Information

[Guest Uncle Screwtape]

Okay, I'm new to this forum and I know that there are some educated scientists who post here, so I was wondering if you could clear something up for me. On another message board a creationist said the following about what constituted information.

 

The sum or range of instructions which is transmitted from an origin to a destination, and is qualitatively new to that destination. Its only quantitative quality is that of specificity, the more specific the more information is transmitted. Information can be broken down into its smallest pieces (in this case nucleotides).

 

The person who was debating them pretty much dismissed the creationists, but I didn't follow his reasoning. Additionally the creationist said the following:

---

Ok, an example of of mutation(s) adding information, well there's a perfect example in the human immune system.

 

In order to increase affinity for antigen, antibodies of B cells undergo what is called somatic hypermutation. The following is a lecture explaining the process more fully

 

Regulation of B Cell Development and the Humoral Response II

 

article as pdf

 

Information is added when B cell AB(antibody) variable regions are mutated and then "tested" for antigen-binding affinity, and if affinity is low the cells undergo apoptosis. After many mayn rounds of random mutation and selection the affinity(specificity) for antigen is incresed extremely and therefore information is increased.

 

Now, before anyone says, "Thats how evolution works!!" read the following article, and also reread the lecture b/c some portions of the lecture make it obvious(even without meaning to).

 

The Unsuitability of B-Cell Maturation as an Analogy for Neo-Darwinian Theory

 

he article is long, but very thorough, and extremely interesting.

 

-----

 

Can someone explain this to me?

[Megistias]

 

The Unsuitability of B-Cell Maturation as an Analogy for Neo-Darwinian Theory

 

he article is long, but very thorough, and extremely interesting.

 

-----

 

Can someone explain this to me?

 

 

I'm getting a bad link error from the above site.

[Guest Uncle Screwtape]

 

The Unsuitability of B-Cell Maturation as an Analogy for Neo-Darwinian Theory

 

he article is long, but very thorough, and extremely interesting.

 

-----

 

Can someone explain this to me?

 

 

I'm getting a bad link error from the above site.

 

 

Sorry about that, this one should work.

[Zach]

Uncle Screwtape-

 

It sounds like you're referring to the use of Information Theory by Creationists to disprove Evolutionary Theory. Without getting too technical, Information Theory allows one to find patterns in data. It's extremely useful for the telecommunications industry, computer science, and can even relate to evolutionary theory through bioinformatics.

 

The problem, however, is when Creationists make this argument:

 

1) For an organism to evolve, the information in its genome must increase.

2) Mutations cannot be shown to increase genomic information.

3) Therefore, mutations cannot drive evolution.

 

The reason why this is a fallacious argument is because evolutionary theory does not claim the first premise. In fact, talking about "increasing information in the genome" is a completely unintelligible concept. What is defined as "information" in this argument? Is it strictly the number of nucleotides in the genome? The number of genes? Something else? The answers to those questions, in my experience, are always either absent or unhelpfully ambiguous.

 

In situations where I'm confronted with somebody making this Information Theory Fallacy, I usually ask the question, "Does a missense mutation add or remove information from a genome?"

[Megistias]

In situations where I'm confronted with somebody making this Information Theory Fallacy, I usually ask the question, "Does a missense mutation add or remove information from a genome?"

 

Hmmm. Made me think of anagrams.

 

Like Anagrams ?

 

Alaskan Grime ?

 

Making a Laser ?

 

 

The same letters are used but just by changing their order we change the meaning - and maybe change the answer.

 

Of course the meaningless jumbles of letters that don't mean anything are simply discarded.

[Zach]

That's a somewhat appropriate analogy for a missense mutation.

 

This might be a better one:

 

Before the mutation:

 

The red car drives down the street.

 

After the mutation:

 

The blue car drives down the street.

 

Which one has more information?

[Light_of_Reason]

From my studies of Information Theory, I recall that it dealt with both the total information of the message and the total entropy (uncertainty) contained within that message.

 

The problem with applying this theory to evolution is that mutations in biological beings does not increase or decrease the amount of information nor the amount of entropy. Instead, a mutation alters the pattern that the information is taking, and thus changes the message somewhat (much like the anagram analogy and the car analogy have shown). Since this can be done without altering the information and entropy within the system, information theory cannot be used to disprove evolution.

 

I guess another way of looking at it would be to say that mutations take advantage of the information, entropy, and noise already inherent within the system to make a change in the message being delivered.

[crazy-tiger]

The problem with applying this theory to evolution is that mutations in biological beings does not increase or decrease the amount of information nor the amount of entropy.

Minor point... there are mutations that do increase or decrease the amount of information. There may not be many, but they're out there.

[Guest Uncle Screwtape]

What is defined as "information" in this argument? Is it strictly the number of nucleotides in the genome? The number of genes? Something else? The answers to those questions, in my experience, are always either absent or unhelpfully ambiguous.

 

Thanks for the reply - I'm curious here, and I haven't read the link yet, but the creationist defined information as follows: "The sum or range of instructions which is transmitted from an origin to a destination, and is qualitatively new to that destination. Its only quantitative quality is that of specificity, the more specific the more information is transmitted. Information can be broken down into its smallest pieces (in this case nucleotides)."

 

I'm not an expert - is this definition ambigious? I don't know, I don't think it is, but I don't really know - he claims that it's falsifiable, but I cna't judge.

 

In situations where I'm confronted with somebody making this Information Theory Fallacy, I usually ask the question, "Does a missense mutation add or remove information from a genome?"

 

What is a missense mutation?

[Light_of_Reason]

Minor point... there are mutations that do increase or decrease the amount of information. There may not be many, but they're out there.

 

I had no idea about those. My specialization is information science, so I know a good bit about information theory, but have very little education in the biological sciences, and thus know very little about these mutations.

 

But tell me, do these mutations that increase information in the system have any effect upon the entropy of the system as well? In other words, as these mutations increase the information, do they increase or decrease the entropy (uncertainty) as a whole? My natural inclination is to assume that they would.

[crazy-tiger]

Minor point... there are mutations that do increase or decrease the amount of information. There may not be many, but they're out there.

 

I had no idea about those. My specialization is information science, so I know a good bit about information theory, but have very little education in the biological sciences, and thus know very little about these mutations.

 

But tell me, do these mutations that increase information in the system have any effect upon the entropy of the system as well? In other words, as these mutations increase the information, do they increase or decrease the entropy (uncertainty) as a whole? My natural inclination is to assume that they would.

I'm not sure... but considering the effects of the best-known nutation of that kind, I'd say so too. Down Syndrome

[Light_of_Reason]

the creationist defined information as follows: "The sum or range of instructions which is transmitted from an origin to a destination, and is qualitatively new to that destination. Its only quantitative quality is that of specificity, the more specific the more information is transmitted. Information can be broken down into its smallest pieces (in this case nucleotides)."

 

The only problem I have with his definition is that he attaches a quantitative quality of specificity to it. It seems that he wants to argue that the more specific the message sent, the more information that is transmitted.

 

I don't think this is necessarily the case. The purpose of most communication systems is to send the maximal meaningful message with the least amount of information required. In other words, most communication systems attempt to be as economical and efficient as possible when sending messages, and thus attempt to provide the most meaning in messages with the smallest amount of information required.

 

Emoticons, lax language rules, contractions, short hand, and many other examples abound where humans attempt maximal communication of a meaningful message with the minimal amount of information.

 

I would imagine that communication within a biological system would follow a similar model, and thus I think it may be premature to argue that the more specific the instruction, the more information transmitted. But I am more than ready to be proved incorrect in that assumption.

 

Minor point... there are mutations that do increase or decrease the amount of information. There may not be many, but they're out there.

 

I had no idea about those. My specialization is information science, so I know a good bit about information theory, but have very little education in the biological sciences, and thus know very little about these mutations.

 

But tell me, do these mutations that increase information in the system have any effect upon the entropy of the system as well? In other words, as these mutations increase the information, do they increase or decrease the entropy (uncertainty) as a whole? My natural inclination is to assume that they would.

I'm not sure... but considering the effects of the best-known nutation of that kind, I'd say so too. Down Syndrome

 

Thanks. I'll have to take a deeper look into that.

[Samurai Tailor]

What is a missense mutation?

It is a point mutation (in which a single nucleotide is altered) whereby one amino acid is substituted for another in a protein product. Often the protein is rendered nonfunctional, but a notable exception is the malfunctional beta-globin that causes sickle-cell disease.

[txviper]

"a missense mutation.

 

 

Before the mutation:

 

The red car drives down the street.

 

After the mutation:

 

The blue car drives down the street"

 

 

More like a wrecked blue car goes to the junkyard.

[All Gods Fail]

 

And your point is...?

[Zach]

More like a wrecked blue car goes to the junkyard.

I'm sorry, did I miss your mechanism of congruent horizontal endogenous retrovirus insertion?

[MrSpooky]

Ha! Burned!

[txviper]

Zach,

 

"I'm sorry, did I miss your mechanism of congruent horizontal endogenous retrovirus insertion?"

 

 

Oh I won't be able to list a mechanism. Do you have one in mind to account for the formation of DNA in the first place? If so, I hope it is more realistic than the nonsense expressed in the abiogenesis discussion.

 

The retovirus insertions make for a good argument. I would consider it valuable (if I were an evolutionist) in making a case for whether humans were closer to African as opposed to Asian apes. But if the dispute is about design vs. evolution, it is meaningless. With so much else unaccounted for, this is a nail clipping.

 

There are also other considerations which include why some infections were common to chimps and gorillas but left humans untouched. Also there are hot spots which suggest that nucleotide changes may not be random in certain locations.

 

Whatever the case, this argument will still always involve a supposed common ancestor which will never be identified.

[Zach]

Oh I won't be able to list a mechanism.

How unfortunate.

 

Do you have one in mind to account for the formation of DNA in the first place?

Dodge. Abiogenesis is not part of evolutionary theory.

 

The retovirus insertions make for a good argument.

I agree, which is why I brought it up.

 

But if the dispute is about design vs. evolution, it is meaningless.

On the contrary, a piece of evidence which can only be explained by common descent is incredibly meaningful to the debate.

 

There are also other considerations which include why some infections were common to chimps and gorillas but left humans untouched.

Cite references, please.

 

Also there are hot spots which suggest that nucleotide changes may not be random in certain locations.

Are the ERVs I referenced inserted at these locations? Please show your work.

[Mr. Neil]

The retovirus insertions make for a good argument. I would consider it valuable (if I were an evolutionist) in making a case for whether humans were closer to African as opposed to Asian apes. But if the dispute is about design vs. evolution, it is meaningless. With so much else unaccounted for, this is a nail clipping.

So in other words, you don't have a response, so you're going to avoid it as much as possible.

 

[Light_of_Reason]

crazy-tiger,

 

From what I learned on the Down Syndrome site you attached, I'd have to agree that the entropy is altered as well.

 

My initial idea would be that since information is increased by the inclusion of at least additional portions of the #21 chromosome, that the entropy within the system is also increased. Further, I would speculate that this increase in uncertainty (not redundancy) is what produces the end result (symptoms) of the disorder.

 

In that respect it appears to work in much the same way a communication system would if you added more information than it could handle. The additional information would increase the entropy, which would reduce the effective communication of messages as a whole.

 

At least those are the ideas rattling around in my head at this point. Of course, all these are predicated upon my understanding of information theory and communications, and my limited understanding of biology.

[Saviourmachine]

From what I learned on the Down Syndrome site you attached, I'd have to agree that the entropy is altered as well.

 

My initial idea would be that since information is increased by the inclusion of at least additional portions of the #21 chromosome, that the entropy within the system is also increased. Further, I would speculate that this increase in uncertainty (not redundancy) is what produces the end result (symptoms) of the disorder.

 

In that respect it appears to work in much the same way a communication system would if you added more information than it could handle. The additional information would increase the entropy, which would reduce the effective communication of messages as a whole.

 

At least those are the ideas rattling around in my head at this point. Of course, all these are predicated upon my understanding of information theory and communications, and my limited understanding of biology.

I definitely disagree with this. If "information" plays a role in the "genetic code" it's in terms of reflecting the survival chances in the environment of an organism. Addition of code does not entail addition of information. What is "information"? When has an event the highest "informative" value? When it deviates from our "expectations"? That was Shannon's idea. Or is "information" that facet of data that restrains it from being compressed? That's more like Kolmogorov Complexity.

[crazy-tiger]

Ok, I'm bowing out of this... It's already getting above my head.

[Light_of_Reason]

From what I learned on the Down Syndrome site you attached, I'd have to agree that the entropy is altered as well.

 

My initial idea would be that since information is increased by the inclusion of at least additional portions of the #21 chromosome, that the entropy within the system is also increased. Further, I would speculate that this increase in uncertainty (not redundancy) is what produces the end result (symptoms) of the disorder.

 

In that respect it appears to work in much the same way a communication system would if you added more information than it could handle. The additional information would increase the entropy, which would reduce the effective communication of messages as a whole.

 

At least those are the ideas rattling around in my head at this point. Of course, all these are predicated upon my understanding of information theory and communications, and my limited understanding of biology.

 

I definitely disagree with this. If "information" plays a role in the "genetic code" it's in terms of reflecting the survival chances in the environment of an organism. Addition of code does not entail addition of information. What is "information"? When has an event the highest "informative" value? When it deviates from our "expectations"? That was Shannon's idea. Or is "information" that facet of data that restrains it from being compressed? That's more like Kolmogorov Complexity.

 

You make a valid point. This really does hinge upon the definition of information, and that is a very tricky concept to nail down. In fact, it may be easier to discuss what is not information.

 

The next hardest part of this is defining information in regards to biological systems, which, as it turns out, isn't really that much easier than defining information in the first place.

 

How then do we define so slippery a concept? And then how do we apply it to biological systems?

 

What exactly do you propose here? Pass it my way, and I'll toy with the concepts as you would define them in regards to the problem Down Syndrome poses us to see if another model can be based off those ideas as well. From there, like good researchers, we should attempt to see which model better explains the problem and has the most potential in figuring it out and resolving it.