World's Oldest Fossils Found In Australia 85
Dexter Herbivore sends this quote from the Washington Post:
"Scientists analyzing Australian rocks have discovered traces of bacteria that lived a record-breaking 3.49 billion years ago, a mere billion years after Earth formed. If the find withstands the scrutiny that inevitably faces claims of fossils this old, it could move scientists one step closer to understanding the first chapters of life on Earth. The discovery could also spur the search for ancient life on other planets. These traces of bacteria 'are the oldest fossils ever described. Those are our oldest ancestors,' said Nora Noffke, a biogeochemist at Old Dominion University in Norfolk who was part of the group that made the find and presented it last month at a meeting of the Geological Society of America."
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Is this something that Curiosity is equipped to find?
No Curiosity isn't equipped with "Scientists analyzing Australian rocks". Sorry maybe next go round...
Lightweight (Score:5, Funny)
I'm sure there's plenty of older ones in Canberra
Its not exactly a secret (Score:5, Funny)
http://en.wikipedia.org/wiki/Rupert_Murdoch [wikipedia.org]
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I second this ;> ( you beat me to the punch )
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.. that the bacteria fossils were persistently aligned into a pattern of a likeness of Mel Gibson.
What... not Rick Astley?
Re:Not interesting (Score:4, Insightful)
OK, so according to the summary there is 1000 million years between formation of Earth and theses fossils.
Assuming that first life wasn't created before Earth or after these bacteria then the interesting timespan covers 20-30% of this time.
Pretty good odds that this will tell us something about its evolution then.
If the 200-300 million years for evolution are reasonably certain and the fossils turns out to be fully evolved then this will help us pinpoint when life first started evolving.
I would say that regardless of the outcome Nora Noffke of Norfolk have some pretty interesting stuff here.
Re:Not interesting (Score:5, Informative)
Re:Not interesting (Score:5, Informative)
Re:Not interesting (Score:5, Interesting)
Yes, but things like how DNA and ribosomes work, and the basic molecular machinery would have already been set in stone even in bacteria that old. All the rest is fine tuning to the current conditions and doesn't tell you much about the evolution of life.
It's the same as looking at the evolution of reptiles after the Mesozoic or the evolution of insects after the Paleozoic. Sure, there is some evolution, but the really interesting changes have already passed.
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I was replying to the "it could move scientists one step closer to understanding the first chapters of life on Earth" part of the summary.
Re:Not interesting (Score:5, Interesting)
Abiogenesis is thought to have taken place somewhere between 3.9 and 3.5 billion years ago and these traces of life (textures on the surface of sandstone that have altered C12/C13 ratios suggestive of life) are dated 3.49 billion years ago. Calling them bacteria, or even saying that they had DNA and/or ribosomes, may be presumptuous. They’re old enough that conditions of the RNA world hypothesis might still apply. They might not have DNA at all but use RNA (or something else) as genetic material. They might use RNA instead of proteins for catalysis, which could obviate the need for protein-building ribosomes. This life might not be cellular, could just be primitive liposomes that chaotically break and reform, briefly shielding some set of catalytic molecules that when you average them out over a large area—say a cubic millimeter—the whole system is able to keep functioning and making more of itself.
But let’s ignore all of that and say that this stuff, whatever it is, has DNA. Does it only use the four canonical bases or does it use them and/or something else? How good is it at keeping deoxyribonucleic acids from being used alongside ribonucleic acids, or is a mix important in some function(s) at this very early stage? Suppose it does use just the four canonical bases, and just the four (five) bases for RNA, and has ribosomes, and has the central dogma in place of DNA->RNA->protein. What’s the protein like? Is the universal* genetic code in place at this point? Are there just 20 amino acids, the same 20 currently in use, and are they encoded by triplet codons? After all valine, leucine, and isoleucine are pretty much the same as far as protein biochemistry is concerned and usually can substitute for each other with little or no impact, so why have all three? Could there be a different set of amino acids, one that is potentially encoded by pairs of codons or mixed pairs and triplets?
Let’s ignore all of that and say we’ve got life, actual cellular life, that uses DNA with just the four bases, with negligible confusion with RNA, that the mRNA and tRNA and ribosomes are all worked out (and ignoring ongoing evolution), with just the 20 amino acids using the universal* genetic code. Does this organism make its own cellular membrane? There’s a whole bunch of synthesis involved with making the components of a membrane. Does it use cholesterol or other steroids? A modern cell membrane has more than phospholipids. Does it have a cell wall? That’s a completely different set of questions as there are many different cell wall structures and components in modern prokaryotes. What is the energy source for these organisms? Are they heterotrophic? How? Are they photosynthetic? How? Are they sulfur-reducing prokaryotes? How? Are they predatory? Do they secrete chemical compounds that lyse their neighboring prokaryotes? How?
It’s trivially easy to ask questions about basic chemistry, biochemistry, and genetics when it comes to these organisms, assuming of course we would grant them as being alive, when we’re dealing with something from 3.49 billion years ago. I do not necessarily agree with “fine tuning” either since there are geologically short periods of time that witness tremendous changes in life forms. The emergence of aerobic life about 2.5 billion years ago is one such point; oxygen would likely have been poisonous to the life forms in TFA. The emergence of eukaryotes about 1.6-2.1 billion years ago would be another, as would multicellular life appearing shortly afterwards. Throughout all of this the archaea, bacteria, and/or their ancestors would be present, and would be evolving in response to their changing environment.
I happen to have done some work in entomology so I have to mention insect evolution.
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I would wager that the fine-tuning to current conditions is all that the evolution of life is and as such is the only part that tells anything about it.
The idea that living things of that time would have already had the basics of our molecular machinery is a hypothesis. We have no way to know if living things from that era used the same systems that we now do, rather than something simpler and less efficient. The majority of them could have used entirely different molecular systems, only to later be dra
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As well, the bacteria that you think of are rather distinctly newcomers on the biology scene and differ in much of their basic machinery from the bacteria we derived from. If you want to study the bacterial types that we derived from, you need to examine what are now referred to as the Archaea. This indicates there were major evolutionary shifts within bacteria since the time we went our own direction as Eukaryotes (estimated to be from 2.0 to 3.5 Bya), which is a negative mark to your central thesis of
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You're probably not descended from them (Score:2)
You might be, but they're more likely to be either evolutionary dead ends or things that other current species are descended from but not mammals. Why? Just numbers, most species that ever existed died out, and there were a number of huge die-backs that killed off large fractions of Earth's life forms.
But as the parent posted says, it's a mistake to think of the evolution of bacteria as having stopped.
Re:Not interesting (Score:5, Interesting)
Re:Not interesting (Score:5, Insightful)
Considering that bacteria replicate by cell division, how quickly they reproduce (a "Generation" can mean a few seconds, food provided) and that with every multiplication the chance for gene errors grow (especially with Prokaryotes, something this bacterium is almost certainly), and if you factor in the survival of the fittest theory, i.e. that bacteria with a beneficial mutation grow while the inferior ones (i.e. the older, not mutated) perish, I'd say the chance that this is even similar to current bacteria is VERY slim. It's the "prototype", it's closer to the point where everything started (because the superior mutations would have wiped out the inferior ones, which this bacterium almost certainly is).
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Not to nitpick, but "survival of the fittest" is one of the greatest misconceptions out there. A male peacock without huge plumes would be far more efficient in mobility. But since the plumage attracts females, the selection pressure is tilted in a direction having little to do with direct survival characteristics. Indeed we often do NOT see the "fittest" survive, but rather species that specialize and carve out little niches. This also explains why the biodiversity we observe exists.
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His criticism makes more sense if you understand that "fittest" is intended for a species, not an individual. This is, for example, almost certainly why homosexuality exists as a frequent phenotype. It helps the *species* out, even if it's not particularly fit for the individual (i.e., can't reproduce). Having more caregivers in a social species gives the species an edge as long as the non-reproducing members don't take away too many scare resources from the reproducing ones.
-l
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Having more caregivers in a social species gives the species an edge as long as the non-reproducing members don't take away too many scare resources from the reproducing ones.
Ahh... that explains the USA's edge. It's the scare resources :D
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Ha! Thanks. The letter c appears to be getting scare.
-l
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Bacteria's evolution finished so early
Why is this modded informative? Bacteria did not, and have not, stopped evolving and their sheer numbers mean they do it a lot faster than mammals do. A simple, modern, amoeba has something like 200X the number of genes found in human DNA.
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Bacteria have NOT stopped evolving (nor has anything else). Evolution is a constant process anyway, but for specific proof, new strains of infectious bacterial diseases are constantly appearing - this is evolution. For a specific example, the use of Penecillin and similar anti-biotics has been an evolutionary selector for microbes that are capable of surviving these drugs - where we now have certain "superbugs" which have evolved from "normal" bacteria. In this case, humans have influenced the process of na
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You didn't understand what I meant by evolution - I meant the development of DNA, RNA, ribosomes, etc. evolved. Those things aren't evolving now, they're already set in stone, and new superbugs aren't telling us anything about the origins of life.
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Again with this billion years shit! ROFL
It doesn't smell a day over a million.
Of Course (Score:1)
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I have a great idea, let's stay out of each other's way. You have your believes, I have my science, and everyone's happy.
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At first I was worried when I read Athens, then I sighed in relief when I noticed it's the one in Georgia.
Makes sense. In Europe, he'd be laughed out of his office (and his party would instantly move a BIG distance to him) if he really said things like this and kept a straight face.
But hey, I'm all for the US becoming the Christian version of the Iran. More legroom for us Euros when your science grinds to a halt.
Like I said. Keep your faith, we'll keep our science.
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Hydrogenium is half greek (hydro-) and half latin (-genium) and means "water creator", which is a completely cromulent name for the element. Where the strange notion comes from, that the ending "-um" or "-ium" means a metal is beyond me. Wolfram, bismut and cobalt have no -um ending and are metals, while helium has the -um ending and is a noble gas.
So I call this bullshit.
Come back when we call the noble gas "hel".
Yeah; I can't get helium to freeze either.
How Old? (Score:1)
I didn't RTF, but how did they determine age for something like that, which Carbon-14, I think, couldn't date?
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Probably tree rings.
Re:How Old? (Score:5, Informative)
The article doesn't actually say and the Washington Post just links to the article abstract, but C-14 dating isn't used except for recent material because of its small half-life. There are a wide variety of methods used for older rocks (see here [wikipedia.org]). For instance, rubidium-strontium dating might be used, since rubidium-87 has a half life of 50 billion years. Rubidium-strontium can be used for isochron dating [wikipedia.org] as well, which doesn't require any assumptions about the amount of the daughter nuclide in the sample.
Having said that, I don't have any details on the methods actually used to date rocks in this particular region.
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Those are our oldest ancestors? (Score:2, Insightful)
The article contains the comment "Those are our oldest ancestors". That got me thinking... Since bacteria are asexual and reproduce by division then, technically, the ancestor of two bacteria was destroyed when it split into it's two children. If this is true then any fossilised bacteria must, since they are dead and in one piece not two, not have reproduced. If they didn't reproduce they can't be the ancestors of anything...
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But their twins could be.
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so this is the oldest known poop every discovered?
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For poop, you need a bowel. Which was not invented until the Cambrian, or just before, about 540 million years ago. So these bacteria pre-date any poop, let alone discovered poop, by getting on for three billion years.
Yes, once upon a time the world was not full of shit. Back then, shit didn't happen.
No shit, Sherlock.
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The same issue exists, albeit to a smaller extent, with any fossil. There's no guarantee that an individual that reproduced will be fossilised, or vice versa.
So much data on our planet's history is lost to the bitter march of time. But we're winning! Eat that, time!
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Why would the original be defined as destroyed in splitting, that is illogical. You have an original living mass, which internal reproduces a copy of it's inner functions and DNA. The internalised copy is then ejected within a new cell wall. You always have the original up until something consumes it or it is destroyed via any one of countless methods.
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That got me thinking... Since bacteria are asexual and reproduce by division then, ...
That's where you went wrong. Bacteria do have a sexual reproduction process, though mostly they produce by division. Their sexual process is a lot different than ours, but it does involve two bacteria joining cell membranes, exchanging and mixing up portions of their DNA, making a few copies, and then splitting up into cells that contain mixtures of both parents' DNA. This has the usual survival advantage: The offspring that have a "better" combination of genes will do better than the other half of the
...and they're deadly! (Score:2)
Like everything else down under, these bacteria coulf kill with big, nasty teeth, poisonous spines, and deadly venom.
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panspermia doesn't suffice (Score:2)
However, panspermia doesn't explain multi-cellular life or backbones, something that didn't happen until just recently in the timescale, less than 500 million years. Bacterial life may arise almost spontaneously across the galaxy but advanced life obviously takes more doing. We aren't eve