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Cuneiformist
The Imperfectionist
USA
4955 Posts |
 Posted - 11/21/2009 : 14:22:52
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I was recently listening to some Christian radio and heard two guys-- presumably the radio talk show host and his guest-- talking about various origins-of-life topics. The guest had some familiarity with basic science, but I didn't catch is name and don't know if he got his degree from Patriot University or an actual school that teaches science. In any case, the focus of the show was obviously "abiogenesis is impossible and therefore God created life, just like Genesis tells us." However, one argument the guest brought up was one I hadn't heard before, namely the "oxygen/uv paradox". Unfortunately, I was driving at the time and only had time to quickly scribble that down so I don't recall the exact argument. The general thrust, though, was something like the presence of one (oxygen or uv) precludes the other, but both were presumed to have been needed in abiogenesis. Or something.
Anyhow, I was wondering if anyhow here has heard of this discussed in creationist circles and if they could explain it more. Some basic Google searching didn't turn up much...
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H. Humbert
SFN Die Hard
USA
4574 Posts |
Posted - 11/21/2009 : 15:40:29 [Permalink]
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Hard to say exactly what the argument was without hearing it. But Ultraviolet Light (UV) is radiation and so can be harmful to life, damaging cells and DNA. On Earth, the Ozone layer in the upper atmosphere filters out about 99% of this harmful UV before it can reach the Earth's surface. Ozone is created when UV strikes an oxygen molecule containing two oxygen atoms and splits them. Oxygen is largely produced as a byproduct of certain lifeforms, such as bacteria and plants.
So I'm guessing the creationist paradox went something like this: You need life to create oxygen. But before life can create oxygen, there needs to be an existing ozone layer to block out harmful UV so life can develop. But ozone is dependent on the existence of oxygen, which requires life to make it, ad infinitum.
The short solution is this: water. Even if the early Earth lacked an Ozone layer, the oceans themselves would provide sufficient protection to organisms provided that they stayed below a certain depth. | Evolution of early reproductive proteins and enzymes is attributed in modern models of evolutionary theory to ultraviolet light. UVB light causes thymine base pairs next to each other in genetic sequences to bond together into thymine dimers, a disruption in the strand which reproductive enzymes cannot copy. This leads to frameshifting during genetic replication and protein synthesis, usually killing the organism. As early prokaryotes began to approach the surface of the ancient oceans, before the protective ozone layer had formed, blocking out most wavelengths of UV light, they almost invariably died out. The few that survived had developed enzymes which verified the genetic material and broke up thymine dimer bonds, known as base excision repair enzymes. Many enzymes and proteins involved in modern mitosis and meiosis are similar to excision repair enzymes, and are believed to be evolved modifications of the enzymes originally used to overcome UV light. |
So there's no "paradox." Early oxygen producing organisms lived deep within the ocean, not directly on the Earth's surface:
| Free oxygen gas was almost nonexistent in Earth's atmosphere before photosynthetic archaea and bacteria evolved. Free oxygen first appeared in significant quantities during the Paleoproterozoic era (between 2.5 and 1.6 billion years ago). At first, the oxygen combined with dissolved iron in the oceans to form banded iron formations. Free oxygen started to gas out of the oceans 2.7 billion years ago, reaching 10% of its present level around 1.7 billion years ago. |
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"A man is his own easiest dupe, for what he wishes to be true he generally believes to be true." --Demosthenes
"The first principle is that you must not fool yourself - and you are the easiest person to fool." --Richard P. Feynman
"Face facts with dignity." --found inside a fortune cookie |
| Edited by - H. Humbert on 11/21/2009 15:46:25 |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 11/21/2009 : 15:45:27 [Permalink]
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Nothing very satisfactory, anyway. It looks to be an old-earth creationist argument against abiogenesis.
No geochemical evidence for primordial soup.
12C/13C ratio of earliest carbonaceous deposits looks biological in origin. [The longtime presumption was that life originated in some kind of warm, shallow body of water which was very rich in the appropriate chemistry, especially carbon-rich substances.]
Early terrestrial conditions inappropriate for it anyway.
Atmosphere: CO2, N2, H2O, O2
Hydrosphere: O2, H2O, ROS
Early volcanic outgassing
O2/UV paradox [the ultraviolet radiation which has been though to be the driver for pre-biological chemical evolution can’t get to the surface if there is significant atmospheric oxygen since that UV simultaneously helps produce and is absorbed by ozone = O3. Besides, very ancient iron deposits indicate our atmosphere wasn’t always rich in free oxygen since they’re not rusted.] |
What a pain in the ass that one was to look up! Also, to this layman's eye, it looks like bullshit.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist! 
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Dave W.
Info Junkie
USA
26020 Posts |
Posted - 11/21/2009 : 22:47:13 [Permalink]
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The paradox is resolved with the knowledge that to the earliest life-forms on Earth, molecular oxygen, O2, was a waste product and a poison. That it didn't stick around in the oceans, but instead accumulated in the atmosphere, to be converted to O3 by UV light, was a good thing (for us).
And anaerobic bacteria are still with us, today... |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Cuneiformist
The Imperfectionist
USA
4955 Posts |
Posted - 11/22/2009 : 13:42:33 [Permalink]
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Thanks for the information. HH, your description sounds something like what they were saying. I wish I could remember the station/program I was listening to, but the only time I really here Christian radio is when I'm driving and on these LA freeways, it's tough to pay attention to all the details.
It does strike me as curious that I can't find more of the actual creationist argument. They tend to more or less parrot standard talking points so you'd think that this would already be all over the internet. |
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H. Humbert
SFN Die Hard
USA
4574 Posts |
Posted - 11/22/2009 : 15:01:36 [Permalink]
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Originally posted by Cuneiformist
Thanks for the information. HH, your description sounds something like what they were saying. I wish I could remember the station/program I was listening to, but the only time I really here Christian radio is when I'm driving and on these LA freeways, it's tough to pay attention to all the details. |
I don't know if I've heard this exact same argument or something similar, but the form of the argument is definitely familiar. Creationists love these so called "paradoxes," which they think prove evolution to be impossible but are always inevitably based on some fundamental misunderstanding, omission, or outright lie. I recall Verlch having a couple of these creationist paradoxes in his signature, one being "How do plants exist without bugs in the soil, and bugs in the soil without plants producing oxygen?"
| It does strike me as curious that I can't find more of the actual creationist argument. They tend to more or less parrot standard talking points so you'd think that this would already be all over the internet. |
Oh, I'm sure this claim has been around in some form or another. Maybe this is closer to what you heard, actually. Talk Origins lists this in their index to creationist claims:Claim CB030.1:
Since the early atmosphere had no ozone layer, ultraviolet (UV) light would have irradiated organic molecules that formed in the atmosphere, destroying complex molecules.
Response:
1. When simple organic molecules are held together in a fairly concentrated area, such as stuck to a dust or ice grain, the UV light actually enhances the formation of more complex molecules by breaking some bonds and allowing the molecules to recombine (Bernstein et al. 1999; Cooper et al. 2001). DNA and RNA are relatively resistant to UV light, because some parts of the molecules shelter others and damage to the bases can provide the materials to repair the backbone. UV light gives nucleic acids a selective advantage and may in fact have been an essential ingredient for abiogenesis (Mulkidjanian et al. 2003; Mullen 2003).
2. The molecules need not all have stayed exposed to UV for long. Some would have dissolved in oceans and lakes. In one proposed scenario, the complex organic molecules form in the deep ocean around geothermal vents, well away from ultraviolet light. |
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"A man is his own easiest dupe, for what he wishes to be true he generally believes to be true." --Demosthenes
"The first principle is that you must not fool yourself - and you are the easiest person to fool." --Richard P. Feynman
"Face facts with dignity." --found inside a fortune cookie |
| Edited by - H. Humbert on 11/22/2009 15:02:34 |
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Oxygen/UV paradox?
