Evolution of complexity/information

But that is the only difference between slime mold and humans. The only difference between you and a blade of Burmuda Grass is the DNA code. That is one of the strongest confirmations that we really are all evolved from some single common ancestor.

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Aslan is not a Tame Lion

Thank you for the example. You gave me what I asked for, but I posed a bad question.This is a perfect example of microevolution which I it is obvious to me that it happens, but has nothing to do with macroevolution.

As I understand the mutation, it is a frame shift. That implies one extra base pair. So it is an increase in information content of the genome. Care to show what is wrong with that?As an additional question and comment:Are there mutations which decrease the information content of the genome. Do you have an example of that?

That was not my understanding of what a frame shift is but I am fairly ignorant of this sort of thing. Supposing this is correct, this would be an increase of 1 pair in a strand of millions and millions of pairs. Hardly a significant increase, but an increase none the less. A good question. Is not information sometimes destroyed by solar radiation and radioactive radiation? I don't know of any specific examples.

What's that dragging sound I hear? Oh, right. It's HD moving the goalposts again.

I'm no expert either. But in this case the change is the addition of a base pair between existing ones thus shifting the whole thing over a bit. This is, indeed, an increase in information if information is defined in any way that I know of.So the impossible just became possible after all."Hardly significant" -- how do you determine that?In the next generation the human race will pick up several 10's of billions of mutations. That's in just one generation.I'm basing that on 6,000,000,000 of us replacing ourselves in a generation and on each individual haveing a few mutations each. (I don't recall the number -- it is IIRC, somewhere between 5 and 100 per individual).A single mutation may or may not be a "significant" (or "big") increase in information but there are a lot of them. And they keep adding up.Anyway it doesn't matter. Your original idea that information can't increase is wrong.

Hit the Submit button at the wrong time, deletedThis message has been edited by Loudmouth, 07-14-2004 12:16 PM

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I've already made reference to the nylon bug. I've read the article about it. My point about it was that the nylon bug changed, but did not increase in complexity or information. It only had a change in the information (DNA code) already present.

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I am getting the feeling that your inexperience with molecular biology is keeping you from seeing the importance of the mutation. What occured is a frameshift mutation. When creating proteins, or chains of amino acids, DNA bases are read in triplets called codons. Each codon specifies a certain amino acid to be linked to the growing protein. Therefore, when you add one base you change all of the codons downstream of the mutation. Here is a portion of the nylC gene (the "new" sequence in the picture below):

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You will notice that the old protein sequence on top is totally different than the new amino acid sequence on the bottom. Even though only one DNA base was changed it totally changed the protein that was produced.

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So how would you define new information? Most would agree that it is an enzyme with a new function that allows an organism to perform a new function. This is EXACTLY what we see with this mutation. Previously, the bacteria needed carbohydrates in order to mutliply and perform normal metabolism. This new enzyme created by the nylC gene allowed the bacteria to live off of nylon derivatives alone without the need for extraneous carbohydrates. This mutation allowed the bacteria to live in a brand new environment, an environment that no other organism was able to live in in all of history.

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Just a summary:

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1. The mutation created a novel protein not seen in the rest of nature.

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2. The new protein preformed an enzymatic reaction not seen in the rest of nature.

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3. The new protein allowed the bacteria to live in an environment that no other organism can take advantage of.

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Evolutionists have longed claimed that changes in already existing DNA is exactly how evolution proceeds. OF COURSE changes in DNA are going to lead to new information, since this is a NEW sequence of DNA. Why is this not an increase in information?

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This message has been edited by Loudmouth, 07-14-2004 12:18 PM

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This message has been edited by Loudmouth, 07-14-2004 12:20 PM

Thank you for your reply. Well..... I concede that you've gained a point on me. However, this is why I originally spoke of increase in information AND complexity.In other words, how do you know that the frame shift didn't make other base pairs gobbledy gook? If one base pair is added at the end of the frame shift and a thousand pairs are swapped causing 20 or 30 or so to form the necessary protein, is it not likely that many many other pairs in that shifted code have become meaningless code? If so, much more information has been lost, than gained.The kind of mutation we are talking about is like this.w w n d w t t a l k s o e
e e t o n o h t a e h rwewentdowntothatlakeshore : we went down to that lake shoreand then frameshifting itt w w n d w t t a l k s o
e e t o n o h t a e h r etewewtnodnwothttaalekhsroe : te we wt no dnwothttaalekhs roeframeshifting againo t w w n d w t t a l k s o
e e t o n o h t a e h r e noetewtwonndowhtttaaelhkrseon: we get won, dow, eon, as true wordsFrom the first frame shift we added one letter pair and got two new words "no" and "roe" (is that a word?) and one old word "we" but lost six other words. All the letters are there plus one, but many of the letters no longer carry information not to mention the fact that they no longer form a sentence.If this were done to a thousand pairs, we would undoubtedly come up with "new" words just like the nylon bug came up with a new protein sequence, but we would also lose many more words, just as I suspect the nylon bug lost meaningful base pairs.Tell me if you think this is an accurate assesment.

Taking my question into the context of the information you have provided:When the frame shift occured and aligned the necessary code to produce the enzyme for digesting nylon, what happened to the other code that was shifted? Certainly the frame shift did not involve only the exact number of base pairs needed for the new enzyme? It was my understanding that such frame shifts effect all the code from that mutation on down the strand. While the new enzyme code was gained, what else was gained or what was lost?

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If this were done to a thousand pairs, we would undoubtedly come up with "new" words just like the nylon bug came up with a new protein sequence, but we would also lose many more words, just as I suspect the nylon bug lost meaningful base pairs.

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Human words and protein sequences are not analogous. Each protein only has two words, what it binds to and it's enzymatic activity. What those protein words are is decided by the amino acid sequence, and therefore the DNA sequence. For instance, an enzyme that I work with can lose the first 40% of its amino acid sequence and still have the same enzymatic capabilities with the same speed of reaction. It loses no reactivity but loses 40% of its length. It is not the sequence but the activity of the protein that matters. Therefore, we can't compare sequence with human words since they are used in different context.

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When the frame shift occured and aligned the necessary code to produce the enzyme for digesting nylon, what happened to the other code that was shifted? Certainly the frame shift did not involve only the exact number of base pairs needed for the new enzyme? It was my understanding that such frame shifts effect all the code from that mutation on down the strand. While the new enzyme code was gained, what else was gained or what was lost?

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This is not an insult, but this is something covered in a college level genetics course (and usually in high school but not in as much depth). A gene includes three significant portions: a promoter, a start codon, and a stop codon.Promoter: This is usually made up of a -10 and a -35 box. This is technical jargon for a set of sequences 10 and 35 base pairs up stream of the start codon. There is also other properties upstream of the gene that affect how much RNA is made. The functions of this area is to allow the RNA transcriptase to bind and produce RNA, and to allow the ribosome to bind the newly transcribed RNA upstream of the start codon.Start codon: Methionine is the first amino acid in almost every protein. The DNA codon for methionine is ATG. You will notice that the insertion of the T between the A and G within the new nylC gene resulted in a new start codon (ie ATG). This allows the ribosome to start making a new protein at this new start codon.Stop codon: The usual stop codon is TAG (and sometimes TAA or TGA). When the ribosome hits this codon it releases the produced protein.Therefore, there are 6 reading frames, three on the "+" strand and three on the "-" strand (DNA has two sides, one is designated + and the other -) and each strand is read in the 5' to 3' direction (5' and 3' are the carbons on the sugar moeity of the DNA backbone). In other words, each strand is read in opposite directions. The three reading frames on each strand refer to reading codons starting from three different bases. I'll use an example here:TTT ATG TAT GCC TAG TTA GGG A= this sequence will start with ATG and end with TAGnow, lets move one base ahead and check the new codons (start with the second T):T TTA TGT ATG CCT AGT TAG GGA = In this sequence, translation of the new protein will start with the third codon and end with the sixth codon. You will also notice that the codons between the start and stop are completely different. This is also what happened in the nylC gene, a completely new codon sequence and hence a new protein sequence.Therefore, even though frameshift mutations will create a new protein sequence within the new gene it will not affect other sequences since the start codon is preserved in the downstream genes. The ATG is like a book marker, it gives the ribosomes a place to start. Also, intra-gene frameshift mutations can also cause protein extension since the stop codon may be shifted. Also, the protein may be shortened as well. This is the power of inserting just one base, a completely new protein that may or may not have a new function.

Thanks for the reply, Ah! The old ‘macro-evolution is not the same as micro-evolution’ chestnut again. I thought that might be the response {sigh}. But at least we can now agree to put the myth that 'a gain in ability means a loss of another function' well and truly to bed I’ll try and show you that the same kind of mechanisms are in effect, whatever scale you look at. Let’s look at another one of the examples I gave you — the evolution of the tetrapod limb from the fish fin — I’d have thought that that’s at the macro end of things, wouldn’t you?Again, its’ another case (like the duck foot) of proteins being produced where they were not produced before. I’ll try and explain :The fish fin and the tetrapod limb develop fairly identically to begin with. The first parts of the limbs share homologous structures, which are controlled by the same pair of control genes (known as HoxD11 and HoxD13). The part where the two types of limbs differ is at the tip of the limb: the tetrapod limb has an extra structure which has the digits radiating from it. This new feature (and the digits) seems to be have formed by a duplication of the bones that make up the rest of the limb. How does this duplication occur? A new set of cells in the limb have gained the ability to produce the HoxD11 and HoxD13 master switch proteins.Hope this is clear — feel free to ask questions if it isn’t, or if you want more details. I tried to find a picture on the ‘net but didn’t get any joy.So, what we have again is an increase in information, and an increase in complexity — both gained by a simple, non-deleterious mutation. Can you think of a ‘complexity step’ on the path from bacteria to man that could not involve this kind of simple change?

Understood. Thanks. It makes sense.

Thank you for your reply. No offense taken. I'm an Mech Eng and admittedly ignorant of much of this.Fascinating. Thanks very much for the explanation that I should already know by now... I'm still not clear how the rest of the code downstream is not affected. Got that, but how does the first ATG of the next protein after the mutated protein stay in the same place? Does the promoter somehow stop the shift, and if so what happens to the promoter code?This message has been edited by Hangdawg13, 07-15-2004 12:54 AM