Posted on 11/04/2005 5:00:06 AM PST by PatrickHenry
Minerals help molecules thought to have been essential for early life to form.
A team of US scientists may have found the 'primordial womb' in which the first life on Earth was incubated.
Lynda Williams and colleagues at Arizona State University in Tempe have discovered that certain types of clay mineral convert simple carbon-based molecules to complex ones in conditions mimicking those of hot, wet hydrothermal vents (mini-volcanoes on the sea bed). Such complex molecules would have been essential components of the first cell-like systems on Earth.
Having helped such delicate molecules to form, the clays can also protect them from getting broken down in the piping hot water issuing from the vents, the researchers report in the journal Geology [Williams L. B., et al. Geology, 33. 913 - 916 (2005).].
"It's very interesting that the clays preserve them," says James Ferris, a specialist on the chemical origins of life at Rensselaer Polytechnic Institute in Troy, New York. "It shows that this could be an environment where complex organic molecules can be formed."
Some like it hot
Hydrothermal vents are created when seawater that has seeped through cracks in the seafloor is heated by magma just below the surface. The water streams back out of the rock in a plume that can reach temperatures of around 400 °C.
Vents are a favourite candidate for the site where life first appeared. Their heat provides an energy source; the minerals provide nutrients; and the deep-sea setting would have protected primitive organisms from the destructive meteorite impacts that scoured the planet's surface early in its history.
But researchers have long wondered how, if early life did form in this environment, it escaped being boiled and fried by the harsh conditions.
The Arizona State team has shown that clay minerals commonly found at vents can encase organic molecules, keeping them intact.
Between the sheets
The group simulated the vent environment in the laboratory, immersing various types of clay in pressurized water at 300 °C for several weeks and looking at the fate of a simple organic compound, methanol, in this stew. They chose methanol because their earlier work had shown that the compound could be formed in a vent environment from simple gases such as carbon dioxide and hydrogen.
Clays generally consist of sheets made of aluminium, silicon and oxygen atoms, which are stacked on top of one another. In some of these materials, such as the clays saponite and montmorillonite, there is room for other atoms and molecules to slip between the layers.
Spouting soup
The researchers found that the methanol in their artificial vent system was converted to various large organic molecules over six weeks or so, so long as the clay's layers were spaced widely enough to hold the compounds.
"The clay provides a safe haven for the organic molecules, essentially like a 'primordial womb'," the team reports. Eventually, changes in the clay's mineral structure caused by heat, pressure and time may cause the sheets to close up and expel the molecules inside. But they think that some of these could spout out from the clay into less hostile environments than the hottest part of the vent, creating an organic soup in which life might arise.
These findings add weight to the idea that clays were the key to the origin of life. Previous research has shown that clays act as catalysts for the formation of polymer molecules such as the precursors of proteins and DNA. They can also encourage lipid molecules to arrange themselves into cell-like compartments called vesicles.
"Where did the SEEDS come from?
Who did the SEEDING?"
Right - it has RULES.
I'm too old to think. I can't remember when I first read Microbe Hunters, but then I can't remember where I left my shoes...
No doubt and the only real purpose of scripture is theological. I think turning scripture into a simple sequence of events strips it of the meaning God and the sacred writers intended.
They're under the coffee table in the living room.
Kinda depends on WHICH crops; don't it?
(Elsie hasn't shown up yet.... ;^)
That's exactly what they did:
The group simulated the vent environment in the laboratory, immersing various types of clay in pressurized water at 300 °C for several weeks and looking at the fate of a simple organic compound, methanol, in this stew.
Sorry, but it DEMONSTRATES nothing.
It just CLAIMS that it does.
I'm not sure I understand this comment - are you suggesting the experiment is a hoax? (The journal Geology has a pretty impeccable reputation and high standard for publication; I'd hate to think they have their guard down..)
You might want to check with Coyoteman about this, as he is a resident Creation Story expert.
(Coyoteman pinged as a courtesy since I mentioned his name, too.)
Only if one GUESSES to what those 'conditions' actually were!
"Only if one GUESSES to what those 'conditions' actually were!"
Don't be silly. The undersea vents exist. They existed before. Simulating their environment seems a good way to experiment with them.
No guesswork is involved.
"Divine Wisdom has arranged for there to be certain stumbling blocks or interruptions of the narrative meaning, by inserting in its midst certain impossibilities and contradictions, so that the very interpretation of the narrative might oppose the reader, as it were, with certain obstacles thrown in the way. By them Wisdom denies a way and an access to the common understanding, and when we are shut out and hurled back, it calls us back to the beginning of another way, so that by gaining a higher and loftier road through entering a narrow footpath it may open for us the immense breadth of divine knowledge."
Origen of Alexandria (ca. 185-254)
I think you're half right. Calculations, yes, observations, no. LeMaitre realized that Einstein's equations of general relativity led naturally to an expanding universe, but the observation of an expanding universe did not yet exist. Einstein (incorrectly) handled the problem by adding an extra term into his GR equations - LeMaitre stated that the term didn't need to be there if the universe originated from a primeval expansion. Eventual observations proved his hypothesis. But you are right - scientists shouldn't have bashed the man's idea, because what he proposed was a testable hypothesis. (Interestingly, Russian physicist Alexander Friedmann drew the same conclusions independently of Lemaitre.)
They are ASSUMING that vents were present on early Earth; aren't they?
Sea floor spreading needs a FLOOR to spread and according to the Pangea theory, there was NO floor until it broke apart into our continents.
At that time there were already fossils imbedded in the rock layers,; weren't they?
They chose methanol because their earlier work had shown that the compound could be formed in a vent environment from simple gases such as carbon dioxide and hydrogen.
I think the existence of this article is pretty good evidence that this statement isn't true....
see 157
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