Genesis

[Geir74]

Every lifeform on earth has evolved from one single string of self-replicating DNA/RNA.

A simple bacteria has a few 100 K basepairs (4 combinations of each pair).

There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.

I would like to get some estimations/guesses as to what this limit is (200/500/5.000/50.000 basepairs).

Please include the number of combinations that nature would have to seek through in order to have a 100 % chance (or 1 % if you like) of finding that unique minimum “working solution”. (You can calculate with replacement for simplicity:1 basepair = 4, 2 basepairs = 16, 3 basepairs = 64 …. basepairs^4)

The observable universe contains about 10^80 atoms, and has existed about 10^10 years.

I often hear highly intelligent and educated people say thing like:

1. If there is water on Mars, we have a good chance of finding life there.
2. The universe is so big, obviously there are other lifeforms out there.
3. The universe is filled with the chemicals of life, of course we’re not alone.


I simply do not get their logic.

Please enlighten me.

PS: I don’t think Darwin was wrong. I just have a very strong feeling that in a 100 years from now, we will wiev his theory of evolution excactly like we see Newton compared to Einstein regarding gravity; Newton was 99.99 % accurate, but … woooow – what a difference.

[vhawk01]

[ QUOTE ]
Every lifeform on earth has evolved from one single string of self-replicating DNA/RNA.

A simple bacteria has a few 100 K basepairs (4 combinations of each pair).

There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.

I would like to get some estimations/guesses as to what this limit is (200/500/5.000/50.000 basepairs).

Please include the number of combinations that nature would have to seek through in order to have a 100 % chance (or 1 % if you like) of finding that unique minimum “working solution”. (You can calculate with replacement for simplicity:1 basepair = 4, 2 basepairs = 16, 3 basepairs = 64 …. basepairs^4)

The observable universe contains about 10^80 atoms, and has existed about 10^10 years.

I often hear highly intelligent and educated people say thing like:

1. If there is water on Mars, we have a good chance of finding life there.
2. The universe is so big, obviously there are other lifeforms out there.
3. The universe is filled with the chemicals of life, of course we’re not alone.


I simply do not get their logic.

Please enlighten me.

PS: I don’t think Darwin was wrong. I just have a very strong feeling that in a 100 years from now, we will wiev his theory of evolution excactly like we see Newton compared to Einstein regarding gravity; Newton was 99.99 % accurate, but … woooow – what a difference.

[/ QUOTE ]

Just as a quick starting point, it helps a lot in these types of discussions if we can get definitions clear up front. What exactly do you mean by 'independent self-replication?' What is it about viruses, specifically, that disqualify them?

[vhawk01]

Also, I think it is important to note, that as far as I can tell nothing you are asking about, nor anything these so-called 'highly intelligent people' are talking about, has anything to do with evolution. Darwin cannot answer your questions for you. What you are talking about is abiogenesis, at least that is how it appears. IOW, evolution takes as a given that imperfect replicators appeared, somehow, some way, and uses that as its starting point.

[Geir74]

[ QUOTE ]
Just as a quick starting point, it helps a lot in these types of discussions if we can get definitions clear up front. What exactly do you mean by 'independent self-replication?' What is it about viruses, specifically, that disqualify them?

[/ QUOTE ]
Viruses cannot replicate without bacterias or cells; they lack the fundamental machinery of independent life.

[vhawk01]

[ QUOTE ]
[ QUOTE ]
Just as a quick starting point, it helps a lot in these types of discussions if we can get definitions clear up front. What exactly do you mean by 'independent self-replication?' What is it about viruses, specifically, that disqualify them?

[/ QUOTE ]
Viruses cannot replicate without bacterias or cells; they lack the fundamental machinery of independent life.

[/ QUOTE ]

Bacteria cannot replicate without materials or a proper environment as well. IOW, is there really any such thing as 'independent' life, or are bacteria and humans simply MORE independent than viruses?

[Geir74]

[ QUOTE ]
Also, I think it is important to note, that as far as I can tell nothing you are asking about, nor anything these so-called 'highly intelligent people' are talking about, has anything to do with evolution. Darwin cannot answer your questions for you. What you are talking about is abiogenesis, at least that is how it appears. IOW, evolution takes as a given that imperfect replicators appeared, somehow, some way, and uses that as its starting point.

[/ QUOTE ]
I'll clearify:
I cannot see how nature can create new functionality by an isolated try and failure approach, simply because the number of search combinations is far to large; for example photo-synthesis.
My point is that the creation of a self-replicating chemical system from a pool of chemicals is by far the most giant evolutionary leap.

[vhawk01]

[ QUOTE ]
[ QUOTE ]
Also, I think it is important to note, that as far as I can tell nothing you are asking about, nor anything these so-called 'highly intelligent people' are talking about, has anything to do with evolution. Darwin cannot answer your questions for you. What you are talking about is abiogenesis, at least that is how it appears. IOW, evolution takes as a given that imperfect replicators appeared, somehow, some way, and uses that as its starting point.

[/ QUOTE ]
I'll clearify:
I cannot see how nature can create new functionality by an isolated try and failure approach, simply because the number of search combinations is far to large; for example photo-synthesis.
My point is that the creation of a self-replicating chemical system from a pool of chemicals is by far the most giant evolutionary leap.

[/ QUOTE ]

I think most people would agree with all of this, as long as this is what you specifically mean. I personally agree that it seems like the greatest leap (not sure I'd use the word evolutionary, but not sure I wouldn't, either) and I also agree that I don't understand it.

There are lots of things I don't understand. Again, I'll repeat, this has nothing to do with Darwin or the theory of evolution. It may sound weird that I keep saying this, but you did make a few allusions in your OP, and experience has made me wary.

[Geir74]

[ QUOTE ]
Bacteria cannot replicate without materials or a proper environment as well. IOW, is there really any such thing as 'independent' life, or are bacteria and humans simply MORE independent than viruses?

[/ QUOTE ]

Viruses need life to replicate.
Bacteria need a "dead" invironment to replicate.

There is a fundamental difference, but this is not my point. Be free to construct a self-replicating virus if you wish.

[Dominic]

[ QUOTE ]

Just as a quick starting point, it helps a lot in these types of discussions if we can get definitions clear up front. What exactly do you mean by 'independent self-replication?' What is it about viruses, specifically, that disqualify them?

[/ QUOTE ]

Tyrell: The facts of life. To make an alteration in the evolvment of an organic life system is fatal. A coding sequence cannot be revised once it's been established.

Roy: Why not?

Tyrell: Because by the second day of incubation, any cells that have undergone reversion mutations give rise to revertant colonies like rats leaving a sinking ship. Then the ship sinks.

Roy: What about EMS recombination.

Tyrell: We've already tried it. Ethyl methane sulfonate as an alkylating agent a potent mutagen It created a virus so lethal the subject was dead before he left the table.

Roy: Then a repressive protein that blocks the operating cells.

Tyrell: Wouldn't obstruct replication, but it does give rise to an error in replication so that the newly formed DNA strand carries the mutation and you've got a virus again. But, uh, this-- all of this is academic. You were made as well as we could make you.

Roy: But not to last.

[vhawk01]

[ QUOTE ]
[ QUOTE ]
Bacteria cannot replicate without materials or a proper environment as well. IOW, is there really any such thing as 'independent' life, or are bacteria and humans simply MORE independent than viruses?

[/ QUOTE ]

Viruses need life to replicate.
Bacteria need a "dead" invironment to replicate.

There is a fundamental difference, but this is not my point. Be free to construct a self-replicating virus if you wish.

[/ QUOTE ]

Of course, the obvious problem is that there isn't really any line between 'life' and a 'dead environment.' There may be, in practice (although I think viruses blur this line) but there isn't really. However, I don't want to hijack any further.

[Geir74]

[ QUOTE ]
Again, I'll repeat, this has nothing to do with Darwin or the theory of evolution.

[/ QUOTE ]

Most people automatically assumes that coincidenses are the only force behind evolution (as Darwin describes it). THIS, I think is very wrong.

To be absolutely clear: Bacteria -> fish -> apes -> humans.

My point: I do not belive that coincidenses are the force behind this story.

I'm not religious by any means.

[CallMeIshmael]

[ QUOTE ]
My point is that the creation of a self-replicating chemical system from a pool of chemicals is by far the most giant evolutionary leap.

[/ QUOTE ]

My main problem with comments like these, is that, although the chances of abiogenesis are likely very very small, the search space for trials is very very large. Keep in mind, of course, IF the nonlife->life argument is true, then the process is only observed after it has happened.

Even if we assign the chances of it occuring over a non-infinite timespan to a very very small number, 10^23 planets(23ish?.. I cant remember) over billions of years still gives the universe a ton of attempts.

[Geir74]

[ QUOTE ]
although the chances of abiogenesis are likely very very small, the search space for trials is very very large.

[/ QUOTE ]

You are avoiding my question. How much is very, very small? Estimate a number of a minimum amount of basepairs needed for self-replication.

[ QUOTE ]
IF the nonlife->life argument is true, then the process is only observed after it has happened.


[/ QUOTE ]
Yes, with an infinite number of universes, abiogenesis is bound to happen. The winner in a giant lottery will always ask "why me? its so unlikely", even though someone was bound to win.

I do not like this argument for several reasons, but I won't argue against at the moment. I'm more interested in the number of basepairs needed to create a self-replicating RNA-string.
Just make an educated guess.

[PairTheBoard]

[ QUOTE ]
Just make an educated guess.


[/ QUOTE ]

1

What's a base pair?

PairTheBoard

[Geir74]

[ QUOTE ]
What's a base pair?

[/ QUOTE ]
Bases are the chemicals that code genetic information.
A computer program consists of a binary code 1011100011...
The software of life (DNA/RNA), looks like GCUGAUAGGCGC...

The 4 bases are:
G is guanine. (Pair with C)
A is adenine. (Pair with U)
C is cytosine.
U is uracil.

[thylacine]

[ QUOTE ]
Every lifeform on earth has evolved from one single string of self-replicating DNA/RNA.

A simple bacteria has a few 100 K basepairs (4 combinations of each pair).

There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.

I would like to get some estimations/guesses as to what this limit is (200/500/5.000/50.000 basepairs).

Please include the number of combinations that nature would have to seek through in order to have a 100 % chance (or 1 % if you like) of finding that unique minimum “working solution”. (You can calculate with replacement for simplicity:1 basepair = 4, 2 basepairs = 16, 3 basepairs = 64 …. basepairs^4)

The observable universe contains about 10^80 atoms, and has existed about 10^10 years.

I often hear highly intelligent and educated people say thing like:

1. If there is water on Mars, we have a good chance of finding life there.
2. The universe is so big, obviously there are other lifeforms out there.
3. The universe is filled with the chemicals of life, of course we’re not alone.


I simply do not get their logic.

Please enlighten me.

PS: I don’t think Darwin was wrong. I just have a very strong feeling that in a 100 years from now, we will wiev his theory of evolution excactly like we see Newton compared to Einstein regarding gravity; Newton was 99.99 % accurate, but … woooow – what a difference.

[/ QUOTE ]

Any short string of DNA can replicate. Take any double strand, as short as you like, unzip it into two single strands, let new bases fall into place to get back to double strands, and TA-DAAAA!, it has replicated. Starting from these, or other, simple replicators, evolution kicks in, and 100million years or so should allow ample time to evolve simple bacteria etc.

You simply don't need highly complicated improbable things to spontaneously form. You just need simple replicators and stable conditions.

Richard Dawkins has explained this more times than there are atoms in the universe.

[Alex-db]

[ QUOTE ]
Most people automatically assumes that coincidenses are the only force behind evolution (as Darwin describes it). THIS, I think is very wrong.

[/ QUOTE ]

You're right, its completely wrong.

Its not what Darwin said. I recommend The Blind Watchmaker by Dawkins for a simple explantation.

Summary; its not driven by coincidence, its driven by selection.

[vhawk01]

[ QUOTE ]
[ QUOTE ]
Again, I'll repeat, this has nothing to do with Darwin or the theory of evolution.

[/ QUOTE ]

Most people automatically assumes that coincidenses are the only force behind evolution (as Darwin describes it). THIS, I think is very wrong.

To be absolutely clear: Bacteria -> fish -> apes -> humans.

My point: I do not belive that coincidenses are the force behind this story.

I'm not religious by any means.

[/ QUOTE ]

None of this has anything to do with your OP, which was about the improbability of nature stumbling upon the first replicators.

Also, perhaps MOST people assume this, but then, most people in the United States do not even believe in evolution. I think its fair to say that what most people believe about evolution is very likely to be wrong.

Coincidence (while still waiting for a definition of what that means exactly) is most certainly not the only thing driving evolution. Its definitely not the only thing Darwin described...perhaps you've heard of natural selection?

[vhawk01]

[ QUOTE ]
[ QUOTE ]
Every lifeform on earth has evolved from one single string of self-replicating DNA/RNA.

A simple bacteria has a few 100 K basepairs (4 combinations of each pair).

There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.

I would like to get some estimations/guesses as to what this limit is (200/500/5.000/50.000 basepairs).

Please include the number of combinations that nature would have to seek through in order to have a 100 % chance (or 1 % if you like) of finding that unique minimum “working solution”. (You can calculate with replacement for simplicity:1 basepair = 4, 2 basepairs = 16, 3 basepairs = 64 …. basepairs^4)

The observable universe contains about 10^80 atoms, and has existed about 10^10 years.

I often hear highly intelligent and educated people say thing like:

1. If there is water on Mars, we have a good chance of finding life there.
2. The universe is so big, obviously there are other lifeforms out there.
3. The universe is filled with the chemicals of life, of course we’re not alone.


I simply do not get their logic.

Please enlighten me.

PS: I don’t think Darwin was wrong. I just have a very strong feeling that in a 100 years from now, we will wiev his theory of evolution excactly like we see Newton compared to Einstein regarding gravity; Newton was 99.99 % accurate, but … woooow – what a difference.

[/ QUOTE ]

Any short string of DNA can replicate. Take any double strand, as short as you like, unzip it into two single strands, let new bases fall into place to get back to double strands, and TA-DAAAA!, it has replicated. Starting from these, or other, simple replicators, evolution kicks in, and 100million years or so should allow ample time to evolve simple bacteria etc.

You simply don't need highly complicated improbable things to spontaneously form. You just need simple replicators and stable conditions.

Richard Dawkins has explained this more times than there are atoms in the universe.

[/ QUOTE ]

This is why I was trying to nail him down with regards to viruses, bacteria, and living organisms. No one would say these strands of yours are living, and yet they may still repeatedly and predictably replicated. As long as they do not replicate 100% accurately, however, eventually some replicants will be slightly different. If these are better at replicating, we have evolution. Evolution, as far as I know (Rduke may need to correct me) does not require living substrates, simply non-perfect replicators. Evolution works on viruses as well as it does on bacteria and humans, and it even works on Thylacine Replicators.

[CallMeIshmael]

[ QUOTE ]
[ QUOTE ]
although the chances of abiogenesis are likely very very small, the search space for trials is very very large.

[/ QUOTE ]

You are avoiding my question. How much is very, very small? Estimate a number of a minimum amount of basepairs needed for self-replication.

[/ QUOTE ]


Your question was: how many base pairs are needed for self replicating DNA. Im not avoiding that, its a very small number. If you have a stand of RNA, getting the DNA from that doesnt require a whole lot. You dont need many bps. This is basic science.

The question of exactly how likely is abiogeneis (which, just in case there is confusion, requires a hell of a lot more than a replicating strand of DNA) is just about impossible to nail down, so trying to ask it is silly.

[ QUOTE ]
I do not like this argument for several reasons, but I won't argue against at the moment. I'm more interested in the number of basepairs needed to create a self-replicating RNA-string.
Just make an educated guess.

[/ QUOTE ]

Educated guess: a few.

Please argue against it; Im curious.

[Jetboy2]

[ QUOTE ]
My point is that the creation of a self-replicating chemical system from a pool of chemicals is by far the most giant evolutionary leap.

[/ QUOTE ]

You're right. A self-replicating chemical system would be extremely unlikely to develop in a stagnant pool of chemicals. Actually, I don't see it happening. However, I could imagine abiogenesis occurring in a dynamic geologic, hydrologic system.

As for Darwin, well, he came up with a general concept at a time without any of our current structural/functional knowledge of genetics or biochemistry. So, I'm thinking he did pretty well considering what he had to work with.

[arahant]

[ QUOTE ]
There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.


[/ QUOTE ]

I would say that 50 is clearly enough for self-replication. IIRC, 3 bp sequences have been found that can self-replicate.

[vhawk01]

[ QUOTE ]
[ QUOTE ]
There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.


[/ QUOTE ]

I would say that 50 is clearly enough for self-replication. IIRC, 3 bp sequences have been found that can self-replicate.

[/ QUOTE ]

Just look at PCR. I don't think you can reliable replicate strands as short as 3 bp, but certainly relatively short segments.

[arahant]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.


[/ QUOTE ]

I would say that 50 is clearly enough for self-replication. IIRC, 3 bp sequences have been found that can self-replicate.

[/ QUOTE ]

Just look at PCR. I don't think you can reliable replicate strands as short as 3 bp, but certainly relatively short segments.

[/ QUOTE ]

Well, here's 32 anyway - Link (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=870022 5&dopt=Abstract)

I'm sure I can find better.

[Jetboy2]

Amusing....

I can make a nice dinner out of a dead pig and some colorful plants....

Otherwise, text on a computer screen is meaningless.

[thylacine]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.


[/ QUOTE ]

I would say that 50 is clearly enough for self-replication. IIRC, 3 bp sequences have been found that can self-replicate.

[/ QUOTE ]

Just look at PCR. I don't think you can reliable replicate strands as short as 3 bp, but certainly relatively short segments.

[/ QUOTE ]

Well, here's 32 anyway - Link (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=870022 5&dopt=Abstract)

I'm sure I can find better.

[/ QUOTE ]

Those are amino chains, and they say they replicate `autocatalytically '. So 32 is pretty small for replication with these sophisticated characteristics.

But my point is that you don't need autocatalysis, or any catalysis at all, for the first replicators. Any kind of replicators are enough for evolution to kick in. And they can be chains (DNA, RNA, amino chains) as short as you like, e.g. length one, or any other kind of very simple replicator. Replication can be direct or indirect. Catalysts can be discovered later as competition escalates.

[arahant]

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[ QUOTE ]
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[ QUOTE ]
There has to exist a theoretical minimum limit amount of basepairs that are needed for independent (not viruses) self-replication; 50 is obviously not enough.


[/ QUOTE ]

I would say that 50 is clearly enough for self-replication. IIRC, 3 bp sequences have been found that can self-replicate.

[/ QUOTE ]

Just look at PCR. I don't think you can reliable replicate strands as short as 3 bp, but certainly relatively short segments.

[/ QUOTE ]

Well, here's 32 anyway - Link (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=870022 5&dopt=Abstract)

I'm sure I can find better.

[/ QUOTE ]

Those are amino chains, and they say they replicate `autocatalytically '. So 32 is pretty small for replication with these sophisticated characteristics.

But my point is that you don't need autocatalysis, or any catalysis at all, for the first replicators. Any kind of replicators are enough for evolution to kick in. And they can be chains (DNA, RNA, amino chains) as short as you like, e.g. length one, or any other kind of very simple replicator. Replication can be direct or indirect. Catalysts can be discovered later as competition escalates.

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Couldn't agree more. I was just establishing an upper bound on how simplistic things could be.

Where's OP now!?

[thylacine]

[ QUOTE ]
Where's OP now!?

[/ QUOTE ]

Hey Geir74 we've explained the flaw in your thinking. Do you understand now?

[vhawk01]

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Where's OP now!?

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Hey Geir74 we've explained the flaw in your thinking. Do you understand now?

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Trying my best not to be cynical...