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.
Yes, we all know that when a lake freezes over in the winter, all life in the lake dies. (sheesh!)
Lakes do not freeze over for millions of years.
And you "know" this how?
For the record, we "know" of several surviving phyla that appear to have arsien long after the Cambrian. Also, we simply do not know how many "phyla" arose pre-Cambrian as we know only the survivors and those few that left unambiguous fossil records.
There may be many additional survivors we don't yet know about and almost certainly we will discover more pre-Cambiran phyla precursors that got edged out in the competition to survive.
Your refutation does not address the article. I suggest reading it to see if any further objections on your part have been anticipated before making them.
In an ice covered sea, the life we know existed before the Cambrian would have been impossible.
What do you know about the viable temperature range of Spriggina? How about Cyclomedusa? What kind of animal is this?
If you know, please tell somebody, because nobody else does!
Could not have lasted a year. The whole article by unScientific American is thus utter nonsense.
Funny how they fool so many.
Hey! You left off the "/sarcasm" - we can't always assume that people know that you can actually fish on frozen lakes in the winter. Or watch Nature TV shows. Or read books. Or ...
Oh please. A drawing is not evidence of anything. Further, there are no genes which are exactly the same in different species. Indeed most genes are not even exactly the same in different human beings, so your argument is false. There are no exact duplicates. There are indeed similar genes in many different species, but this is not to be wondered at, no reason why similar functions should not use similar genes. This is not proof of evolution.
Furthermore, if similarity of genes is proof of evolution kindly explain the fugu fish, whose genes are so similar to humans that they were able to find some 1200 previously unknown genes by examining the fugu fish genes. Proof that the fugu is man's ancestor not the apes???????????????
And you "know" this how?
The way most people learn things. I read.
Yes, from the 19th Chaper of Job - the Old Testament. I prefer the truths of the New Testament - especially the words of Jesus.
I'm confused -- if we "can't find any evidence" for our position, how do we keep posting the evidence? For example, I know we've posted this to you at least a dozen times now (in response to the many times you've asserted that there was "no" evidence): 29+ Evidences for Macroevolution: The Scientific Case for Common Descent.
so they keep posting just so stories like this one that has no facts, no evidence, but says that evolution has been proven again.
Okay, I'll bite -- where does the above article "say 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,
Where does it purport to be a "prediction"?
It's an announcement of a model which incorporates known processes and conditions to accurately match known historical transitions.
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.
You're being unclear here -- are you claiming that Gould and Eldredge a) claimed that the Cambrian explosion destroys the theory of evolution, or b) their claims about the theory of evolution were allegedly destroyed by the Cambrian explosion?
Either way your claim would be incorrect, but I'd rather not spend time refuting the wrong one. So let me know which you meant and then I'll refute it.
Your refutation does not address the article.
As usual trying to put the burden of proof on the other person. It is up to you to show that life can continue to exist for hundreds of millions of years under ice. It cannot. Life needs sunlight to produce the food which all life needs. And do not talk to me about chemosynthesis, because the life that existed before the Cambrian was photosynthetic bacteria.
To make up stories about something which is already known is not science. Computer models can prove anything and are thus not evidence. The article is nonsense.
As for the rest, you know exactly what I meant. Whether you try to refute it or not is your choice.
There are whole ecosystems in the deep sea vents of the world's oceans now that don't depend upon photosynthesis, that live in total darkness, and that don't know or care whether the top of the ocean is frozen over. Also, some of the most extremophile life forms on earth are thought to be some of the earliest-appearing, the Archaea.
Intelligence. Science is indeed about how did God do it. It has shown us quite well how many things were indeed done.
Yes, and science indicates that the way God did it was via evolution.
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.
Then it's a good thing that evolution does not proceed entirely by randomness.
If a Christian has free will, does that mean evil is a possible choice and if not how can the choice be free?
Could it be that free will is an illusion for everyone?
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