Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
2 online now:
Newest Member: popoi
Post Volume: Total: 915,820 Year: 3,077/9,624 Month: 922/1,588 Week: 105/223 Day: 3/13 Hour: 1/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Information Changes in DNA by logical Analysis
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 15 of 80 (531437)
10-17-2009 9:01 PM
Reply to: Message 3 by Wounded King
10-16-2009 9:00 AM


Wounded King writes:
In Percy's 'new allele => new information' example, see Evolving New Information, the number of alternative alleles and the frequency of the alleles can all change the amount of Shannon information conveyed by sampling one specific allele from the population. Using this approach the information content in a string can be changed by changing the environment rather than the string itself, i.e. in Percy's example the de novo mutation creating a new allele means that the pre-existing allele sequences can communicate more information.
That's an interesting way of looking at it. To put it in concrete terms via a simple example, let's say a population has alleles A, B and C for a certain gene, so the gene has a message set of size 3. The information conveyed when one of these genes is "sampled" (presumably this means the organism has just become a proud parent) is 1.585 bits. But now one organism in the population experiences a mutation in this gene, call it allele D, so now there are 4 alleles, a message set of size 4, for this gene. This means that when any individual in this population reproduces that the allele it contributes for this gene now conveys more than 1.585 bits.
But as we've discussed before, the likelihood of communicating this new allele to the next generation is very low because only one individual in the population possesses it at this point, so this means that the other alleles communicate only slightly more than 1.585 bits. As the new allele propagates through the population in subsequent generations the amount of information communicated by one of these alleles will gradually rise to 2 bits, assuming equal probability for all alleles.
But that's more complicated than I like to make it. I've never succeeded in getting even my simplified example across.
--Percy

This message is a reply to:
 Message 3 by Wounded King, posted 10-16-2009 9:00 AM Wounded King has not replied

Replies to this message:
 Message 16 by Dr Adequate, posted 10-17-2009 11:34 PM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 17 of 80 (531480)
10-18-2009 7:22 AM
Reply to: Message 16 by Dr Adequate
10-17-2009 11:34 PM


If you're only considering the genes of a single individual then reproduction cannot be part of the conversation, so you must be looking at DNAs role in controlling the cell machinery. Do I have that right?
--Percy

This message is a reply to:
 Message 16 by Dr Adequate, posted 10-17-2009 11:34 PM Dr Adequate has replied

Replies to this message:
 Message 19 by Dr Adequate, posted 10-19-2009 6:59 AM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 21 of 80 (531655)
10-19-2009 9:25 AM
Reply to: Message 19 by Dr Adequate
10-19-2009 6:59 AM


Dr Adequate writes:
What I'm analyzing is the question of "information" (whatever that is) increasing or decreasing...
If you want to know whether information is increasing or decreasing then you need to be able to quantify it. What I haven't been able to figure out yet is how you're quantifying information.
--Percy

This message is a reply to:
 Message 19 by Dr Adequate, posted 10-19-2009 6:59 AM Dr Adequate has not replied

Replies to this message:
 Message 22 by NosyNed, posted 10-19-2009 9:29 AM Percy has replied
 Message 46 by JonF, posted 10-19-2009 1:40 PM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 23 of 80 (531662)
10-19-2009 9:45 AM
Reply to: Message 22 by NosyNed
10-19-2009 9:29 AM


Re: Quantification
I guess I don't understand the argument Dr Adequate is making. The OP refers to an article at SkepticWiki, but the provided link is to the main page. Is this the relevant article:
Anyway, I began rereading this thread from scratch trying to make sure I understood it at each step along the way, and then I came to Dr Adequate's Message 4 where he refers to λ:
Dr Adequate writes:
Well, I think everyone would have to admit that λ contains no information by any sensible metric; which is why I introduced it into the argument.
So once someone explains what λ is I'll continue rereading the thread.
But in the meantime, I notice that in the SkepticWiki article it says:
SkepticWiki writes:
The most obvious problem with this argument is that the creationists who use it never say how information is to be measured in this context.
I'm seeing the same problem in this thread.
--Percy

This message is a reply to:
 Message 22 by NosyNed, posted 10-19-2009 9:29 AM NosyNed has not replied

Replies to this message:
 Message 24 by Wounded King, posted 10-19-2009 9:47 AM Percy has seen this message but not replied
 Message 25 by Modulous, posted 10-19-2009 9:48 AM Percy has seen this message but not replied
 Message 26 by PaulK, posted 10-19-2009 9:54 AM Percy has replied
 Message 31 by Dr Adequate, posted 10-19-2009 11:33 AM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 27 of 80 (531668)
10-19-2009 10:17 AM
Reply to: Message 26 by PaulK
10-19-2009 9:54 AM


Re: Quantification
I'm having trouble trying to put what Dr Adequate is saying into a context I'm familiar with. For example, when he says this in the Mutations and Information article:
SkepticWiki writes:
Any mutation that lengthens the DNA will increase the number of "bits" in it...
If by "bits" he means a measure of information, then this is by no means always true. It depends upon your message set. For example, let's say this is the set of possible messsages:
  • CAG
  • TAC
  • ACT
  • CAGACT
  • TACGTA
  • ACTCGT
Assume each messages is equally likely. Let's say that our beginning DNA string is TAC and that it experiences a mutation to become TACGTA. Since both TAC and TACGTA are in the message set and are equally likely, no more bits of information are communicated.
You have to keep separate the information from the encoding for the information, which frequently includes redundancy. If you're counting the redundancy then you're overstating the amount of information. In my example the amount of information represented by any one of the DNA strings is log26 or 2.58 bits. Mutating TAC to TACGTA doesn't increase it.
--Percy

This message is a reply to:
 Message 26 by PaulK, posted 10-19-2009 9:54 AM PaulK has replied

Replies to this message:
 Message 28 by PaulK, posted 10-19-2009 10:36 AM Percy has replied
 Message 34 by Dr Adequate, posted 10-19-2009 11:44 AM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 29 of 80 (531677)
10-19-2009 10:55 AM
Reply to: Message 28 by PaulK
10-19-2009 10:36 AM


Re: Quantification
PaulK writes:
The section you quote actually precedes the argument that Dr Adequate refers to (labelled "Problem 2: A Mathematical Argument") which partly explains your problem.
Well, I'll try to slog on, but to the extent that his conclusions depend upon faulty assumptions they will in turn be faulty.
I think that the specific point you object to refers to a straight binary encoding, rather than your arbitrary selection of "messages".
There's no such thing as a "straight binary encoding." This becomes obvious when one tries to answer the question, "What is the straight binary encoding of 1.585 bits of information?" The theoretical amount of information rarely has any precise encoding in an integer number of bits, and the excess number of bits are redundant.
It feels to me like this is a case of trying to make into a general principle something that is not always true.
--Percy

This message is a reply to:
 Message 28 by PaulK, posted 10-19-2009 10:36 AM PaulK has replied

Replies to this message:
 Message 30 by PaulK, posted 10-19-2009 11:13 AM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 33 of 80 (531688)
10-19-2009 11:40 AM
Reply to: Message 30 by PaulK
10-19-2009 11:13 AM


Re: Quantification
PaulK writes:
The relevant section is short and largely self-contained. I think that you are pretty much wasting your time trying to critique the other sections.
Oh, okay. Can you point me to the relevant section? Or is it referenced in a message in this thread?
That is a weird thing to say. Of course you can produce a straight binary encoding of a DNA sequence. SImply assign a distinct pair of bits to each of the 4 possible bases.
You're confusing the encoding (the DNA) with the information it encodes. That's the same mistake as saying that the amount of information in a book is equal to its size in bytes on a disk.
--Percy

This message is a reply to:
 Message 30 by PaulK, posted 10-19-2009 11:13 AM PaulK has replied

Replies to this message:
 Message 36 by PaulK, posted 10-19-2009 11:51 AM Percy has replied
 Message 37 by Dr Adequate, posted 10-19-2009 11:51 AM Percy has seen this message but not replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 35 of 80 (531691)
10-19-2009 11:50 AM
Reply to: Message 31 by Dr Adequate
10-19-2009 11:33 AM


Re: Quantification
Dr Adequate writes:
But that's the whole point. Didn't you read the article?
Maybe. I couldn't find a link to the article in this thread, so I made a guess as to which one it was over at SkepticWiki, and no one has confirmed my guess yet. The article I found appears to contain errors, or I don't understand it.
The point is that I can prove that it is possible for mutations to increase information given only the following axioms:
* The null string contains no information.
* Two identical strings contain the same amount of information.
Rather than me trying to figure out where in some article the argument appears, maybe someone could present the argument in this thread?
--Percy

This message is a reply to:
 Message 31 by Dr Adequate, posted 10-19-2009 11:33 AM Dr Adequate has not replied

Replies to this message:
 Message 38 by Dr Jack, posted 10-19-2009 11:56 AM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 39 of 80 (531700)
10-19-2009 12:03 PM
Reply to: Message 34 by Dr Adequate
10-19-2009 11:44 AM


Re: Quantification
Dr Adequate writes:
By "bits" I meant bits. Not a measure of information, but that particular measure of information. The length of the string of DNA, times two.
Sorry, I'm just not getting what you're saying. Are you using the units of bits of Shannon information? It doesn't seem like it, because you're defining the amount of information in a string of DNA as double its length.
Information theory shares a great deal conceptually with 2LOT and the concept of entropy. It's easy for those on the science side to make incorrect statements about 2LOT because how it really works can be very unintuitive. Information theory is the same way.
--Percy

This message is a reply to:
 Message 34 by Dr Adequate, posted 10-19-2009 11:44 AM Dr Adequate has replied

Replies to this message:
 Message 47 by Dr Adequate, posted 10-19-2009 1:48 PM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 40 of 80 (531702)
10-19-2009 12:11 PM
Reply to: Message 36 by PaulK
10-19-2009 11:51 AM


Re: Quantification
PaulK writes:
I told you back in Message 28 The section you want is called ""Problem 2: A Mathematical Argument"
Oops, you're right. I guess I got caught up replying to your "straight binary encoding" statement, speaking of which:
I'm sorry Percy but I hardly think that it is likely that I am confused about what I meant. And I meant a straight binary encoding of the DNA sequence.
Well, let me put it another way. Clearly you understand precisely what you mean, and clearly I don't. Can you help me understand what you're saying?
--Percy

This message is a reply to:
 Message 36 by PaulK, posted 10-19-2009 11:51 AM PaulK has replied

Replies to this message:
 Message 41 by PaulK, posted 10-19-2009 12:20 PM Percy has seen this message but not replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 42 of 80 (531705)
10-19-2009 12:21 PM
Reply to: Message 38 by Dr Jack
10-19-2009 11:56 AM


Re: A flawed mathematical argument?
Interesting that you have a problem with that quote because I think I actually buy it, let me quote it again:
quote:
If one mutation decreases information, then the opposite mutation must increase it; otherwise, it would be possible for a DNA sequence to undergo two successive opposite mutations, leaving it back exactly how it started, and to have undergone a net decrease of information compared to the original, with which it is identical, in violation of condition 2. It follows that if some mutations decrease information, then others must increase it.
  —SkepticWiki
I agree with the sense of your objection that says, I think, that one can't assume that a mutation *must* increase information, but I don't think it applies to the quote because to me he's saying to assume we're considering a mutation that does actually increase information.
--Percy

This message is a reply to:
 Message 38 by Dr Jack, posted 10-19-2009 11:56 AM Dr Jack has replied

Replies to this message:
 Message 43 by Dr Jack, posted 10-19-2009 12:26 PM Percy has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 45 of 80 (531712)
10-19-2009 12:48 PM
Reply to: Message 43 by Dr Jack
10-19-2009 12:26 PM


Re: A flawed mathematical argument?
Oh, wow, what a beautiful insight into the creationist mind! I think you must be right. So if Dr Adequate's approach isn't, er, adequate, then I wonder how one might compose an argument that creationists would accept that de novo information is not impossible.
--Percy

This message is a reply to:
 Message 43 by Dr Jack, posted 10-19-2009 12:26 PM Dr Jack has not replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 50 of 80 (531728)
10-19-2009 2:31 PM
Reply to: Message 46 by JonF
10-19-2009 1:40 PM


JonF writes:
Not really. All you need to be able to do is order it from smaller to larger.
If I gave you three containers each with different amounts of information in them, but you have no way of finding out how much information each contains, how are you going to order them?
I'm not talking about explicit numbers versus variables. It's no problem comparing x to x+1 to x+2 and so forth. But you can't assume that:
Where the function I is the amount of information. It is a false assumption that adding a mutation to DNA increases its information.
--Percy
Edited by Percy, : Latex rerendered.

This message is a reply to:
 Message 46 by JonF, posted 10-19-2009 1:40 PM JonF has replied

Replies to this message:
 Message 53 by Dr Adequate, posted 10-19-2009 3:14 PM Percy has seen this message but not replied
 Message 56 by JonF, posted 10-19-2009 4:33 PM Percy has seen this message but not replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 51 of 80 (531729)
10-19-2009 2:35 PM
Reply to: Message 47 by Dr Adequate
10-19-2009 1:48 PM


Re: Quantification
I think just a few more insults and the light of understanding is sure to go on in my head. Don't bother trying anything silly like actually explaining anything. Ad hominem is so much more enlightening.
--Percy

This message is a reply to:
 Message 47 by Dr Adequate, posted 10-19-2009 1:48 PM Dr Adequate has replied

Replies to this message:
 Message 52 by Dr Adequate, posted 10-19-2009 3:04 PM Percy has seen this message but not replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 61 of 80 (531768)
10-19-2009 5:48 PM
Reply to: Message 59 by NosyNed
10-19-2009 5:25 PM


Re: Weighing DNA
I guess I had the same question that Mr. Jack did for JonF, but the way I was going to phrase it was to ask him about the informational equivalent to his fulcrum. His fulcrum answers the question of which has more mass because gravity handily provides this means of differentiation for us, but what is the equivalent differentiator for the amount of information? He needs something that, continuing the analogy, can weigh bits.
We know what information is, it's measured in bits, and so I can see no other method besides quantifying the bits to determine which has more information. Until shown otherwise I don't believe any other method exists.
--Percy

This message is a reply to:
 Message 59 by NosyNed, posted 10-19-2009 5:25 PM NosyNed has not replied

Replies to this message:
 Message 62 by Dr Adequate, posted 10-19-2009 5:55 PM Percy has seen this message but not replied
 Message 63 by JonF, posted 10-19-2009 5:56 PM Percy has replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024