the self replicating watch argument

[xianghua]

...Biology 101.

any reference? calculation? something?

 

[doubtingmerle]

any reference? calculation? something?

Yes. Biology 101 has references and calculations.

 

[Speedwell]

any reference? calculation? something?

It's not a matter of calculation, its a matter of definition. If evoluution of mammals ocurred twice it would be a violation of the nested heirarchy principle.

 

[pitabread]

i dont think its possible. we need to start from something. we know for instance that even a simple function like binding to a molecule will need about 40-50 amino acids (by experiment). so if we assume at least 2 parts for a minimal protein function (say a protein that bind two molecules to each other). we will need about 90-100 aa to begin with.

IIRC, functionally minimal proteins can have as a few as only 10 amino acids. So no, you don't need 90-100 to begin with.

 

[xianghua]

Yes. Biology 101 has references and calculations.

where them?

 

[doubtingmerle]

where them?

In the textbook.

 

[xianghua]

It's not a matter of calculation, its a matter of definition. If evoluution of mammals ocurred twice it would be a violation of the nested heirarchy principle.

no its not. it will be call "convergent evolution".

 

[xianghua]

In the textbook.

so you have no real reference. thanks .

 

[xianghua]

IIRC, functionally minimal proteins can have as a few as only 10 amino acids. So no, you don't need 90-100 to begin with.

its depent in the function. even a single amino acid may do something in the cell. but we are talking about a tipical function that required something like 100aa to begin with.

 

[Speedwell]

no its not. it will be call "convergent evolution".

No, that's not what "convergent evolution" means. Convergent evolution is about mere functional similarty, not identity.

 

[pitabread]

its depent in the function. even a single amino acid may do something in the cell. but we are talking about a tipical function that required something like 100aa to begin with.

What is the minimum number of letters required to fold a protein? - PubMed - NCBI

Experimental studies have shown that the full sequence complexity of naturally occurring proteins is not required to generate rapidly folding and functional proteins, i.e. proteins can be designed with fewer than 20 letters. This raises the question of what is the minimum number of amino acid types required to encode complex protein folds? Here, we investigate this issue from three aspects. First, we study the minimum sequence complexity that can reserve the necessary structural information for detection of distantly related homologues. Second, we compare the ability of designing foldable model sequences over a wide range of reduced amino acid alphabets, which find the minimum number of letters that have the similar design ability as 20. Finally, we survey the lower bound of alphabet size of globular proteins in a non-redundant protein database. These different approaches give a remarkably consistent view, that the minimum number of letters required to fold a protein is around ten.

 

[xianghua]

No, that's not what "convergent evolution" means. Convergent evolution is about mere functional similarty, not identity.

if so the similalrity between apes and human is also the result of convergent evolution rather then a common descent. since they arent identical.

 

[xianghua]

What is the minimum number of letters required to fold a protein? - PubMed - NCBI

its just folding. not function. as i said: even a single amino acid may be functional. but it doesnt mean that complex proteins can evolve stepwise from a single amino acid. this protein for instance need at least 2 pockets for its substrate (the function in this case is to separate a molecule into two pieces). so 10 aa will not help you in this case:

(image from File:Figure 06 05 03.jpg - Wikimedia Commons)

 

[Speedwell]

if so the similalrity between apes and human is also the result of convergent evolution rather then a common descent. since they arent identical.

No. "Ape" is not a single species--it's a family of species to which humans belong.
In any case, to show convergent evolution you would have to show that the two ancestral lines started out as something different. for example, some mammals, insects and birds developed the ability to fly. That is convergent evolution. Similarities between closely related species is not.

 

[xianghua]

Similarities between closely related species is not.

actually many traits among closely related species suppose to be the result of convergent evoluton. so its not realy true.

 

[Speedwell]

actually many taits among closely related species suppose to be the result of convergent evoluton. so its not realy true.

You have an example in mind?

 

[xianghua]

You have an example in mind?

here for instance:

Extreme morphological and ecological homoplasy in tropical salamanders

 

[Anguspure]

First of all: Happy new years day to you.

1. That would be fine if we only had one draw from the hat, and

2. We had to get the entire sequence in one shot.

In respect of a self replicating system, I am afraid that one shot is all you've got before you have to start all over again.

But neither applies here. As has been pointed out, a huge number of draws from the hat likely occurred. Given enough draws from the hat, an incredibly improbable event becomes LIKELY...in fact, a fantastically improbable event even becomes a virtual certainty if given infinite draws.

There have only been 15 billion years or so and the vast majority of that time has not been conducive to any form of biogenesis. Nevertheless for th sake of good humour we'll give you 15 billion years. The chances don't even come close. The number runs to a factor of more than 120. It is an actual physical impossibility to have drawn from the hat that many times.

Secondly, the 50 amino acid sequence need not happen all at once, if a smaller sequence is sufficient to sustain the organism. Then small changes can be added piecemeal after that.

Your probability estimate is not analogous to evolution or abiogenesis, because it assumes 1 pull from the hat, and a larger initial target from that one pull.

Larger target? A larger target increases probability, but even the larger target is irrellevant really because it still does not produce a self replicating organism.
So how long do you expect the parts of the sequence to hang aroud blindly? 3 or 4 billion years?
Don't go doing what Dawkins has done by introducing a direction to your calculations, that would not be representative.

 

[Anguspure]

You have an example in mind?

One of the greatest ironies in the field of evolutionary biology is the point made by Rupert Riedl that if the homologs were not in fact distinct, if no Type-defining homologs existed, then it would be impossible to build a tree of life showing the derivation of all extant forms of a particular clade from a common ancestor.... How ironic that for Richard Dawkins and other defenders of the Darwinian faith the very notion of evolution depends on the fixity of the Type.
Denton, Michael. Evolution: Still a Theory in Crisis
So we have (inter alia):

• The living cell;
• The enucleate red cell (mammals);
• Angiosperms;
• The Pentadactyl limb;
  
• Avian Feathers;
• Bat wings;
• The life cycle of the European Fresh Water Eel;
• Language.

According to Fred Hoyle’s famous calculation, the probability of the evolution of cellular life by chance is about one in 10 to the 40,000. (Evolution from Space a Theory of Cosmic Creation 1984)
Denton, Michael. Evolution: Still a Theory in Crisis (p. 226). Discovery Institute Press. Kindle Edition.

 

[Anguspure]

What argument? All I have seen is your argument from probability that a specific chain is unlikely. Sure, but I am not taking about specific chains, but about non-specific chains that have a slight tendency to catalyze something like themselves.





Are you aware that in an open system entropy at a local point can decrease?

Yes, and I have just bought a Lotto for every week of this year, full in the expectation that each and every one will win the major prize.
I promise that I will share the winnings with you at the end of the year if indeed this happens.