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Voom! Evolution in Fourier Space: part 1


volcanic lightningIn a previous blog, I mentioned the fact that meteoritic amino acids are undoubtedly a signature of extraterrestrial life and not abiotic, because they are all chiral. However, they are all L-amino (none are D-amino), which is unexpected from the hypothesis of independent spontaneous generation for each event, which should randomly select between L- and D-. There are three possibilities:
(1) we hit the lottery with a one-in-a-million chance of never having seen a common D-amino;
(2a) there’s a “Darwin-of-the-gaps” materialist explanation for the prevalence of L-amino life;
(2b) another “Darwin-of-the-gaps” materialist explanation for abiotic formation of L-amino life;
(3) all these meteorites are actually infected from the same source of life.

Now (1) offends my mathematical sense as it should yours, and (2a) and (2b) require too much faith in materialism for my skeptical mind, but (3) matches everything we know about the ubiquity of life on Earth. That is, despite our best efforts at sterilization, hospitals get infected with superbugs. Likewise, extremophiles grow from -30C Mt Everest to 400C black smokers on the sea floor, even in mines miles deep, along with every square inch of our planet’s surface. So am I surprised that these meteorites, widely believed to be extinct comets, are all infected by the same sort of life? Not a bit.

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http://rbsp.info/rbs/RbS/TEQM/index.html Interesting article. Escaping the "prison of objectivity" sounds like fun. Where do I join up? tragic mishap
I also have a question about your post, the first link in this current post. You say:
Given that cosmic rays or heat can break/remake chemical bonds, an originally chiral amino acid will become racemic given enough time... They are noticeably non-racemic, with a bias toward L-amino showing that they are either very old life, and/or mixed with some non-biological racemic amino acids.
So...if they are noticeably non-racemic, and any non-racemic mixture will become racemic over a long period of time, wouldn't that indicate they are young not "very old"? tragic mishap
Well I'm operating on old information then. I had not heard of anything more than a 9% L-form excess before, from the Murchison meteorite I believe. I apologize but your long post did not contain that information, and we've heard this sort of rhetoric before on the basis of excess as small as 2% which is hardly convincing. When you say 12 amino acids are you talking about 12 amino acids of the 20 in earth biology? tragic mishap
bornagain77, I have no bone to pick with Fuz, but it seems a little extravagant to have God doing this OOL thing multiple times. Either he did it only once, or he is still doing it as we speak. Any other position will need evidence of contingency. Fuz doesn't really provide any, so it smacks of some sort of accommodationism. Lock, Extremophiles are standard terminology in astrobiology, and the point about temperatures is that life exists in places where it was thought impossible a mere 10 years ago. We have bugs in our lab that thrive at -5C and at 150C. (We grow them in an autoclave.) The only requirement is that water be liquid, and we now know that life survives in water at -30C (biological antifreeze), and 160C (deep ocean pressure). That opens up a lot of environments previously thought inhospitable--Mars, Europa, comets, asteroids... Tragic Mishap, Okay, I will correct you. Glycine isn't chiral. But meteorites have a lot more than glycine on them. They have some 12 different amino acids, excepting the unstable ones. This is actually solid evidence that they are exceedingly old amino acids. Read, for example, Bartholomew Nagy's book "Carbonaceous Chondrites" 1972. The excesses L-amino component (and any excess is exceptional seeing as we can't duplicate this feat in the lab) vary from 90 to 60%, or from nearly entirely chiral to nearly racemic. None of them are perfectly racemic, and none are D-amino. Recent work can be read either in the proceedings of a recent conference on Homochirality (Apr 2010) or recent books and papers by Richard B Hoover. (I can get you a list if you need one.) I don't have the reprint handy on which nucleobases were the more stable. Its in the same 2003 collection edited by Hoover. And yes, you should be surprised, because that's why they just had a conference on the subject. And no, you can't get L-abundance by coin flips, you can't generate L-abundance from a racemic mixture by random steps because the noise you are suggesting goes as root(n)/n. When n is, say, 100, then the error is 10%. When it is 10000, the error is 1%. The number of amino acid bases discovered in meteorites is, say, ppb in a few ml, or 6x10^24 * 1x10^-9 = 6x10^15==> root(n)/n = 0.0000001% Or pretty indistinguishable from racemic if you started with a random L- D- generator. You'd have better luck arguing that the noise in the detector was masking the signal, than to suggest that it was a true signal created randomly. Robert Sheldon
Um, what in blazes is the big deal about this? Correct me if I'm wrong but from what I understand glycine, easily the simplest of the 20 biological amino acids and the only one that does not have a chiral center, is the only earth-like one that has been found in space. Even the Miller-Urey experiment got glycine. As for chirality, it would really be something if the chiral amino acids from outer space, not glycine since it's not chiral and no other biological ones, had more than a 9% excess of the L form. Unless I'm mistaken, they don't. And considering that this is an issue of probability in a very small sample size as was so eloquently explained in the post, I see much ado about nothing. Your alien amino acids losing their chiral centers over time is my racemic mixture that by chance has a slight excess in one direction. I'll make you a bet. I do a hundred coin flips ten times. I'll bet you that at least one of those data sets shows a 9% excess of heads. Oh and let me guess. Those two nucleobases were the pyrimidines weren't they? tragic mishap
Ahem... "Likewise, extremophiles grow from -30C Mt Everest to 400C black smokers" I do not like the implications of the term 'extremophile'. Smacks of leading the witness (or jury) to me. Is that really extreme given the range of temperatures in the universe? It's not just silly, it is possibly dangerous, that we latch on to such terms so quickly. Lock
Dr. Sheldon, you may find this following article interesting: Late Heavy Bombardment Intensity and the Origin of Life - Hugh Ross - 2009 Excerpt: As Fuz and I described in our book, Origins of Life, the existence of liquid water conditions within a few limited refuges at intermittent times throughout 4.38 to 3.85 bya provides a superior explanation for the zircon and rock remains.5 This scenario leaves open the possibility that God intervened every time, or nearly every time, liquid water was present on Earth to create life. When that life was destroyed by a bombardment event, God simply waited for the liquid water to reappear to create life again. (This is why we used the word "origins"–as opposed to "origin"–in our book title.) In More Than a Theory, I suggest that God might have chosen this repeated origins-of-life strategy as a tool to jumpstart the chemical transformation of Earth's atmosphere.6 http://www.reasons.org/LateHeavyBombardmentIntensityandtheOriginofLife bornagain77

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