27 Feb 05
1 edit
Originally posted by DarfiusThat's a rude post, Darfius. That attitude is why many others aren't respectful to you.
If you're waiting for an atheist to post, you'll be waiting for awhile. They don't have any answer except "God didn't do it, that's for sure!"
And then they drool.
Anyway, God did it.
I'm not sure how far before the beginning of life you want me to go. I'll start here:
The Earth probably formed about 4.5 billions years ago. It was a hot, inorganic ball of rock with oceans and an atmosphere containing nitrogen, carbon and hydrogen atoms in some gaseous form or another, but no oxygen gas (O2). I don't really know what molecules these atoms were organized into, but it doesn't really matter. When gasses of made up of these elements are exposed to lightning, ultraviolet light or heat, simple organic molecules will form, as demonstrated by Stanley Miller and Harold Urey in 1953, and I believe others since.
Amino acids, short proteins, nucleotides, ATP (and probably other nucleoside triphosphates), and other molecules characteristic of living things are some of the organic molecules that have been observed to form in laboratory recreations of these conditions. In addition, we know from present day meteorites that such meteorites often cary such simple organic molecules with them. Such molecules are vulnerable to uv radiation exposure from the sun (no ozone layer yet) but some places, like tidal pools hidden under rocky shelfs, would be shielded from uv exposure.
Some such pools would have had ocean water splashing into them during high tide, bringing with it the organic molecules in it, and during low tide some of the water in the pool might have evaporated. By this or some other mechanism pools of water sheltered from uv radiation would become highly enriched in the organic molecules. As there was not yet any life and no free oxygen, these molecules had no environmental influences that would break them down.
When organic molecules like these are placed in concentrated enough solutions, they spontaneously react to form more complex organic molecules, such as RNA.
RNA molecules with all kinds of random sequences would spontaneously form. Now we know that RNA, like proteins, folds into specific configurations depending on the sequence of bases it is made up of. Sometimes the folded RNA is catalytic; that is, it makes an enzyme. Such RNA enzymes are called ribozymes.
Now RNA, like DNA, already has an obvious mechanism by which it could replicate itself. This is the point at which substances began to catalyze the synthesis of smaller molecules into copies of themselves; that is, they reproduced. Being genetic material with no proofreading systems with the potential to be exposed to uv light, such RNA chains began to mutate into chains with slightly different base sequences. Any of these which folded into enzymes that catalyzed their own reproduction would begin to out compete the other RNA chains in terms of reproduction and using up the raw materials for reproduction. The process of evolution has begun, even before life existed.
Now, it's been shown that amphipathic molecules like phospholipids will tend to aggregate and form one of three different formations depending on the conditions; micelles, solid molecular sized balls of phospholipid molecules, a bilayer, or flat sheet (which would need to be anchored on the edges away from water), or a combination of the two, a vesicle. A vesicle is lipid bilayer bent into a spherical shape and closed upon itself. Such vesicles trap water and the contents of water in their cavities when they form. Small molecules can pass through the phospholipid bilayers of such vesicles far more easily than larger molecules.
Some of these vesicles probably formed around RNA which was already evolved into a form that catalyzed it's own reproduction quite effectively. Such RNA still had access to the small molecules it needed as raw material for self reproduction, but large molecules that might damage it or otherwise interfere were kept out. The RNA would reproduce and reproduce, and the new ribozymes wouldn't be able to get out of the vesicle. Maybe more than one kind of self replicating RNA would get trapped inside the vesicle and begin to reproduce.
This stage of prebiotic evolution is known as the protocell. Such protocells could collect more and more phospholipid molecules and keep reproducing the RNA inside, causing the protocell to grow.
At this point, a number of the characteristics of life have come into being. The protocell has begun to aquire and use materials and energy from it's environment and to convert them into different forms. It was growing. It had the capacity to evolve. And, once these things grew big enough, and possibly with the help of the ribozymes inside, they would divide. This is reproduction of the entire protocell.
Now, sometimes more than one molecule of RNA would get trapped inside and begin to self-replicate; sometimes some copies of the RNA inside the protocell would mutate into different forms. In this way different enzymes would come into being, providing a more varied environment inside the protocell. Sometimes these various chains of RNA would begin to specialize into symbiotic relationships, helping one another reproduce and do other things.
As you can see, it makes perfect sense based on much experiment that such a pattern of change from inorganic, simple molecules to complexity in the form of protocells could plausibly come into being. Any entropy lessened in the formation and reproduction of these ordered objects would be compensated for by breakup of nucleoside triphosphates. This effectively changes sunlight or other ordered forms of energy to heat, which I think counts as increased entropy. So, unlike what some creationists suggest, the Second Law of Thermodynamics is not broken by this proposed mechanism.
Some of these ribozymes would begin to assemble amino acids into short chains through catalysis of dehydration reactions. Once proteins were being formed, similar evolution would produce protein catalysts or enzymes. At some point some RNA would catalyze the formation of the more stable DNA molecules, which would take over as the genetic material of these protocells.
At this point we pretty much have a primitive cell, or something close to it. Life is a poorly defined word, so there isn't any exact moment at which one could say it has been crossed. It's more of a long process full of small changes that caused the protocell - not alive - to the cell - alive. The cell then began to evolve, but that's beyond the scope of the question asked here.
This of course is not definitely known. It's simply the hypothesis that makes the most sense based on the evidence, and is generally accepted as the most likely situation by biologists. I and the scientific community are always exploring the possibilities and plausibilities of the possibilities. We're checking each other's work and competing to discover the most accurate models. As the economy of the U.S. and the First World in general shows, competition works wonders.
The other option is that I could say God did it, and we can't understand him. I could say I believe this because I had a powerful emotional experience. That sort of explanation has never really worked for anything else once it had to compete with scientific rigor, though. It also kind of ignores the fact that people often use the same process to come up with entirely different ideas about things, like Islam vs Christianity.
I prefer the first explanation. It explains more and doesn't invoke fairies or spirits or magical beings with superpowers who don't have to follow the laws of physics which everything else does. It also makes much more definite predictions which are testable, and in the past has survived such testing.
Creationism is kind of like explaining how stars work by saying there are invisible, undetectable pink leprechauns inside them making all the heat and light with pixie dust.
27 Feb 05
Originally posted by AThousandYoungI think you should brush up on your Miller, Thousand.
That's a rude post, Darfius. That attitude is why many others aren't respectful to you.
I'm not sure how far before the beginning of life you want me to go. I'll start here:
The Earth probably formed about 4.5 billions years ago. It was a hot, inorganic ball of rock with oceans and an atmosphere containing nitrogen, carbon and hydrogen at ...[text shortened]... of evolution has begun, even before life existed.
(Still working on this, will edit in more)
He used Methane, ammonia, hydrogen and water.
Too bad methane and ammonia were damn near non existent in the early earth atmosphere. =P
They don't respect me no matter how I post. Figured I'd have a little fun with them while I get slammed.
27 Feb 05
2 edits
Originally posted by DarfiusYes, this is true of Miller's first experiment. However my biology book suggests that this sort of experiment has been done under many different circumstances since.
I think you should brush up on your Miller, Thousand.
He used Methane, ammonia, hydrogen and water.
Too bad methane and ammonia were damn near non existent in the early earth atmosphere. =P
They don't respect me no matter how I p ...[text shortened]... st. Figured I'd have a little fun with them while I get slammed.
Similar experiments [to Miller and Urey's first experiment with ammonia, methane etc.] by Miller and others have produced aminos acids, short proteins...(ATP), and other molecules characteristic of living things. Interestingly, the exact composition of the "atmosphere" used in these experiments is unimportant, provided that hydrogen, carbon and nitrogen are available and oxygen gas is excluded. Similarly, a variety of energy sources, including ultraviolet light, electrical discharge, and heat, are all about equally effective.
(Italics added by me)
27 Feb 05
Originally posted by AlcraCrack open a science book.
[b]Too bad methane and ammonia were damn near non existent in the early earth atmosphere. =P
Hmmm, early atmosphere. Where is that written? Genesis 0:0?
[/b]
And no, Thousand, you absolutely CANNOT get the same reaction with carbon and nitrogen (two inert gases).
The best theory nowadays is that life began around deep sea earth vents. Utterly ridiculous, but more plausible than anything else.
27 Feb 05
Originally posted by Darfiusnitrogen inert?? dont think so, nitrogen is a group 5 element and has only 5 electrons in its outer shell, therefore it has the ability to take on more electrons during reactions with other elements, also nitrogen is found in many organic polymers and polyimides so it cannot be ruled out in this theory.
Crack open a science book.
And no, Thousand, you absolutely CANNOT get the same reaction with carbon and nitrogen (two inert gases).
The best theory nowadays is that life began around deep sea earth vents. Utterly ridiculous, but more plausible than anything else.
carbon a gas??? nope!!! its a solid and can take up two main allotropic forms as diamond or graphite. Also its unique ability to form chains or rings allows for the creation of complex organic compounds.
27 Feb 05
Originally posted by PullhardI've read science reports at NASA that state what the early earth atmosphere was made of.
How do you know?
I mean, is that what you're willing to do to deny God? Inject the elements that are most convenient to make the experiment have a chance of making amino acids that no one can explain why they felt obligated to chain together anyway?
27 Feb 05
Originally posted by DarfiusWell, I don't have the sources that my biology book used to make that claim, except that Miller did some of those experiments.
Crack open a science book.
And no, Thousand, you absolutely CANNOT get the same reaction with carbon and nitrogen (two inert gases).
The best theory nowadays is that life began around deep sea earth vents. Utterly ridiculous, but more plausible than anything else.
You've made a pretty strong scientific claim: N2 gas could not be used as the sole source of nitrogen in this sort of experiment. Did I get that right? Because now I can look through literature and see if anyone did those experiments. My biology book implies someone did. Now, what if I find papers that describe such experiments in the scientific literature? Would you accept that as evidence that the theory of evolution is plausible? How much would you go through to deny the possibility that maybe it could have happened this way?
And "crack open a science book"? I have a degree in biochemistry and have made a special effort to look up this subject, and I don't recall ever seeing a concrete description of what the early atmosphere was like. Please reference the science books you're looking at. You have a crappy attitude and you're making your position look really weak. I just wrote a page and a half answering in detail an eleven word post and you can't be bothered to support your own claims when challenged.
No matter whether 'they' will respect you, my respect for you and your position as a creationist is affected by your attitude. I am sure there are quite a lot of other people who are willing to listen to both sides who won't take yours seriously because you make scientific claims and then you don't back them up.
I've read science reports at NASA that state what the early earth atmosphere was made of.
Can you reference these? Last time I asked someone to reference this topic (maybe it was you?) they offered a few papers that had nothing to do with the claims being made. It's like the creationist thought throwing out the names of a few technical sounding journal articles would scare or impress skeptics into accepting the creationist point of view.
You are far more biased about this issue than I am, Darfius. You're the one going out of your way to deny possibilities other than the one you want to be true.
28 Feb 05
Originally posted by AThousandYoungATY: "That's a rude post, Darfius. That attitude is why many others aren't respectful to you. "
That's a rude post, Darfius. That attitude is why many others aren't respectful to you.
I'm not sure how far before the beginning of life you want me to go. I'll start here:
The Earth probably formed about 4.5 billions years ago. It was a hot, inorganic ball of rock with oceans and an atmosphere containing nitrogen, carbon and hydrogen at ...[text shortened]... isible, undetectable pink leprechauns inside them making all the heat and light with pixie dust.
What a humorous remark ..... I like people with a good sense of humour ATY ......... 😀