of dead people's skeletons went! If %99 of the global human population suddenly dropped dead virtualy overnight... don't you think the paleontologists would have noticed by now? Way to theorize. :rolls eyes: Allthenamesarealreadytaken (talk) 17:20, 10 April 2009 (UTC)

Given the paucity of human remains generally, no I don't think they would notice, except via indirect means such as the genetic evidence. --Michael C. Price ^talk 18:41, 27 July 2009 (UTC)

I've wondered that myself. What I have been unable to find out is how many humans are estimated to have existed at the time of the catastrophe. Does anyone know? 64.19.148.242 (talk) 20:10, 24 July 2009 (UTC)

Do not know. The genetic Eve should be 140k years old, the genetic Adam 50k years old, everything in the Stone Age, infant death 50%?, life expectancy 40 years?, one in two dozen births ends with the death of the mother? no domesticated animals, no farming. This gives low inhabitants per square km, I guess. "The population of Indigenous Australians at the time of permanent European settlement has been estimated at between 318,000 and 750,000"; Australia's area: 7,686,850 square km; so 0.040 to 0.095 inhabitants per square km. --Chris.urs-o (talk) 05:02, 25 July 2009 (UTC)

Mount Toba Eruption

I hope someone can help here. I ended up at this page looking for information on the volcano and it's geological history. Sure there is a fair slice of that information the Lake Toba article and the first part of this entry. However, there is an excessive focus on the anthropological side of things in this article especially. Right now the introduction reads like it is an anthropological theory rather than outlining of the facts and possible impacts. I am going to put a clean up tag on this entry and I hope all editors realise this isn't a malicious or hostile act. —Preceding unsigned comment added by 203.206.80.17 (talk) 15:48, 26 August 2009 (UTC)

For further comparison

The comparison between Toba and Mount Tambora are given in different units of measure (metric tons vs. cubic kilometers). These cannot be compared in their different units and one should be converted to the other.Jarhed (talk) 07:35, 28 October 2009 (UTC)

67 million years ago or 75?

This article says 70 to 75 thousand years ago, but Lake Toba says 67.5 to 75.5 years ago, and Volcanic_Explosivity_Index says 73. Can we have a bit more consistency with the dates in Wikipedia? Maybe we can have a section or paragraph that discusses the various date ranges or explains why there are different answers. Maybe some of the dates are more accurate than the others?--Sonjaaa (talk) 15:08, 20 May 2009 (UTC)

You may wonder, but we know well that our Earth is only 6,000 years old. Kitty555 (talk) 17:37, 30 May 2009 (UTC)

And there is a teapot orbiting Jupiter! —Preceding unsigned comment added by 86.142.113.174 (talk) 19:41, 17 December 2009 (UTC)

TNT equivalent

The article originally said that the eruption released 1 Gigaton of TNT, which would make it barely bigger than the 1816 Mt. Tambora eruption (800 Megatons), and the amount of material ejected was many orders of magnitude more.

I have updated the figure to 1 Teraton, in line with the Lake Toba article. —Preceding unsigned comment added by 86.144.63.8 (talk) 23:41, 21 December 2009 (UTC)

How much ejected?

We are invited to compare with the Mount Tambora ejection of around 100 km3 of "rock." But I don't find any figure for estimated volume of matter ejected by Toba. So we can't compare. User:joaquin 1 Oct 09 —Preceding undated comment added 17:19, 1 October 2009 (UTC).

Indeed, I was about to ask the same question... -- Beland (talk) 08:09, 17 October 2009 (UTC)

This section is in serious need of cleanup. This part: "the Toba caldera in Indonesia underwent an eruption of category 8 (or 'mega-colossal') on the Volcanic Explosivity Index... and made 1816 the 'Year Without a Summer' in the whole northern hemisphere" is nearly identical to the section: "The Toba eruption (the Toba event) occurred at what is now Lake Toba about 67,500 to 75,500 years ago... and made 1816 the 'Year Without a Summer' in the whole northern hemisphere, whilst the 1980 eruption of Mount St. Helens in Washington State ejected around 1.2 km3 (0.29 cu mi) of material" from the Lake Toba entry, except that the latter includes citations and more details. My guess is that this entry was copied from that one, but some things were added (like the questionable reference to "1 Gigaton"--see comment below). Either way, they should be made consistent, and this entry should use consistent units for these comparisons. 194.29.70.80 (talk) 15:07, 20 January 2010 (UTC)

What is wiser? Write the estimated volume of erupted tephra or just give the Volcanic Explosivity Index with figure. The erupted amount of sulfur-dioxide that cools down the Earth afterwards is more important at eruptions of category 8 (or 'mega-colossal'). The same could happen nowadays with Yellowstone. --Chris.urs-o (talk) 11:11, 22 January 2010 (UTC)

VEI and ejecta volume correlation

In my experience, geologists use the cubic kilometer (estimated or not) measurement much more often than VEI (which, of course, is also an estimate for past eruptions like this one). I understand why you'd want to include the figure to the right, but a) it does not show VEI=8 and b) can be accessed by clicking on the link, so I'd side with not including it. The main reason I added the cubic km is for the comparison with Tambora and the emphasis it has in the literature. Agreed on the SO2 comment, maybe it should be highlighted more in the article?--Qfl247 (talk) 21:11, 22 January 2010 (UTC)

Ok, but VEI Index is open ended, and Yellowstone 640,000 years ago on the figure was VEI 8. The last Toba VEI 8 eruption is important because of the bottleneck on the human population at this time, the Y-chromosomal Adam (most recent common ancestor). A volcano has many eruptions; maybe it becomes easier to comprehend if the key facts of the eruptions VEI 7 & 8 are shown with a small table (infobox) or a list. I think this information could be essential, as the Pacific Ring of Fire shows recent “activity”, the Kamchatka Peninsula shows an unusual high number of active volcanoes at the same time, San Francisco gets by probability an earthquake magnitude 7 all 101 years (the last one, 1906). Yellowstone has a sequence of VEI 8 eruptions: 2.1 million, 1.3 million, and 0.640 million years ago and its detectors show recent earthquake swarms. It is never good when a mountain shows movement. --Chris.urs-o (talk) 09:57, 23 January 2010 (UTC)

Analysis of Helicobacter pylori genes

What does this entire subsection have to do with the Toba Catastrophe? It is not at all clear from what's written. —Preceding unsigned comment added by 99.227.86.155 (talk) 02:49, 16 January 2010 (UTC)

Helicobacter pylori causes ulcer in the human stomach, it is one prove that the human population had a bottleneck by the time of the Toba eruption --Chris.urs-o (talk) 21:23, 21 January 2010 (UTC)

AfD of John D. Hawks

This article was attacked as nonnotable and proposed for deletion. You can comment at Wikipedia:Articles_for_deletion/John_D._Hawks#John_D._Hawks. --JWB (talk) 22:41, 2 February 2010 (UTC)

You mean AfD of John D. Hawks not Toba catastrophe theory ??? Right ??? --Chris.urs-o (talk) 10:54, 3 February 2010 (UTC)

Inconsistency

Toba catastrophe theory "In addition, it has been calculated that one hundred million metric tons of sulphuric acid were ejected into the atmosphere by the event, causing acid rain fallout." Lake Toba "In addition it has been calculated that 10,000,000,000 metric tons of sulfuric acid (Citation needed, perhaps Sulfurous acid, date: June 2009) was ejected into the atmosphere by the event, causing acid rain fallout.(Huang C.Y., Zhao M.X., Wang C.C., and Wei G.J. 2001. "Cooling of the South China Sea by the Toba eruption and correlation with other climate proxies ca. 71,000 years ago." Geophysical Research Letters 28:3915-3918, noted by Weber."

Perhaps sulfuric acid is only determined in the ice core. --Chris.urs-o (talk) 20:58, 28 February 2010 (UTC)

Bottleneck Theory

Here is a possible source later in the decade than Gibbons paper. WBardwin (talk) 08:55, 1 March 2010 (UTC)

• Jorde, Lynn B., Michael Bamshad, and Alan R. Rogers. "Using Mitochondrial and Nuclear DNA Markers to Reconstruct Human Evolution." BioEssays 20 (1998): 126-136.

Yes, I know. There are various more recent articles than Gibbons. I just mentioned it, in order to illustrate the history of the bottleneck theory in relation with the Toba eruption, namely how it first appeared and who were those who first (at least partially) articulated it, before Ambrose's more systematic argumentation on the issue.--Yannismarou (talk) 11:47, 2 March 2010 (UTC)

Martin A.J. Williams et al., 2009 - Quotes

These are quotes of: Williams, Martin A.J. (30 December 2009). "Environmental impact of the 73 ka Toba super-eruption in South Asia". Palaeogeography, Palaeoclimatology, Palaeoecology. 284 (3–4). Elsevier: 295–314. Retrieved 5 March 2010. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

• Global cooling may have been enhanced by increasing terrestrial albedo over India from the ash blanket (Jones et al., 2007).
  • Jones, M.T., Sparks, R.S.J., and Valdes, P.J. (2007). "The climatic impact of supervolcanic ash blankets". Climate Dynamics. 29 (6): 553–564.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• The purity of the ash and its widespread distribution across India show that a layer of ash sufficiently thick to preclude contamination with underlying soils covered much of the sub-continent to a maximum of 10-15 cm, as in the adjacent of Bengal marine cores (Ninkowich et al., 1978a; Acharaya and Basu, 1993; Gasparotto et al., 2000).
  • Ninkovich, D. (September 1978). "The exceptional magnitude and intensity of the Toba eruption, Sumatra: An example of the use of deep-sea tephra layers as a geological tool". Bulletin of Volcanology. 41 (3). Springer: 286–298. Retrieved 5 March 2010. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Acharyya, S.K. (July 1993). "Toba ash on the Indian subcontinent and its implications for correlation of late Pleistocene alluvium". Quaternary Research. 40 (1): 10–19. doi:10.1006/qres.1993.1051. Retrieved 5 March 2010. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Gasparotto, G. (2000). "Contribution of grain size and compositional data from the Bengal Fan sediment to the understanding of Toba volcanic event". Marine Geology (162): 561–572. doi:10.1016/S0025-3227(99)00090-0. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• The 73,000 years age for the Toba eruption used in our model is based on the K-Ar age of 73,500 ±3,000 obtained for the eruption by Ninkovich et al., 1978b and single-grain laser fusion ⁴⁰Ar/³⁹Ar age of 73,000 ±4,000 obtained by Chesner et al., 1991.
  • I think we could stuck to this age for now. 69,000-77,000 years ago.
  • Chesner, C.A.; Westgate, J.A.; Rose, W.I.; Drake, R.; Deino, A. (1991). "Eruptive History of Earth's Largest Quarternary caldera (Toba, Indonesia) Clarified" (PDF). Geology. 19: 200–203. Retrieved 2010-01-20. {{cite journal}}: Unknown parameter |month= ignored (help)
  • Ninkovich, D. (7 December 1978). "K−Ar age of the late Pleistocene eruption of Toba, north Sumatra". Nature (276). Nature Publishing Group: 574–577. Retrieved 5 March 2010. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• ...(Petraglia et al., 2007). Our work challenge this conclusion because they show that the Toba eruption led to prolonged drought and deforestation in India, probably lasting for 1,000-2,000 years.
  • Petraglia, M. (6 July 2007). "Middle Paleolithic Assemblages from the Indian Subcontinent Before and After the Toba Super-eruption" (PDF). Science. 317 (5834): 114–116. doi:10.1126/science.1141564. Retrieved 5 March 2010. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• However, cores from three large, deep lakes in tropical Africa (Lakes Malawi, Tanganyika and Bosumtwi) have unusual depositional events at around 73 ka, reflecting apparently synchronous abrupt drops in lake lavels (Scholz et al., 2007).
  • Scholz, Christopher A. (October 16, 2007). "East African megadroughts between 135 and 75 thousand years ago and bearing on early-modern human origins". Proceedings of the National Academy of Science. 104 (42): 16416–16421. doi:10.1073/pnas.0703874104. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Rousseau and Kukla (2000) noted rapid monsoon retreat in China at the S1/L1 boundary of the long loess-paleosol sequence of the Loess Plateau,...
  • Rousseau, Denis-Didier (November 2000). "Abrupt retreat of summer monsoon at the S1/L1 boundary in China". Global and Planetary Change. 26 (1–3): 189–198. doi:10.1016/S0921-8181(00)00044-8. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• The cooling generated by the Toba sulfates (Zielinski et al., 1996) may have been accentuated in high latitudes through positive feedback effects related to increased albedo from persitent snow cover at high latitudes (Rampino and Self, 1993; Zielinski et al., 1996; Kelly et al., 1996; Jones et al., 2005).
  • Rampino, Michael R.; Self, Stephen (1993). "Climate–Volcanism Feedback and the Toba Eruption of ~74,000 Years ago" (PDF). Quaternary Research. 40: 269–280. doi:10.1006/qres.1993.1081.
  • Zielinski, G.A.; Mayewski, P.A.; Meeker, L.D.; Whitlow, S.; Twickler, M.S.; Taylor, K. (1996). "Potential Atmospheric Impact of the Toba Mega‐Eruption ~71,000 years ago" (PDF). Geophysical Research Letters. 23 (8): 837–840. doi:10.1029/96GL00706.
  • Kelly, P.M. (1996). "The spatial response response of the climate system to explosive volcanic eruptions". International Journal of Climatology (16): 537–550. Retrieved 2010-03-08. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Jones, Gareth S.; Gregory, Jonathan M.; Stott, Peter A.; Tett, Simon F.B.; Thorpe, Robert B. (2005). "An AOGCM model of the climate response to a volcanic super-eruption". Climate Dynamics (25): 725–738. doi:10.1007/s00382-005-0066-8.
• If the Toba eruption did indeed coincide with the onset of the very cold event just after interstadial 20, as seems probable (Zielinski et al., 1996), then the Toba eruption may have provided the catalyst for the prolonged cooling and drying that followed.
  • The timing, it might be that the event got very cold because Toba hit the global climate in the beginning of the cooling period
• If global primary productivity declined catastrophically for nearly two millenia following the Toba eruption then it may have been responsible for the late Pleistocene population bottlenecks reflected in the genetic structure of living human (Harpending et al., 1993; Mountain and Cavalli-Sforza, 1997; Watson et al., 1997; Ke et al., 2001; Forster, 2004), eastern African chimpanzee (Goldberg, 1996), Bornean orangutan (Steiper, 2006), central Indian macaque (Hernandez et al., 2007) and all tiger (Luo et al., 2004), and the separation of the nuclear gene pools of eastern and western lowland gorillas (Thalman et al., 2007). Molecular genetic dating indicates that all these species recovered from very low population sizes during the early last glacial, around 70,000-55,000 years.
  • So we have: humans, lice (human parasite), Heliobacter pilori (human pathogen), chimpanzees, orangutans, macaques, tigers, and gorillas; quite a lot... --Chris.urs-o (talk) 05:22, 6 March 2010 (UTC)
    • But for the humans the problem is that there is no such scientific consensus - some scientists say the bottleneck(s) may have occured much earlier!--Yannismarou (talk) 22:26, 6 March 2010 (UTC)
    • So what, above there are 5 refs, plus the louse and the Heliobacter pylori ones, there is always somebody challenging it. An article for the majority, a note for the challenge... --Chris.urs-o (talk) 22:48, 6 March 2010 (UTC)
  • Harpending, Henry C. (1993). "The genetic structure of ancient human populations". Current Anthropology. 34 (4): 483–496. Retrieved 2010-03-08. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Mountain, Joanna L. (September 1997). "Multilocus genotypes, a tree of individuals, and human evolutionary history". Am. J. Hum. Genet. 61 (3): 705–718. Retrieved 2010-03-08. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Watson, E. (September 1997). "Mitochondrial footprints of human expansions in Africa". Am. J. Hum. Genet. 61 (3): 691–704. Retrieved 2010-03-08. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Ke, Yuehai (11 May 2001). "African Origin of Modern Humans in East Asia: A Tale of 12,000 Y Chromosomes". Science. 292 (5519): 1151–1153. doi:10.1126/science.1060011. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Forster, Peter (2004 February 29). "Ice Ages and the mitochondrial DNA chronology of human dispersals: a review". Philosophical Transactions of the Royal Society of London B Biological Sciences. 359 (1442): 255–264. Retrieved 2010-03-08. {{cite journal}}: Check date values in: |date= (help)
• I am sorry but it is not just a challenge! Petraglia, Oppenheimer and others are among those who challenge the theory. If, for instance, Petraglia's findings are correct, this is a clear blow for the theory; and another blow for the theory is the possiblity that Huff et al. are correct. Even scientists who seem more positive towards the theory, like Robock, they not say that the theory is a fact, but that it is just a plausible theory! "Strengthens his argument" is the exact wording Robock uses for Ambrose.

I thus definitely disagree with your approach (an article for the majority; a not for the challenge), because there is no clear-cut majority! There are scientists who accept is as a possibility, and scientists who reject it. And both of these two sides should be equally represented and expressed in the article, according to the Wikipedia'a NPOV policy.--Yannismarou (talk) 16:49, 10 March 2010 (UTC)

• Ok, I expressed myself a lil bit lightly. As I see it, Robock thinks the Toba event on its own, a lil bit weak to cause a genetic bottleneck. It could be. But then there is the higher albedo, when the snow line gets lower. And then there is the timing, if a Toba like event hits the climate at the beginning of a cooling period or at the beginning of a warming period, matters. As I see it. Petraglia and others will get a weak stance, if every hunting mammal got a genetic bottleneck in this period of time. Of course, a serious challenge must cited, but nobody knows the whole story yet. --Chris.urs-o (talk) 18:05, 10 March 2010 (UTC)

• Ok, I also think I partly misunderstood you. We basically agree.--Yannismarou (talk) 21:47, 12 March 2010 (UTC)

Multiple problems

The article faces multiple problems, especially repetitions and overlaps. I decided to start a rewriting of the article, being intrigued by the theory after a documentary I watched, but I make clear that I am neither a geologist nor an anthropologist; there are various issues which confuse me, and experts' contributions would be welcome. To be more specific:

• Every scientific article I read has a (slightly) different estimate of the time of the eruption: 71,000 years ago, 73,000 years ago, 74,000 ago etc.! Scientists seem unable to agree even on that! That is why I preferred the broader possible versions ("The Toba eruption or Toba event[1] occurred at what is now Lake Toba about 71,000 years (± 5000 years)[2] or 74,000 (± 2000 years).[3] ago." "The Toba supereruption (Young Toba Tuff or simply YTT[1]) occurred between 66,000 and 76,000 ago at Lake Toba"). If anybody has to propose something better, I am all ears!

Do not use the maximum uncertainty cited, you can use the estimate given at the global volcanism program site instead ("Toba". Global Volcanism Program. Smithsonian Institution. Retrieved 2010-03-05.). They should know which work is of higher quality. Maybe it is better to assume that Toba gives the name to this event and was just one of the causes of this event.

Martin A.J. Williams, Stanley H. Ambrose, Sander van der Kaars, Carsten Ruehlemann, Umesh Chattopadhyaya, Jagannath Pal, and Parth R. Chauhan, Environmental impact of the 73 ka Toba super-eruption in South Asia, Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 284, Issues 3-4, 30 December 2009, Pages 295-314 [5]

John A. Westgate, Philip A. R. Shane, Nicholas J. G. Pearce, William T. Perkins, Ravi Korisettar, Craig A. Chesner, Martin A. J. Williams, and Subhrangsu K. Acharyya, All Toba Tephra Occurrences across Peninsular India Belong to the 75,000 yr B.P. Eruption, Quaternary Research, Volume 50, Issue 1, July 1998, Pages 107-112 [6]--Chris.urs-o (talk) 13:24, 5 March 2010 (UTC)

• I deleted a phrase in the "Genetic bottleneck theory" section, third paragraph, according to which Ambrose argues that only three hominids survived: modern humans, neadertals, and hobbits. I read Hawkins and elsewhere that modern studies suggest that all hominids survived! Maybe even erectus. Does anybody have the 1998 paper of Ambrose? Does he say that only three hominids survived? Does he insist on this view nowadays? By the way, can anybody provide a better source than Hawkins' blog?
• There are overlaps and repetitions between the "Bottleneck theory" and "Migrations" sections, which should be avoided. For instance:

Bottleneck section: "Gene analysis of some genes shows divergence anywhere from 60,000 to 2 million years ago. This does not contradict the Toba theory, however, because Toba is not conjectured to be an extreme bottleneck event. The complete picture of gene lineages, including present-day levels of human genetic variation, allows the theory of a Toba-induced human population bottleneck.

Migrations section: "Recent analyses of mitochondrial DNA have set the estimate for the major migration from Africa from 60,000 to 70,000 years ago".

I underline that these overlaps existed before my ongoing rewriting. The two sections could be combined and merged, but, in any case, we should reconsider their relation and structure. The last sentence of "Migrations" is also of particular consideration:

"How the populations of Homo erectus soloensis on Java, and of Homo floresiensis on the island of Flores, Indonesia, survived has yet to be determined, but it appears they (like Homo neanderthalensis in Europe) were not affected by the fallout"

Weren't they affected?! But we said previously that they may have been affected (according to the catastrophe theory), although we are not sure to what extent were they affected? I think that this sentence is inconsistent with the rest of the article.

• "The complete picture of gene lineages, including present-day levels of human genetic variation, allows the theory of a Toba-induced human population bottleneck.[27]" The source provided in citation [27] is Dawkins. Does Dawkins actually say that and refers to the Toba eruption?
  • Peter Forster's review is a full free text (2004), maybe it is of higher quality. --Chris.urs-o (talk) 12:29, 8 March 2010 (UTC)

I am sure that I have further question, which I forget now, but let's start dealing with these issues, which are already numerous and important, and then we see how we proceed.--Yannismarou (talk) 08:58, 4 March 2010 (UTC)

I am a bit lost with this sentence "analysis of Alu sequences across the entire human genome has shown that the effective human population was already less than 26,000 as far back as 1.2 million years ago, suggesting that no Toba bottleneck was necessary". Can we talk about human population 1.2 million years ago?. Should we change it for "hominid population" or "The effective population of hominids"?. At any rate, maybe that should be a bit more explained, given the gigantic temporal difference. Leirus (talk) 08:59, 28 April 2010 (UTC)

It is true, this sentence is not good enough, but I do not understand enough about Alu sequences yet to be able to improve it. It does not help that it is one of the battlefields in Science. E.g.: Most recent common ancestor vs. Alu sequences; K-T Extinction event: Deccan Traps vs. Chicxulub crater; sea level increase: IPCC vs. Nils-Axel Mörner; Global warming: sulfur dioxide vs. carbon dioxide... --Chris.urs-o (talk) 10:18, 28 April 2010 (UTC)

Notes:

• 1.8 Ma, Homo erectus.
• 516 ka, Homo antecessor is the common genetic ancestor of humans and Neanderthal.
• 355 ka, Homo heidelbergensis is the common ancestor of both Homo neanderthalensis and Homo sapiens.
• 195 ka, Omo remains. --Chris.urs-o (talk) 06:58, 19 May 2010 (UTC)

My compliments

I know this doesn't relate to improving the article, but I am very impressed by how it details the scientific controversies over the theory in such a well balanced way. Very readable and informative. Great article! Huw Powell (talk) 01:29, 25 April 2010 (UTC)

Yannismarou (talk) did a good job sorting it out :) --Chris.urs-o (talk) 07:19, 25 April 2010 (UTC)

genetic bottleneck

Is there any information about how the Toba eruption may have affected the Neandertal genetic viability? —Preceding unsigned comment added by 212.93.199.154 (talk) 13:53, 9 May 2010 (UTC)

How about Dead Clade Walking ??? --Chris.urs-o (talk) 14:00, 9 May 2010 (UTC)

I find it curious that this article mentions different estimates of the human population AFTER the incident, mentions repeatedly that this was a catastrophic reduction in the population, but never mentions any estimates for the size of the population BEFORE this bottleneck. What was the reduction? Was it reduced from 20,000 people to 5,000 people? Was it reduced from 2 million to 5,000 (give or take a few)? Charts like this one world population begin at 70,000 BC and do not indicate the estimated population before that.Deproduction (talk) 17:14, 15 May 2010 (UTC)

I agree. But to estimate this you must at least know the area occupied by the population. Quote: "The population of Indigenous Australians at the time of permanent European settlement has been estimated at between 318,000 and 750,000." This quote might give you an idea. --Chris.urs-o (talk) 07:04, 19 May 2010 (UTC)

Referencing

This article has its citations formatted in the brief "author-date" format (aka Harvard referencing), where the citations are supposed to link to the full bibliographic citation in the References section. However, the citations here have only been formatted to look like links; they do not actually link.

Would there be any objection if I convert these citations to actual working links (using the 'Harvard' templates)? The main change in the appearance of the article (aside from working links) would be replacement of "et al." with "& others". - J. Johnson (JJ) (talk) 22:21, 9 July 2010 (UTC)

I don't see any objections, but neither do I see any support. I am not going to presume consensus to proceed unless I hear a voice or two in support. - J. Johnson (JJ) (talk) 20:45, 14 July 2010 (UTC)

Be bold. I good editing does not get a thx on Wiki ;) --Chris.urs-o (talk) 04:10, 15 July 2010 (UTC)

Okay, I have boldly jumped in, with my big clodhoppers on. I have cloned the References section, straightened out the formatting so it is clearer, and added the 'ref' tags. However, some of the sources ({{Cite}} templates) were buried in the article, and I have not yet dug them out and moved them. I have not presumed to fix various other irregularities.

I have also converted most of the citations in the article to 'Harv' templates, added punctuation to footnotes, and added a couple of tags. (Not yet done in the "Genetic bottle neck" section because it is a real ugly mess.) All editors please note: one of the excellent reasons for hooking these up is to check that there is an actual bibliographic reference for the citations to point to. Already I can see that several are missing (e.g.: Jones; Oppenheimer), and I will leave it to the cognizant editors to amend those omissions. But please observe the form: put the bibliographic details (in a {{cite}} or {{citation}} template, including a 'ref=CITEREFxxxx' term) in the References section, observing the format used there.

Another excellent reason for keeping the bibliographic details (the 'Cite' templates) in the References section is that both maintenance and checking of the bibliography and editing of the text are MUCH EASIER. Mixing this stuff in with the article text just unnecessarily clutters both. - J. Johnson (JJ) (talk) 23:03, 17 July 2010 (UTC)

I have completed this demonstration of how to improve bibliographic citation. Feel free to look at the markup; please note how less cluttered most of it is, how much easier it is to see the text. (The exception is in the Genetic bottlenecks section, where there is a profusion of weblinks to sources too incompletely documented for a proper citation.) I have not (except for a few trifles) tried to "improve" anything.

Setting up the references/citations in this way really is easier, overall, than the rather ad hoc approach you all have been doing. (And it looks better, and is better.) It does require a little discipline, but seeing how much work some of you have done in coercing the format to look good, I am sure you all can handle this. And it really is easier. I strongly recommend this approach. - J. Johnson (JJ) (talk) 20:21, 18 July 2010 (UTC)

I have removed the original, and now redundant, References section. Various problems in source referencing remain; I urge the original editors to review the sections they have added or modified and correct the more egregious problems. - J. Johnson (JJ) (talk) 20:34, 18 August 2010 (UTC)

Criticism

This article is interesting, and fairly well done; I commend all of you that have worked on it. But it has some very serious shortcomings. I would like to offer some critical comments towards improving the article, and towards improvement of editorial skills. I hope no one will take offense. I point to past failings not to embarrass anyone, but to correct matters, and to avoid future embarrassment.

One glaring shortcoming is several instances of gross inattention to detail. Like copying in names of authors by cut-and-paste, without going back to remove the extraneous superscripts. Everyone: please don't be in such a hurry whip up yet another article that you fail to do elementary copy editing! Put new material in a 'sandbox', then go over it several times before you add it to an article. Also, dig out the details! Pretty nearly every scientific journal has abstracts of their articles on-line, with all the bibliographic details. And in the last decade the use of DOI's has become near universal. Failure to include this kind of simple stuff suggests that the editor was in too much of a hurry — or perhaps too lazy? — to bother, and reflects poorly on the work.

Another shortcoming is mixing bibliographic details (in 'cite' or 'citation' templates) of source references in the text. (Building partial bibliographies in the notes is especially bad practice.) This just tangles up both references and text, and makes both hard to work with. Put the references in a separate section ("References"), and use 'Harv' templates to link specific citations with the reference. I have just done this to the article (comments above), and if you look at the markup you can see it is now much more readable it is now.

A major problem in this article is the citing of news stories about research, and not the research itself, and in heavy reliance on web sites. Such sources may be useful in explaining the significance of research, or documenting controversies, or just providing a less technical overview. But these are not research, and not as reliable as actual research. Don't use them as substitutes. And where you do use them, don't just point to where some statement exists on the Web — identify who said it, and when.

There are also some missing references (click through the links in the notes to find them) and a few other problems. Hopefully each of you will give the article a close read and correct any problems. - J. Johnson (JJ) (talk) 21:49, 18 July 2010 (UTC)

In some of your remarks you are right. In some others IMO you are not. For instance, although I have worked on quite a few FAs, I have never used the "Harv" templates. The fact that you like them does not mean that they are the best choice; there are other alternatives as well. Not having a separate "References" section has also been acceptable is some good Wikipedia scientific articles, including FAs. It is not something I prefer, but it often works fine. In this particular article, when I did some editing, I felt that we had first to fix and improve what we have, and then decide about how the references – citations are going to be structured. It seems that you adopted a different approach. As regards the "news" citations, I agree that they cannot substitute the researches themselves, but, when I have no access to the researches (e.g. when I have to pay amounts of money I do not want to), I'll use news sources, especially when they adequately summarize the research itself; and in this case, at least IMO, such sources are fine, in terms of verifiability and comprehensiveness.--Yannismarou (talk) 09:53, 12 February 2011 (UTC)

I do not say that Harv is absolutely the best way in all cases. I do say that there is strong case in favor of Harv, and my prior effort here was to demonstrate some of the benefits. A principal benefit is disentangling text and bibliographic details, so they don't confuse each, and errors and problems with each made clearer.

In your second point I am not clear on what you mean by "first to fix and improve what we have". It suggests the very discreditable "write first (based on what one already knows), then find sources to support it." But hopefully this is not what you meant. In any event, I would say that "structure" or style or method of citation is something that should be decided right at the start. Else there is all sorts of rework required, often when the details needed are no longer at hand. And the expectation that people will come back and do the rework is, sadly, naive, as can be seen by all the rework done on this article.

Your last point, about sources behind paywalls, can be a definite problem. Of course, that is mostly primary research, and we are supposed to use secondary sources. And "news" stories from many sources (Science, Nature, the N.Y. Times science writers) are generally quite reliable. But not perfect, and editors should not take any source as holy writ. Fortunately, I have found that many for-pay articles have been downloaded and posted somewhere; it just takes a lot of patience (and good search terms) to dig them out. - J. Johnson (JJ) (talk) 21:09, 12 February 2011 (UTC)

Two remarks and a conclusion:

• Yes, I partly mean what you do not like; I basically support the approach: "write first; decide later on the stylistic issues". Right or wrong (both subjective notions), this is what I believe, and this is how I have worked in Wikipedia with not so bad results I could say.
• I know that some of these articles can be found free sometimes in other sites. And, believe me, once upon a time I spent nights and nights searching such sites using every possible combination of search terms you can imagine; and I may have many deficiencies as an editor, but I do know that "digging" is one of the things I am good at. But, unfortunately, you cannot always find what you search for, even if you "dig" for hours and even if you concentrate in your efforts all the patience of the world.

Summarizing my experience from this article: I was fascinated by its topic after watching a documentary in the tv, and I decided to work on it, in order to upgrade it, and, why not, some time in the future see it FA or GA. I dedicated hours and hours of my precious everyday life; I digged and googled using all my imagination; I even spent money, when digging was hopeless. But, as much as I tried, and as much as I may be still fascinated by this article, at one point I came to a dead end. Why? Simply, because I am not a geologist, neither a specialist of any other related science. I did what I could up to a certain level, but to go higher from this level I needed the help (more accurately: the article needs the help) of a specialist. When your abilities are not enough, you must admit it and go on. However, I am certain that, putting on a balance the pros and cons of my edits, I believe that my rewritting overall benefited the article. Now, If there is such a willing specialized person willing to seriously work on this article, and if he/she decided that he/she needs my assistance (if such an assistance may be of any use for him/her), then I can wholeheartedly offer it, and he/she can count on me.--Yannismarou (talk) 15:47, 13 February 2011 (UTC)

  Yes, it is a fascinating topic. But credibility suffers if sourcing is screwed up.

  I agree that sometimes papers just can't be found in the Internet for free. (And I do spend hours on searches.) If I feel I really need them I look for paper copies. Sometimes interlibrary loan works, other times I go over to the school and photocopy. But if the article isn't really necessary, I just say the hell with it. And fantasize that the authors feel the sting of my disdain.  :-)

  I am pretty strongly against the "write first" approach. Possibly we could have good discussion on it, but for the most part this is probably not the proper place. [Woops! Belated signing.]   - J. Johnson (JJ) (talk) 00:09, 14 February 2011 (UTC)

  On thinking about this overnight, I am wondering if you might have taken some of my criticisms to heart. That was not my intent! I did point out some things that were done pretty sloppily. If any of that was your work, well, clean them up (much simpler than finding obscure articles), be more careful in the future, and it's all just a minor learning experience. Indeed, anyone that wants to improve the article should consider straightening out some of those details. - J. Johnson (JJ) (talk) 23:55, 14 February 2011 (UTC)

There is a glaring factual error in the 2nd to last paragraph of section on the Bottleneck Theory: "the effective human population was already less than 26,000 as far back as 1.2 million years ago,..." 1.2 million years ago for Homo-sapiensItalic text? Most anthropologists suggest a date for Homo-sapiens at about 500,000 years ago, and I've seen the figure at 200,000 years ago. That 1.2 million years ago is way off base. Colin Renfrew and Paul Bain, ARCHAEOLOGY, page 167-169 suggest Homo-sapiens at less than 500,000 years ago. And for those who don't know when the Late Stone Age occurred: about 50,000 years ago. Whoever is responsible for the essay, should correct the discrepancy. Thank you. StevenTorrey (talk) 02:05, 16 March 2012 (UTC)

What on earth have I done?

I have just made (what I had believed to be) a very small change at the end of one paragraph - what appeared to be an editing error from earlier this year. However, going back and checking this using "differences" seems to indicate that I have made extensive changes to the whole article. Help! Please, someone, advise!! Quartic (talk) 21:49, 23 September 2010 (UTC)

Hmmm, interesting. Someone else will have to explain what happened, but undoing it is easy. Go to the article, click on "View history", and you will see a list of every edit, including yours. Note the (undo) link at the end of the line — just click on that. (If you get a message that it can't be undone, undo the the edit at the top of the list first, then yours.) If you totally screw it up, don't panic, it can all be recovered. Good luck. - J. Johnson (JJ) (talk) 19:44, 24 September 2010 (UTC)

I know I'm late to the party, but the error Quartic made was to edit an old version of the page instead of the current one (which was reverted by another editor). Also, the typo Quartic was trying to remove was still in the article today, which I have now taken out. SpinningSpark 10:04, 12 March 2011 (UTC)

Tuff?

I know what tuff is, but why "Youngest Toba Tuff?" Why tuff, younger than what, etc.? --Vaughan Pratt (talk) 20:38, 18 April 2011 (UTC)

"The Toba eruption was the latest of the three major eruptions which occurred at Toba in the last 1 million years." Each eruption leaves a ash layer. --Chris.urs-o (talk) 01:41, 19 April 2011 (UTC)

Further work

For anyone interested in extending/improving this article: There's a good review of of topic (as of 2010) in Science ("Of Two Minds About Toba's Impact", 5 March 2010, p. 1187). It also mentions articles in American Journal of Genetics (Richards, June 2009) and Science (9 October 2009).

Also, some of the current references are wretchedly formatted, and really should be revised. (The initial seem uninterested, so feel free to jump right in.) - J. Johnson (JJ) (talk) 23:09, 17 July 2011 (UTC)

---

There is an error of omission under "Genetic bottleneck theory", at paragraph twelve ["It has been suggested that nearby hominid populations, such as Homo erectus soloensis on Java, and Homo floresiensis on Flores, survived because they were upwind of Toba."];

and under "Migration after Toba" at paragraph three ["A 2009 study by Martin A.J. Williams's team challenges Petraglia's findings. Williams analysed pollen from a marine core in the Bay of Bengal with stratified Toba ash, and argued that the eruption caused prolonged deforestation in South Asia. Ambrose, who is a co-author of the study, calls the evidence "unambiguous", and further argues that YTT may have forced our ancestors to adopt new survival strategies, which permitted them to replace Neanderthals and "other archaic human species". However, both Neanderthals in Europe and the small-brained Homo floresiensis in Southeastern Asia survived YTT by 50,000 and 60,000 years respectively."].

This is the Denisova hominin.

Under Wikipedia's "Homo" entry it reads: "All species of the genus except Homo sapiens (modern humans) are extinct. Homo neanderthalensis, traditionally considered the last surviving relative, died out about 24,000 years ago, while a recent discovery suggests that another species, Homo floresiensis, discovered in 2003, may have lived as recently as 12,000 years ago. The Denisova hominin, whose discovery was announced in March 2010, may be yet another past species in the genus." Under the Wikipedia entry for Denisova hominin it is stated more definitively: "The Denisova hominin is the remains (a finger bone, toe bone and tooth) of a member of the genus Homo that may belong to a previously unknown species based on an analysis of their mitochondrial DNA (mtDNA)". The Wikipedia entry also states "This history of interaction suggests that Denisovans once ranged widely over eastern Asia."

I suggest that the Denisova hominin should at least be included in both paragraph three and twelve, and that if Wikipedia changes the entry title from Denisovan hominin to Homo Denisovan in the future to then use that naming reference (it seems likely to me that the change in nomenclature is bound to occur, it is only that the discovery has been recent). If Java man can be referred to then Denisovan man should be too, especially as it is alleged to have lived in the area of strongest ashfall of the Toba event. Star A Star (talk) 14:49, 24 October 2011 (UTC)

Migration section

The last paragraph (footnote 60 as of today's date) cites a vague claim by George Weber in his magnum opus at www.andaman.org regarding survival of species "upwind" who were also "protected by being in the southern hemisphere". However, Toba is not that far from Java and Flores (only about 10 degrees of latitute) and all lie in the equatorial region where the wind pattern is Doldrums -- calm and unpredictable. To declare that a mega explosion like Toba would have effects only downwind is even more strange, so I think we should cut or modify the final paragraph. Martindo (talk) 05:13, 24 January 2012 (UTC)

Neandertals

As the Neandertals were around at the time of the Toba eruption is there any information about what happened to them? Mostly apparently living in Europe, did the eruption also affect their numbers as well?AT Kunene (talk) 17:14, 8 March 2012 (UTC)

There is an incomplete citation in the text: "Green 2007." Would someone familiar with this subject please determine whether the following reference and abstract are the information intended to be cited there?

Richard E. Green, Johannes Krause, Susan E. Ptak, Adrian W. Briggs, Michael T. Ronan, Jan F. Simons, Lei Du, Michael Egholm, Jonathan M. Rothberg, Maja Paunovic & Svante Pääbo Analysis of one million base pairs of Neanderthal DNA Nature 444, 330-336 (16 November 2006)

| doi:10.1038/nature05336; Received 14 July 2006; Accepted 11 October 2006

Richard E. Green, Johannes Krause, Susan E. Ptak, Adrian W. Briggs, and Svante Pääbo were affiliated with Max-Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany

Michael T. Ronan, Jan F. Simons, Lei Du, Michael Egholm, and Jonathan M. Rothberg were affiliated with 454 Life Sciences, 20 Commercial Street, Branford, Connecticut 06405, USA

Maja Paunovic was affiliated with Institute of Quaternary Paleontology and Geology, Croatian Academy of Sciences and Arts, A. Kovacica 5/II, HR-10 000 Zagreb, Croatia, but is deceased.

Address correspondence to: Richard E. Green. Neanderthal fossil extract sequences were deposited at EBI with accession numbers CAAN01000001–CAAN01369630. Correspondence and requests for materials should be addressed to R.E.G. (Email: green@eva.mpg.de).

Abstract [re-written for copyright compliance; please check against the original in Google Scholar] Among extinct hominids, Neanderthals are the closest to modern humans. Comparing their genome to modern ones helps identify genes specific to humans having fully modern anatomy. This work concerns one Neanderthal fossil, 38,000 years old, that appears not to be contaminated with modern human DNA. Comparing sequences containing more than one million base pairs of hominoid nuclear DNA (obtained by direct high-throughput sequencing) to modern human DNA suggests that modern human DNA sequences diverged from those of Neanderthals ca. 500,000 years ago. Using present technology and the fossils available, an effort to sequence a Neanderthal genome can begin. — Preceding unsigned comment added by Nhy67ygv (talk • contribs) 04:20, 26 May 2012 (UTC)

Confusing citations

Some of the citations are unclear. In the second paragraph of 'Volcanic winter and cooling' there is the sentence: "In contrast, Oppenheimer believes that estimates of a drop in surface temperature by 3–5 °C are probably too high, and he suggests that temperatures dropped only by 1 °C." His first name is not given, and the reference is Oppenheimer 2002. Another reference is Openheimer 2001, but this is almost certainly the same book judging by the page numbers.. The citations (which are not in alphabetical order) refer to Stephen and Clive Oppenheimer, but none of them is dated 2001 or 2002. Which Oppenheimer and which work is being cited? Dudley Miles (talk) 21:51, 5 January 2013 (UTC)

I have now found and added the missing reference and put them in alphabetical order. Dudley Miles (talk) 18:40, 10 January 2013 (UTC)

Article split

After reading this article its seems clear there are 2 topics going on here. One being the supereruption that according to the text here is not disputed - then we have the bottleneck theory portion of the article. Should these not be divided - one as a geological event that has happened - and the other the event related to the conjectured aftermath bottleneck theory. I came to this article to find info on the Toba supereruption (a geological event) - not the human aftermath that should in my opinion be separated. What do others think?Moxy (talk) 17:19, 24 January 2013 (UTC)

I completely agree. An separate article on the event could easily link to the "theory" or vice versa (but see below) PeterDz (talk) 14:51, 29 April 2013 (UTC)PeterDz

Hypothesis or Theory?

At different points in the article what may or may not have happened to the human race as a result of the Toba event is described as both a theory and as a hypothesis. It is either one or the other, but NOT both. My personal understanding is that the impact is conjectural, with little evidence one way or the other and a great deal of disagreement in the field, but I am not an expert on the subject. Could an expert please correct, choosing one. Or is that itself too controversial? PeterDz (talk) 14:46, 29 April 2013 (UTC)PeterDz

Hypothesis is the correct word - hopefully I'll get around to changing it. Maybe now, we have Pole shift hypothesis. Dougweller (talk) 15:38, 29 April 2013 (UTC)

Ah, saw your post about splitting the article. That might have to be done first. More thought needed. Dougweller (talk) 15:39, 29 April 2013 (UTC)

Oxford team "puts a nail in the coffin of the disaster-catastrophe theory": Toba super-volcano catastrophe idea 'dismissed' Jyg (talk) 06:16, 1 May 2013 (UTC)

One paper does not negate the theory

We have to be careful here - although I agree that in recent years the theory has been under the microscope - we cant change the whole tone of the article because of the conclusion of one paper dealing with East Africa.Moxy (talk) 14:57, 9 June 2013 (UTC)

three-way split

I think there are three topics here, each meriting a separate article.

• Toba supervolcano ~70000 BP, well established by direct evidence
• Acute human genetic bottleneck somewhere between 100000 and 50000 BP, a respectable hypothesis that has its rivals such as the long bottleneck hypothesis
• Lastly, the causative linking of these events, which is now regarded as a fairly shaky hypothesis.Ordinary Person (talk) 21:47, 26 October 2014 (UTC)

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Original link does not seem to be dead anymore (at least to me). -- Kendrick7^talk 01:19, 22 October 2015 (UTC)

Most studied super-eruption

I've tagged this declaration and moved it to the bottom of the lede section over concerns that it's a fairly trivial statement. It's probably obvious enough just looking at the vast number of refs and WP:ELs currently listed, and I can't even conceive of a List of super-volcano eruptions by amount of study article. At the same time, I suspect the supporting refs could be repurposed to say something more relevant and meaningful, so I didn't want to throw the baby out with the bathwater.... -- Kendrick7^talk 01:12, 22 October 2015 (UTC)

There are articles where I could fill a whole Lancaster Bomber with these tags and happily drop them. Not the case here. I could possibly see how it may have been jarring in its original place, but if this eruption really is so important that the comment is true then I think it good to put it in the lede. Excessive detail would (exagerating to show the point) be: John Doe swam in the lake in 1949. If there are no further objections, I would like to remove the tag at the end of the month. Op47 (talk) 21:02, 2 November 2015 (UTC)

[Citation needed] tag on third paragraph should be removed.

The tag has been applied to this sentence:

>>Both the link and global winter theories are highly controversial

The discussion of the controversies presented in the body article, all properly cited, is evidence that the matters are controversial. No source could be more authoritative than that. In any case, the description is in the nature of a prelude to the material that follows rather than a claim of fact about the subject. It thus does not call for citation.

DavidPreston (talk) 01:13, 24 January 2016 (UTC)

Self-contradicting

Twice it is stated (correctly) that the eruption did not significantly alter the climate of East Africa. So how in the world could it nearly wipe out humanity? The claim is heavily contested anyways. Bataaf van Oranje (talk) 17:44, 21 March 2016 (UTC)

Minor issue with reference to H. Florensis

Was just looking at the article after reading about new research conducted on H. Florensis which would suggest information in the Toba article is now inaccurate.

This article says that H. Florensis' survival after 50,000 YBP is now considered to be an open question. Newer research is finding a lack of H. Florensis fossils post-Toba.

Just asking if this needs to be updated or is there further clarifying information?

205.186.52.204 (talk) 08:19, 4 April 2016 (UTC)

Not really; the Toba catastrophe occurred more than 70,000 years ago, while H. floresiensis survived to at least 60,000 or 50,000 years ago, so clearly survived the event. --Florian Blaschke (talk) 19:23, 27 June 2016 (UTC)

Conflicting estimations of occurance

The first sentence says "occurred some time between 69,000 and 77,000 years ago". Then, in the next section the time frame is given as "The Toba eruption or Toba event occurred .... about 75000±900 years Before Present (BP)".

± 4,000 or ± 900? — Preceding unsigned comment added by SteveOak (talk • contribs) 07:34, 11 December 2015 (UTC)

I have now changed the intro to reflect the discussion in the sections "Supereruption" and "Volcanic winter and cooling". The dating "some time between 69,000 and 77,000 years ago" is unnecessary imprecise when there is now a consensus that the event occurred about 75,000 years ago. --Florian Blaschke (talk) 19:47, 27 June 2016 (UTC)

References

the reference link http://toba.arch.ox.ac.uk/pub_files/Petraglia2007Science.pdf is host not found: Petraglia, M.; Korisettar, R.; Boivin, N.; Clarkson, C.; Ditchfield, P.; Jones, S.; Koshy, J.; Lahr, M.M.; Oppenheimer, C.; Pyle, D.; Roberts, R.; Schwenninger, J.-C.; Arnold, L.; White, K. (6 July 2007). "Middle Paleolithic Assemblages from the Indian Subcontinent Before and After the Toba Super-eruption" (PDF). Science. 317 (5834): 114–116. -- correct URL appears to be http://dx.doi.org/10.1126/science.1141564 Teledyn (talk) 16:21, 27 December 2016 (UTC)

Unused 'Sources'

25 of the 'Sources' are not linked from any reference in the text. Chiswick Chap (talk) 11:32, 4 November 2017 (UTC)

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