Posted on 10/30/2003 5:04:39 PM PST by Dales
LIVERMORE, Calif. -- A trio of scientists including a researcher from the Lawrence Livermore National Laboratory has found that humans may owe the relatively mild climate in which their ancestors evolved to tiny marine organisms with shells and skeletons made out of calcium carbonate.
In a paper titled "Carbonate Deposition, Climate Stability and Neoproterozoic Ice Ages" in the Oct. 31 edition of Science, UC Riverside researchers Andy Ridgwell and Martin Kennedy along with LLNL climate scientist Ken Caldeira, discovered that the increased stability in modern climate may be due in part to the evolution of marine plankton living in the open ocean with shells and skeletal material made out of calcium carbonate. They conclude that these marine organisms helped prevent the ice ages of the past few hundred thousand years from turning into a severe global deep freeze.
"The most recent ice ages were mild enough to allow and possibly even promote the evolution of modern humans," Caldeira said. "Without these tiny marine organisms, the ice sheets may have grown to cover the earth, like in the snowball glaciations of the ancient past, and our ancestors might not have survived."
The researchers used a computer model describing the ocean, atmosphere and land surface to look at how atmospheric carbon dioxide would change as a result of glacier growth. They found that, in the distant past, as glaciers started to grow, the oceans would suck the greenhouse gas -- carbon dioxide out of the atmosphere -- making the Earth colder, promoting an even deeper ice age. When marine plankton with carbonate shells and skeletons are added to the model, ocean chemistry is buffered and glacial growth does not cause the ocean to absorb large amounts of carbon dioxide from the atmosphere.
But in Precambrian times (which lasted up until 544 million years ago), marine organisms in the open ocean did not produce carbonate skeletons -- and ancient rocks from the end of the Precambrian geological age indicate that huge glaciers deposited layers of crushed rock debris thousands of meters thick near the equator. If the land was frozen near the equator, then most of the surface of the planet was likely covered in ice, making Earth look like a giant snowball, the researchers said.
Around 200 million years ago, calcium carbonate organisms became critical to helping prevent the earth from freezing over. When the organisms die, their carbonate shells and skeletons settle to the ocean floor, where some dissolve and some are buried in sediments. These deposits help regulate the chemistry of the ocean and the amount of carbon dioxide in the atmosphere. However, in a related study published in Nature on Sept. 25, 2003, Caldeira and LLNL physicist Michael Wickett found that unrestrained release of fossil-fuel carbon dioxide to the atmosphere could threaten extinction for these climate-stabilizing marine organisms.
The article is still garbage. It shows absolutely no evidence for evolution and the tremendous climactic change claimed in it is very doubtful. If it was correct there would be tremendous amounts of evidence for it and such a claim would have been made decades ago. There is no evidence for these claims that is why they use 'computer models'. You can model whatever you like on a computer and make it come out any way you wish. Sometimes I think that more lies are told with spreadsheets than with tongues.
Very special guest: Gary Bauer
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Tune in and hear terrifying stories about: LIBERAL INSANITY!!!
Not a dumb question to a fellow tree-hugger.-g-
Seriously, I've planted dozens of trees and have hundreds on my property - if you asked me what kind of tree I'd like to be, I'd have an answer (red maple). And I'd be interested in the answer of anybody who loved trees. Those of you who aren't tree-huggers, I won't be offended if you gag. ;^)
Whoa, that's a new one on me! Where did Gould & Eldredge ever claim that the Cambrian explosion "completely destroys the theory of evolution"?
Gould and Eldredge completely rejected Darwinian evolution because the Cambrian showed that organisms appeared suddenly and could not have evolved over time. For this reason they took up and formulated what they themselves called punk-eek, a totally silly theory similar to claiming that ghosts exist but have never been photographed because they are too shy to have their picture taken. They said that new species arise suddenly and leave no trace of what happened.
But then you knew that already did you not?
Sounds tempting, but I have to answer a $50 ordained minister named Eschoir. He's having a little trouble understanding what he paid the $50 dollars for.
AND GOD DID...
The article is from Januay 2000, so they were going wherever almost four years ago now. It deals extensively with the freezing and killing effects of the glaciation, of course.
These extreme glaciations occurred just before a rapid diversification of multicellular life, culminating in the so-called Cambrian explosion between 575 and 525 million years ago. Ironically, the long periods of isolation and extreme environments on a snowball earth would most likely have spurred on genetic change and could help account for this evolutionary burst.It also mentions an apparent extreme genetic bottleneck just before the otherwise unexpectedly late Cambrian blossoming of diversity.
Image: HEIDI NOLAND ALL ANIMALS descended from the first eukaryotes, cells with a membrane-bound nucleus, which appeared about two billion years ago. By the time of the first snowball earth episode more than one billion years later, eukaryotes had not developed beyond unicellular protozoa and filamentous algae. But despite the extreme climate, which may have "pruned" the eukaryote tree (dashed lines), all 11 animal phyla ever to inhabit the earth emerged within a narrow window of time in the aftermath of the last snowball event. The prolonged genetic isolation and selective pressure intrinsic to a snowball earth could be responsible for this explosion of new life-forms.
No fair Jim! I once told this joke here on FR and nobody laughed...you must have better delivery than me!
Where is the other thread, link? name' would like to check it out.
However, I am afraid you gave yourself away again. Creationism and creationist are words made up by evolutionists to attack the opponents of evolution. Those opponents most often call themselves Christians or ID'ers or just non-believers in evolution than creationists. If I were quickly looking for a thread opposing evolution for example I would look under intelligent design. This is just to show that it is quite hard to hide one's position. There are tell tale signs in most things one says.
Very much so. Coke adds life.
check this out Phylun-level evolution by former creationist Glenn Morton
I promised myself I wouldn't post to you again, gore, but I just got done laughing and decided to break that.
You have just proven, beyond any reasonable doubt, that you are in complete denial. f.christian has not stopped, ever, calling everyone he disagrees with a nazi, socialist, athiest, liberal, etc. He is the epitome of libel and, given his name, hypocrisy. You are perfectly aware of this, however, you feel his actions are justified.
Is he the only flamer? No. But to somehow reach the conclusion that people are unfairly vitriolic to him, when he clearly holds the Crypto-Libel THRONE, is much more incomprehensible to me than your creationist posts.
P.S. If you feel I am insulting f.christian, I will happily cite every other post of his rife with libel.
Hard to imagine the dead changing...
Embalming hadn't been invented yet.
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