|
Register | Sign In |
|
QuickSearch
Thread ▼ Details |
|
Thread Info
|
|
|
Author | Topic: How well do we understand DNA? | |||||||||||||||||||
TheLiteralist Inactive Member |
CF,
Thanks for posting the chart. I wonder WHY the slippage occurs, though. --TL
|
|||||||||||||||||||
pink sasquatch Member (Idle past 6022 days) Posts: 1567 Joined: |
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?
|
|||||||||||||||||||
crashfrog Member (Idle past 1467 days) Posts: 19762 From: Silver Spring, MD Joined: |
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:
You can lose/slip the first triplet and get
and your strands still bind because the right nucleotides still pair up. On the other hand, if you have
and slip the first triplet, you get
and the strands wouldn't bind because they're not complimentary.
|
|||||||||||||||||||
TheLiteralist Inactive Member |
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.
|
|||||||||||||||||||
TheLiteralist Inactive Member |
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
|
|||||||||||||||||||
crashfrog Member (Idle past 1467 days) Posts: 19762 From: Silver Spring, MD Joined: |
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-repetitive2) 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.
|
|||||||||||||||||||
TheLiteralist Inactive Member |
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
|
|||||||||||||||||||
pink sasquatch Member (Idle past 6022 days) Posts: 1567 Joined: |
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?
|
|||||||||||||||||||
crashfrog Member (Idle past 1467 days) Posts: 19762 From: Silver Spring, MD Joined: |
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.
|
|||||||||||||||||||
TheLiteralist Inactive Member |
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
|
|||||||||||||||||||
crashfrog Member (Idle past 1467 days) Posts: 19762 From: Silver Spring, MD Joined: |
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.
|
|||||||||||||||||||
TheLiteralist Inactive Member |
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.
|
|||||||||||||||||||
crashfrog Member (Idle past 1467 days) Posts: 19762 From: Silver Spring, MD Joined: |
Looks like you had a little "copying error" yourself. I know what you were replying to, though.
|
|||||||||||||||||||
pink sasquatch Member (Idle past 6022 days) Posts: 1567 Joined: |
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?
|
|||||||||||||||||||
TheLiteralist Inactive Member |
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
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024