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World's Oldest Fossils Found In Australia
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."
I'm sure there's plenty of older ones in Canberra
Just because you're paranoid doesn't mean there isn't an invisible demon about to eat your face
http://en.wikipedia.org/wiki/Rupert_Murdoch
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.
its where all the UK's old entertainers go to retire.....
"The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
It is really a mistake to think of the evolution of bacteria having ended at any point. They've been evolving just fine since they formed, as evidenced in part by your existence (not a joke, as you/we are derived from those early life forms). There is reasonable reason to believe that what we think of as bacteria (Eubacteria specifically) evolved after we (Eukaryotes) went our own way. At the time quoted, the atmosphere of our planet was significantly different than now, so the basic physiology of the 'bacteria' of the time would have been rather different than most 'bacteria' now.
Is this something that Curiosity is equipped to find?
No Curiosity isn't equipped with "Scientists analyzing Australian rocks". Sorry maybe next go round...
I was going to say more or less the same thing. Modern bacteria have completely different metabolisms, internal and external structures and materials from early anaerobic prokaryotes. To say that bacteria stopped evolving from that state would be deliberately ignorant/obtuse (since you'd essentially have to argue that animal life doesn't exist).
I support the Slashcott and will not be reading or commenting from 2/10/14 to 2/17/14. Beta is steaming pile of dog shit
So tell me why there are bacteria, which can only exist in our guts? We didn't exist 200-300 mio years ago. So how can a lifeform, whose evolution stopped 200-300 mio years ago, suddenly be adapted solely to an environment forming just 65,000 years ago? No, the evolution of bacteria continues and continues and doesn't stop at an arbitrary point in time.
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.
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).
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
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.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Again with this billion years shit! ROFL
It doesn't smell a day over a million.
I didn't RTF, but how did they determine age for something like that, which Carbon-14, I think, couldn't date?
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...
Sure, just don't get in the way of my belief that evolution and the big bang are Lies Straight From the Pit Of Hell when I'm setting the agenda for the country.
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.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Like everything else down under, these bacteria coulf kill with big, nasty teeth, poisonous spines, and deadly venom.
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.
Of the earliest atoms in the Galaxy we have plenty, they are called Hydrogenium atoms. As they just consist of an electron and a proton, and an electron is (as far as we know) elementar, and a proton seems not to decay into other particles (experiments have shown a life span of more than 10^32 seconds without decay, which means protons stay stable for far longer than the Universe, whose age is a mere 10^18 seconds), it means that basicly all Hydrogenium atoms today formed just a few moments after the Big Bang.
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 natural selection, and the result is that only those fit to survive Penecillin have survived in these environments. That's how evolution works.
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.
-- We live in a world where lemonade is artificial and soap has real lemon.
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".
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.
Your understanding of "survival of the fittest" is flawed. "Fittest" does not mean "fitness" to do battle with the environment, it means fit to reproduce. A male peacock who is highly mobile yet fails to attract a mate will not pass on its genes. A male peacock who can't move but attracts females who bring him food, protect him, and reproduce with him is considerably more "fit" to survive. In fact, he'd just be a level 90 Paladin away from living a lot of people's dream life.
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.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
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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With the quick appearance of algae on Earth, it makes it seems as if basic life as cyanobacteria evolves quickly from chemicals or else evolved slowly some other place but survives the depths of space (which is possible).
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 even off the planet yet. (Off the planet means establishing a self-sustaining colony someplace else).
.. that the bacteria fossils were persistently aligned into a pattern of a likeness of Mel Gibson.
What... not Rick Astley?
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
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.
Ha! Thanks. The letter c appears to be getting scare.
-l
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”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.”
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.
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 dramatically out-competed by a relative latecomer that we derive from.
Even now there are variations in the basic molecular machinery used by different organisms. Some organisms have genomes that are de-compressed (as in information compression, not physical compaction) before being translated into proteins, most don't. Many organisms don't use the same DNA coding scheme that you use. Many organisms use alternate DNA bases, totaling to more than four base-pair combinations that are biologically important. Many don't use histones, while others do. Some have cytoskeletons composed of actin and tubulin fibers, some don't.
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Under some reasonable models of abiogenesis, the central metabolic circuits intrinsic to all living things developed before living things had DNA or cell membranes. Cells could easily have formed and been actively 'alive' without having any sort of central genetic molecule (they would have been less efficient at replicating themselves). As such, it is perfectly possible that the fossils being discussed came from cells which explicitly did not share much of our core molecular systems.
We can learn things from early biology that we do not expect, but we won't learn things from early biology if we simply assume that we know what was going on. (This is a general statement that applies to all of scientific endeavor.)
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 "not much of significance has happened to bacteria since 3.5 Bya".
I agree, Its not what this fossil can say about evolution that is important, but rather what it might say about how life started in the first place. At some point something interesting must have happened to create something that could harness the energy and chemicals in its environment to make copies of itself. Once that started, evolution was inevitable.
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.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
I never noted that I posted that anonymously. Silly me. But now I'm a slashdot trainee.
Another inadvertent anonymous posting. /slashdot trainee.
? Bacteria has sturdy cell walls as ancestral trait (cf mycobacteria who lack it), eukaryotes with nucleus have only membranes.
Unlikely. See my longish comment above how ~ 30 000 years is now known to suffice until cellular ancestors arise. They only need 2 individually self-assembling and spontaneously replicating components, liposomes and the thermodynamically driven crystallising RNA replicators. For example, Mars with its mere ~ 3 million year until accretion got a head start on Earth with its ~ 30 - 300 million years (latest core formation theories) had an impactor tramway of material raining down on Earth as it formed. Calculate cellular mass content of average crust and its survivability under launch impact and shortest route to Earth (all researched and published, thankfully). Even if the martian tramway delivery rate was order of magnitude larger than today's ~ 200 kg/year estimate, you don't get the average delivery rate of 1 (one) surviving cell up to the above abiogenesis rate. I don't think we can reject the possibility at 3 sigma, but the simplest pathway of "in-house assembly" is the superior at 1-2 sigma. As for incoming life at later times, we don't see it in mass sequencing. Indeed, it would have a hard survive will already adapted life makes lunch out of it.