Life from a petri-dish

Originally posted by Halitose
As I pointed out in another thread, viruses need a host to reproduce, so you are still stuck.

I never asserted that God is deciphering DNA, a shameless strawman and red herring on your part. The cell itself deciphers the DNA, hence you need an already functioning cell.

The assumption that the ONLY way DNA can be created is by copying other DNA is m solved; what/where is this chemical capable of reproducing itself, and where did it come from?

This is circular reasoning - where, pray, has something been conclusively proven to become more complex?

Your intellect, no doubt, has become more complex over the years.

Originally posted by stocken
[b]This is circular reasoning - where, pray, has something been conclusively proven to become more complex?

Your intellect, no doubt, has become more complex over the years.[/b]

Lol, should I be taking this as proof for abiogenesis? My intellect (I hope) is an accumulation of years of intelligent input.

Edit:Ahem... To clarify (and put my snide remark in context), in this debate twhitehead claims that life originated from non-life without the interference of intelligence. My claim is that without intelligent input, things become more rundown, more random and less complex.

Originally posted by twhitehead
[b]As I pointed out in another thread, viruses need a host to reproduce, so you are still stuck.
The nevertheless reproduce and evolve. Are they alive ?

I never asserted that God is deciphering DNA, a shameless strawman and red herring on your part. The cell itself deciphers the DNA, hence you need an already functioning cell.

You state ...[text shortened]... e more complex?[/b]

I see the conclusive proof all around me in the plants and animals I see.[/b]

The[sic] nevertheless reproduce and evolve. Are they alive ?

Err... if they were the first organisms, they couldn't have reproduced.

First of all you have restricted your view to plants and animals which we know use DNA as a central part of their mechanisms. However we know that even the DNA in plants and animals is continuously changing, with bits being inserted, removed, rearranged etc all the time. Many of the added bits do not originate as other DNA but come from viruses etc. In fact a GM crop is often created by transfering genes via viruses. Surely it would be possible for a few viruses to get together and create a brand new strand of DNA ?

Has this new info culminated in anything different, i.e. maize become something other than a hybrid of itself. And where would the first DNA originate? Could you propose a hypothesis for this randomly generating a living, functioning organism?

I see the conclusive proof all around me in the plants and animals I see.

I see variation, never the culmination of brand new genetic information.

Originally posted by Halitose
My claim is that without intelligent input, things become more rundown, more random and less complex.

This is similar to a claim made by RBHILL that systems naturally degenerate into uniform chaos without intelligent input. This is a totally false claim unless you have an unusual meaning for the word Intelligent. What do you mean by intelligent input? The universe is full of things which are far from random or rundown and yet they have formed with nothing more than the basic laws of physics. If that is intelligence then "Intelligent Design" must be another term for physics.
Take an ordinary glass of muddy water, leave it to stand for a while, the sand will sort itself by size due to nothing more than gravity - The result is more complex than the start.

Place Hydrogen and Oxygen together and Bang you have Water - definately more complex !

Place Hydrogen and Carbon together and a few trace elements and soon you will have Hydrocarbons, the building blocks of life. - definately more complex !

Originally posted by scottishinnz
Indeed. That's why life evolved in the oceans - water is very effective at absorbing UV-B. About 90% of solar UV-B can be absorbed by the top 2 cm of the water column.

Actually, you bring up a point I am interested in. I must admit my ignorance on this one, and thusly would appreciate input.

Formost, in a vast pimordial ocean, wouldn't the oxygen in the ocean (which would be vastly more than today, yes?) interact with the developing building blocks of life (amino acids, sugars, purines, etc.)?

I am also concerned about:

The matter quantities (the diluting effects of a vast primordial ocean). For example, would there be sufficient concentrations of nitrogen for molecular formation?

Synthesis versus destrucion. For chemical bonds to form there needs to be an external source of energy. The same energy that creates the bonds is frequently much more likely to destroy them.In the famous Miller experiment (1953) that synthesized amino acids, a cold trap is used to selectively isolate the reaction products. Without this, the would be no products. Where is the "trap" in such an ocean? Given the principles of chemical thermodynamics and kinetics, I can not see how this occurs when we need an ocean full of organic compounds to form even lifeless coacervates.

Lastly, incompatability. different molecules will react with one another. For example, amino acids and sugars combine and destroy each other. In lab experiments the component chemicals are neatly separated from one another. How is this possible in a primitive ocean?

I am interested in hearing what you or others have to say about these matters. Again, I'm no expert trying to promote my perspecite. Just a guy trying to learn. 🙂

Best Regards,

Omnislash

Originally posted by Halitose
Lol, should I be taking this as proof for abiogenesis? My intellect (I hope) is an accumulation of years of intelligent input.

Edit:Ahem... To clarify (and put my snide remark in context), in this debate twhitehead claims that life originated from non-life without the interference of intelligence. My claim is that without intelligent input, things become more rundown, more random and less complex.

I'm on the side of twitehead on this particular matter. I, too, believe that life doesn't need to originate from any form of previous intelligence, but that in fact, life has slowly evolved from something less to something more complex. [Edit: with focus on believe I'm beginning to understand]

You are an intelligent person Halitose, there can be no doubt about that (having read a lot of your posts). I consider myself intelligent (to some degree). One of us is wrong in this matter - I just hope we never find out who. What would life be without discussions like these?

Keep living

Originally posted by stocken
One of us is wrong in this matter - I just hope we never find out who.

You could both be. Creation, life, is a cancer in the body of God--now undergoing accelerated metastasis. At the same time, God is giving birth to God.

Originally posted by Bosse de Nage
You could both be. Creation, life, is a cancer in the body of God--now undergoing accelerated metastasis. At the same time, God is giving birth to God.

Now, that's deep. So, are we all the parts of the new God? Are we slowly evolving into One? Or am I just destroying your post, here? 😕

[Edit]

No wait, I see. We're the cancer destroying God. Well, no doubt the new God will inherit us, so we'll live on forever. Yeay, to that...

Originally posted by Omnislash
Foremost, in a vast pimordial ocean, wouldn't the oxygen in the ocean (which would be vastly more than today, yes?) interact with the developing building blocks of life (amino acids, sugars, purines, etc.)?
[...]
(the diluting effects of a vast primordial ocean). For example, would there be sufficient concentrations of nitrogen for molecular formation? ...[text shortened]... ent chemicals are neatly separated from one another. How is this possible in a primitive ocean?

A potential energy source would be naturally occuring heat vents on the ocean floor.
Yes, many chemical reactions would continually occur that would interfere with the proper chemicals getting together. However, we only need the beginnings of life to happen once in all of the ocean over an indefinite (but quite lengthy) period of time.

Originally posted by Omnislash
Actually, you bring up a point I am interested in. I must admit my ignorance on this one, and thusly would appreciate input.

Formost, in a vast pimordial ocean, wouldn't the oxygen in the ocean (which would be vastly more than today, yes?) interact with the developing building blocks of life (amino acids, sugars, purines, etc.)?

I am also concerned ...[text shortened]... rt trying to promote my perspecite. Just a guy trying to learn. 🙂

Best Regards,

Omnislash

Omnislash,

Always a pleasure discussing things with you so here goes (I may try and stick some references in, but mostly I write from memory)

Ocean oxygen concentration.

Surpisingly for many people, oxygen doesn't actually dissolve very well, CO2 dissolves far better (but still not very well). Current understanding is that the atmosphere was very reducing (a huge amount of energy from the earths creation still remained) and oxygen (as in di-oxygen, O2) did not exist in the atmosphere. This can be pretty much verified by the composition of rocks older than, say, 2 billion year old or so. Were there O2 in the water then yes, it would probably screw things up, but since there wasn't it's a moot point.

Diluting effects of the ocean volume.

Yes, nowadays that would represent a huge problem but since the atmosphere was such a strong reducing environment these problems were less than now. Lightning discharges in the atmosphere even today can split the triple bond between two nitrogen atoms. This nitrogen tends not to revert to N2, but is converted to NH3. Ammonia dissolves well in water becoming ammonium (NH4+). There would be some kind of equalibrium between the atmosphere and the ocean, probably quite strongly ocean based.


Synthesis vs. destruction.

A very very good point on two fronts.
1) The assumption of your statement is that the oceans are a homogenous environment. This is patently not the case. Amino acids (for example) formed would adhere to surfaces, such as rocks etc, where they would be afforded some protection against desctruction. It is on the surfaces of rocks / shallow pools that life is inferred to have evolved.
2) There would be differential breakdown of products based on their chemical stability. Some things will breakdown readily (simple hydrocarbons, etc), but other things are far more chemically stable and will remain for longer such as DNA or RNA (even if they initially were very short strands). If these molecules had the ability to reproduce in a high evergy environment (and we certainly know they have the ability to split apart DNA strands at certain temperatures, it's how th Polymerase Chain Reaction for DNA amplification works) and some are more stable than others, then the most stable configurations would come to predominate the ocean. Once the available resources had been used up then the variants that breakdown less readily will be there to reproduce when shorter 'lived' molecules breakdown. This was the first case of Natural Selection, based on the stability and reproductive 'fecundity' of simple, but relatively stable, molecules (probably RNA). From here, more and more complex situations arose, each one made the chemical replicator more successfull than it's competition.

Incompatability.

Again a chemical stability thing. Same answer as above really.

Originally posted by scottishinnz
Omnislash,

Always a pleasure discussing things with you so here goes (I may try and stick some references in, but mostly I write from memory)

Ocean oxygen concentration.

Surpisingly for many people, oxygen doesn't actually dissolve very well, CO2 dissolves far better (but still not very well). Current understanding is that the atmosphere was ...[text shortened]... petition.

Incompatability.

Again a chemical stability thing. Same answer as above really.

Thank you for your reply. I found it very informative, and I shall research these matters further. 🙂

Originally posted by Omnislash
Thank you for your reply. I found it very informative, and I shall research these matters further. 🙂

A pleasure - please do continue your research, and I shall look forward to your thoughts.

Originally posted by Halitose
How do you cross the hickup that DNA can currently only be created in a DNA controlled environment?

One likely possibility; the current forms of life take up nucleotides so that there are none available for non DNA based DNA formation.

Originally posted by Halitose
[b]The[sic] nevertheless reproduce and evolve. Are they alive ?

Err... if they were the first organisms, they couldn't have reproduced.

First of all you have restricted your view to plants and animals which we know use DNA as a central part of their mechanisms. However we know that even the DNA in plants and animals is continuously changing, ...[text shortened]... d animals I see.

I see variation, never the culmination of brand new genetic information.[/b]

Has this new info culminated in anything different, i.e. maize become something other than a hybrid of itself.

This is a strawman. Evolutionary theory does not claim that organisms stop being part of the group they originated from. Sure; the descendent of maize will be maize; likewise, the descendents of cells are cells, the descendents of mammals are mammals, etc.

And where would the first DNA originate?

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.


http://www.redhotpawn.com/board/showthread.php?threadid=20290

I see variation, never the culmination of brand new genetic information.

What's 'genetic information'? How would you know if there were brand new genetic information?

Originally posted by Halitose
Lol, should I be taking this as proof for abiogenesis? My intellect (I hope) is an accumulation of years of intelligent input.

Edit:Ahem... To clarify (and put my snide remark in context), in this debate twhitehead claims that life originated from non-life without the interference of intelligence. My claim is that without intelligent input, things become more rundown, more random and less complex.

My claim is that without intelligent input, things become more rundown, more random and less complex.

According to thermodynamics, this does not apply to an open system, like life.