Anyone catch this article on Science Daily? Would be interesting to hear what Francis Crick would have had to say about this...
SImple life form may have existed 700 million years earlier than previously thought
Established Member
Anyone catch this article on Science Daily? Would be interesting to hear what Francis Crick would have had to say about this...
SImple life form may have existed 700 million years earlier than previously thought
Banned
The article talks about traces of light carbon trapped in diamonds and graphite. It's a slight possibility that an organic life form MAY have created those pockets of light carbon.Originally Posted by toothdust
But it's all total speculation at this time.
There isn't much here to day except for , "Hey.. Maybe... Just maybe there might have could been..."
So much for sensationalized drama...
Order of Kilopi
It generally takes more than "Hey.. Maybe... Just maybe there might have could been..." to get a paper into Nature.
http://www.nature.com/nature/journal...AD58EEFB0C3284
The median istopic fractionation of -31 per mil is well beyond what would normally be considered as indicating inorganic processes (-6 per mil in younger diamonds is normally considered as indicative of a possible biogenic carbon source). Not proof of life, but strongly suggestive of it and certainly more than "total speculation".
Jon
Banned
In that case, I stand corrected.
Sometimes, the finer details really help...
Order of Kilopi
I had hoped that the lead author would be speaking at the coference I am going to tomorrow, but no luck
But finding these diamonds is quite an extraordinary saga of persistance and analytical precision. The Jack Hills conglomerate is ~3.6 Ga, and zircons are less than 1% of the rock. The zircon grains are perhaps a mm across, or smaller. Only a fraction of these are ancient (>4.0 Ga). The diamonds themselves are found in only a very few of these and are miniscule.
Jon
Order of Kilopi
It's very interesting and the technique is similar to what was used to determine an earlier 3.8 billion year old figure for life:
http://news.nationalgeographic.com/n...amicrobes.html
Some explaination other than life may be found for the isotope ratios, but that seems unlikely to me.
Of course it is possible that life may have arisen and gone extinct several times in earth's early history due to bombardment or whatever. If this turns out to be the case it would suggest that life isn't too improbable and may be common. However, I would guess that life underground could survive a lot of pounding provided the earth's crust didn't get too cooked.
Established Member
While its nice to think life got started on earth almost immediately under the right conditions, the earlier the start point the longer it took for our evolution to occur. Still what's a billion years in the grand scheme of things.
Order of Kilopi
The signs seem to be pointing to: evolution of nanobacteria and then bacteria: easy. Going from bacteria to anything more complicated (e.g. something with a nucleus): very very hard. (incidentally, the time between bacteria and cell with nucleus was a lot more than the time between cell with nucleus and multicellular--plenty of reasons the former is a lot harder than the latter--both are probably the result of parasite -> symbiosis -> merging of the life forms.)
Order of Kilopi
Yeah--just like cold fusion and Martian fossils!
The abstract itself says "Low Δ13CPDB values may also be produced by inorganic chemical reactions, and therefore are not unambiguous evidence for life on Earth as early as 4,250 Myr ago." But it certainly adds "élan" to the debate, and is sure to generate much "buzz" for Nature and so keep those $199 subscriptions rolling in! I'd like to read the article itself for more details; too bad they want $30 USD for it.
Last edited by Warren Platts; 2008-Jul-20 at 12:06 PM. Reason: sp.
Established Member
Hey are you at AESC 2008?I had hoped that the lead author would be speaking at the coference I am going to tomorrow, but no luck
Jon
if so, check out Dynamic earth session at 1440 tomorrow by Bob Nicoll. Its a Ordovician paleobiogeography paper I am co-authoring.
Order of Kilopi
Fascinating!
And so now there's even less time to go from inorganic goo to Life.
Where the telescope ends, the microscope begins. Which of the two has the greater view?
Established Member
So that means it had to be panspermia, right?Fascinating!
And so now there's even less time to go from inorganic goo to Life.
Not necessarily. Sorry.
Order of Kilopi
Nah, it only means that Life from inorganic goo occurred rapidly and easily on Earth, if in fact it originated on Earth.
Right.Not necessarily. Sorry.
Where the telescope ends, the microscope begins. Which of the two has the greater view?
Established Member
Hmmm, I'll have to read the actual paper. But it would be a major finding if it holds up... the evidence for life from the Isua supracrustal rocks at ~3.8 Ga is not unambiguous either. And at least one of those detrital zircon grains is 4.4 billion years old...
Order of Kilopi
If you get it, could you send me a copy of the pdf because they're charging $30 for it without a subscription. It looks interesting--but not $30 interesting.
Order of Kilopi
Interesting. If they are right they just moved back the origin of life 150 million years father than from today to the beginning of the paleozoic.
It also seems to me that if life was getting a foothold that early, we are prolly pretty likely to find some evidence of something that lived on Mars.
Established Member
Got it. Send me a PM with your email address and I'll forward it along.
Order of Kilopi
Excellent!
Established Member
Both would be amazing:
(a) life arising several times on Earth,
or (b) life arising that early and surviving disasters underground to resurface later.
Hope to hear more about this!
Order of Kilopi
If it's so easy to create life, then why can't we do it in the laboratory?
Banned
To the best of my knowledge- we have created it in a lab.
In fact, Posted a link to an article a while back about a scientist that "grew some" in a test tube- took him about 25 years.
I think it's easy to create life.
I almost think, that given the chemical nature, it's almost inevitable considering the time involved. As long as the conditions are right- as long as it survives... I wouldn't be the least bit surprised at the discovery of life elsewhere int he Solar System as well.
Established Member
Could you repost that link? Would be interesting to see. I have heard that some chemists have come close, but haven't heard of them actually succeeding. By 25 years, do you mean the experiment "cooked" for 25 years, or just that he was working on it for 25?
I will also not be surprised to find life in our own backyard.
Banned
Oh.. a hunting I shall go...
[This space reserved for an ETA with said link once it's found]
Ok, didn't find it on BAUT_ so hit Google- Different article- basic same content:
http://discovermagazine.com/2008/feb...-evolve-in-ice
Same server as what the B.A. is now hogging, so tread carefully.
Established Member
Oh yeah! I had this magazine actually. Really interesting. Sounded like he got as far as amino acids and nucleobases. I didn't catch in their how close he actually got to a functioning simple organism. Makes a trip to Europa much more exciting.
Banned
Oh no.
I'm sorry, I didn't mean to mislead...
I meant the basic building blocks OF life- not actual organisms.
Nonetheless, to a chemist, that kind of mixture is an inevitability to lead to them, not just a freak accident.
Order of Kilopi
If it were easy we would have done it by now. Despite 55 years of research we still have not got much further than the original work of Urey, Miller, and Fox, in the botttom up approach. Simple proteinoids and microspheres.
Despite 22 years of work into the RNA world concept, a top down approach, we have not gotten much further than recognising the need for a pre RNA world. This have might have used other nucleotide precursors - GNA, TNA, PNA - or even PAHs.
The abiogenic formation of life is still a hard problem, and it is getting harder as the time available for it is getting shorter.
Jon
Banned
What's 22 measly Sol's compared to several million of them and a laboratory with all kinds of conditions the size of a planet?
Order of Kilopi
Indeed!
But the fact remains that there is far less time for life to have appeared than thought 50 years ago, when it was believed to have originated perhaps billions after the formation of the Earth (the oldest fossils were then the 1.88 Ga stromatolites of the Gunflint Fm in Canada). Now it looks like life may well have appeared immediately after or even during the LHB. This is also a period for which we have almost no evidence for the surface conditions on Earth (a few intensely metamrophsed outcrops the size of a table and a scattering of single mineral grains is all we have), which makes any ideas even more speculative.
Which is why finding evidence of fossil life on Mars would be most interesting as the >3.5 Ga record on Mars is much better preserved than its terrestrial counterpart.
Jon
Order of Kilopi
According to Peter D. Ward, author of Rare Earth, it has already been done. Mind you, he counts viruses as being alive and is in favour of naming them as Wardian life.If it's so easy to create life, then why can't we do it in the laboratory?
Order of Kilopi
If you count viruses, then OK, but they don't metabolise which is a key component of most definitions of life. They also have no independent existance, as they require cells to reproduce. So they had to have come after other organisms.
If a virius is alive, how about a prion? Since they can reproduce without cells they are in some ways show more of the characteristics of life than viruses, despite the absence of nucleotides.
Jon
Order of Kilopi
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