Climate Change Killed Dinosaurs, Scientist Says

[جوري]

Climate Change Killed Dinosaurs, Scientist Says

(March 28) -- Was it long-term climate change, rather than a rogue asteroid, that killed off the dinosaurs?

That's the conclusion of German paleontologist Michael Prauss, who studied 65-million-year-old fossils drilled out of the earth in the Brazos River area of Texas and argues that radical changes to the flora and fauna of the era began long before arrival of the massive space rock widely associated with one of the largest mass extinctions in the history of the planet.

That impact, at what is now Chicxulub, Mexico, in the past 30 years has become the primary suspect in the death of the dinosaurs. And it was the subject of an article in the journal Science earlier this month in which 41 scientists from around the world argued that a wealth of global data show the extinctions began at the same time that the asteroid's crash sent debris across the atmosphere and blocked out the sun for years.
DEA Picture Library/Getty Images
A German scientist refutes the widely accepted theory that an asteroid led to dinosaurs' extinction, saying long-term climate change was to blame instead. Above, an illustration shows a herd of Hadrosaurus running away from fire.


But Prauss, writing in next month's edition of the journal Palaeogeography, Palaeoclimatology, Palaeoecology and working with Princeton paleontologist Gerta Gerta Keller -- a well-known critic of the Chicxulub theory -- maintained the impact was just one in a chain of catastrophic events that caused substantial environmental upheaval.

"The resulting chronic stress, to which of course the meteorite impact was a contributing factor, is likely to have been fundamental to the crisis in the biosphere and finally the mass extinction," Prauss said.

Those events include the massive, years-long volcanic activity in what is now the Deccan Plateau of India, and which, like the Chicxulub asteroid impact, is conventionally used by paleontologists to separate the Cretaceous period from the Paleogene period.

The Cretaceous, with a relatively warm climate a high sea levels, was the last era of the dinosaurs and the large marine reptiles that lived at the same time. And Prauss also takes issue with other paleontologists' use of Chicxulub as the historical demarcation point.

"The actual impact took place well before the geochemically and micropaleontologically defined Cretaceous Paleogene boundary," he said.

In support of his theories, Prauss cites his analysis of samples taken from drill cores and rock sections dating to the Cretaceous-Paleogene boundary near Brazos, which is about 620 miles from the Chicxulub crater.

The appearance and distribution of microfossils -- the remains of algae, pollen and plant spores -- demonstrate that significant and persistent variations of the ecosystem built steadily over the late Cretaceous and continued over several million years, Prauss said. They can especially be seen in the fluctuation of sea levels and productivity of marine algae, and the so-called fern spike -- a widespread surge in fern spores that signaled landscapes were repopulating after an ecosystem was destroyed.

Prauss said the fern spike began well before the Paleogene period began, and that the Cretaceous-Paleogene boundary -- and the asteroid impact -- marked only the peak of a trend that began millions of years earlier.

"In the light of the new data, both of these points have to be refuted," Prauss said.

Earlier this month, when the Chicxulub paper appeared in Science, one of its authors told AOL News that a goal of the team's work was to respond to arguments coming from the minority of paleontologists who cast doubt on the asteroid's role in killing the dinosaurs.

"It is almost impossible to change the skeptics' minds," Tamara Goldin said. "But we hope we can communicate to the scientific community and the public that this impact-induced environmental catastrophe did happen."

Still, it's important to note that both papers are using geological data to tie environmental events to the period that produced the latest dinosaur fossils scientists have found. In other words, paleontologists are dating the scene of the crime and placing environmental suspects at the scene with some pretty strong arguments.

But there's no direct evidence showing what killed the dinosaurs, leaving open a debate that's likely to continue.
http://www.aolnews.com/science/artic...ays%2F19417294

[Chuck]

First, following verses come to my mind:

Behold, [O believers,] it is you who are called upon to spend freely in God’s cause: but [even] among you are such as turn out to be niggardly! And yet, he who acts niggardly [in God’s cause] is but niggardly towards his own self: for God is indeed self-sufficient, whereas you stand in need [of Him]; and if you turn away [from Him], He will cause other people to take your place, and they will not be the likes of you!
[47:38]

But nay! I call to witness [Our being] the Sustainer of all the points of sunrise and sunset: verily, well able are We
to replace them with [people] better than they are; for there is nothing to prevent Us [from doing what We will].
Hence, leave them to indulge in idle talk and play [with words] until they face that [Judgment] Day of theirs which they have been promised –
the Day when they shall come forth in haste from their graves, as if racing towards a goal-post,
with downcast eyes, with ignominy overwhelming them: that Day which they were promised again and…
[70:40-44]

Behold, they [who are unmindful of God] love this fleeting life, and leave behind them [all thought of] a grief-laden Day.
[They will not admit to themselves that] it We who have created them and strengthened their make - and [that] if it be Our will We can replace them entirely with others of their kind.
VERILY, all this is an admonition: whoever, then, so wills, may unto his Sustainer find a way.
[76:27-29]

Second, it should be apparent that evolutionary biology is plagued with debates, some of them crosses path with religions and other are secular like the above one. Evolutionary biology is not exact science, it leaves lot of room for arguments.

[جوري]

. Evolutionary biology is not exact science, it leaves lot of room for arguments.

Precisely!

[Lynx]

First, following verses come to my mind:


Second, it should be apparent that evolutionary biology is plagued with debates, some of them crosses path with religions and other are secular like the above one. Evolutionary biology is not exact science, it leaves lot of room for arguments.

I might be misunderstanding your post but what does this have to do with evolutionary biology? Or even biology except in a really really broad sense? How the Dinosaurs died according to the theory presented by these scientists or according to the asteroid theory does not seem to make a difference at all. They both say that the environment changed and the Dinosaurs died. Again I might have misunderstood what you were implying so apologize in advance!

[جوري]

How the Dinosaurs died according to the theory presented by these scientists or according to the asteroid theory does not seem to make a difference at all. !

Theories of speciation ergo 'evolution' don't seem to make any difference at all either.. in fact as irrelevant as the folks who constantly bring it up!

all the best

[Lynx]

Theories of speciation ergo 'evolution' don't seem to make any difference at all either.. in fact as irrelevant as the folks who constantly bring it up!

all the best

Whether or not the dinosaurs died by some extinction event x or y it would not change anything in evolutionary biology.

[جوري]

Whether or not the dinosaurs died by some extinction event x or y it would not change anything in evolutionary biology.

indeed, yet in and of itself as irrelevant as 'evolutionary biology' which is in fact the purpose of the thread, to show the non-consensus and the constant, limitations and alterations in the more esoteric branches of science!

all the best

[Lynx]

indeed, yet in and of itself as irrelevant as 'evolutionary biology' which is in fact the purpose of the thread, to show the non-consensus and the constant, limitations and alterations in the more esoteric branches of science!

all the best

What is irrelevant?

Who said there was no debate in science? Science is inductive not deductive so there is always going to room for error and alterations. Everyone debates how gravity works but no one denies gravity exists. Everyone debates how evolution works but no one denies it ever happened. I mean one classic debate is the theory of punctuated equilibrium versus gradualism.

[جوري]

What is irrelevant?

Who said there was no debate in science? Science is inductive not deductive so there is always going to room for error and alterations. Everyone debates how gravity works but no one denies gravity exists. Everyone debates how evolution works but no one denies it ever happened. I mean one classic debate is the theory of punctuated equilibrium versus gradualism.

The theory of gravity vs. evolution are as similar as tandem biking and the Byzantine Empire.. you can always drop a pen and demonstrate gravity.. you can't enter a lab with an ape and come out human however so pls. quit pulling things out of your hat in an effort at an intelligent dialogue!

all the best

[Lynx]

The theory of gravity vs. evolution are as similar as tandem biking and the Byzantine Empire.. you can always drop a pen and demonstrate gravity.. you can't enter a lab with an ape and come out human however so pls. quit pulling things out of your hat in an effort at an intelligent dialogue!

all the best

Well speciation has occurred in labs and natural selection is observable so in that respect they're the same. Oh and the theory of gravity isn't 'what goes up must come down'; i told you in the previous post, everyone knows gravity exists but no body quite knows how it works. But anyway, i didn't see the relationship between the OP and evolutionary biology so i guess there wasn't one. cya

[جوري]

Well speciation has occurred in labs and natural selection is observable so in that respect they're the same. Oh and the theory of gravity isn't 'what goes up must come down'; i told you in the previous post, everyone knows gravity exists but no body quite knows how it works. But anyway, i didn't see the relationship between the OP and evolutionary biology so i guess there wasn't one. cya

really what 'sepciation' occurred in labs let me applaud the scientist that turned coco into corbin I must have missed his trip down to Stockholm for that Nobel prize .. natural selection though is observable has major flaws, we see many trinucleotide repeat disorders where the least favorable heritable traits are selected and become progressively worse with each generation.

There was no relationship as you lack abstract thought, and there is nothing we can do to help you with that.

all the best

[Chuck]

I might be misunderstanding your post but what does this have to do with evolutionary biology? Or even biology except in a really really broad sense? How the Dinosaurs died according to the theory presented by these scientists or according to the asteroid theory does not seem to make a difference at all. They both say that the environment changed and the Dinosaurs died. Again I might have misunderstood what you were implying so apologize in advance!

This is paleontology to be precise. It comes under evolutionary biology with regards to evolutionary history. The point was the nature of the argument as they are not exact science it leaves a lot of room for argument unlike physics which is exact science.

['Abd Al-Maajid]

I would say one thing "Allahu'Aalam" " Allah knows best"....

[Danah]

I remember reading about this theory when I was in school but I never question the accuracy of it. Thanks for bringing up this topic.....it made me think again.

[Lynx]

This is paleontology to be precise. It comes under evolutionary biology with regards to evolutionary history. The point was the nature of the argument as they are not exact science it leaves a lot of room for argument unlike physics which is exact science.

I'd imagine evolutionary biology was a different field from evolutionary history. Evolutionary biology is more of the science behind evolution and how it works. A debate about what happened in the history of the planet doesn't strike me as something that an evoultionary biologist would argue or research about.


Also I don't know what you mean by an exact science. Do you mean a science that has no debate? Well if that's the case then there is no such thing as an 'exact' science except the study of logic (maybe). Even math, if you can call it a science, is not exact and contains much debate. But I think you are talking about the natural sciences and I don't know if you can call physics exact. Newton was replaced with Einstein and now Einstein is being showed to have been wrong by Quantum Physics. There is still debate over how Gravity works!

[Chuck]

I'd imagine evolutionary biology was a different field from evolutionary history. Evolutionary biology is more of the science behind evolution and how it works. A debate about what happened in the history of the planet doesn't strike me as something that an evolutionary biologist would argue or research about.

It is studied under evolutionary biology, because theories in evo-bio depends on interpreting historical data. In any case, the point is the nature of the evidence which leaves lot of room for argument.

Also I don't know what you mean by an exact science. Do you mean a science that has no debate? Well if that's the case then there is no such thing as an 'exact' science except the study of logic (maybe). Even math, if you can call it a science, is not exact and contains much debate. But I think you are talking about the natural sciences and I don't know if you can call physics exact. Newton was replaced with Einstein and now Einstein is being showed to have been wrong by Quantum Physics. There is still debate over how Gravity works!

Do you know what is the meaning of exact science and why biology is not considered exact science as opposed to physics?

[The Adogmatist]

Do you know what is the meaning of exact science and why biology is not considered exact science as opposed to physics?

I must admit that I am puzzled as to what you mean by "exact science". From your previous posts in this topic it almost looks like you're saying that there are no arguments in physics. Naturally there are loads of arguments in physics, as arguments are a necessary part of the scientific process. If there were no debates, disagreements and arguments in physics (or any of the other sciences) it would be dogma, and not science. How can knowledge be improved if it is not debated?

[Lynx]

It is studied under evolutionary biology, because theories in evo-bio depends on interpreting historical data. In any case, the point is the nature of the evidence which leaves lot of room for argument.

But the debate isn't about anything to do with the truth or falsity or even mechanisms of evolution. I can sort of see what you're getting at though but the debate isn't about any science behind evolution though is it? It's more of a debate about the history of the planet (its physical history). But I think the point you bring up is rather trivial anyway.

Do you know what is the meaning of exact science and why biology is not considered exact science as opposed to physics?

No that's why the very first thing I said was "I don't know what you mean by an exact science".

I must admit that I am puzzled as to what you mean by "exact science". From your previous posts in this topic it almost looks like you're saying that there are no arguments in physics. Naturally there are loads of arguments in physics, as arguments are a necessary part of the scientific process. If there were no debates, disagreements and arguments in physics (or any of the other sciences) it would be dogma, and not science. How can knowledge be improved if it is not debated?

This is exactly the intuition I had upon reading his posts. Couldn't have put it better myself.

[CosmicPathos]

I'd imagine evolutionary biology was a different field from evolutionary history. Evolutionary biology is more of the science behind evolution and how it works. A debate about what happened in the history of the planet doesn't strike me as something that an evoultionary biologist would argue or research about.


Also I don't know what you mean by an exact science. Do you mean a science that has no debate? Well if that's the case then there is no such thing as an 'exact' science except the study of logic (maybe). Even math, if you can call it a science, is not exact and contains much debate. But I think you are talking about the natural sciences and I don't know if you can call physics exact. Newton was replaced with Einstein and now Einstein is being showed to have been wrong by Quantum Physics. There is still debate over how Gravity works!

Your imagination is a conjecture of a feeble mind. "Evolutionary history" is very much an important part of evolutionary biology. Without studying how Earth's history and geography has evolved, studying evolutionary biology would be futile. Did it ever cross your mind that evolutionary biologists rely heavily on studies done by paleontologists, geologists and physical chemists in order to test their hypothesis regarding evolution, existence and extinction of species in the past? I doubt you'd know provided your display of "nerdiness" or lack there of on these boards.

[Lynx]

Your imagination is a conjecture of a feeble mind. "Evolutionary history" is very much an important part of evolutionary biology. Without studying how Earth's history and geography has evolved, studying evolutionary biology would be futile. Did it ever cross your mind that evolutionary biologists rely heavily on studies done by paleontologists, geologists and physical chemists in order to test their hypothesis regarding evolution, existence and extinction of species in the past? I doubt you'd know provided your display of "nerdiness" or lack there of on these boards.

Yes Yes I posted that I get what he's trying to get at but the conclusion he is drawing is a little inaccurate. He is trying to say, as far as I can tell, that there is no consensus in biology on the truth of evolution because there is still debate about the history of species. My point was that regardless of how the debate about how dinosaurs go extinct, whether it be from an asteroid impact or gradual climate change or both, it wouldn't make evolution any less factual. That's why I said this is a trivial topic.