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Author Topic:   How well do we understand DNA?
TheLiteralist
Inactive Member


Message 61 of 98 (182618)
02-02-2005 3:34 PM
Reply to: Message 58 by crashfrog
02-02-2005 3:16 PM


Nice Chart
CF,
Thanks for posting the chart. I wonder WHY the slippage occurs, though.
--TL

This message is a reply to:
 Message 58 by crashfrog, posted 02-02-2005 3:16 PM crashfrog has replied

Replies to this message:
 Message 63 by crashfrog, posted 02-02-2005 3:48 PM TheLiteralist has replied

  
pink sasquatch
Member (Idle past 6022 days)
Posts: 1567
Joined: 06-10-2004


Message 62 of 98 (182619)
02-02-2005 3:44 PM
Reply to: Message 57 by TheLiteralist
02-02-2005 3:06 PM


Re: Non-random mutation can drive evolution... and disease.
Tremendous!
Glad you enjoyed it.
Could this fact that copying errors are inherent in certain sequences where there is a lot of repetitiveness be the mechanism I'm looking for?
First, they're not necessarily "inherent", they are just much more likely. Repetitive sequences are still subject to the repair machinery others have been describing, it is just that the machinery doesn't do as well with repeats.
More importantly, there is no evidence whatsoever that these sequences are the result of design rather than evolution. Since these sequences are highly mutable their initial development likely occurred quite readily by natural means, precisely because changes in the repeats evade replication machinery.
Do all or most traits that vary have this quality of highly repetitive sequences?
All traits vary, not just some. I believe few genes have long repeats in their coding sequence; the paper I cited tested 36 genes precisely because they had such coding repeats.
Importantly - even though some of the genes had repeats, many of them did NOT undergo mutation within the repeats; so again, the repeats do not equal mutation.
Are there other mechanisms that work like this?
I'm not sure what you mean - this isn't so much a 'mechanism' as the tendency for some sequence to undergo mutation more often than others. That is, mutation of repetitive sequence still undergoes selection like any other type of mutation.
..since sin has entered the world death and suffering are the lot of humanity in general in this life.
Sounds like you are suggesting that the Creator added repetitive sequence to certain genes after "The Fall".
This is always a serious problem when dealing with detection of an intelligent designer: If something appears to be made exquisitely well, the argument is made that intelligent design was required; if something is made poorly or in a way that doesn't make sense, then The Fall is often cited as an explanation.
With this kind of logic, if something is "good", that is evidence of a Creator; if something is "bad", that is also evidence of a Creator. Such "logic" cannot be discussed logically - which is why people in this thread keep bringing up the need for a way to detect design.
So to return to the repetitive sequence: We have evidence that repetitive sequence is evolvable by natural means. What evidence (or tests for evidence) can you propose that supports repetitive sequence as the product of a supernatural being?

This message is a reply to:
 Message 57 by TheLiteralist, posted 02-02-2005 3:06 PM TheLiteralist has replied

Replies to this message:
 Message 64 by TheLiteralist, posted 02-02-2005 3:57 PM pink sasquatch has replied

  
crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 63 of 98 (182622)
02-02-2005 3:48 PM
Reply to: Message 61 by TheLiteralist
02-02-2005 3:34 PM


Re: Nice Chart
Thanks for posting the chart. I wonder WHY the slippage occurs, though
It's not obvious? It slips because it can slip; a non-repetitive sequence cannot slip because there's no way to skip a gene and have the opposing strand bind correctly. (You remember of course that A can only bind to T and G can only bind to C.)
For instance, if I have:

5' AGA AGA AGA AGA 3'
3' TCT TCT TCT TCT 5'

You can lose/slip the first triplet and get

5' AGA AGA AGA 3'
3' TCT TCT TCT TCT 5'

and your strands still bind because the right nucleotides still pair up.
On the other hand, if you have

5' AGC CGT TGG GAA 3'
3' TCG GCA ACC CTT 5'

and slip the first triplet, you get

5' CGT TGG GAA 3'
3' TCG GCA ACC CTT 5'

and the strands wouldn't bind because they're not complimentary.

This message is a reply to:
 Message 61 by TheLiteralist, posted 02-02-2005 3:34 PM TheLiteralist has replied

Replies to this message:
 Message 65 by TheLiteralist, posted 02-02-2005 3:59 PM crashfrog has replied

  
TheLiteralist
Inactive Member


Message 64 of 98 (182625)
02-02-2005 3:57 PM
Reply to: Message 62 by pink sasquatch
02-02-2005 3:44 PM


Sequences
Well, to me, the mere existence of genetic sequences that get translated is the indication of intelligence. It is sequential information that codes for various processes...including it's own duplication.

This message is a reply to:
 Message 62 by pink sasquatch, posted 02-02-2005 3:44 PM pink sasquatch has replied

Replies to this message:
 Message 68 by pink sasquatch, posted 02-02-2005 4:11 PM TheLiteralist has replied

  
TheLiteralist
Inactive Member


Message 65 of 98 (182629)
02-02-2005 3:59 PM
Reply to: Message 63 by crashfrog
02-02-2005 3:48 PM


Slipping
CF,
I gotcha part way--but not all the way I'm afraid. That, in my mind, explains how it can sucessfully slip, but not why it slips in the first place.
I mean it might explain that, too, but I'm not getting it, yet.
--TL

This message is a reply to:
 Message 63 by crashfrog, posted 02-02-2005 3:48 PM crashfrog has replied

Replies to this message:
 Message 69 by crashfrog, posted 02-02-2005 4:14 PM TheLiteralist has replied

  
crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 66 of 98 (182630)
02-02-2005 3:59 PM
Reply to: Message 60 by TheLiteralist
02-02-2005 3:30 PM


Re: MUTATIONS
I am then curious about two things: (1) are certain segments in any given genome strangely much less likely to have a random mutation
I believe that's what's meant by a "conserved" gene. For instance my wife is working with COI, a mitochondrial gene that is highly conserved across insect species. But maybe I'm wrong.
I don't know that there would be anything "strange" about a gene that did not mutate as often; we would probably find that one or more of several things was true:
1) The gene was non-repetitive
2) The gene was not expressed or transcribed often;
3) The gene was located in a section of the DNA that was not often "unwound" or "unzipped"
In other words mutations are often "opportunistic" in that they happen when normal cell machinery doesn't quite work right. A gene that was not often manipulated by the cell would probably not often mutate. Sort of like, we might find that collector automobiles are involved in less fatal accidents per car than, say, the Honda Civic; not because of any flaw in the Civic or virtue of a collector's car, but simply because a collector automobile isn't taken out on the road that often.
also just happen to be the ones that should a mutation occur have deleterious effects on the resultant organism?
I dunno. There are a number of speculations I could make about what might happen to the genetics of a population of organisms burdened by a gene very vulnerable to mutation, and how that population might evolve to deal with that vulnerability. But I don't have the data to answer your question.

This message is a reply to:
 Message 60 by TheLiteralist, posted 02-02-2005 3:30 PM TheLiteralist has replied

Replies to this message:
 Message 67 by TheLiteralist, posted 02-02-2005 4:08 PM crashfrog has replied

  
TheLiteralist
Inactive Member


Message 67 of 98 (182632)
02-02-2005 4:08 PM
Reply to: Message 66 by crashfrog
02-02-2005 3:59 PM


Re: MUTATIONS
CF,
Hey, has your wife seen this thread? If she has, has she found it interesting...or has she had a roll-your-eyes type reaction?
Just curious,
-TL

This message is a reply to:
 Message 66 by crashfrog, posted 02-02-2005 3:59 PM crashfrog has replied

Replies to this message:
 Message 71 by crashfrog, posted 02-02-2005 4:18 PM TheLiteralist has not replied

  
pink sasquatch
Member (Idle past 6022 days)
Posts: 1567
Joined: 06-10-2004


Message 68 of 98 (182633)
02-02-2005 4:11 PM
Reply to: Message 64 by TheLiteralist
02-02-2005 3:57 PM


Re: Sequences (elves?)
Well, to me, the mere existence of genetic sequences that get translated is the indication of intelligence.
That just sidesteps my previous question.
We know that novel, coding genetic sequences can arise by natural means. There is no need to produce an undetectable, intelligent, superpowerful entity to provide an explanation, unless you have evidence for such an entity's involvement in the process.
To put it another way, you need to have some positive evidence for your view if it is to be anything other than personal opinion. Simply stating that its "mere existence" is indication of design doesn't work (beyond opinion). It is obvious to millions of people all over the world that every year their toys are manufactured by elves at the North Pole and delivered by one man utilizing flying reindeer. That doesn't make it true.
Similarly, arguing that natural evolution of DNA sequence is implausible doesn't provide any evidence whatsoever for design.
Is there any evidence beyond "obviousness" that indicates intelligent design?

This message is a reply to:
 Message 64 by TheLiteralist, posted 02-02-2005 3:57 PM TheLiteralist has replied

Replies to this message:
 Message 70 by TheLiteralist, posted 02-02-2005 4:17 PM pink sasquatch has replied

  
crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 69 of 98 (182634)
02-02-2005 4:14 PM
Reply to: Message 65 by TheLiteralist
02-02-2005 3:59 PM


Re: Slipping
That, in my mind, explains how it can sucessfully slip, but not why it slips in the first place.
It slips because there's nothing preventing it from doing so. Just like you "slip" on a puddle because there's no friction preventing you from doing so, and you fall on your ass because there's no magic hand that reaches out to catch you.
The question that might make it clearer in your head is to ask instead of what makes it "slip", what makes it come together in the first place? These are all just chemical reactions happening in water, and the complimentarity of nucleotides is the only thing that makes the two strands of DNA "zip up" correctly. Repetition compromises the effecacy of that complimentarity, and so they don't "zip up" quite right.
Does that help any? I think a better understanding of the genetic transcription/replication mechanisms might aid you.
DNA - Wikipedia
The wiki article is pretty comprehensive, and should give you an idea about how DNA is strutured, stored in the cell, transcripted, and replicated. Also you might follow the link and read about Polymerase Chain Reaction, or PCR, which is the lab process for replicating DNA. It proceeds much like the cellular version (indeed, uses most of the same enzymes, I believe. Well, not exactly. Specifically it uses the polymerase enzyme from thermophile bacteria, which can survive the heating process needed to cleave the two strands.)
Clear as mud, I'm sure. My head mostly spins when my wife explains what she's doing in the lab.

This message is a reply to:
 Message 65 by TheLiteralist, posted 02-02-2005 3:59 PM TheLiteralist has replied

Replies to this message:
 Message 72 by TheLiteralist, posted 02-02-2005 4:22 PM crashfrog has replied

  
TheLiteralist
Inactive Member


Message 70 of 98 (182636)
02-02-2005 4:17 PM
Reply to: Message 68 by pink sasquatch
02-02-2005 4:11 PM


Re: Sequences (elves?)
PS,
We know that novel, coding genetic sequences can arise by natural means.
I think this is a different topic, but one I'm interested in. Would you like for me to try to get a new thread going about this?
Or do you think we can make short work of it? I really hate off-topic pile-on...now that it's happened to one of my threads I'm starting to understand AdminNosy's harshness about topic purity a bit more.
--TL

This message is a reply to:
 Message 68 by pink sasquatch, posted 02-02-2005 4:11 PM pink sasquatch has replied

Replies to this message:
 Message 74 by pink sasquatch, posted 02-02-2005 4:42 PM TheLiteralist has replied

  
crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 71 of 98 (182637)
02-02-2005 4:18 PM
Reply to: Message 67 by TheLiteralist
02-02-2005 4:08 PM


Re: MUTATIONS
Hey, has your wife seen this thread? If she has, has she found it interesting...or has she had a roll-your-eyes type reaction?
She posts here, ever-so-rarely, as "Entomologista". (For some reason, no matter how she tries to log on with her computer, her posts wind up under my name, even though I've never logged on at her machine. Maybe the new BB code has fixed that, though. I don't think she's tried recently.)
As a biologist, though, she's not really that interested in the creationism debate. You'd be surprised, I think, how much of a non-entity the creationism movement is to actual biology professionals. It's only us amateurs for whom the debate doesn't go right under the radar. She's too busy doing real work.

This message is a reply to:
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TheLiteralist
Inactive Member


Message 72 of 98 (182638)
02-02-2005 4:22 PM
Reply to: Message 69 by crashfrog
02-02-2005 4:14 PM


Re: Slipping
CF,
Thanks for the link.
We know that novel, coding genetic sequences can arise by natural means.
Hah! I bet it does...probably not so bad as mine would, though, I'm sure.

This message is a reply to:
 Message 69 by crashfrog, posted 02-02-2005 4:14 PM crashfrog has replied

Replies to this message:
 Message 73 by crashfrog, posted 02-02-2005 4:30 PM TheLiteralist has replied

  
crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 73 of 98 (182643)
02-02-2005 4:30 PM
Reply to: Message 72 by TheLiteralist
02-02-2005 4:22 PM


Cut-n-paste error
Looks like you had a little "copying error" yourself. I know what you were replying to, though.

This message is a reply to:
 Message 72 by TheLiteralist, posted 02-02-2005 4:22 PM TheLiteralist has replied

Replies to this message:
 Message 75 by TheLiteralist, posted 02-02-2005 11:55 PM crashfrog has not replied

  
pink sasquatch
Member (Idle past 6022 days)
Posts: 1567
Joined: 06-10-2004


Message 74 of 98 (182647)
02-02-2005 4:42 PM
Reply to: Message 70 by TheLiteralist
02-02-2005 4:17 PM


off-topic?
We know that novel, coding genetic sequences can arise by natural means.
I think this is a different topic, but one I'm interested in. Would you like for me to try to get a new thread going about this?
How is it off-topic? A major theme of this thread is distinguishing natural from supernatural origins of DNA sequence. There is evidence for the "natural"; I'm asking for evidence (or tests for evidence) for the "supernatural".
On-topic, no?

This message is a reply to:
 Message 70 by TheLiteralist, posted 02-02-2005 4:17 PM TheLiteralist has replied

Replies to this message:
 Message 76 by TheLiteralist, posted 02-03-2005 12:25 AM pink sasquatch has replied

  
TheLiteralist
Inactive Member


Message 75 of 98 (182707)
02-02-2005 11:55 PM
Reply to: Message 73 by crashfrog
02-02-2005 4:30 PM


Re: Cut-n-paste error
CF,
Looks like you had a little "copying error" yourself. I know what you were replying to, though.
ROFL! That is hilarious...I didn't even realize this till hours later!
Clear as mud, I'm sure. My head mostly spins when my wife explains what she's doing in the lab.
That is what was supposed to be in the quote box...if that makes my previous post to you any clearer...
cut-n-paste error, indeed!
--TL

This message is a reply to:
 Message 73 by crashfrog, posted 02-02-2005 4:30 PM crashfrog has not replied

  
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