h a l f b a k e r yNaturally, seismology provides the answer.
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Find the Secret of Life
A methodology optimised to determine composition and structure of earliest lifeforms on earth | |
We all wonder where we came from. What was the first self-replicating form of life?
Questions that are not so easy to answer. But lets start by making an assumption-life started in the oceans. Life started about 4 billion years ago, so it would be really nice to have a sample of sea-water from
this period, probably it might contain these earliest life-molecules.
So how to do it? Well the crystals of the Silica (SiO2)-based minerals like amethyst and agate were formed when the ancient oceans slowly evaporated, and the salts crystallized out (see link for description). What is interesting for us is that these crystals trapped water inclusions. Thus these crystals contain microlitre samples of ancient seawater, hermetically sealed (see link for picture).
Molecular biology is at the stage where sub microlitre sample analysis is the norm. I propose that we select crystals of different ages backwards and forwards from the age where life is postulated to have started. We then use micro Fourier Transform Infrared to non invasively localise the water pools in the crystal. We then analyse the contents of this water pool spectroscopically (UV, Circular dichroism, light scattering etc.). We could also carefully extract the contents and try mass spec, gas chromatograpy etc. All these techniques are already optimised to analyse tiny sample volumes.
Cynics response: yeah right, and those life molecules will still be intact after 4 billion years...
Answer:
1. I predict the early earth was a pretty rough place to be, thus the early lifeform would have to be chemically very stable in order to survive the challenges of such an unstable environment.
2. I don't say that the entire lifeform will have survived intact, rather that residues of its component parts may still remain, we can use our current chemical knowledge to piece together how it might have been joined up.
3. Practical proof that biomolecules are stable on the billion year timescale: Scientists have managed to isolate intact dinosaur DNA from 120 million years ago (see link), and DNA nucleotides are likely to be much more fragile than early life (dump DNA in the primordial sea and it would last about 5 minutes!).
Picture of quartz crystal with water inclusion
http://www.feralold...enhydromar20two.htm
[cevilthedevil, Oct 04 2004, last modified Oct 06 2004]
Quartz crystal formation
http://ist-socrates...sc/Lect3.html#water
[cevilthedevil, Oct 04 2004, last modified Oct 06 2004]
Life on earth timescale
http://www.biology-...10/1_first_life.htm
[cevilthedevil, Oct 04 2004, last modified Oct 06 2004]
Intact ancient dinosaur DNA extracted
http://www.newscien...s/dinosaurs/dna.jsp
[cevilthedevil, Oct 04 2004, last modified Oct 06 2004]
Quartz Inclusions
http://www.globalte...13thNov01/rocks.htm
[bungston, Oct 04 2004, last modified Oct 06 2004]
[link]
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42. No, wait, what was the question again? |
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I predict all you will see is fossilized blowfish remnants up againts the inside surface of the crystal. |
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Wouldn't it be ironic if it involved primitive skeletal fish somehow? |
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lintkeeper, not with our special 'peel-away blowfish tearaways' |
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I think I've forgotten how to read. |
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[Rayford] They hadn't been invented yet.
[snarf] in a nutshell: examine ancient sea water trapped inside crystals from billions of years ago to find first life form ever.
[reensure]: harnessing the power of something trapped inside a water container has been covered (Roaming Goldfish Bowl), although I'd sure enjoy that discussion again. |
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Very cool idea. Not super original, as analyses of ancient water have been done before to answer questions about atmosphere etc. I have never heard before that these water inclusions are actually ancient, trapped when the crystals were formed. |
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I see two problems.
1 - Crystals are old, water is recent. Water may have worked into the crystal, or dissolved more soluble parts, replacing them with water. |
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2 - Quartz is metamorphic rock. I am pretty sure that quartz undergoes great heat and pressure in the course of its formation. This would pretty much autoclave any critters or molecules trapped inside. |
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I am trying to think of a hiding spot where some water might have hung around, unmolested, at normal temperatures, for 3 billion years. Hmmm. Hmm. |
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Why the necessity of normal temperatures? Just take an ice core sample. |
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[Bungston] No quartz is a crystal, it doesn't udergo any heat or pressure changes on formation (see the link provided on quartz crystal formation). it simply forms if a sea starts to dry up. The not so soluble salts precipitate out, and form nice crystals. |
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I don't think that the water will enter the crystal afterwards, dissolving the more soluble parts. I cant see how it can penetrate the crystal lattice. Think glass (yes yes i know a glass is not a crystal...) It is a silicate nonetheless, and i think it is pretty impermeable to water, even over long timescales. |
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Regarding originality, yes probably geologists have analysed for dissoved atmospheric gases, but has anyone looked for life before? |
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[RaymondSteele] I don't know if there is any ice sample that is 4 billion years old. |
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So - questions answered. Quartz does form at high temperatures and pressures. Silica is not very soluble (which is why beaches are made of it) and it requires high temperature and pressure fluids to dissolve it. Such fluids occur deep in the earth. This is why granite is often shot through with veins of quartz - hot water with dissolved silica deposits the silica into cracks over time. |
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But it looks like inclusions might actually be ancient. The link talks about this some. I am not sure this ancient water would be representative of ancient oceans, though. More likely it represents deep groundwater. |
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[Bungston], you are right about the quartz, but I *think* (ie am not sure!) that you can get quartz crystals forming from evaporation of a sea, because the silica does have some solubility, I mean I think silicates dissolve up to about 0.004g/L. This is nothing, I agree, but imagine a sea 100m deep, 100m wide and 100m deep (this is tiny, for our calc 1m~1yard, if you dont like metric). Calculate how much silicate there is in this sea. You will find it is about 4 tonnes, now imagine a sea like the Mediterranean, how much there will be! When it starts to dry out the silicates have to go somewhere! Therefore there should be some quartz crystals which form, providing the evaporation is very slow, but don't quote me on that! |
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In any case, it doesn't have to be quartz, but any evaporite, and these crystals, as the name suggests, *definitely* form from evaporation of seas, just choose the one with the lowest solubility product (ie the one that will precipitate out first, therefore trapping sea samples that are closest to the original (ie before evaporation started) water composition) |
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Neat idea, though I'm not sure anything
would have survived that would be
distinguishable from non-biogenic
gloop. Reports of the dino DNA turned
out to be mitaken, alas (though DNA
can survive in recoverable form for at
least a few tens of thousands of years;
but not in watery places). Also, I'm not
sure if it's right to assume that ancient
life must have been tougher than it is
today: modern life spends most of its
time avoiding becoming food for other
modern life. The croutons in the
primordial soup didn't have to worry
about proteases, nucleases, and
whathaveyouases; if anything, they were
probably a lot more vulnerable to
degradation than modern DNA, proteins
and sugars. I think a better option
would be to look at anomalous ratios of
isotopes: lots of biological processes
sift different isotopes (eg, of oxygen) at
very slightly different rates, so that the
isotopic composition of rocks, water etc
can reflect their biological roles. Neat
idea though. |
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I have one question for anyone attempting to discover the origin of life, or any other such question: |
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Firstly, it really doesn't matter how the ball got rolling.
Secondly, even if, after countless of billions of dollars and thousands of manhours, you do figure it out, any member of an organized religion (I.E., most of the world,) would still refuse to believe you. When you drag religious fundamentalists into the picture, the issue is not clarified; it becomes a mudslinging contest. Thirdly, the time and energy going into this sort of scientific research could probably be utilised for some greater cause. |
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But I guess this would probably be time better spent than building a Mars Rover. |
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Anyways, (+) because I'm curious myself. |
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Why bother, WordUp? Shame on you! |
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if this helps you figure out how life first forms, very simple cell membranes can naturally be formed by some chemical reactions. i think it involves volcanic eruptions, though i am not sure. anyway, its possible that dna/rna and other protiens "housed" themselves in these non living naturally occuring membrames. life existed before it could replicate. one day i suppose the proteins just started copying it self, and viola!
a lot of scientists today attempt to recreate the first life forms with these membranes. i'll look up the name if it helps... |
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