Posted on 06/07/2006 1:35:56 PM PDT by areafiftyone
WASHINGTON (AP) -
The best evidence yet for the oldest life on Earth is found in odd-shaped, rock-like mounds in Australia that are actually fossils created by microbes 3.4 billion years ago, researchers report.
"It's an ancestor of life. If you think that all life arose on this one planet, perhaps this is where it started," said Abigail Allwood, a researcher at the Australian Centre for Astrobiology and lead author of the new study. It appears Thursday in the journal Nature.
The strange geologic structures - which range from smaller than a fingernail to taller than a man - are exactly the type of early life astrobiologists are looking for on Mars and elsewhere.
They are known as stromatolites. They're produced layer by layer when dirt sediments mix with carbon dioxide expelled from bacteria, water, and minerals - all trapped in the microbes' sticky mucilage.
The theory is that these ancient mounds dotting a large swath of western Australia are not merely dirt piles that formed randomly into odd shapes, but that microbes built them a few billion years ago.
Some look like frosting swirls on cupcakes; others look like the inside of an egg carton. Allwood even nicknamed one 6 1/2-foot mound "crocodile back" because of its appearance.
Stromatolites have been studied for a long time, but the big question has been: Were they once teeming with life? Recently, more scientists have been leaning toward answering yes.
Allwood's research included examining thousands of the rocky mounds and grouping them into seven subtypes. It is the most comprehensive and compelling evidence that these are fossils of life, not funny-shaped rocks, according to a top expert not on her team.
"It is the best bet for the best evidence of the oldest life on Earth," said Bruce Runnegar, director of the NASA Astrobiology Institute in Moffett Field, Calif. "These are too complicated to be attributed to non-biological processes - but we don't know that for a fact."
Allwood said her study made the case for life by looking at how the stromatolites fit with the rock formations around them, with each other, and with what would have been happening on Earth at that time. One of the clinchers was categorizing them into seven repeating subtypes, which indicates they weren't random.
"It's just the sheer abundance of material and to be able to put it all in context," Allwood said.
Runnegar who has examined the mounds in western Australia several times said the first time he saw them - some of which jut out from hills at eye-level - he experienced an otherworldly feeling.
In a similar situation 10 years ago, scientists at NASA claimed they found evidence of fossilized microbial life in a Martian meteorite. Those claims have been sharply disputed and are not generally accepted.
One of the chief skeptics of the Martian meteorite claims, Ralph Harvey, a geology professor at Case Western Reserve University in Cleveland, said he is far more inclined to believe that the Australian mounds were once alive.
The key difference is that on Mars, scientists were looking for evidence of life on "a potentially dead planet" and the requirement for proof is extraordinary, Harvey said. Less evidence, he said is needed for Allwood's claims because "we already know that life has been on Earth for a very, very long time; all we're trying to do is push it further back."
Shove that grapefruit...he was so mean in that film...thanks...
Food Fight Part Two Place Marker.
"So, you said 'the thing which is NOT the thing which you said it is.'"
OK, what did i lie about now?
Just tell us what your story is.
huh?
Probationary placemarker
Knock it off.
probabtion officer, since I have never been imprisioned it would be pretty hard for me to have a parole officer. I have never spent 1 second behind bars.
You know, JennyP and I never post at the same time. You do the math...
Your post #346 was pulled, which is why you believe you're on relatively stable ground. However, not all of us failed to keep a copy. Maybe you remember this little phrase:
I'm not on probation anymore... another assault charge wouldn't bother me... are you in MN?Ring a bell? Evidently, by your own admission, you've been charged with assault before (hence the use of the phrase "another assault charge"). You have also been on probation, whether because of said assault charge or from another charge is not apparent.
Please don't insult our intelligence any more.
Um, disregard the previous message.
Some of us legal system outsiders get this stuff confused.
It is confusing, though, how a fellow who never got arrested could have even a probation officer.
No. For many reasons, I stopped arguing with them years ago. It wasn't getting me anywhere, it wasn't making any impact with them, it cluttered up the board with threads having absurdly long replies and retorts, and only made enemies where none existed before.
Indoctrinated people often have a nearly unbreakable will to win. Fundamentalists are usually dangerous no matter what political or religious bent they come from. If you enjoy engaging them, it's really your own selfish little pleasure. Allow me to explain:
My general demeanor that I've developed over years of posting at FR essentially comes down to 'If you're not the person I'd feel comfortable with speaking to in real life for a few moments, I'm not going to spend any time with you in a digital forum'.
If I were walking down the street and some fundamentalist Christian tried to push a handbill off on me that explained that the world was 10,000 years old, and that Noah saved all the animals in the world by gathering up the Chinese Panda bears, American bald eagles, Australian wombats, African kudus, Middle Eastern dung beetles, Laplandic Elk, South American tapir pigs, lightning fast tiny green monkeys from the Amazonian rainforest canopy that spend their whole lives living up in trees that no elderly robe-wearing Jew from , Indian tigers, and tens of thousands of other geographically remote genus on the same boat before a flood came and wiped out everything on the planet, I'd do what any normal person ought to do: Regard them as utterly insane and keep on walking. I'm also not going to listen to their Bible study explanations about how the Bible doesn't say what it does in order to try to make it appealing to people who haven't been conditioned since childhood to believe those old Hebrew campfire tales. I'm especially not going to listen to some former meth addict on top of it all, as if I need some screw-up's keen advice.
So, if I'd do that walking down the boulevard, why would I seek to engage them in my spare time through the Internet? See, I wouldn't, so I no longer do. Maybe one day you'll get to where I am. You still seem to think that you have some battles to wage with them. I am no atheist, mind you.
What am I doing in this thread, you may ask? Well, I wanted to see the information about Stromatolite fossils. I admit that I kinda figured that a science post going over 500 replies had a holy war brewing in here, but the topic was interesting enough to me that I still clicked on the thread anyway.
Why was I charged with assault?
Because I almost killed a man for beating up a 16 year old girl.
Was that wrong? If presented with the same scenario I'd do it again.
God works in mysterious ways.
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