where did the first cell come from? [Archive]

vhawk01

05-08-2007, 01:47 AM

[ QUOTE ]
[ QUOTE ]
It might be a stretch but...define cell? I think its reasonable that there were microorganelles before they decided it would be nice living in a lipid bilayer instead of out on the street.

But really, I have no good answers for this. Fascinating question though, I really hope someone on here knows.

[/ QUOTE ]

cell as in the basic unit of life.

not that it's important outside of trivial knowledge, but i'de like to hear some of your opinions. you guys usually have plausable, or at least intresting theories on a variety of subjects.

i don't think there really is an explination except for cells were either a) always around since the begining of time [atheist point of view] or b) supernaturally created [God beleiver]. i'm religious but i do like to consider purely scientific fact without throwing in God, and there seems to be no realistic scientific explination for this to occur.

[/ QUOTE ]

The problem is, cells aren't really required for life, so I'm not sure I'm fully on board with the 'basic unit of life' definition. For instance, mitochondria are found within cells, and while you probably couldn't call them independent life on their own right now, it seems nearly certain that they were at some point and moved into other cells.

The benefit of a cell is that the replicating 'organism' is able to control and maintain a 'constant' environment. But there isn't really anything special about cells. The first 'living' things probably werent cells....and of course, there never WERE any 'first living things.'

EDIT: Wow, that is a lot of scare-quotes for one post. I am an annoying person.

thylacine

05-08-2007, 01:53 AM

[ QUOTE ]
Drop a some phospholipids in some water. You will see tiny spheres (cells) form automatically. It has to do with hydrophobic/hydrophilic interactions. The most dominant organism in the ocean has only 1.3 million base pairs and 500,000 of these cells can fit in a milliliter of water. There are 3.612 x 10^20 gallons of sea water in the ocean. And there are 3784 milliliters per gallon. Multiply all that by half a million to get the number of these cells that could fit in the ocean.

In other words, you have one gigantor sample set. I doubt anyone here can truly appreciate just how big those numbers are.

[/ QUOTE ]

Okay so the arithmetic gives that the number of these cells that could fit in the ocean is about 10^(30) which is about 4^(50) which is the number of possible length-50 DNA strands. This 50 is much less than 1.3million. Throw in a factor of 10^(20) favorable planets doesn't help much. The numbers you mention are not remotely big enough to give enough chances for something as complex as the simplest cell to spontaneously form.

Of course the simple way to beat the exponentially large number 4^k different possible length-k DNA strands, is to just consider the exponentially large number 2^n copies of a replicator after n doublings (just take n>2k, or better, take n>>2k).

To explain something as complex as the simplest cell, you absolutely must use the fact that it is the product (and definitely not the starting point) of a long sequence of evolutionary steps starting with genuinely very simple replicators such as very small (length<<50) strings of DNA or RNA or some other replicators. You can reasonably allow up to 100million years for evolution of the cell from simple replicators. Even if these replicators doubled only once a week then if it weren't for limited resources (which in any case gives rise to natural selection) you could have 2^(5billion) copies after 100million years.

As Crocodile Dundee could say: that's not a big number (i.e. 10^(30)), mate, this is a big number (i.e. 2^(5000000000))!

There is a good discussion in Dawkins' "The God Delusion" Chapter 4.

And to the OP "ill rich", the basic answer is that the cell is the product of up to 100million years of evolution, starting with very simple replicators, going through maybe billions of generations. Also bear in mind that IDCreationists are sneaky and devious and they try to rig the numbers game by leaving out the exponential power of repeated duplication.

Prodigy54321

05-08-2007, 02:14 AM

[ QUOTE ]
cells were either a) always around since the begining of time [atheist point of view]

[/ QUOTE ]

/images/graemlins/confused.gif /images/graemlins/confused.gif /images/graemlins/confused.gif /images/graemlins/confused.gif

seriously?

ill rich

05-08-2007, 08:21 PM

[ QUOTE ]
This is a soap bubble. Slap some DNA or RNA in it and you have a cell. Do it enough times and you will eventually get one that works.

[/ QUOTE ]

not quite. a cell needs proteins. DNA in a "soap bubble" cannot replicate, and by scienfic definition it is not a cell. Also, by definition living cells must have DNA, not RNA. your idea is too simplistic to actually work.

ill rich

05-08-2007, 08:28 PM

[ QUOTE ]
Actually a lot of the steps really are that simple. If you have the raw parts you can create a TMV virus just by throwing them in a jar and mixing the water. The TMV virus will literally assemble itself. The outer coating of a simple cell is literally a soap bubble.

[/ QUOTE ]

the problem is getting the raw parts from nothing. a virus basically is DNA or RNA in a protein coat, it dosen't have anything to actually replicate or assemble itself. a virus cannot replicate without hijacking the machinery of a cell.

the outer coating of a cell is hardly a "soap bubble". the simplist prokaryotes have a cell wall made of peptidoglycan, and gram-negative bacteria have a cell membrane made out of porin proteins. not to mention each of these membranes have selective ion channels, transport pumps, etc.

a simple "soap bubble" membrane cell would not live.

ill rich

05-08-2007, 08:30 PM

[ QUOTE ]
The problem is, cells aren't really required for life, so I'm not sure I'm fully on board with the 'basic unit of life' definition. For instance, mitochondria are found within cells, and while you probably couldn't call them independent life on their own right now, it seems nearly certain that they were at some point and moved into other cells.

The benefit of a cell is that the replicating 'organism' is able to control and maintain a 'constant' environment. But there isn't really anything special about cells. The first 'living' things probably werent cells....and of course, there never WERE any 'first living things.'

EDIT: Wow, that is a lot of scare-quotes for one post. I am an annoying person.

[/ QUOTE ]

according to scientific definition cells ARE required for life, and anything that that is not a cell that contains DNA is not life (by definition).

mitochondria are only found in eukaryotes and yes it is theorized that they were once outside of the cell and possibly devoured, but cannot be considered life because they are not cells.

Justin A

05-08-2007, 09:04 PM

Somewhere in Hawking's A Brief History of Time he mentions something about replicating molecules(non-living). He doesn't give much of an explanation though and just mentioned them in passing. Does anyone know what he is talking about?

vhawk01

05-08-2007, 09:11 PM

[ QUOTE ]
[ QUOTE ]
The problem is, cells aren't really required for life, so I'm not sure I'm fully on board with the 'basic unit of life' definition. For instance, mitochondria are found within cells, and while you probably couldn't call them independent life on their own right now, it seems nearly certain that they were at some point and moved into other cells.

The benefit of a cell is that the replicating 'organism' is able to control and maintain a 'constant' environment. But there isn't really anything special about cells. The first 'living' things probably werent cells....and of course, there never WERE any 'first living things.'

EDIT: Wow, that is a lot of scare-quotes for one post. I am an annoying person.

[/ QUOTE ]

according to scientific definition cells ARE required for life, and anything that that is not a cell that contains DNA is not life (by definition).

mitochondria are only found in eukaryotes and yes it is theorized that they were once outside of the cell and possibly devoured, but cannot be considered life because they are not cells.

[/ QUOTE ]

This is a quick-and-dirty definition that doesn't actually represent any legitimate boundary in reality. There aren't any universally accepted definitions of life, for one thing. Viruses are considered alive by some (for instance, me!) and not by others. You know why there cannot truly be a consensus? Because the definitions are arbitrary. There aren't any lines in the sand, as it were. So, you say life needs a cell, I say it doesn't, but you aren't correct and me wrong. Your definition is useful for some things (for example, making life harder on people trying to explain evolution to you) and my definition is better for other things.

Unless you know differently? Do you know of some universally accepted definition of life that all of us are forced to acknowledge? I'm willing to listen to arguments about it, and if your definition truly is better in all respects, I'll adapt my explanations to fit.

This is a pretty standard tactic of creationists, however. There is strong incentive to make the basic requirements to be considered 'life' as complicated as possible, because the intuitive step then becomes more difficult and improbable. If we make 'eukaryotic cells' the baseline defintion of life, it is easier to make the Argument from Incredulity that "Surely these complicated eukaryotes could not have sprung from nothing!" But its all disingenuous. No matter how complicated you choose to make your baseline definition of life, the first living organisms came from slightly less complicated ones that you now decide not to call life.

I can defend my virus-inclusive definition of life by drawing attention to the objection to viruses. The standard complaint is that they cannot replicate without a very specific substrate, i.e. the host cell, and therefore cannot be considered life. I hope its obvious that 'very specific substrate' is a matter of degree, and ALL cells or 'life' need somewhat specific substrates to replicate. To me, it is rarely meaningful to consider any dividing line other than 'ability to replicate.'

thylacine

05-08-2007, 10:01 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
The problem is, cells aren't really required for life, so I'm not sure I'm fully on board with the 'basic unit of life' definition. For instance, mitochondria are found within cells, and while you probably couldn't call them independent life on their own right now, it seems nearly certain that they were at some point and moved into other cells.

The benefit of a cell is that the replicating 'organism' is able to control and maintain a 'constant' environment. But there isn't really anything special about cells. The first 'living' things probably werent cells....and of course, there never WERE any 'first living things.'

EDIT: Wow, that is a lot of scare-quotes for one post. I am an annoying person.

[/ QUOTE ]

according to scientific definition cells ARE required for life, and anything that that is not a cell that contains DNA is not life (by definition).

mitochondria are only found in eukaryotes and yes it is theorized that they were once outside of the cell and possibly devoured, but cannot be considered life because they are not cells.

[/ QUOTE ]

This is a quick-and-dirty definition that doesn't actually represent any legitimate boundary in reality. There aren't any universally accepted definitions of life, for one thing. Viruses are considered alive by some (for instance, me!) and not by others. You know why there cannot truly be a consensus? Because the definitions are arbitrary. There aren't any lines in the sand, as it were. So, you say life needs a cell, I say it doesn't, but you aren't correct and me wrong. Your definition is useful for some things (for example, making life harder on people trying to explain evolution to you) and my definition is better for other things.

Unless you know differently? Do you know of some universally accepted definition of life that all of us are forced to acknowledge? I'm willing to listen to arguments about it, and if your definition truly is better in all respects, I'll adapt my explanations to fit.

This is a pretty standard tactic of creationists, however. There is strong incentive to make the basic requirements to be considered 'life' as complicated as possible, because the intuitive step then becomes more difficult and improbable. If we make 'eukaryotic cells' the baseline defintion of life, it is easier to make the Argument from Incredulity that "Surely these complicated eukaryotes could not have sprung from nothing!" But its all disingenuous. No matter how complicated you choose to make your baseline definition of life, the first living organisms came from slightly less complicated ones that you now decide not to call life.

I can defend my virus-inclusive definition of life by drawing attention to the objection to viruses. The standard complaint is that they cannot replicate without a very specific substrate, i.e. the host cell, and therefore cannot be considered life. I hope its obvious that 'very specific substrate' is a matter of degree, and ALL cells or 'life' need somewhat specific substrates to replicate. To me, it is rarely meaningful to consider any dividing line other than 'ability to replicate.'

[/ QUOTE ]

Right. And the simplest replicators are simple molecules(and other simple things). As soon as you have replicators, exponential growth and evolution kicks in. Cells come maybe 100million years later.

It doesn't matter where you try to shift the life/non-life dichotomy, because evolution doesn't need something to fit someone's definition of "alive" to be able to operate. Evolution just needs replicators.

So OP "ill rich", I challenge you to address this point (see also my post above). I'm interested to see if you are willing to acknowledge the bait-and-switch that IDCreationists engage in (namely the bait-and-switch between (a) simple molecular replicators and (b) extremely complex unambiguosly living entities such as cells). One classic sign of the intellectual bankruptcy of IDCreationists is that they continue to use false and fraudulent arguments, even after it has been clearly shown to them that they are false and fraudulent. This is not the first thread on this topic. But I'm yet to see someone admit that they have learned something, and that they now realize the flaw (and the trick) in the IDCreationists' arguments.

wacki

05-08-2007, 10:42 PM

[ QUOTE ]
[ QUOTE ]
This is a soap bubble. Slap some DNA or RNA in it and you have a cell. Do it enough times and you will eventually get one that works.

[/ QUOTE ]

not quite. a cell needs proteins...... your idea is too simplistic to actually work.

[/ QUOTE ]

In the early 1950s, Professor Harold Urey and one of his students, Stanley Miller, began experimenting to prove Oparin's theory. Miller built an apparatus which circulated gasses likely to be present in the early atmosphere (Methane (CH4), Ammonia (NH3), Water (H2O), and hydrogen (H2) ) past an electrical discharge, simulating the UV Rays and violent electrical storms present in the early atmosphere.

After allowing the experiment to continue for a week, the results where startling. The previously colorless solution inside the apparatus had turned red. Upon analyzing the solution, Miller found many organic molecules present, some of which couldn't be readily identified. The most important of created compounds, however, where amino acids. This, in effect, proved Oparin's theory that organic compounds could have been created in the early atmosphere. Further studies showed that some amino acids would have combined with hydrogen cyanide (HCN), which is a byproduct of volcanic activity. This combination would form purines and pyrinidines, which are used to make nucleic acids, which in turn create DNA

After these compounds had been created on the early earth, the earth eventually began to cool. Water vapor the condensed, which formed vast oceans, seas and lakes, in which simple organic molecules began to accumulate for millions of years, producing an "organic soup" of sorts. The amino acids would have then polymerized (which means they formed chains, such as proteins. E.g... (aa=amino acid) aa-aa-aa-aa-aa = protein). The most likely theory as to how the amino acids combined is that they where washed up into clay/rock depressions on land, where the water evaporated, leaving behind concentrated organic compounds in high heat.

Sidney W. Fox set out to prove this. He took a mixture of approximately 20 different amino acids, and heated then to the melting point. When they cooled, Fox observed that they had polymerized into proteins. 

http://mediatheek.thinkquest.nl/~ll125/en/life-2.htm

We have now covered how pretty much all of the building blocks could have randomly formed in nature.

The rest is just chance....

vhawk01

05-08-2007, 10:54 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
This is a soap bubble. Slap some DNA or RNA in it and you have a cell. Do it enough times and you will eventually get one that works.

[/ QUOTE ]

not quite. a cell needs proteins...... your idea is too simplistic to actually work.

[/ QUOTE ]

In the early 1950s, Professor Harold Urey and one of his students, Stanley Miller, began experimenting to prove Oparin's theory. Miller built an apparatus which circulated gasses likely to be present in the early atmosphere (Methane (CH4), Ammonia (NH3), Water (H2O), and hydrogen (H2) ) past an electrical discharge, simulating the UV Rays and violent electrical storms present in the early atmosphere.

After allowing the experiment to continue for a week, the results where startling. The previously colorless solution inside the apparatus had turned red. Upon analyzing the solution, Miller found many organic molecules present, some of which couldn't be readily identified. The most important of created compounds, however, where amino acids. This, in effect, proved Oparin's theory that organic compounds could have been created in the early atmosphere. Further studies showed that some amino acids would have combined with hydrogen cyanide (HCN), which is a byproduct of volcanic activity. This combination would form purines and pyrinidines, which are used to make nucleic acids, which in turn create DNA

After these compounds had been created on the early earth, the earth eventually began to cool. Water vapor the condensed, which formed vast oceans, seas and lakes, in which simple organic molecules began to accumulate for millions of years, producing an "organic soup" of sorts. The amino acids would have then polymerized (which means they formed chains, such as proteins. E.g... (aa=amino acid) aa-aa-aa-aa-aa = protein). The most likely theory as to how the amino acids combined is that they where washed up into clay/rock depressions on land, where the water evaporated, leaving behind concentrated organic compounds in high heat.

Sidney W. Fox set out to prove this. He took a mixture of approximately 20 different amino acids, and heated then to the melting point. When they cooled, Fox observed that they had polymerized into proteins. 

http://mediatheek.thinkquest.nl/~ll125/en/life-2.htm

We have now covered how pretty much all of the building blocks could have randomly formed in nature.

The rest is just chance....

[/ QUOTE ]

Wait...the REST is just chance? The M-U experiment demonstrated the ONLY part that was chance. None of the rest of it is.

m_the0ry

05-08-2007, 11:03 PM

Discussion of (astronomical) scale versus (infinitesimal) probability are always fun, because they never go anywhere /images/graemlins/laugh.gif

wacki

05-08-2007, 11:03 PM

[ QUOTE ]

Wait...the REST is just chance? The M-U experiment demonstrated the ONLY part that was chance. None of the rest of it is.

[/ QUOTE ]

Experiments have shown how the building blocks of the major parts of the cell can be created in a prehistoric earth. If you have all of the building blocks then it is only a matter of chance that they might come together correctly. You can argue that the odds of that happening is so remote it will almost surely never happen. But given that the mechanisms for building the basic blocks of life have been shown, I don't see how you can say that it's impossible.

wacki

05-08-2007, 11:06 PM

[ QUOTE ]
Somewhere in Hawking's A Brief History of Time he mentions something about replicating molecules(non-living). He doesn't give much of an explanation though and just mentioned them in passing. Does anyone know what he is talking about?

[/ QUOTE ]

prions, they are nasty little buggers. The source of mad cow disease.

Then there are an entirely different class of self replicating molecules: amino adenosine triacid esters
http://web.mit.edu/newsoffice/tt/1990/may09/23124.html

RNA is thought to self replicate as well.

ill rich

05-08-2007, 11:07 PM

[ QUOTE ]
Do you know of some universally accepted definition of life that all of us are forced to acknowledge?

[/ QUOTE ]

no, i'm just using the one used and accepted by modern scientists.

that being, a cell is the basic unit of life, and a living cell must have DNA and the ability to grow, replicate, respond to stimuli, reproduce, and maintain homoeostasis. this is the scientific community's definition of life.

i am in my last semester of my b.s. in microbiology, and this is the definition we use.

a virus is not considered life, because it does not respond to stimuli, grow, maintain homoeostasis, replicate, have DNA, not is it a cell.

accepted theory is that cells ONLY come from other cells. and therefore by scientific definition the first cell can never be explained.

vhawk01

05-08-2007, 11:10 PM

[ QUOTE ]
[ QUOTE ]

Wait...the REST is just chance? The M-U experiment demonstrated the ONLY part that was chance. None of the rest of it is.

[/ QUOTE ]

Experiments have shown how the building blocks of the major parts of the cell can be created in a prehistoric earth. If you have all of the building blocks then it is only a matter of chance that they might come together correctly. You can argue that the odds of that happening is so remote it will almost surely never happen. But given that the mechanisms for building the basic blocks of life have been shown, I don't see how you can say that it's impossible.

[/ QUOTE ]

Definitely not saying its impossible, just that it isn't chance. Maybe I misunderstood what you were trying to say, but I am generally wary anytime the word 'chance' is used. IMO, chance only really applies to the building blocks and the creation of the first replicators (and possibly not even THESE first replicators, but some other, simpler replicators) and from then on, its an abuse of the term to call it chance. So, if our definition of life involves cells, it was not chance that brought us there, but selection.

ill rich

05-08-2007, 11:11 PM

[ QUOTE ]
Right. And the simplest replicators are simple molecules(and other simple things). As soon as you have replicators, exponential growth and evolution kicks in. Cells come maybe 100million years later.

[/ QUOTE ]

the idea behind evolution is that living things randomly mutate and the mutations that give a competetive edge to the organism succeed in colonizing and reproducing better than those without it.

a non-living molecule does not adapt to "survive".

vhawk01

05-08-2007, 11:13 PM

[ QUOTE ]
[ QUOTE ]
Do you know of some universally accepted definition of life that all of us are forced to acknowledge?

[/ QUOTE ]

no, i'm just using the one used and accepted by modern scientists.

that being, a cell is the basic unit of life, and a living cell must have DNA and the ability to grow, replicate, respond to stimuli, reproduce, and maintain homoeostasis. this is the scientific community's definition of life.

i am in my last semester of my b.s. in microbiology, and this is the definition we use.

a virus is not considered life, because it does not respond to stimuli, grow, maintain homoeostasis, replicate, have DNA, not is it a cell.

accepted theory is that cells ONLY come from other cells. and therefore by scientific definition the first cell can never be explained.

[/ QUOTE ]

Worker ants are not alive. Huh, never knew.

Obviously I'm being sarcastic, but the point is, the usual definition of life is flawed because it is trying to draw lines when there aren't any in reality. You are wrong if you think your definition is the only one.

Also, as to your last part, that is something you added in on your own. I've never seen any definition of cell that includes "can only come from other cells." That would be a stupid definition.

Are you seriously finishing your degree in microbiology? Mind if I ask, from where? They don't bother explaining the shortcomings of various definitions of life?

vhawk01

05-08-2007, 11:14 PM

[ QUOTE ]
[ QUOTE ]
Right. And the simplest replicators are simple molecules(and other simple things). As soon as you have replicators, exponential growth and evolution kicks in. Cells come maybe 100million years later.

[/ QUOTE ]

the idea behind evolution is that living things randomly mutate and the mutations that give a competetive edge to the organism succeed in colonizing and reproducing better than those without it.

a non-living molecule does not adapt to "survive".

[/ QUOTE ]

If we take your definition of 'living' then you are flat out wrong here. Viruses adapt to survive.

ill rich

05-08-2007, 11:16 PM

[ QUOTE ]
prions, they are nasty little buggers. The source of mad cow disease.

Then there are an entirely different class of self replicating molecules: amino adenosine triacid esters
http://web.mit.edu/newsoffice/tt/1990/may09/23124.html

RNA is thought to self replicate as well.

[/ QUOTE ]

prions are not self-replicating. a prion is a formerly functional protein that comes in contact with a protein with the identical sequence and induces a conformational change, denaturing the protein into a prion.

that is not replication.

and how does RNA self-replicate?

ill rich

05-08-2007, 11:19 PM

[ QUOTE ]
Worker ants are not alive. Huh, never knew.

Obviously I'm being sarcastic, but the point is, the usual definition of life is flawed because it is trying to draw lines when there aren't any in reality. You are wrong if you think your definition is the only one.

Also, as to your last part, that is something you added in on your own. I've never seen any definition of cell that includes "can only come from other cells." That would be a stupid definition.

Are you seriously finishing your degree in microbiology? Mind if I ask, from where? They don't bother explaining the shortcomings of various definitions of life?

[/ QUOTE ]

these definitions are used in all textbooks and journals. accepted definitions. of course there are challanges to them all the time, but they aren't accepted.

and yes i am finishing up my degree from central connecticut state university.

vhawk01

05-08-2007, 11:19 PM

[ QUOTE ]
[ QUOTE ]
prions, they are nasty little buggers. The source of mad cow disease.

Then there are an entirely different class of self replicating molecules: amino adenosine triacid esters
http://web.mit.edu/newsoffice/tt/1990/may09/23124.html

RNA is thought to self replicate as well.

[/ QUOTE ]

prions are not self-replicating. a prion is a formerly functional protein that comes in contact with a protein with the identical sequence and induces a conformational change, denaturing the protein into a prion.

that is not replication.

and how does RNA self-replicate?

[/ QUOTE ]

Wait...its not replication? A prion uses a substrate to make a copy of itself. I mean, all of things that are in my new cells were SOMETHING before they became a new cell. In the case of prions, that something is a protein.

ill rich

05-08-2007, 11:20 PM

[ QUOTE ]
If we take your definition of 'living' then you are flat out wrong here. Viruses adapt to survive.

[/ QUOTE ]

how so?

vhawk01

05-08-2007, 11:22 PM

[ QUOTE ]
[ QUOTE ]
Worker ants are not alive. Huh, never knew.

Obviously I'm being sarcastic, but the point is, the usual definition of life is flawed because it is trying to draw lines when there aren't any in reality. You are wrong if you think your definition is the only one.

Also, as to your last part, that is something you added in on your own. I've never seen any definition of cell that includes "can only come from other cells." That would be a stupid definition.

Are you seriously finishing your degree in microbiology? Mind if I ask, from where? They don't bother explaining the shortcomings of various definitions of life?

[/ QUOTE ]

these definitions are used in all textbooks and journals. accepted definitions. of course there are challanges to them all the time, but they aren't accepted.

and yes i am finishing up my degree from central connecticut state university.

[/ QUOTE ]

Its not that there are objections and these objections aren't taken seriously. Its that the 'accepted defintion' is tenuous and only applicable in certain (many) situations. For other situations, we use a different definition. And the reason for this is because ALL of the definitions are flawed. There are things that are CLEARLY alive that would not be considered alive under the definition you are using...like worker ants. How do you reconcile this? Use a different definition, or call worker ants non-living?

ill rich

05-08-2007, 11:22 PM

[ QUOTE ]
Wait...its not replication? A prion uses a substrate to make a copy of itself. I mean, all of things that are in my new cells were SOMETHING before they became a new cell. In the case of prions, that something is a protein.

[/ QUOTE ]

cells divide. prions don't. cells don't touch cell materual and turn them into cells. prions touch proteins and turn them into prions.

vhawk01

05-08-2007, 11:23 PM

[ QUOTE ]
[ QUOTE ]
If we take your definition of 'living' then you are flat out wrong here. Viruses adapt to survive.

[/ QUOTE ]

how so?

[/ QUOTE ]

First thing I found on Google (http://vir.sgmjournals.org/cgi/content/abstract/86/5/1467)

vhawk01

05-08-2007, 11:23 PM

[ QUOTE ]
[ QUOTE ]
Wait...its not replication? A prion uses a substrate to make a copy of itself. I mean, all of things that are in my new cells were SOMETHING before they became a new cell. In the case of prions, that something is a protein.

[/ QUOTE ]

cells divide. prions don't. cells don't touch cell materual and turn them into cells. prions touch proteins and turn them into prions.

[/ QUOTE ]

So? None of those things are necessary to be considered replication.

ill rich

05-08-2007, 11:27 PM

[ QUOTE ]
There are things that are CLEARLY alive that would not be considered alive under the definition you are using...like worker ants. How do you reconcile this?

[/ QUOTE ]

worker ants don't do all the things I mentioned? are you thinking of reproduce since workers are sterile? for one, "worker ants" are not an species, they are an social catergory of an ant species that obviously do replicate. and even sterile ants reproduce their own tissues.

ill rich

05-08-2007, 11:30 PM

here's something from the first thing on Google you may have overlooked:

[ QUOTE ]
virus adaptation may be dependent on host biology

[/ QUOTE ]

so... viruses don't "adapt", but the host's replication machinery does mutate them. that has nothing to do with the virus.

Justin A

05-08-2007, 11:31 PM

[ QUOTE ]
[ QUOTE ]
There are things that are CLEARLY alive that would not be considered alive under the definition you are using...like worker ants. How do you reconcile this?

[/ QUOTE ]

worker ants don't do all the things I mentioned? are you thinking of reproduce since workers are sterile? for one, "worker ants" are not an species, they are an social catergory of an ant species that obviously do replicate. and even sterile ants reproduce their own tissues.

[/ QUOTE ]

You're missing the point. The point is that we're talking about whether or not life could have sprung up from non-life in the early days of the earth. It isn't necessary for the first cells to have come about by chance if the predecessors to the cell were able to replicate. Your arbitrary definition of what is and isn't life is irrelevant.

vhawk01

05-08-2007, 11:32 PM

vhawk01

05-08-2007, 11:33 PM

[ QUOTE ]
here's something from the first thing on Google you may have overlooked:

[ QUOTE ]
virus adaptation may be dependent on host biology

[/ QUOTE ]

so... viruses don't "adapt", but the host's replication machinery does mutate them. that has nothing to do with the virus.

[/ QUOTE ]

Do you understand the two words, 'virus adaptation?' That means that viruses...adapt. That this adaptation is contingent is obvious...ALL adaptation is contingent.

ill rich

05-08-2007, 11:36 PM

[ QUOTE ]
Reproduce their own tissues? Yeah, thats not what that means.

[/ QUOTE ]

with a cell being the basic unit of life, and the cells in the tissues reproducing, it's exactly what that means.

arahant

05-08-2007, 11:50 PM

[ QUOTE ]
[ QUOTE ]
Worker ants are not alive. Huh, never knew.

Obviously I'm being sarcastic, but the point is, the usual definition of life is flawed because it is trying to draw lines when there aren't any in reality. You are wrong if you think your definition is the only one.

Also, as to your last part, that is something you added in on your own. I've never seen any definition of cell that includes "can only come from other cells." That would be a stupid definition.

Are you seriously finishing your degree in microbiology? Mind if I ask, from where? They don't bother explaining the shortcomings of various definitions of life?

[/ QUOTE ]

these definitions are used in all textbooks and journals. accepted definitions. of course there are challanges to them all the time, but they aren't accepted.

and yes i am finishing up my degree from central connecticut state university.

[/ QUOTE ]

Who the hell are you trying to kid?
1)'Scientists' don't use a definition of 'life'...like, ever.
2) Even if there were some definition of life that was somehow enshrined in the halls of science, it is still irrelevant to the question at hand.
3) I assume you are full of [censored], and your OP wasn't so much a question as some sort of [censored] challenge.
4) If it really was a question, and you really are a microbiology major, I strongly suggest you take this up with one of your professors. I'm sure they'll be happy to explain this to you. Slowly. Assuming you aren't the brain-washed close-minded ass that you appear to be.

Phil153

05-09-2007, 12:01 AM

[ QUOTE ]
[ QUOTE ]
Do you know of some universally accepted definition of life that all of us are forced to acknowledge?

[/ QUOTE ]

no, i'm just using the one used and accepted by modern scientists.

i am in my last semester of my b.s. in microbiology, and this is the definition we use.

[/ QUOTE ]

[ QUOTE ]
accepted theory is that cells ONLY come from other cells. and therefore by scientific definition the first cell can never be explained.

[/ QUOTE ]

Holy mother of God.

You have a microbiology degree, and if you're ever going to contribute anything worthwhile to human knowledge or industry, you'll need to learn to think for yourself. It's a truly wonderful thing. So let me break it down for you.

Cells are purely based in the laws of physics. You can think of them as extremely complex organic machines. This is true whether God made them or not. Your microbiology and chemistry classes should have given you some insight into the internal working of cells, and the physics/chemistry working behind the scenes. With that in mind, I hope you can see that the definitions of life you so rigidly adhere to are nonsense. They're just rules of thumb that scientists use.

You say that cells can only come from cells. Well, that's true, in the same way that German shepherds can only come from German shepherds. But < 10,000 years ago, German shepherds were wolves. As were many other breeds of dog. A more recent example is cauliflower and brocoli, which have been bred out from wild cabbages (http://en.wikipedia.org/wiki/Brassica_oleracea) over the last 2000 years so well that don't even resemble their ancestors. So while it's true a cauliflower or German shepherd can only come from the same, over long periods of time, this is simply false.

On to cells. You claim cells can only come from cells. Today, this is true. But over long periods of time, it is simply false. To demonstrate this, let's work backwards, and see what kind of non cell a cell could come from, given enough time.

Consider the simplest cell the could survive for an extended period of time, and reproduce.

Is a human skin cell an example of such a cell? No. We can get much simpler and smaller.
Is E. Coli and example of such a cell? No, because E. Coli could still survive, reproduce and mutate with a simpler set of components.

So what is the simplest organism we could construct that would satisfy the criteria for life? Well, you could likely make one without flagellum, without certain metabolic pathways, with less efficient and simpler ion pumps, and so on. In fact, I'd say you could greatly reduce the complexity the simplest living cell today and still have something that could survive for extended periods and reproduce.

Now let's take another step back, to the very boundary between "life" and "non life", to a point where the metabolic pathways, ion pumps and the like are so inferior as to almost be useless, but there are still self replicating proteins inside it. If I remove a particular enzyme (just a protein, really) of the last metabolic pathway available in that cell, energy production in that simple cell will grind to a halt. Ergo, we no longer have life. Now imagine that non-cell, protected by its lipid wall and still containing self replicating proteins , is floating about aimlessly, occassionally splitting in half, mopping up stray amino acids with it's simple prion-like replicators, and when full, splitting in half again under its internal pressure from the liquid gained through osmosis. Eventually, a mutation occurs in the protein soups of one of these trillions of cells, enabling the simple processing of some fuel available to it (sulphur or methane from a volcanic vent, say). That cell is now on the way to having functional units inside it that can enable response to the outside environment - the remaining criteria for life. Because it is now able to respond to its environment, and grow faster, it replaces its ancestors.

So I hope you can see how life can indeed come from non life. The first steps are very, very easy (lipid walls, simple replicators) and well within the realm of possibility. A few later steps are still under question because we don't know enough, and there are so many possible ways of getting from A to B. The final steps, non life to life, I hope you can see are very simple and highly likely.

A final thing to note is that life doesn't have to have come from what we see today. Replicating structures could have developed in other ways, and then slowly been integrated with things like RNA, DNA, and the ATP metabolic pathway. The existence of an amazing array of metabolic pathways in bacteria today lends strong support to this idea.

BTW, I don't have a microbiology degree. Just common sense understanding and an IQ higher than your average fundamentalist.

ill rich

05-09-2007, 01:45 AM

[ QUOTE ]
Who the hell are you trying to kid?
1)'Scientists' don't use a definition of 'life'...like, ever.
2) Even if there were some definition of life that was somehow enshrined in the halls of science, it is still irrelevant to the question at hand.
3) I assume you are full of [censored], and your OP wasn't so much a question as some sort of [censored] challenge.
4) If it really was a question, and you really are a microbiology major, I strongly suggest you take this up with one of your professors. I'm sure they'll be happy to explain this to you. Slowly. Assuming you aren't the brain-washed close-minded ass that you appear to be.

[/ QUOTE ]

1. there are certain criteria needed to be considered life. The Red Rain cells of India, although they can replicate, are not considered life simply because they don't have DNA.
2. it is a crucial part
3. it's both, obviously
4. they can't explain it. nobody can. there can be theories about it though.

ill rich

05-09-2007, 01:52 AM

[ QUOTE ]
Now let's take another step back, to the very boundary between "life" and "non life", to a point where the metabolic pathways, ion pumps and the like are so inferior as to almost be useless, but there are still self replicating proteins inside it. If I remove a particular enzyme (just a protein, really) of the last metabolic pathway available in that cell, energy production in that simple cell will grind to a halt. Ergo, we no longer have life. Now imagine that non-cell, protected by its lipid wall and still containing self replicating proteins , is floating about aimlessly, occassionally splitting in half, mopping up stray amino acids with it's simple prion-like replicators, and when full, splitting in half again under its internal pressure from the liquid gained through osmosis. Eventually, a mutation occurs in the protein soups of one of these trillions of cells, enabling the simple processing of some fuel available to it (sulphur or methane from a volcanic vent, say). That cell is now on the way to having functional units inside it that can enable response to the outside environment - the remaining criteria for life. Because it is now able to respond to its environment, and grow faster, it replaces its ancestors.

[/ QUOTE ]

good response.

my main problem with that is "self replicating proteins" don't really exist within a cell.

all the proteins in a cell are made by ribosomes translating mRNA messages, and the ribosomes themselves are made by other ribosomes.

Phil153

05-09-2007, 02:28 AM

[ QUOTE ]
my main problem with that is "self replicating proteins" don't really exist within a cell.

[/ QUOTE ]
They don't now, billions of years later. If they did exist, they would have been replaced by far more efficient and robust systems (DNA).

But even the requirement for self replicating proteins is too narrow. For a non cell blob to improve toward a cell simply requires

- some stability from external threats to blob integrity
- The ability to synthesize needed components from available materials to fulfill (1) above
- The ability to replicate these synthesizing mechanisms.
- The very rare addition of novel, useful parts, either from the environment or internal processes
- The ability to form new, independent units (this is trivial with the mechanisms of lipid-blob splitting and reforming)

All of these can be achieved with far less than the incredibly complex, interconnecting systems we see today.

I agree that it remains to be seen whether the steps leading to and from this point are likely or even possible. But the idea that life must come from life, or cells must come from cells, is flawed. As is the idea that something must contain DNA in order to be life. I find it hard to believe that biologists require this. Perhaps wacki or rduke (two working biologists) can chime in.

bocablkr

05-09-2007, 09:31 AM

Phil,

One of your best posts ever...

Justin A

05-09-2007, 01:32 PM

In the future our grandkids will add this to the long list of things that religious people used as proof of God's existence, only to find out that science came up with a perfectly natural explanation.

vhawk01

05-09-2007, 04:49 PM

[ QUOTE ]
In the future our grandkids will add this to the long list of things that religious people used as proof of God's existence, only to find out that science came up with a perfectly natural explanation.

[/ QUOTE ]

1. Rainbows
2. Cells

Mr. Now

05-09-2007, 06:40 PM

It came from prime primordial ooze on Earth. Not.

www.panspermia.org (http://www.panspermia.org)

oe39

05-09-2007, 07:09 PM

[ QUOTE ]

i don't think there really is an explination except for cells were either a) always around since the begining of time [atheist point of view] or b) supernaturally created [God beleiver]. i'm religious but i do like to consider purely scientific fact without throwing in God, and there seems to be no realistic scientific explination for this to occur.

[/ QUOTE ]

you should call both the ignorant point of view

Phil153

05-09-2007, 07:17 PM

[ QUOTE ]
It came from prime primordial ooze on Earth. Not.

www.panspermia.org (http://www.panspermia.org)

[/ QUOTE ]
Believing in that is as bad as creationism. There is zero evidence for this idea, however sexy it might appear.

thylacine

05-09-2007, 08:00 PM

[ QUOTE ]
It came from prime primordial ooze on Earth. Not.

www.panspermia.org (http://www.panspermia.org)

[/ QUOTE ]

Oh no, here comes "Mr. Now" again with Michael Jackson's fantasy website about Peter Pan. /images/graemlins/tongue.gif

Rduke55

05-09-2007, 09:46 PM

[ QUOTE ]
Phil,

One of your best posts ever...

[/ QUOTE ]

Phil, you and I disagree on a lot but I have to agree here.

OP, how the hell did you make it through the classes you had to take and still think like this?

vhawk01

05-09-2007, 10:02 PM

[ QUOTE ]
[ QUOTE ]
Phil,

One of your best posts ever...

[/ QUOTE ]

Phil, you and I disagree on a lot but I have to agree here.

OP, how the hell did you make it through the classes you had to take and still think like this?

[/ QUOTE ]

I generally dislike condescending questions like this, but in this case I think its entirely warranted (and I even asked a similar question earlier). It doesn't speak much to his intellectual honesty, assuming he was a creationist before he took these classes.

ill rich

05-10-2007, 03:23 AM

[ QUOTE ]
OP, how the hell did you make it through the classes you had to take and still think like this?

[/ QUOTE ]

think like what? beleif in God?

simple. i accept all of this as scientific fact. scientific fact doesn't have to be true, it just has to fit observations.

Stu Pidasso

05-10-2007, 10:17 AM

[ QUOTE ]
This is a soap bubble. Slap some DNA or RNA in it and you have a cell. Do it enough times and you will eventually get one that works.

[/ QUOTE ]

And it if a monkey types on a typewriter long enough it will eventually reproduce a work from Shakespear. It might take a googleplex of years but it will happen eventually.

Stu

bluesbassman

05-10-2007, 10:33 AM

Excellent post Phil, but please don't "feed the monkeys" with reason and science. You might upset them.

vhawk01

05-10-2007, 11:43 AM

[ QUOTE ]
[ QUOTE ]
OP, how the hell did you make it through the classes you had to take and still think like this?

[/ QUOTE ]

think like what? beleif in God?

simple. i accept all of this as scientific fact. scientific fact doesn't have to be true, it just has to fit observations.

[/ QUOTE ]

Of course. Apparently you aren't big on parsimony, though. I suppose thats ok.

thylacine

05-10-2007, 12:22 PM

[ QUOTE ]
[ QUOTE ]
This is a soap bubble. Slap some DNA or RNA in it and you have a cell. Do it enough times and you will eventually get one that works.

[/ QUOTE ]

And it if a monkey types on a typewriter long enough it will eventually reproduce a work from Shakespear. It might take a googleplex of years but it will happen eventually.

Stu

[/ QUOTE ]

I made it very clear above that this type of argument is a complete red herring. You must have, and you do have REPLICATORS.

IDCreationists conveniently ignore this point, with the assistance of those of their opponents who miss this point. Dawkins makes this point clear in "The God Delusion" Chapter 4 and in many other places.

Hopey

05-10-2007, 01:55 PM

Classic SMP trolling:

1) OP: Can someone please explain X to me?
2) SMP regulars waste their time providing answers.
3) OP: You're all wrong!
4) SMP regulars waste more time asking OP why he thinks they're wrong.
5) OP: Oh, I forgot to mention earlier that I'm an expert in the field.
6) SMP regulars: How can you be an expert in the field if you don't even know X,Y, and Z?
7) OP: Praise the Lord!

vhawk01

05-10-2007, 02:36 PM

[ QUOTE ]
Classic SMP trolling:

1) OP: Can someone please explain X to me?
2) SMP regulars waste their time providing answers.
3) OP: You're all wrong!
4) SMP regulars waste more time asking OP why he thinks they're wrong.
5) OP: Oh, I forgot to mention earlier that I'm an expert in the field.
6) SMP regulars: How can you be an expert in the field if you don't even know X,Y, and Z?
7) OP: Praise the Lord!

[/ QUOTE ]

Yeah, but honestly, its still fun. I get to satsify all sorts of personal character flaws.

arahant

05-10-2007, 04:11 PM

vhawk01

05-10-2007, 04:20 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
OP, how the hell did you make it through the classes you had to take and still think like this?

[/ QUOTE ]

think like what? beleif in God?

simple. i accept all of this as scientific fact. scientific fact doesn't have to be true, it just has to fit observations.

[/ QUOTE ]

Touche.

[/ QUOTE ]

I'm still waiting for the meaningful definition of 'true.'

flipdeadshot22

05-10-2007, 04:32 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
OP, how the hell did you make it through the classes you had to take and still think like this?

[/ QUOTE ]

think like what? beleif in God?

simple. i accept all of this as scientific fact. scientific fact doesn't have to be true, it just has to fit observations.

[/ QUOTE ]

Touche.

[/ QUOTE ]

[/ QUOTE ]

Doesn't 'fitting observations' imply factual truth?

arahant

05-10-2007, 05:11 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
OP, how the hell did you make it through the classes you had to take and still think like this?

[/ QUOTE ]

think like what? beleif in God?

simple. i accept all of this as scientific fact. scientific fact doesn't have to be true, it just has to fit observations.

[/ QUOTE ]

Touche.

[/ QUOTE ]

[/ QUOTE ]

Doesn't 'fitting observations' imply factual truth?

[/ QUOTE ]

Not at all...here is an easy example:
"I have $20 Billion in my checking account" is true, despite the fact that this conflicts with all observations, even those made by me.

To vhawk...illrich and I apparently use the same definition of true. True - (adj) Reflecting my belief irrespective of....anything.

Stu Pidasso

05-10-2007, 07:50 PM

Hi Thylacine,

[ QUOTE ]

I made it very clear above that this type of argument is a complete red herring. You must have, and you do have REPLICATORS.

[/ QUOTE ]

I understand Dawkins argument regarding mutating replicating molecues and how he believes it drives abiogenisis. Essentially when a correct portion of the "puzzle" is solved, that partial solution continues to be passed on to the next generation; ultimately through this process the entire puzzle is solved. I can see how a process like that can work very well and quite fast mind you, but only when there exist a puzzle to be solved.

I'm certainly no expert on biology. Perhaps you can edumacate me on a couple of things. Are any of these self replicating molecues found in significant numbers outside the lab or outside cells/viruses etc? Are there any naturally occuring bioreactors that exist today(other than the ones that exist in living beings)?

Also, it seems to me that if Dawkins were correct we would see a progression in self replicating molecues that runs from the very simple, to the complex, to ultimately life. Like on earth today we see very simple single cell beings. We also see beings which are just slightly more complex, and if we continue looking we see beings that are slightly more complex still. It goes on and on that way until you reach the most complex organisms in existence. Do we observes this same progression amoung self replicating molecues Dawkins speaks of?

Stu

thylacine

05-10-2007, 08:18 PM

[ QUOTE ]
Hi Thylacine,

[ QUOTE ]

I made it very clear above that this type of argument is a complete red herring. You must have, and you do have REPLICATORS.

[/ QUOTE ]

I understand Dawkins argument regarding mutating replicating molecues and how he believes it drives abiogenisis. Essentially when a correct portion of the "puzzle" is solved, that partial solution continues to be passed on to the next generation; ultimately through this process the entire puzzle is solved. I can see how a process like that can work very well and quite fast mind you, but only when there exist a puzzle to be solved.

I'm certainly no expert on biology. Perhaps you can edumacate me on a couple of things. Are any of these self replicating molecues found in significant numbers outside the lab or outside cells/viruses etc? Are there any naturally occuring bioreactors that exist today(other than the ones that exist in living beings)?

Also, it seems to me that if Dawkins were correct we would see a progression in self replicating molecues that runs from the very simple, to the complex, to ultimately life. Like on earth today we see very simple single cell beings. We also see beings which are just slightly more complex, and if we continue looking we see beings that are slightly more complex still. It goes on and on that way until you reach the most complex organisms in existence. Do we observes this same progression amoung self replicating molecues Dawkins speaks of?

Stu

[/ QUOTE ]

I don't really have any details to add to my above posts. My main point is that the exponential growth due to iterated replication is crucial to explaining the existence of complex entities such as cells.

As far as seeing all the intermediate stages of sub-cellular entites in the present, my guess is these days they would get eaten, but at the appropriate time 3.4-3.5billion years ago they would have been king of the pond.

wacki

05-10-2007, 11:47 PM

[ QUOTE ]
and how does RNA self-replicate?

[/ QUOTE ]

http://www.rsc.org/Publishing/ChemScience/Volume/2005/11/RNA_replication.asp

Clemens Richert and colleagues at the University of Karlsruhe have now shown that, without the use of enzymes, an RNA strand bound to a longer template strand of RNA can grow more than one order of magnitude faster than previously believed.

....

The researchers have accelerated this previously sluggish replication reaction by using novel azabenzotriazole activated ribonucleotides. They further enhanced the reaction by introducing short oligomers of RNA, which bind downstream from the incorporation site.

The replication steps take place on the timescale of hours rather than weeks, giving further support to the theory that RNA strands spontaneously replicated during prebiotic evolution.

Stu Pidasso

05-11-2007, 04:39 AM

[ QUOTE ]

I don't really have any details to add to my above posts. My main point is that the exponential growth due to iterated replication is crucial to explaining the existence of complex entities such as cells.

As far as seeing all the intermediate stages of sub-cellular entites in the present, my guess is these days they would get eaten, but at the appropriate time 3.4-3.5billion years ago they would have been king of the pond.

[/ QUOTE ]

They all got ate up? Doesn't sound too plausible to me. Dawkins explaination of abiogenisis seems to have a lot of holes in it. We really should be observing all the stages of abiogenisis from start to finish. Apparently we don't and his explanation is really not much better than "God did it". I think Pansepermia gives him an out however.

Stu

Phil153

05-11-2007, 04:45 AM

[ QUOTE ]
We really should be observing all the stages of abiogenisis from start to finish.

[/ QUOTE ]
Why?

tolbiny

05-11-2007, 05:48 AM

[ QUOTE ]

I'm certainly no expert on biology. Perhaps you can edumacate me on a couple of things. Are any of these self replicating molecues found in significant numbers outside the lab or outside cells/viruses etc? Are there any naturally occuring bioreactors that exist today(other than the ones that exist in living beings)?

Also, it seems to me that if Dawkins were correct we would see a progression in self replicating molecues that runs from the very simple, to the complex, to ultimately life. Like on earth today we see very simple single cell beings. We also see beings which are just slightly more complex, and if we continue looking we see beings that are slightly more complex still. It goes on and on that way until you reach the most complex organisms in existence. Do we observes this same progression amoung self replicating molecues Dawkins speaks of?

[/ QUOTE ]

The existence of these molecules would, almost paradoxically (I've written that twice today), change the very conditions that allow it to replicate. Say a molecule is called NC (I'm just making this crap up, don't bug me about the chemistry), when a NO2 molecule hits the C side and a CO2 molecule hits the N side the original one splits and reattaches to the new partners 50% of the time, leaving you with two NC molecules and two O2 molecules. Give it enough time and you will run out of either NO2 or CO2 molecules and NC molecules won't be able to replicate anymore. Their existence and success changed the conditions necessary for their replication. If one of the next links in the chain doesn't release new CO2 or NO2 to react before all the NCs have been converted to a different molecule or succumbed to their half life, then you would get a gap in the chain.

prohornblower

05-11-2007, 03:59 PM

http://www.planetgadget.be/uploaded_images/1985cellphone-743277.JPG

I put this thing on vibrate once in 1982 and it shattered my glass table.

Stu Pidasso

05-11-2007, 04:30 PM

Hi Tolbiny,

[ QUOTE ]
The existence of these molecules would, almost paradoxically (I've written that twice today), change the very conditions that allow it to replicate. Say a molecule is called NC (I'm just making this crap up, don't bug me about the chemistry), when a NO2 molecule hits the C side and a CO2 molecule hits the N side the original one splits and reattaches to the new partners 50% of the time, leaving you with two NC molecules and two O2 molecules. Give it enough time and you will run out of either NO2 or CO2 molecules and NC molecules won't be able to replicate anymore. Their existence and success changed the conditions necessary for their replication. If one of the next links in the chain doesn't release new CO2 or NO2 to react before all the NCs have been converted to a different molecule or succumbed to their half life, then you would get a gap in the chain.

[/ QUOTE ]

I don't buy your explaination either. The molecules we are talking about are amino acids, phospholipids, and nucleotides. These are made from methane, amonia, water, hydrogen sulfide, carbondioxide, carbonmonoxide, and phosphate. They are all quite common in the environment. The stuff of life didn't get used up in chemical reactions as you suggest or eaten up by more evolved predators molecues as suggested by another poster.

Stu

Borodog

05-11-2007, 04:49 PM

Even if "abiogenis" were continuing right now, you would never see it, as the rudimentary self-replicating molecules could never compete with the end product of 3.5 billion years of natural selection. That's the point of natural selection.

Duh.

CORed

05-11-2007, 05:28 PM

[ QUOTE ]
according to scientific definition cells ARE required for life, and anything that that is not a cell that contains DNA is not life (by definition).

[/ QUOTE ]

repeat that 10,000 more times. It will still be wrong.

CORed

05-11-2007, 05:48 PM

[ QUOTE ]
what are your thoughts on where the first cell came from.

[/ QUOTE ]

The simple answer to the whole abiogenesis question is, nobody knows. As Wacki pointed out, cells membranes are pretty much self assembling. The real question is how the whole genetic apparatus came to be. As it currently works, DNA is replicated, transcribed to RNA, and translated to proteins by enzymes made of protein, which is encoded by DNA, which is replicated, transcribed and and translated by protein, which is .....

The ID folks claim that this "irreducible complexity" proves that God had to create the whole apparatus. I would respond that the fact that we don't know all of the answers proves only that we don't know all of the answers. Whatever happened happened 3.5 billion years ago, probably took thousands if not millions of years, and likely involved some events with a very low probability of occurring in the time span of a human life. We certainly can't replicate the process in the laboratory. We have a pretty good idea of how the building blocks -- nucleotides, amino acids, etc. were made, but no clue how we got from those building blocks to bacteria. OTOH, we have a pretty good idea how we got from bacteria to the complex organisms we have now (evolution).

Stu Pidasso

05-11-2007, 07:16 PM

Hi Borodog

[ QUOTE ]
Even if "abiogenis" were continuing right now, you would never see it, as the rudimentary self-replicating molecules could never compete with the end product of 3.5 billion years of natural selection. That's the point of natural selection.

[/ QUOTE ]

Sorry about the misspelling. Anyways since you brought up natural selection, what exactly do these self replicating molecules compete against? To my knowledge there arn't any organisms which feed on self replicating rudimentary molecules. The bottom of the food chain consist of things like iron or sulfer(which are oxidized for energy) or carbondioxide combined with water and sunlight(photosynthesis).

In a way your making my point. If life arose from self replicating molecules, then those self replicating molecules should be part of the food chain. There isn't any evidence that is the case.

I'm not saying life didn't arise on this planet by some natural process. Its possible a that an occurence which happens 1 in googleplex hit on this planet and life was born. I am saying Dawkins explanation is bunk. If self replicating molecules "evolved" over millions of years into the first simple living organisms then evidence of that should be readily available. The fact is, it isn't.

Stu

vhawk01

05-11-2007, 07:33 PM

[ QUOTE ]
Hi Borodog

[ QUOTE ]
Even if "abiogenis" were continuing right now, you would never see it, as the rudimentary self-replicating molecules could never compete with the end product of 3.5 billion years of natural selection. That's the point of natural selection.

[/ QUOTE ]

Sorry about the misspelling. Anyways since you brought up natural selection, what exactly do these self replicating molecules compete against? To my knowledge there arn't any organisms which feed on self replicating rudimentary molecules. The bottom of the food chain consist of things like iron or sulfer(which are oxidized for energy) or carbondioxide combined with water and sunlight(photosynthesis).

In a way your making my point. If life arose from self replicating molecules, then those self replicating molecules should be part of the food chain. There isn't any evidence that is the case.

Stu

[/ QUOTE ]

Why? Why would they STILL be a part of the food chain? They got outcompeted, they went extinct. No reason to think they'd make a comeback.

Stu Pidasso

05-11-2007, 07:47 PM

[ QUOTE ]

Why? Why would they STILL be a part of the food chain? They got outcompeted, they went extinct. No reason to think they'd make a comeback.

[/ QUOTE ]

Chemical reactions do not go extinct. The laws of chemistry haven't changed in the last 4.5 billion years.
All the elements and base molecules are still around. There is no reason life is going to stop the process described in Dawkins explanation from occuring(if it ever occurred at all).

Stu

m_the0ry

05-11-2007, 08:19 PM

Obviously reactions don't go extinct. Equally obvious is the fact that every reaction has constituents and an end product. Carbon and oxygen can form polymers with basically limitless permutations. They are also the product of supernovae or equally extreme events only, you can't just 'create' them. They are a limited resource.

If you can't understand how darwinian chemical processes are for our Earth - which does not receive 'care packages' of elements that needed for reactions - I strongly recommend you read up on the Oxygen Catastrophe and how it affected the cyanobacteria concentration in Precambrian earth.

Borodog

05-11-2007, 10:35 PM

[ QUOTE ]
Sorry about the misspelling.

[/ QUOTE ]

Stu,

I wasn't trying to rag on any misspelling; I hadn't noticed you misspelled anything. I simply misspelled it myself. So if you did, we're even. /images/graemlins/wink.gif

Stu Pidasso

05-12-2007, 12:38 AM

Hi M_theory

[ QUOTE ]

If you can't understand how darwinian chemical processes are for our Earth - which does not receive 'care packages' of elements that needed for reactions - I strongly recommend you read up on the Oxygen Catastrophe and how it affected the cyanobacteria concentration in Precambrian earth.

[/ QUOTE ]

You've got it confused. I'm not saying chemical processes can't have a darwinian effect. I'm saying the earth doesn't have a darwinian effect on chemical processess.

Its laughable that otherwise intelligent people on this forum are saying that some magical chemical process no longer exists because all the molecules involved in the process were eaten to exstinction in some darwinesque competition.

If life evolved from self replicating RNA molecules why aren't RNA molecules self replicating now?

Stu

vhawk01

05-12-2007, 12:41 AM

[ QUOTE ]
Hi M_theory

[ QUOTE ]

If you can't understand how darwinian chemical processes are for our Earth - which does not receive 'care packages' of elements that needed for reactions - I strongly recommend you read up on the Oxygen Catastrophe and how it affected the cyanobacteria concentration in Precambrian earth.

[/ QUOTE ]

You've got it confused. I'm not saying chemical processes can't have a darwinian effect. I'm saying the earth doesn't have a darwinian effect on chemical processess.

Its laughable that otherwise intelligent people on this forum are saying that some magical chemical process no longer exists because all the molecules involved in the process were eaten to exstinction in some darwinesque competition.

If life evolved from self replicating RNA molecules why aren't RNA molecules self replicating now?

Stu

[/ QUOTE ]

Maybe they are and it just takes a really long time? Or it requires conditions that don't often occur any more? Thats what I meant earlier by outcompeted, by the way. RNA self-replication was a horrible process, it was just the only game in town (in theory).

Phil153

05-12-2007, 01:18 AM

[ QUOTE ]
Its laughable that otherwise intelligent people on this forum are saying that some magical chemical process no longer exists because all the molecules involved in the process were eaten to extinction in some darwinesque competition.

[/ QUOTE ]
Eaten? Well, kind of. Proteins are in such short supply they get quickly mopped up by bacteria. Leave a protein rich food on the bench for a couple of days with adequate water (such as meat or an egg) and then try eating it. The vomiting that ensues is due the billions of bacteria that are turning the proteins into toxins.

The Earth is teeming with life. Bacteria colonize everything, from boiling volcanic vents at the bottom of the sea, to dust particles in the atmosphere, to 100 trillion bacteria spanning thousands of generations living in the insides of a human intestine.

Free proteins and amino acids don't last long in this environment, at least not in zones that are conducive to the needed chemical processes. Life mops it up. Similarly, much of the sea is devoid of life because plankton flourish wherever nutrient rich waters well up from the depths, leaving little behind. Life is constantly recycling and rebuilding any resources available to it. In addition, any concentration of such resources, needed for the development you see, causes a flourishing of life which quickly depletes those resources.

Another potential problem is that oxygen appears harmful to the molecules needed to build life. Oxygen is one of the free radicals (http://en.wikipedia.org/wiki/Radical_(chemistry)) you hear about so much in popular literature, and it's death to organic polymers. It may well be that life cannot develop via chemistry in an oxygen rich environment.

[ QUOTE ]
If life evolved from self replicating RNA molecules why aren't RNA molecules self replicating now?
Stu

[/ QUOTE ]
Self replicating RNA molecules isn't even a requirement for life. It's only one possible way it's thought to have happened.

There are valid objections to current theories of abiogenesis, mostly based on the lack of knowledge we have about critical processes and the early Earth. But this particular argument is barking up the wrong tree.

m_the0ry

05-12-2007, 01:32 AM

So the question in its most general form is, 'Why aren't there remnant 'species' from the evolution of cellular life'?

We define complexity as the number of possible permutations in a system. Thus for a self-assembling system of increasing complexity there are more possible variants in its defects. The point being, we aren't going to see a lot of diversity in 'species' at the so-called 'self replicating RNA' level. Very few permutations will arrive throughout evolution and only a certain number of them will survive.

That said, I think the presence of virii and -far more importantly- the presence of prions in the modern world shows that there is in fact evidence of an intermediary evolution stage prior to cellular life. But our evidence of these stages will always be sparse.

Piers

05-20-2007, 07:24 PM

Lipids naturally form a spherical bilayer structure in water solutions, so anyone can crate ‘empty cells’ in a test tube.

Imagine a water solution containing both lipids and RNA molecules or RNA’s precursor.

It is not too difficult to imagine an RNA molecules getting trapped inside a lipid bilayer.

Now say the RNA does its self-replicating trick.

So now we have several almost identical RNA molecules floating around inside a lipid bilayer.

Say some random accident happens to cause the our lipid bilayer to break apart, then reform into two different spherical lipid bilayers, by chance some of the RNA material is caught in both spheres.

So we have a cell wall surrounding genetic material that splits into two cell walls surrounding similar genetic material.

A cell yet?

So how many millenniums before the RNA material starts to interact with the cell wall in some way?

Stu Pidasso

05-21-2007, 12:04 AM

[ QUOTE ]
Now say the RNA does its self-replicating trick.

[/ QUOTE ]

RNA doesn't self replicate except in highly artificial conditions. Thats the problem. You have to ascribe to prebiotic RNA molecules properties modern RNA molecules are lacking. Thats not much better than saying life originated when Gil Gerald went back in time and jacked off into the primordial soup.

Stu

vhawk01

05-21-2007, 12:06 AM

Or you just have to say "Why, nothing at all would PREVENT RNA from replicating, its at least possible" and then admit you don't know for sure what actually happened.

Stu Pidasso

05-21-2007, 12:29 AM

[ QUOTE ]
"Why, nothing at all would PREVENT RNA from replicating, its at least possible"

[/ QUOTE ]

Which is just a more polite way of saying the theory is far fetched.

Stu

vhawk01

05-21-2007, 12:34 AM

[ QUOTE ]
[ QUOTE ]
"Why, nothing at all would PREVENT RNA from replicating, its at least possible"

[/ QUOTE ]

Which is just a more polite way of saying the theory is far fetched.

Stu

[/ QUOTE ]
Not at all, its a polite way of saying its 'near-fetched' but that there isn't enough evidence for it. This explanation is within the realm of reasonability, whereas your Gil Gerard explanation is within the realm of possibility (maybe, probably not). Thats what divides far-fetched and reasonable possibility, at least in my mind.

ApeAttack

05-21-2007, 01:59 AM

In the early 1950s, Professor Harold Urey and one of his students, Stanley Miller, began experimenting to prove Oparin's theory. Miller built an apparatus which circulated gasses likely to be present in the early atmosphere (Methane (CH4), Ammonia (NH3), Water (H2O), and hydrogen (H2) ) past an electrical discharge, simulating the UV Rays and violent electrical storms present in the early atmosphere.

After allowing the experiment to continue for a week, the results where startling. The previously colorless solution inside the apparatus had turned red. Upon analyzing the solution, Miller found many organic molecules present, some of which couldn't be readily identified. The most important of created compounds, however, where amino acids. This, in effect, proved Oparin's theory that organic compounds could have been created in the early atmosphere. Further studies showed that some amino acids would have combined with hydrogen cyanide (HCN), which is a byproduct of volcanic activity. This combination would form purines and pyrinidines, which are used to make nucleic acids, which in turn create DNA

After these compounds had been created on the early earth, the earth eventually began to cool. Water vapor the condensed, which formed vast oceans, seas and lakes, in which simple organic molecules began to accumulate for millions of years, producing an "organic soup" of sorts. The amino acids would have then polymerized (which means they formed chains, such as proteins. E.g... (aa=amino acid) aa-aa-aa-aa-aa = protein). The most likely theory as to how the amino acids combined is that they where washed up into clay/rock depressions on land, where the water evaporated, leaving behind concentrated organic compounds in high heat.

Sidney W. Fox set out to prove this. He took a mixture of approximately 20 different amino acids, and heated then to the melting point. When they cooled, Fox observed that they had polymerized into proteins. 

[/ QUOTE ]

The story of this experiment is pretty standard in all 8th grade+ biology books. Took a while for someone to quote it.

MidGe

05-21-2007, 04:29 AM

[ QUOTE ]
[ QUOTE ]
"Why, nothing at all would PREVENT RNA from replicating, its at least possible"

[/ QUOTE ]

Which is just a more polite way of saying the theory is far fetched.

Stu

[/ QUOTE ]

Which is to say it is no way near as far ( /images/graemlins/smile.gif )fetched as positing an entity endowed with some kind of godlike (whatever that is?!) characteristics as responsible for the whole schmozzle

Piers

05-21-2007, 08:46 AM

You can change RNA to DNA in my post if you want, its irrelevant to the point I was making.

As to RNA being the precursor to DNA, I have to admit to not really understanding the process, but was just quoting my biology textbook. Anyhow something must have predated DNA?

[ QUOTE ]
RNA doesn't self replicate except in highly artificial conditions.

[/ QUOTE ]

Are you sure you don’t just mean that RNA self-replicate molecules do not exist in the wild any more?

[ QUOTE ]
Thats not much better than saying life originated when Gil Gerald went back in time and jacked off into the primordial soup.

[/ QUOTE ]

No, the difference is that we have not identified a mechanism whereby a human can go back in time but we can form RNA from simpler molecules.

Stu Pidasso

05-21-2007, 11:44 AM

Hi Piers,

[ QUOTE ]
You can change RNA to DNA in my post if you want, its irrelevant to the point I was making.

[/ QUOTE ]

DNA molecules do not self replicate. Neither do RNA molecules. Thats the fundamental problem with the theory you cited.

[ QUOTE ]
Are you sure you don’t just mean that RNA self-replicate molecules do not exist in the wild any more?

[/ QUOTE ]

For the theory to be plausible the molecules would have to readily self replicate. So far all the research shows RNA molecules do not self replicate in conditions that are plausible to a prebiotic earth.

Stu

arahant

05-21-2007, 04:29 PM

[ QUOTE ]

DNA molecules do not self replicate. Neither do RNA molecules. Thats the fundamental problem with the theory you cited.

[/ QUOTE ]

Let's just say, hypothetically, that you were wrong about this (http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=432262) . Would that change your opinion of ANYTHING? (that was 10 seconds of googling. another few minutes could add 20 more results.).

Seriously...you really think that there is some huge cabal of 100's of thousands of scientists who are following some theory with dozens of massive holes in it? And that the only people who see these holes happen to be biblical literalists? Doesn't that strike you as a bit odd?

Stu Pidasso

05-21-2007, 10:44 PM

Hi arahant.

To answer your question, when Stanley Miller showed amino acids could be created in labatory conditions that simulated a plausable prebiotic earth environment, the likely hood of abiogenesis having occurred on this planet increased....substantially as a matter of fact. If it could be shown that DNA, RNA or similar molecules could be created in a plausable prebiotic earth environment and could self replicate, I'd say abiogenesis becomes almost a lock.

I skimmed over your link, but stopped reading because RNA created by viruses using enzymes has nothing to do with abiogenesis. I'm sorry you wasted your time.

[ QUOTE ]
Seriously...you really think that there is some huge cabal of 100's of thousands of scientists who are following some theory with dozens of massive holes in it? And that the only people who see these holes happen to be biblical literalists? Doesn't that strike you as a bit odd?

[/ QUOTE ]

Amoung bubbalical literalist abiogenesis is considered a false theory. To reputable scientist working on discovering the origins or life, abiogenesis is considered merely a hypothesis. They don't consider it a theory yet because there is so little evidence to support it.

Here's the problem I have with abiogenesis. It seems intuitive to me that we should have accumulated a mass of evidence since the time Stanley Miller conducted his experiments. How long ago was that? 50 years? 50 years of additional research and we really haven't moved much down the road of actually being able to call abiogenesis a scientific theory. Panspermia, on the other hand, has accumalted a lot of evidence during that same time period.

Stu

vhawk01

05-21-2007, 11:05 PM

[ QUOTE ]
Hi arahant.

To answer your question, when Stanley Miller showed amino acids could be created in labatory conditions that simulated a plausable prebiotic earth environment, the likely hood of abiogenesis having occurred on this planet increased....substantially as a matter of fact. If it could be shown that DNA, RNA or similar molecules could be created in a plausable prebiotic earth environment and could self replicate, I'd say abiogenesis becomes almost a lock.

I skimmed over your link, but stopped reading because RNA created by viruses using enzymes has nothing to do with abiogenesis. I'm sorry you wasted your time.

[ QUOTE ]
Seriously...you really think that there is some huge cabal of 100's of thousands of scientists who are following some theory with dozens of massive holes in it? And that the only people who see these holes happen to be biblical literalists? Doesn't that strike you as a bit odd?

[/ QUOTE ]

Amoung bubbalical literalist abiogenesis is considered a false theory. To reputable scientist working on discovering the origins or life, abiogenesis is considered merely a hypothesis. They don't consider it a theory yet because there is so little evidence to support it.

Here's the problem I have with abiogenesis. It seems intuitive to me that we should have accumulated a mass of evidence since the time Stanley Miller conducted his experiments. How long ago was that? 50 years? 50 years of additional research and we really haven't moved much down the road of actually being able to call abiogenesis a scientific theory. Panspermia, on the other hand, has accumalted a lot of evidence during that same time period.

Stu

[/ QUOTE ]
So many turtles!!!

Nah, I'm just kidding, I'd love to hear about all this evidence that supports panspermia, and your theories on why panspermia isn't considered a serious probable candidate among researchers in the field.

Phil153

05-21-2007, 11:44 PM

Stu,

What you don't seem to realize is that RNA and DNA are largely irrelevant for the development of the first functioning cells. While they may have played a part, the first cells didn't necessarily run on anything this complex. See my post above for the four requirements for first life.

I also disagree that abiogenesis becomes a lock if RNA and DNA could be created. There are many other questions to be answered.

Stu Pidasso

05-22-2007, 12:02 AM

[ QUOTE ]
I'd love to hear about all this evidence that supports panspermia, and your theories on why panspermia isn't considered a serious probable candidate among researchers in the field.

[/ QUOTE ]

Hi Vhawk,

This is off the top of my head. Since the 1950s we've discovered.

A)evidence of liquid water on other bodies in this solar system.
B)Microbial life can survive space journeys
C)The earth endured a period of heavy bombardment
C)Rocks can be blasted off one planet and land on another planet as a meteorite.
D)A meteorite of martian orgin found in antartica may contain microstructures of biogenic orgin.
E)Life can survive firery re-entries.

Now its your turn. What evidence to support abiogenesis has been discovered since Stanly Millers discovery that amino acids could be created in a plausable prebiotic earth environment(in the last 50 years)?

Stu

Stu Pidasso

05-22-2007, 12:09 AM

[ QUOTE ]
What you don't seem to realize is that RNA and DNA are largely irrelevant for the development of the first functioning cells.

[/ QUOTE ]

Hi Phil,

When I said "or similar molecules" I was referring to molecules other than RNA or DNA.

Stu

vhawk01

05-22-2007, 12:33 AM

[ QUOTE ]
[ QUOTE ]
I'd love to hear about all this evidence that supports panspermia, and your theories on why panspermia isn't considered a serious probable candidate among researchers in the field.

[/ QUOTE ]

Hi Vhawk,

This is off the top of my head. Since the 1950s we've discovered.

A)evidence of liquid water on other bodies in this solar system.
B)Microbial life can survive space journeys
C)The earth endured a period of heavy bombardment
C)Rocks can be blasted off one planet and land on another planet as a meteorite.
D)A meteorite of martian orgin found in antartica may contain microstructures of biogenic orgin.
E)Life can survive firery re-entries.

Now its your turn. What evidence to support abiogenesis has been discovered since Stanly Millers discovery that amino acids could be created in a plausable prebiotic earth environment(in the last 50 years)?

Stu

[/ QUOTE ]

Doesn't all of that evidence sound very similar to "RNA are able to self-replicate, although not in standard conditions, but hey, its possible," and "It is entirely logically possible that some simpler self-replicating molecule existed prior to RNA taking over?" I mean, yeah, all those points are great as conjecture, but none of them is evidence of anything, except for D, which MIGHT be, but you used some hedge-type words in your list. Why is this "Hey, at least its possible" evidence such great support for your side?

Stu Pidasso

05-22-2007, 01:52 AM

[ QUOTE ]
Doesn't all of that evidence sound very similar to "RNA are able to self-replicate, although not in standard conditions, but hey, its possible," and "It is entirely logically possible that some simpler self-replicating molecule existed prior to RNA taking over?"

[/ QUOTE ]

It would sound similiar if we said something like "we proved in computer simulations that its possible for rocks to be blasted off mars and land on earth" However thats not the case...in actuallity we can hold in our hands rocks that have been blasted off mars and landed on earth as meteorites.

Its a fact, that in the natural environment, material passes between mars and the earth. We can't say the same for the self replicating molecules necessary for abiogenesis. Those molecules don't exist in the natural environment, and in the 50 years since Millers experiment they haven't been produced in the labatory in plausable prebiotic earth conditions. The flow of evidence for the hypothesis of abiogenesis is stalled, but for hypothesis of panspermia it continues to move forward.

Stu

arahant

05-22-2007, 02:05 AM

[ QUOTE ]
[ QUOTE ]
Doesn't all of that evidence sound very similar to "RNA are able to self-replicate, although not in standard conditions, but hey, its possible," and "It is entirely logically possible that some simpler self-replicating molecule existed prior to RNA taking over?"

[/ QUOTE ]

It would sound similiar if we said something like "we proved in computer simulations that its possible for rocks to be blasted off mars and land on earth" However thats not the case...in actuallity we can hold in our hands rocks that have been blasted off mars and landed on earth as meteorites.

Its a fact, that in the natural environment, material passes between mars and the earth. We can't say the same for the self replicating molecules necessary for abiogenesis. Those molecules don't exist in the natural environment, and in the 50 years since Millers experiment they haven't been produced in the labatory in plausable prebiotic earth conditions. The flow of evidence for the hypothesis of abiogenesis is stalled, but for hypothesis of panspermia it continues to move forward.

Stu

[/ QUOTE ]

I'm fairly confident that some of your assertions are untrue, but don't wish to look into it right now, so I'll grant (hypothetically) everything you say.

I would, however, like to know your stance here (sorry if you've mentioned it in previous posts). Is it that evolution is cool('natural'...you know my drift i presume), but abiogenesis required intervention of some sort?

So you know where I come from...I think it is much easier to defend evolution than baturalistic abiogenesis, for obvious reasons...but I that for philosophical reasons, accepting the former and not the latter is problematic.

Neuge

05-22-2007, 04:50 AM

[ QUOTE ]
A)evidence of liquid water on other bodies in this solar system.

[/ QUOTE ]
So abiogenesis can occur on other planets with liquid water, but not this one?

[ QUOTE ]
B)Microbial life can survive space journeys

[/ QUOTE ]
And?

[ QUOTE ]
C)The earth endured a period of heavy bombardment

[/ QUOTE ]
And?

[ QUOTE ]
C)Rocks can be blasted off one planet and land on another planet as a meteorite.

[/ QUOTE ]
Again, and?

[ QUOTE ]
D)A meteorite of martian orgin found in antartica may contain microstructures of biogenic orgin.

[/ QUOTE ]
So that precludes abiogenesis on Earth?

[ QUOTE ]
E)Life can survive firery re-entries.

[/ QUOTE ]
See above.

The biggest problem with panspermia is that it doesn't explain anything other than why life is on this insignificant planet. No matter what, you're still left with the question of where life originated from on these interstellar vessels and their precursors. What are you explanations for that? And why do you presume abiogenesis was more likely on those worlds than Earth?

PairTheBoard

05-22-2007, 09:39 AM

[ QUOTE ]
[ QUOTE ]
I'd love to hear about all this evidence that supports panspermia, and your theories on why panspermia isn't considered a serious probable candidate among researchers in the field.

[/ QUOTE ]

Hi Vhawk,

This is off the top of my head. Since the 1950s we've discovered.

A)evidence of liquid water on other bodies in this solar system.
B)Microbial life can survive space journeys
C)The earth endured a period of heavy bombardment
C)Rocks can be blasted off one planet and land on another planet as a meteorite.
D)A meteorite of martian orgin found in antartica may contain microstructures of biogenic orgin.
E)Life can survive firery re-entries.

Now its your turn. What evidence to support abiogenesis has been discovered since Stanly Millers discovery that amino acids could be created in a plausable prebiotic earth environment(in the last 50 years)?

Stu

[/ QUOTE ]

Isn't abiogenesis just a fancy word for the observation that life must have come from nonlife sometime in the past? Since we don't think that life was present during the Big Bang, don't we have to conclude that abiogenesis happened somewhere along the line, somewhere in the Universe? Panspermia insists it must have happened somewhere other than Earth with life migrating to Earth in some way. But it must have still happened somewhere.

It seems to me that what makes Panspermia a kind of concocted explanation for the appearance of life on Earth, is that it gives no reason for why we would expect the abiogenesis that must have happened somewhere to have been more likely to happen somewhere other than Earth. While there are gaps in our knowledge of how it happened on Earth, the gaps for how it might have happened elsewhere are even greater. And the gaps in how it might have migrated in a likely way to Earth are even greater than that.

PairTheBoard

vhawk01

05-22-2007, 12:44 PM

[ QUOTE ]
[ QUOTE ]
Doesn't all of that evidence sound very similar to "RNA are able to self-replicate, although not in standard conditions, but hey, its possible," and "It is entirely logically possible that some simpler self-replicating molecule existed prior to RNA taking over?"

[/ QUOTE ]

It would sound similiar if we said something like "we proved in computer simulations that its possible for rocks to be blasted off mars and land on earth" However thats not the case...in actuallity we can hold in our hands rocks that have been blasted off mars and landed on earth as meteorites.

Its a fact, that in the natural environment, material passes between mars and the earth. We can't say the same for the self replicating molecules necessary for abiogenesis. Those molecules don't exist in the natural environment, and in the 50 years since Millers experiment they haven't been produced in the labatory in plausable prebiotic earth conditions. The flow of evidence for the hypothesis of abiogenesis is stalled, but for hypothesis of panspermia it continues to move forward.

Stu

[/ QUOTE ]

Right, but we arent trying to prove rocks blast off, we are trying to prove that life came here on some of those rocks. All you are doing is demonstrating the basic, theoretical steps required for something like panspermia to be possible. None of that is evidence, in itself, of any sort of panspermia. This is very analogous to all the RNA data you are dismissing...none of it is proof of abiogenesis, but it demonstrates how it could be possible for it to occur.

Stu Pidasso

05-22-2007, 02:58 PM

[ QUOTE ]
I would, however, like to know your stance here (sorry if you've mentioned it in previous posts). Is it that evolution is cool('natural'...you know my drift i presume), but abiogenesis required intervention of some sort?

[/ QUOTE ]

Hi Arahant,

I don't have a problem with abiogenesis being accepted as a hypothesis. The issues I have is otherwise intelligent people authoritively accept its conclusions. I guess everyone needs thier own theology.

Whats my stance on evolution? The theory explains what is observed. There is a tremendous amount of fossil evidence to support it. We can actually observe evolution occurring on the micro level. Once life started on earth its very likely it developed through an evolutionary process.

Abiogenesis requires, for lack of a better term, chemical evolution" to occur. If chemical evolution is a natural process why don't we observe it today?

Stu

vhawk01

05-22-2007, 04:35 PM

[ QUOTE ]
[ QUOTE ]
I would, however, like to know your stance here (sorry if you've mentioned it in previous posts). Is it that evolution is cool('natural'...you know my drift i presume), but abiogenesis required intervention of some sort?

[/ QUOTE ]

Hi Arahant,

I don't have a problem with abiogenesis being accepted as a hypothesis. The issues I have is otherwise intelligent people authoritively accept its conclusions. I guess everyone needs thier own theology.

Whats my stance on evolution? The theory explains what is observed. There is a tremendous amount of fossil evidence to support it. We can actually observe evolution occurring on the micro level. Once life started on earth its very likely it developed through an evolutionary process.

Abiogenesis requires, for lack of a better term, chemical evolution" to occur. If chemical evolution is a natural process why don't we observe it today?

Stu

[/ QUOTE ]

There are people who 'authoritatively accept its conclusions?' It seems to me that all talk about abiogenesis is constantly infused with hedge words, and it is made abundantly clear that the data is not in yet, and no hard conclusions can be made.

The only reason we 'prefer' abiogenesis over panspermia is that panspermia doesn't really help us much, although it helps a little.

The only reason we prefer abiogenesis over divine providence is because divine providence doesn't help us AT ALL.

PairTheBoard

05-22-2007, 05:14 PM

[ QUOTE ]
The only reason we 'prefer' abiogenesis over panspermia is that panspermia doesn't really help us much, although it helps a little.

[/ QUOTE ]

I don't see how panspermia helps us at all. The fundamental question is, how did life in the Universe come about? We know it did come about because we have it here on Earth. Assuming there was no life during the Big Bang, life in the Universe must have come from nonliving matter. Panspermia does nothing to explain how that could have happened. Our observations of how that could have happened right here on Earth does do something to explain it.

Of course, Divine intervention does something to explain it as well. It's just not something science includes in its working assumptions about how the universe works.

PairTheBoard

vhawk01

05-22-2007, 07:14 PM

[ QUOTE ]
[ QUOTE ]
The only reason we 'prefer' abiogenesis over panspermia is that panspermia doesn't really help us much, although it helps a little.

[/ QUOTE ]

I don't see how panspermia helps us at all. The fundamental question is, how did life in the Universe come about? We know it did come about because we have it here on Earth. Assuming there was no life during the Big Bang, life in the Universe must have come from nonliving matter. Panspermia does nothing to explain how that could have happened. Our observations of how that could have happened right here on Earth does do something to explain it.

Of course, Divine intervention does something to explain it as well. It's just not something science includes in its working assumptions about how the universe works.

PairTheBoard

[/ QUOTE ]

The reason panspermia helps us is because it answers some questions...just not the one you posed. But thats not the ONLY question that matters. It would tell us there is certainly life elsewhere in the universe (ZOMG OTHER THREAD OVER!) and it would explain how life got started on Earth. It doesn't answer your question, but I don't know that yours is the penultimate question anyhow.

Divine intervention 'answers' the question just fine, it just doesn't help us. We can't base anything else on that knowledge, there wouldn't be any practical implications. It would be knowledge in a vaccuum.

PairTheBoard

05-22-2007, 08:00 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
The only reason we 'prefer' abiogenesis over panspermia is that panspermia doesn't really help us much, although it helps a little.

[/ QUOTE ]

I don't see how panspermia helps us at all. The fundamental question is, how did life in the Universe come about? We know it did come about because we have it here on Earth. Assuming there was no life during the Big Bang, life in the Universe must have come from nonliving matter. Panspermia does nothing to explain how that could have happened. Our observations of how that could have happened right here on Earth does do something to explain it.

Of course, Divine intervention does something to explain it as well. It's just not something science includes in its working assumptions about how the universe works.

PairTheBoard

[/ QUOTE ]

The reason panspermia helps us is because it answers some questions...just not the one you posed. But thats not the ONLY question that matters. It would tell us there is certainly life elsewhere in the universe (ZOMG OTHER THREAD OVER!) and it would explain how life got started on Earth. It doesn't answer your question, but I don't know that yours is the penultimate question anyhow.

Divine intervention 'answers' the question just fine, it just doesn't help us. We can't base anything else on that knowledge, there wouldn't be any practical implications. It would be knowledge in a vaccuum.

[/ QUOTE ]

I wouldn't call it "punulitmate". But I think it is one that the Science of Evolution is intensely interested in.

PairTheBoard

vhawk01

05-22-2007, 08:43 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
The only reason we 'prefer' abiogenesis over panspermia is that panspermia doesn't really help us much, although it helps a little.

[/ QUOTE ]

I don't see how panspermia helps us at all. The fundamental question is, how did life in the Universe come about? We know it did come about because we have it here on Earth. Assuming there was no life during the Big Bang, life in the Universe must have come from nonliving matter. Panspermia does nothing to explain how that could have happened. Our observations of how that could have happened right here on Earth does do something to explain it.

Of course, Divine intervention does something to explain it as well. It's just not something science includes in its working assumptions about how the universe works.

PairTheBoard

[/ QUOTE ]

The reason panspermia helps us is because it answers some questions...just not the one you posed. But thats not the ONLY question that matters. It would tell us there is certainly life elsewhere in the universe (ZOMG OTHER THREAD OVER!) and it would explain how life got started on Earth. It doesn't answer your question, but I don't know that yours is the penultimate question anyhow.

Divine intervention 'answers' the question just fine, it just doesn't help us. We can't base anything else on that knowledge, there wouldn't be any practical implications. It would be knowledge in a vaccuum.

[/ QUOTE ]

I wouldn't call it "punulitmate". But I think it is one that the Science of Evolution is intensely interested in.

PairTheBoard

[/ QUOTE ]

I wouldn't call it punulitmate either! /images/graemlins/grin.gif

PairTheBoard

05-22-2007, 09:14 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
The only reason we 'prefer' abiogenesis over panspermia is that panspermia doesn't really help us much, although it helps a little.

[/ QUOTE ]

I don't see how panspermia helps us at all. The fundamental question is, how did life in the Universe come about? We know it did come about because we have it here on Earth. Assuming there was no life during the Big Bang, life in the Universe must have come from nonliving matter. Panspermia does nothing to explain how that could have happened. Our observations of how that could have happened right here on Earth does do something to explain it.

Of course, Divine intervention does something to explain it as well. It's just not something science includes in its working assumptions about how the universe works.

PairTheBoard

[/ QUOTE ]

The reason panspermia helps us is because it answers some questions...just not the one you posed. But thats not the ONLY question that matters. It would tell us there is certainly life elsewhere in the universe (ZOMG OTHER THREAD OVER!) and it would explain how life got started on Earth. It doesn't answer your question, but I don't know that yours is the penultimate question anyhow.

Divine intervention 'answers' the question just fine, it just doesn't help us. We can't base anything else on that knowledge, there wouldn't be any practical implications. It would be knowledge in a vaccuum.

[/ QUOTE ]

I wouldn't call it "punulitmate". But I think it is one that the Science of Evolution is intensely interested in.

PairTheBoard

[/ QUOTE ]

I wouldn't call it punulitmate either! /images/graemlins/grin.gif

[/ QUOTE ]

LOL. Pardon the pun.

PairTheBoard

m_the0ry

05-22-2007, 09:22 PM

way too many nested quotes!

PairTheBoard

05-22-2007, 09:39 PM

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
The only reason we 'prefer' abiogenesis over panspermia is that panspermia doesn't really help us much, although it helps a little.

[/ QUOTE ]

I don't see how panspermia helps us at all. The fundamental question is, how did life in the Universe come about? We know it did come about because we have it here on Earth. Assuming there was no life during the Big Bang, life in the Universe must have come from nonliving matter. Panspermia does nothing to explain how that could have happened. Our observations of how that could have happened right here on Earth does do something to explain it.

Of course, Divine intervention does something to explain it as well. It's just not something science includes in its working assumptions about how the universe works.

PairTheBoard

[/ QUOTE ]

The reason panspermia helps us is because it answers some questions...just not the one you posed. But thats not the ONLY question that matters. It would tell us there is certainly life elsewhere in the universe (ZOMG OTHER THREAD OVER!) and it would explain how life got started on Earth. It doesn't answer your question, but I don't know that yours is the penultimate question anyhow.

Divine intervention 'answers' the question just fine, it just doesn't help us. We can't base anything else on that knowledge, there wouldn't be any practical implications. It would be knowledge in a vaccuum.

[/ QUOTE ]

I wouldn't call it "punulitmate". But I think it is one that the Science of Evolution is intensely interested in.

PairTheBoard

[/ QUOTE ]

I wouldn't call it punulitmate either! /images/graemlins/grin.gif

[/ QUOTE ]

LOL. Pardon the pun.

PairTheBoard

[/ QUOTE ]

way too many nested quotes!

[/ QUOTE ]

Less than a googolplex!!

PairTheBoard