Skip to comments.Scientists find evolution of life
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.
Not a single email about abuse. You know what that tells me? It tells me that there was never a reason for all the crap that usually goes on in these threads.It tells me "when the cat's away the mice will play"!
It tells me that a watched pot never boils.
It tells me that the sun never sets on the British Empire.
But everything is still OK,
On the road to Mandalay.
Methinks I wish you had kept to your resolution. Somehow I had not missed your posts.
f.christian has not stopped, ever, calling everyone he disagrees with a nazi, socialist, athiest, liberal, etc.
Has it occurred to you that perhaps he is correct? Has it occurred to you that perhaps those he calls nazis are nazis, that those he calls socialists are socialists, that those he calls atheists are atheists, and that those he calls liberals are liberals?
The truth should always be told and if it is to be silenced just because those who are being called on the carpet do not like it, then you are trying to silence the truth. OJ is a murderer, whether he was convicted of it or not and calling him a murder is not an insult but a statement of fact. When you can provide proof that his accusations are false, I may entertain listening to them.
However, since all I see from you is a Clintonite type tactic of accusing someone of being politically incorrect in calling a spade a spade, it makes me think more highly of f.christians posts than before you made these remarks.
Nope. The oceans are one. Life could not exist for hundreds of millions of years without light. We are not talking of a piece (a large piece, but nevertheless a piece) of the ocean being covered with ice, we are speaking of the whole earth being covered with ice. So yes it is impossible. And no, there is no light under the deep antartic ice.
Yes, that is what the global warming crowd is about. It should also be noted that some 30 years ago the threat was global cooling.
As to your statements about the cooling, they are true. We know there was a fairly large population in Greenland that was farming and living as in warmer climes. The evidence is undeniable.
Or have you ever really cared about the truth?
*It's just too bad there isn't a font color called "ignorant, puerile, and outright disgusting", so I was forced to just use "blue".
Thank you very much and God bless. I will now become, once again, a "quidam".
You really have to learn to read. I said:
And do not talk to me about chemosynthesis, because the life that existed before the Cambrian was photosynthetic bacteria.
There was photosynthetic bacteria before the Cambrian - as I said. Your posting does not refute that, and indeed it cannot be refuted because it is true. Such bacteria could not have survived for hundreds of millions of years in an ice covered world. So stop misrepresenting my statements and stop evading the point. SciAm has turned to nothing more than a joke under its evolutionist editor and the article you refer to is total nonsense - and totally dishonest since any scientist should have seen the problem with it.
Actually, the worst thing about us evos is not only are we nazis, socialists, atheists, and liberals, but we don't discuss the science but rather just slime people who disagree with us.
The link says nothing substantial, it does not even mention introns. One would have to read the whole article to see what it says. Your claimed evidence is therefore just not there - as is usual with evolutionist links - they do not say what the poster claims they say.
That is not an assumption of evolution.
Totally false and you know it. The 'force' of evolution is so called natural selection. That is the mechanistic replacement for God which is central to evolutionary theory. Nowhere does evolution claim that God did anything. It claims that the creation of species was accomplished gradually by natural selection. That the Cambrian creatures were created directly refutes evolution since the claim of evolution is universal. In addition to which as I said, if God created life there is no way that evolutionists can deny that God created man in His own image instead of in the image of an ape as Darwin and evolutionists claim. The Creator cannot be said to be a force that does not exist and could not have accomplished changes in His creation. So yes, evolution is both materialistic and atheistic.
God no more figures in the theory of evolution than he figures in the theory of relativity. So, if the theory of relativity is a 'Godless' theory, then by your idiotic 'logic' modern physics is atheistic.
Oh well, you led the horse to water...
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