According to this article, dinosaurs were killed by global warming. Personally I think it's crap, but I found it an interesting theory.
http://economictimes.indiatimes.com/...how/997983.cms
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According to this article, dinosaurs were killed by global warming. Personally I think it's crap, but I found it an interesting theory.
http://economictimes.indiatimes.com/...how/997983.cms
I don't think we will ever know what happened to God's early slimy phase, but I think we can say it was a dramatic temperature change. What the catalyst was will remain a theory.
I find a super volcano a convincing idea - just as an asteroid or comet.
So what's your theory on their demise then? They all got colds and died?Originally Posted by Locke
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Not colds, but disease vectors may well have contributed as continents shifted and isolated populations were exposed to one another. That's what occurred when Asian bovines were introduced into Africa.
Of course, the most likely theory, according to geological evidence, is asteroidal impact - a consistent iridium layer found all over the world at the K/T boundary, but that only tells of the coup de grace, not of the inevitable changes in speciation that occurred during the 200 million years preceding the Cretaceous. A minority of paleo-investigators cling to the volcanic outgassing hypotheses for the K/T boundary, pointing to the phenomenon of the Deccan Traps, but they have yet to explain the iridium anonmalies and the shocked quartz, both artifacts of extraterrestrial bolide impacts.
By the way, Locke, it appears that the article you cited does not refer to the dinosaur extinction at all, but an earlier one.![]()
Has there been more than one 'massive extinction of a species' that I'm not aware about? And they just found the oldest bilaterian fossil in China thats been dated to be 580 million years old, so an extinction 2.5 million years ago would have to be the same one that killed the dinosaurs, right? This is not my area of study, so feel free to correct me.Originally Posted by jett
Several.Has there been more than one 'massive extinction of a species' that I'm not aware about?
...so an extinction 2.5 million years ago would have to be the same one that killed the dinosaurs, right?
I'm sure this is a typo, but I'll correct you anyway. The extinction event in the story took place 250 million years ago. It is called the Permian-Triassic Extinction Event. The Cretaceous-Tertiary Event happened 65 million years ago and is what killed the dinosaurs.
I've found a couple of better articles about the story than the one you've linked to:
http://www.sci-tech-today.com/story....story_id=29906
http://msnbc.msn.com/id/6848487/
I'll paste some exerpts in a bit.
I've also located the relevant papers in Science:
Hypoxia, Global Warming, and Terrestrial Late Permian Extinctions
Raymond B. Huey and Peter D. Ward
Science 15 April 2005; 308: 398-401
Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the Karoo Basin, South Africa
Peter D. Ward, Jennifer Botha, Roger Buick, Michiel O. De Kock, Douglas H. Erwin, Geoffrey H. Garrison, Joseph L. Kirschvink, and Roger Smith
Science 4 February 2005; 307: 709-714;
Also, a related corroborating paper was mentioned in the MSNBC story:
Photic Zone Euxinia During the Permian-Triassic Superanoxic Event
Kliti Grice, Changqun Cao, Gordon D. Love, Michael E. Böttcher, Richard J. Twitchett, Emmanuelle Grosjean, Roger E. Summons, Steven C. Turgeon, William Dunning, and Yugan Jin
Science 4 February 2005; 307: 706-709
The latter two papers, I have access to and have just gone over (Science, issue 5710). But, I don't have the first paper which is the key paper referenced in these stories.
Basically, the paper on the Photic Zone was summed up nicely in the MSNBC article:
"Kliti Grice of Curtin University of Technology in Perth, Australia, and colleagues studied sediment cores drilled off the coasts of Australia and China and found evidence that the ocean was lacking oxygen and full of sulfur-loving bacteria at that time.
This finding would be consistent with an atmosphere low in oxygen and poisoned by hot, sulfurous, volcanic emissions..."
The second paper in the list on Abrupt and Gradual Extinction basically shows evidence that the extinctions of this boundary event were gradual and not sudden. And, not only were the extinctions not sudden, but also origination of new Triassic species was similarly spread out, with some even occurring before the boundary event. This shows that considerable evolutionary turmoil was going on during a large period of time.
Again. This is summed up nicely in the MSNBC article:
"They found two patterns, one showing gradual extinction over about 10 million years leading up to the time of the extinction, and then a spike in extinction rates that lasted another 5 million years, Ward’s team reported."
The key paper is the one on Hypoxia. And, unfortunately, I don't have access to it. Howver, the MSNBC article summed up the others nicely and I presume that it would sum this last one up nicely as well. I'd still like to see it though. My collection of Science magazines are sparse, at best. I loathe how expensive they are. Non-profit my ass.
Anyway, it would appear that the state of the seas was crucial to the lack of oxygen. For some reason, the sea levels dropped greatly and exposed vast stretches of the 'carbon-rich sea sediment' (carbonate? calcium-carbonate?) which actually sucked the oxygen out of the air.
Also, the shallow seas would likely have caused the release of methane from the methane pockets under the seas which would have contributed to the greenhouse effect.
Also contributing to the greenhouse effect were the volcanoes in what is now Siberia. It is these that released the sulfur dioxide and that filled the seas with sulfur for the sulfur-eaters.
And. By what might be a coincidence, it would appear that a possible meteor strike occurred near the boundary which might have added it's own little bit to the fun. Tipping the scales, so to speak.
So. All in all, it would appear that the oxygen level dropped drastically and this is what caused the extinctions. But it did so over a long period of time thus allowing selection of species that could cope. There's a cute little theory mentioned in the sci-tech article about dinosaurs being a low-oxygen adaptation. Birds, apparently, can survive in low oxygen environments (which makes sense, I suppose, for the high fliers at least. Interesting if you think about it.)
That's the general gist of it that I've been able to make out. Don't think I've left anything out.
(In)Sanity: "So what's your theory on their demise then? They all got colds and died?"
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M*W: Maybe they evolved into birds and flew away.
Some did but most of them died out due to diseases and other things as climate changes as well as meteor impacts. I'd believe that the meteor impact was one of the largest things that caused extinctions at a given point in time but diseases were always killing off the weak.Originally Posted by Medicine*Woman
Global Warming could have been a cause of their extinction. If a comet did strike the Earth, the sun would have been blocked. Gases would not have escaped the atmosphere and caused the Earth to warm up.
poly_nightmare: "Global Warming could have been a cause of their extinction. If a comet did strike the Earth, the sun would have been blocked. Gases would not have escaped the atmosphere and caused the Earth to warm up."
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M*W: Hasn't the Earth always been affected by global warming? The stories of infant Earth tell of vast ice plates that covered most of the Earth. Since then, the oceans have warmed up and melted most of the ice. With this global warming that has been going on for millions of years, wouldn't that likely promote the evolution of plants and animals? I believe that "global warming" is nothing new, and there is still a lot of ice on this planet left to melt, but in doing so, we may become a thing of the past, too. Any comments?
So than you are Saying Medicine Woman is that there IS A POSSIBILITY of a Comet?Originally Posted by Medicine*Woman
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To flodnag:
poly_nightmare said: "Global Warming could have been a cause of their extinction. If a comet did strike the Earth, the sun would have been blocked. Gases would not have escaped the atmosphere and caused the Earth to warm up."
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Then M*W responded: "Hasn't the Earth always been affected by global warming? The stories of infant Earth tell of vast ice plates that covered most of the Earth. Since then, the oceans have warmed up and melted most of the ice. With this global warming that has been going on for millions of years, wouldn't that likely promote the evolution of plants and animals? I believe that "global warming" is nothing new, and there is still a lot of ice on this planet left to melt, but in doing so, we may become a thing of the past, too. Any comments?"
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flodnage then asked M*W: "So than you are Saying Medicine Woman is that there IS A POSSIBILITY of a Comet?"
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M*W: Sorry if there was some confusion on who said what to whom. It is my view that the Earth has been "globally warming" since the big bang, and that all of us on Earth, as well as in our solar system, are still "big banging" as we speak. I don't think we should fear "global warming" anymore than we should fear the sun rising and setting tomorrow. However, although I know it is certainly possible that a comet could have bombarded the Earth and killed off the dragons and dinosaurs (I believe them to be allegorically one and the same), I'm just not a proponent of the comet theory. I tend to believe they disappeared as part of the naturally occuring evolution of all species. So, to answer your question, sure I believe the comet theory is a possibility, I'm just not sure that I want to bite into the comet theory at this time.
The Earth is still in the expanding universe stage. Look how far down into the Earth oil wells are drilled to reach the fossil oil fuels which evolved from dinosaur remains. Then think how long it must have taken for our Earth to expand to the point where it is today. With the expansion of the Earth, surely humans have caused the Earth to increase greatly in weight by being fruitful and multiplying, erecting structures from the pyramids to massively tall skyscrapers, etc. In other words, the Earth and our solar system (I would think) is still expanding. Due to global warming, ancient humans went from being hairy all over with layers of fat to keep them warm in the icier times. We've come a long way, baby, from there!
As long as the Earth is in the expansion phase, I believe we will be in a state of global warming. I foresee our human race losing more bodily hair, and our skin becoming either thicker, thinner or scalier, as we lose the insulation of fat some of us have to protect us from our ever increasing expansion closer to the Sun. I suspect that dinosaurs fell victim to global warming that may have killed off the vegetation that was their food. From my point of view, it seems that fossil oil fuels are more prevalent in dry, desert-like climates where vegetation is scarce. When the Earth starts to contract, the sands of time will be sloughed off back out into deep space, and the Earth and everything in it will begin to devolve and end up being farther and farther away from the Sun. Then the ice caps will return and humans will become more hirsute with ampler fatty insulation, but I don't believe anyone of us alive today will experience it.
I wonder if our human intelligence will devolve, too, leaving our survival up to genetic memory and instinct?
Is it me, or is it getting warmer in here? The theories I've stated are not based on any scientific research. They are my opinions only.
Well.... That is why I think that oil is not all a fosil fuel but there's a ongoing debate wether oil is fosil or abiotic. I think that theres a good chance that oil is abiotic, rather than fosil fuel.Look how far down into the Earth oil wells are drilled to reach the fossil oil fuels which evolved from dinosaur remains. Then think how long it must have taken for our Earth to expand to the point where it is today.
http://www.questionsquestions.net/docs04/peakoil1.html
http://www.enviroliteracy.org/article.php/1130.html
RUSSIA PROVES "PEAK OIL" IS A SCAMThe Abiotic Fingerprint
January 28, 2005, PST 0800 (FTW)—Guess what? The Earth does produce abiotic methane. It can be found in minute quantities along the world’s mid-ocean ridges, venting from some volcanoes, and in some mine shafts. The amount of methane generated in these situations is minor, especially when compared to commercial natural gas reserves. As stated in part 2 of this series (and elsewhere), there is more methane produced annually from cow farts than from abiotic sources. No scientist has ever denied the existence of abiotic methane. We have said that there is no evidence that it is produced in useful quantities, and we have stated that abiotic generation of simple hydrocarbons such as methane does not indicate abiotic production of the complex hydrocarbons we refer to as crude oil.http://mkane.gnn.tv/blogs/4839/ABIOTIC_OIL_EXISTS
http://reactor-core.org/peak-oil.html
Yeap I say that there is some evidence showing that the theory may just be correct that some oil is abiotic.However, several cracks have started to appear in the fossil fuel (and hence, the peak oil) theory: some oil fields seem to be re-filling almost as fast as they are being drained. The Wall Street Journal reported the case of Eugene Island 330, an oil field in the Gulf of Mexico, which hit peak production of 15,000 bpd, slowing to 4,000 a day by 1989.
"Then suddenly -- some say almost inexplicably -- Eugene Island's fortunes reversed. The field... is now producing 13,000 bpd, and probable reserves have rocketed to more than 400 mm barrels from 60 mm. Stranger still, scientists studying the field say the crude coming out of the pipe is of a geological age quite different from the oil that gushed 10 years ago.http://www.gasandoil.com/goc/features/fex52182.htm
Godless
Let's be clear, once and for all - oil is not the product of decaying dinosaurs and no serious scientist, at least in the last hundred years, has ever claimed it was.
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