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.
All your base are belong to us!
Talk about a leap of faith!
No, the tentative language clearly indicates that this is *not* a "leap of faith", it's a careful indication of the preliminary nature of the models.
A "leap of faith" *would* have been a valid charge if they had simply declared their conclusions in declarative language like "...is due to...", etc. -- but they did not do that.
Like any preliminary scientific finding, they're careful not to overstate the amount of certainty. And also like all scientific proposal, no one experiment, model, or paper can (nor should) instantly establish the idea beyond question. "New" ideas are always presented tentatively, no matter how well they are supported by experiment or evidence.
Only after they have been put out into the arena of scientific verification (via peer review, replication, etc.) and have withstood all objections that could be raised to them, and successfully predict new findings, well enough to achieve widespread acceptance in the scientific community (and do so better than current or opposing theories), will the new ideas reach the point where they can be reasonably written in language that implies a good degree of confidence in its trustworthiness.
You were Hugh Akston were you not?
Close, but no cigar:
Actually it is quite easy to tell you are an evolutionist from the posting of this thread. Evolutionists cannot find any evidence for their position so they keep posting just so stories like this one that has no facts, no evidence, but says that evolution has been proven again.
Scientific predictions are made either about things which may occur in the future or things that have never been observed. This is neither, this is a story about something which has been observed and is already known. It is not a prediction, it is not science, it is an attempt to cover up the fact that the Cambrian explosion completely destroys the theory of evolution as the evolutionists Gould and Eldredge claimed.
Thanks for the explaination. I have always wondered.
Not when they're talking about "buffering." If they start talking about potty-brains, yes.
BTW, I think calcium carbonate is a neutral salt. It probably won't do much to react with carbon dioxide because it essentially already contains a C02 molecule and precipitates out of solution as soon as it is formed.
And I seem to remember you saying that you avoid these threads like the plague...hmmmm.
Whoa, that's a new one on me! Where did Gould & Eldredge ever claim that the Cambrian explosion "completely destroys the theory of evolution"? Cite, please. (Pretty please.)
Intelligence. Science is indeed about how did God do it. It has shown us quite well how many things were indeed done. There are numerous laws in the scientific fields which hold true day after day, year after year and which enable us to predict and learn how to do things. It is these laws, these predictable consequences of actions which should tell any unbiased person that the universe is not a place where randomness is the cause of all things.
Fine, so we'll throw Gould and Eldredge to the wolves. Gould is dead, anyway, he won't care.
So, here we are in the Cambrian, new life forms everywhere - regardless of where they came from - and then they evolve.
Because, most of the life forms on earth today weren't around in the Cambrian. Agreed?
I doubt that is the case. From the vitriol shown at f.christian's postings one can clearly see that he is getting his point accross very clearly and those who disagree with them don't like it.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.