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World's Oldest Fossils Found On Australian Beach
sciencehabit writes "Researchers say they have discovered the fossils of 3.4-billion-year-old cells in between the cemented sand grains of an ancient beach in Western Australia, possibly the oldest fossils ever found (abstract). Chemical analyses of the minerals near the cells suggest the microorganisms depended on sulfur for fuel. Such a beach might have been life's first breeding ground, one author says."
That was careless. You'd think people would pay more attention to their fossils.
Dewey, what part of this looks like authorities should be involved?
TFA notes that this work was done by Martin Brasier's team and that Brasier has generally been a strong critic of a lot of the claims about early fossilized life. That may be strong evidence that this claim should be taken seriously. However, there have been times before where scientists have criticized claims coming from other groups even as they've made nearly identical claims. It looks like Brasier et al. have done much more careful chemical work than some of the other early life claims which makes this look promising but this probably won't be completely clear until a bit more work by other groups is done. It is also important to note that it is extremely unlikely that we are finding the very first life. Most likely, life had to be pretty common already in order for it to have a decent chance to leave fossils. This means that one can tentatively guess that life arose at least a few million years before when these fossils were formed.
We keep pushing farther and farther back in time when life arose on Earth. This is important since it helps us figure out just how likely life is to arise in general. The argument goes that if life is easy to start then we should expect to see life arise soon after heavy bombardment of Earth begins. And that's what we do seem to be seeing. This suggests that life may be plentiful. There's a substantial very recent argument against this line of reasoning by David Spiegel and Edwin Turner http://www.physorg.com/news/2011-07-astrophysicists-logic-downplay-probability-extraterrestrial.html. Spiegel and Turner argued that if it generally takes a lot of time to get intelligent life to develop then intelligent life will have an observer bias since it will only arise on the planets where life started very early. This means that seeing life early on in our history might be something which we should expect even if life arises really rarely.
I am not a geologist.
Good thing.
They are fossils OF a beach, not fossils ON a beach -- More specifically what appear to be fossil remains of microbes that lived in beach sand.
You can't see ANYTHING from a car, You've got to get out of the goddamned contraption and walk...Edward Abbey
If Mars has a biology, it may involve sulfur a lot more than the Earth's does, so this is very interesting from the standpoint of seeding life between the two planets.
The fossils were from a sedimentary formation that was most likely a beach. They date back to 3.4 billion years ago and there is evidence that large amounts of water existed as far back as 4.4 billion years.
"Yet another indication of the lying liberal media trying to desecrate our young childrens minds with scientific theory". He then went on to submit emergency legislation to designate Australia as imaginary, all fossils (now and to be discovered) as fake and scientists as the devil incarnate. After this his poll ratings climb 5 points in South Carolina.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort.
Paul Hogan.
G'day Mate!
4.5 billion years ago, probably not. At least not for long, any water probably getting vaporized by gigantic collisions on a regular basis. But by 4.4 billion years ago, there is evidence for detrital (i.e. eroded on the surface and redeposited) zircon mineral grains in what are now highly metamorphosed sedimentary rocks. The original rocks did not survive unaltered from that period, but the recycled zircons did, implying there had to be some process to erode them from the rock in which they initially crystallized and redeposit them, likely water. Refer to this web page and this paper. They're kind of technical, so good luck if you don't have some familiarity with geology and isotope geochemistry, but if you google "cool early Earth hypothesis", you'll find more general accounts from media reports too. It's fair to say that these interpretations are relatively new and thus tentative, but if they are correct it would mean the Earth wasn't the completely lava-covered hell that most geologists used to think it was when they named the pre-4-billion-year period of its history the Hadean Era. So, you have the right idea and it's a legitimate question to wonder whether there was water so early, but the science has changed in recent years.
By 3.4 billion years (the estimated age of these new fossils), there's plenty of unambiguous evidence for oceans having been around for quite a while before.
That they found stromatolites ? Previously thought to be the oldest fossils.. I remember seeing them on various Discovery/NatGeo shows (and probably the original Cosmos, and Attenborough documentaries.