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.
That is not an assumption of evolution. Scientific evidence indicates that all life descended from a common ancestor; the LUCA, or last universal common ancestor. Where the LUCA came from cannot be probed by most of the tools of evolution - for example, you can't do phylogenetic analysis on a single unbranched line. I suppose in principle you could do analysis on the LUCA's genes, but except in a few cases (e.g. ribosomal proteins) that may never be practical.
The LUCA could have been transported to earth from another planet, it could have arisen abiogenetically; or it could have been created by a higher being. Deciding between these possibilities doesn't really impact evolution.
A good scientist must be both--passionate in pursuit of new ideas, but dispassionate in his examination of the data "testing" those ideas. And yes, achieving that seemingly contradictory state is hard, indeed.
But those aren't "scientists", they are simply the newest category in "the oldest profession".
Four threads up in two days. Over 400 replies made on them.
Not a single abuse report. Not a single 'ping' to the moderators about abuse. 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. Good. Let's keep it this way.
If everything God created was good, as the Bible states, then how could anything He created turn away from Him (which would be bad)? Since He did not create evil, who did? My point is that you can't logically have a world of both good and evil powers created by an "Only Power" which is "Only Good". You have to believe in two powers or gods and that is contrary to monotheism (Christianity).
"Evil" can only result from free will. Only man can do evil
That means evil is a creation of man. So man can create what God did not? Man has the power to rival God? God created man in His image (good), how can the image of good create evil?
This pretty much describes the history of science. What's missing from your scenerio is the necessity of doing the dirty work, digging in the trenches, coming up with verifiable hypotheses, having ideas checked by others for self-consistency and consistency with other known facts. In short, science speculates, but does not try to inhabit the castles it builds in the air. Having said this, I have to admit that scientists, as individuals, can have looney political ideas and write looney tracts for the public. But every family has a crazy aunt in the closet.
That's what socialists say about the economy. If we know in advance what direction we need to go, why not just let the best and the brightest just plan it and eliminate all this wasteful competition.
I'm not sure how to convince you that unplanned economies are better than planned economies, or that free competition in the realm of ideas is better than just taking a shortcut to the truth.
So the tricks are as follows:
I read where there is a certain kind of radiation that has a half life of something like .034 of a second found trapped inside granite, and there was speculation that granite had to have just come into being in an instant to trap that radiation. They may have found other explinations for that now like gas, etc, I haven't followed it.
But wouldn't it save time if scientist speculated in the direction of an instantaneous earth? If scientist had began with the theory that some species developed suddenly and in the same time frame, wouldn't the evidence to support that have been found much sooner and wouldn't that have saved time? If they look into when this event happened and find that it coincides with the time period that the earth was watered from a mist rising from the ground they could then tie man's appearance on earth as his being a part of that sudden species eruption and therefore existed at the time that the earth was watered by a mist rising from the earth.
Likewise if they begin with the speculation that the earth was also an instantaneous event and then gather their evidence based on that theory, it could save decades of time at the least. I feel confident some young bright turk will come along and slaughter alot of sacred cows, it's just a shame he will have to endure the wrath and loss of prestige that organized science will heap on him.
That was the original assumption of science several hundred years ago. The evidence has led elsewhere.
I dunno. It tells me "when the cat's away the mice will play"!Not a single abuse report. Not a single 'ping' to the moderators about abuse. 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. Good. Let's keep it this way.
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