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.
Department of Redundacy Department? :) In any event, I'm afraid I don't see your point about "putting together two spearted evolutionary processes in one." What one? Reading that it seems like you had to work overtime to try to come up with some way to use another logical fallacy epithet, which is someting evo-groupies like to do as opposed to, say, actually discussing the issues. It's next on the list right after "launch ad hominem attack" as a way to quash debate.
In any event, the probability of two independat processes both occuring is even more damning for your side, don't you think? The improbablity expands algebraically. Thanks for helping to make my point.:)
I don't know what you mean by "land animals" -- maybe modern mammals? -- but the first land animals existed hundreds of millions of years before the first birds.
See my post #54.
Actually, there aren't two processes, there are four (selection, mutation, gene flow, and genetic drift). But they aren't independent. They are directly interrelated. Mutation is random on the individual level, but it is guided by natural selection, which is inherently non-random and purpose-driven.
Or two red herrings stink four times as badly as one.
Sounds like abiogenesis to me.
oh brother!
Well these people are getting closer to the truth; but they are not quite there yet: man did come from clay, but it took God (a miracle) to cause life ;)!
As the previous posters say land animals came before birds. Genesis one isn't about sequences. The sacred writers purposefully placed stumbling blocks in the writing to take certain ideas off the table. Genesis two isn't about sequences either (my bad interpretation included) but it does refute the idea that man was created ex nihilo.
The science behind abiogensis is all about what is possible. If we find a number of different conditions that lead to some sort of life forming we will have shown that life on earth forming spontaneously is not fantasy. No one is supposing that the research will lead to 'the' one path life on earth did take. To poke around into the possible paths does not take faith, it does take curiosity, patience and education.
What is your point?
Oh yeah that isn't a 'fallacy' in among itself: a generalization, that is not necessarily true and an attack on ~all~ of one group of people; yeah I really respect your opionion..
It specifcally mentions cattle and beasts of the earth. It says creeping things but does not specifically mention anything like lizard or serpent. That's open to interpretation. Where do snakes fit in? Are they reptiles that lost their lega or did they come first and legs develop later? Or is there no good fossil record of this? I imagine that snake skeletons are pretty fragile.
For growing crops clay soil is better than sandy soil.
Did mammals appear at the same time as birds then, or does the evidence show whether birds appeared first or mammals appear first?
Hair triggers, all. :)
:^)
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.