|
|
|
|
|
Users viewing this topic:
none
|
|
Login  | |
|
DNA Damage repair - 6/26/2009 2:01:42 PM
|
|
|
GHitch
Posts: 998
Joined: 7/6/2008
Status: offline
|
From wikipedia: quote:
DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and Radiation can cause DNA damage, resulting in as many as 1 million individual molecular lesions per cell per day.[1] Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. Consequently, the DNA repair process is constantly active as it responds to damage in the DNA structure.
The rate of DNA repair is dependent on many factors, including the cell type, the age of the cell, and the extracellular environment. A cell that has accumulated a large amount of DNA damage, or one that no longer effectively repairs damage incurred to its DNA, can enter one of three possible states:
1. an irreversible state of dormancy, known as senescence
2. cell suicide, also known as apoptosis or programmed cell death
3. unregulated cell division, which can lead to the formation of a tumor that is cancerous
The DNA repair ability of a cell is vital to the integrity of its genome and thus to its normal functioning and that of the organism. Many genes that were initially shown to influence lifespan have turned out to be involved in DNA damage repair and protection.[2] Failure to correct molecular lesions in cells that form gametes can introduce mutations into the genomes of the offspring and thus influence the rate of evolution.
...
Cells cannot function if DNA damage corrupts the integrity and accessibility of essential information in the genome (but cells remain superficially functional when so-called "non-essential" genes are missing or damaged). Depending on the type of damage inflicted on the DNA's double helical structure, a variety of repair strategies have evolved to restore lost information. If possible, cells use the unmodified complementary strand of the DNA or the sister chromatid as a template to losslessly recover the original information. Without access to a template, cells use an error-prone recovery mechanism known as translesion synthesis as a last resort.
http://en.wikipedia.org/wiki/DNA_repair#DNA_repair_mechanisms Notice the obligatory hit tip to Darwinism - "...repair strategies have evolved..." Like as if evolution had any strategies at all!
So, is this repair strategy even plausible without directing intelligence?
quote:
A variety of repair mechanisms and machinery have been elucidated in recent decades, but research published earlier this year illustrates how these different mechanisms work together, in a coordinated fashion. In the experiments, researchers used methyl-methanesulfonate to damage DNA in yeast cells, causing minor structural aberrations.
In the painstaking experiments, the exposed cells rapidly identified the damage, ceased several normal functions as if going into a lock-down mode, removed the damaged DNA, and coordinated a battery of mechanisms to insert a fresh copy of the DNA segment. As one researcher put it, "it’s almost as if cells have something akin to a computer program that becomes activated by DNA damage, and that program enables the cells to respond very quickly." Indeed, what was discovered is an elaborate system of genetic control that is triggered by DNA damage. - C. Hunter Indeed, something akin. It is a program.
Here's one problem with the evolved hypothesis :
Q: How can a repair mechanism arise without pre-knowledge of correct system state?
A: It cannot. Not when the damage caused interrupts and corrective facilities are this complex
Implication? DNA had to be designed by an intelligent agent.
In software development, programmers build what we call exception trapping mechanisms.
Such mechanisms 'watch' a given function progress and trap errors (exceptional system events) when detected. The trapping code then directs program flow either to analysis functions and correctional code or if the error is minor simply continue processing after the code block that failed (caused the exception) and may possibly alert the user to a faulty input situation.
DNA has it's own special codes for detecting and 'catching' the exceptions that occur. Triggered by a diverse range of cell signals.
NDE cannot explain the existence of such built-in functions.
Worse (for NDE) : Not only is there repair of damage available to the cell's system but there is even a last resort "correction" (but not repaired) measure called apoptosis - pre-programmed cell death! "a type of cell death in which the cell uses specialized cellular machinery to kill itself; a cell suicide mechanism that enables metazoans to control cell number and eliminate cells that threaten the animal's survival" (also plays a role in preventing cancer). Its a key process in multicellular organisms.
This too is not explicable under NDE.
So, in a more engineering like term we can look at this process as something like a control-feedback loop. Such 'loops' exist in many places in the cell; like the circadian oscillator (Paely's watch!) - "a clockwork mechanism that controls these global rhythms of transcription, chromosomal topology, and cell division." Well gee the evolutionary ancestor to that was what? A cellular sundial or hour glass?! 
But control-feedback loops also fall into the category of requires intelligence! Do the math.quote:
Every aspect of human physiology has multiple facets, steps, purposes, managers, feedback loops, and anticipated outcomes. The idea that ten or more trillion cells can even coordinate with each other is mind-boggling. - Simmons It's getting worse and worse for the NDE scenario, with every passing day - sooner or later it's going to leak out into the public arena and St Charles D. will be excommunicated.
_____________________________
"The success of Darwinism was accompanied by a decline in scientific integrity. ...To establish the continuity required by the theory, historical arguments are invoked even though historical evidence is lacking." -W. R. Thompson, PhD
|
|
|
|
|
RE: DNA Damage repair - 6/26/2009 5:30:41 PM
|
|
|
demolay
Posts: 269
Joined: 10/31/2008
Status: offline
|
These kind of elaborate "strategies" in life make me want to ask the chicken&egg question for evolutionists.
Which came first; DNA damage, or a DNA damage repair mechanism?
If there was no reason to "evolve" an elaborate repair mechanism without DNA damage occurring, how long would such life have survived without one? In other words, how many random chances did life get to evolve one before... oops....they're all dead? I mean, "evolved" means first it didn't have a repair "strategy, then later it did, right?
Do they imagine an Earth that started out with no harmful UV, bad chemicals, free radicals, etc., so that infant life could have started and survived with simple DNA that didn't have a repair mechanism? Truly, it boggles the imagination.
|
|
|
|
|
RE: DNA Damage repair - 6/26/2009 7:48:48 PM
|
|
|
DanJames
Posts: 865
Joined: 12/13/2007
Status: offline
|
quote:
ORIGINAL: demolay
These kind of elaborate "strategies" in life make me want to ask the chicken&egg question for evolutionists.
Which came first; DNA damage, or a DNA damage repair mechanism?
If there was no reason to "evolve" an elaborate repair mechanism without DNA damage occurring, how long would such life have survived without one? In other words, how many random chances did life get to evolve one before... oops....they're all dead? I mean, "evolved" means first it didn't have a repair "strategy, then later it did, right?
Do they imagine an Earth that started out with no harmful UV, bad chemicals, free radicals, etc., so that infant life could have started and survived with simple DNA that didn't have a repair mechanism? Truly, it boggles the imagination.
Well, if it started in the ocean, UV rays would be less harmful, so the changes that occur due to UV radiation (there aren't very many) would have been greatly limited. But yes, the damage repair mechanisms to our DNA are so convoluted, that I don't see how they would have evolved in the first place. That and there are specific enzymes that react to certain damage. Almost every single type of damage has its own enzyme which repairs it. Damage due to UV light is repaired specifically by the photolyase enzyme and a specific wavelength of light. What was the photolyase enzyme before it became the photolyase enzyme? I don't know. Make up a story.
|
|
|
|
|
RE: DNA Damage repair - 6/27/2009 12:09:02 PM
|
|
|
GHitch
Posts: 998
Joined: 7/6/2008
Status: offline
|
quote:
ORIGINAL: DanJames
GHitch you crazy loon! Tryin to rock the boat again? HAHA! Always 
quote:
The problem with DNA repair mechanisms is that what it is actually doing is responding to chemistry, ...So "preknowlede" isn't necessarily a good word for it because chemicals don't know that they're fixing a transcript, they're just doing it because it's their obligatory function as DNA polymerase, ligase, etc. Yes I know. But then the whole of DNA is chemistry at the base. And yes pre-knowledge may not be the exact term but intelligent agency is certainly involved. Chemical pathways like this don't just happen to be there and just happen by pure luck to be actually involved in a vital life process. As always I'm trying to get at the roots here.
Repair systems, chemical or not, need an informational, and indeed, an algorithmic basis to operate. But those 2 words imply intelligence - not just chemical laws. As Dean Kenyon discovered there are no chemical laws that could have coordinated the creation of living systems. DNA needs protein and protein needs DNA Chicken and egg - so the old song "Like jam and peanut butter ya can't have one without the other"
which comes first:
the ATP energy or
the information coding the ATP, or
the system transcribing the genes to ATP proteins, or
the ATP energy needed to replicate the coded DNA, or
the ATP needed to power the transcription to the ATP, or
the photosynthesis system needed to convert photons to ATP?
See what I mean? NDE simply can never explain such things.
quote:
A feedback loop is really just as follows: a chemical that is produced during step 1 causes step 2 of the process to begin. The absence of said chemical arrests the process. Granted, this is all very much evidence of design because all of this is programmed into the code. Almost as though the DNA knew that problems could arise so we'll have to call out the inspectors to make sure that our work is proceeding as planned. Exactly my point! Thanks. If you have any further reflections on these processes - there are many different repair mechanisms in DNA depending on the type of damage (yet another clue to design!) - feel free to add more.
I cannot fathom how all of this - I mean the whole system is friggin' amazing to the nth degree!! It's utterly astounding to find all of these coordinated inter-active systems working ceaselessly within every living cell! Probabilities are multiplicative in cases like this. Once you start multiplying the P of one coordinated function of DNA or other cellular stuff by the P's of all the other complex machines working concurrently and in cooperation with each other you cannot but come to the conclusion that this is uncannily like a vast manufacturing and repair factory of indescribable exactitude.
As each year and lately sometimes each month, passes we are confronted with new aspects of a system that is so intricate and functionally coordinated that it boggles the mind.
_____________________________
"The success of Darwinism was accompanied by a decline in scientific integrity. ...To establish the continuity required by the theory, historical arguments are invoked even though historical evidence is lacking." -W. R. Thompson, PhD
|
|
|
|
|
RE: DNA Damage repair - 6/27/2009 4:42:12 PM
|
|
|
DanJames
Posts: 865
Joined: 12/13/2007
Status: offline
|
quote:
ORIGINAL: GHitch
Yes I know. But then the whole of DNA is chemistry at the base. And yes pre-knowledge may not be the exact term but intelligent agency is certainly involved. Chemical pathways like this don't just happen to be there and just happen by pure luck to be actually involved in a vital life process. As always I'm trying to get at the roots here.
Repair systems, chemical or not, need an informational, and indeed, an algorithmic basis to operate. But those 2 words imply intelligence - not just chemical laws. As Dean Kenyon
.......
P's of all the other complex machines working concurrently and in cooperation with each other you cannot but come to the conclusion that this is uncannily like a vast manufacturing and repair factory of indescribable exactitude.
As each year and lately sometimes each month, passes we are confronted with new aspects of a system that is so intricate and functionally coordinated that it boggles the mind.
Maybe preknowledge can be a justifiable word to use. I don't know. The more I get into the finer details of cellular machinery, the more I realize that... wow, it's so convoluted, but yet so automated. It takes away some of the magic and mystery of life to think that the DNA code really is just chemical fate wrapped in a lipid bi-layer, but somehow I still find myself wiping the dribble off my chin while learning about it.
|
|
|
|
|
RE: DNA Damage repair - 6/28/2009 4:08:01 PM
|
|
|
GHitch
Posts: 998
Joined: 7/6/2008
Status: offline
|
quote:
ORIGINAL: DanJames
Maybe preknowledge can be a justifiable word to use. I don't know. The more I get into the finer details of cellular machinery, the more I realize that... wow, it's so convoluted, but yet so automated. It takes away some of the magic and mystery of life to think that the DNA code really is just chemical fate wrapped in a lipid bi-layer, but somehow I still find myself wiping the dribble off my chin while learning about it. Chemical fate is just materialism's view. It applies well to crytal formation but not at all to information processing. Where information processing is concerned with precise multipart cellular machinery fate has and cannot have anything to do with it. No more than magnetic fate or optical fate have anything to do with computer info storage or electrical fate has to do with computer hardware.
We are already coming into organic computing - will that be called chemical fate too?
The cell is a huge factory of intricate productions lines all coordinated to work in the correct order. Adding repair mechanisms that pick up chemical signals to go into action is no different than adding a transistor (0 or 1) 'switch' state to determine the presence of a faulty checksum. Someone programmed it that way.
I suggest you look up Stuart Pullen's material here - he examines the questions from the point of view of a chemist and electrical engineer (He's both). I think you'll enjoy it - the whole book is readable on line.
_____________________________
"The success of Darwinism was accompanied by a decline in scientific integrity. ...To establish the continuity required by the theory, historical arguments are invoked even though historical evidence is lacking." -W. R. Thompson, PhD
|
|
|
|
|
RE: DNA Damage repair - 6/30/2009 11:33:13 AM
|
|
|
SamSpick
Posts: 31
Joined: 12/13/2005
From: England
Status: offline
|
quote:
Q: How can a repair mechanism arise without pre-knowledge of correct system state?
Why assume that it is a repair mechanism at all? Isn't it just some chemicals resisting a change in state according to prevailing energy conditions? It appears complex because of the countless chemical interactions at play but that doesn't mean there's some sort of purpose being played out, necessarily. Or does it? I dunno.
_____________________________
Of all your limitations, the greatest are the ones you don't even know about.
We cannot be judged guilty for our deviation from the alien moral code of our conqueror.
|
|
|
|
|
RE: DNA Damage repair - 6/30/2009 2:33:10 PM
|
|
|
GHitch
Posts: 998
Joined: 7/6/2008
Status: offline
|
quote:
ORIGINAL: SamSpick
Why assume that it is a repair mechanism at all? Because that's what it is.
quote:
Isn't it just some chemicals resisting a change in state according to prevailing energy conditions? No, its not a matter of resistance but a matter of damage/signal/response/repair. Like when you call an ambulance.
quote:
It appears complex because of the countless chemical interactions at play but that doesn't mean there's some sort of purpose being played out, necessarily. Or does it? I dunno. Well yes it does. You can't repair things if you don't know how they are supposed to be. And you cant write an informational repair code function if you don't know what the original should be like. The analogy is not perfect but good enough to help understand. The thing is that if there were no signal/response mechanism in DNA there would be no life on earth. So how did it arise without intelligent guidance of someone who knew what the correct states are? And, how to fix damage using other informational chemicals?
The whole thing is found throughout the cell. When you see a factory with the mechanics running around fixing machines you don't assume they just happened by and just happen to know that something is broke and how to fix it.
We take these "little things" for granted to the point where we no longer see the wonder of it all. Ours bodies also have general repair mechanisms based on underlying cellular repair mechanisms, without which none of us would live long enough to reproduce. To speculate that all this happened by luck, i.e. random mutations and selection, is poor science and bad logic.
< Message edited by GHitch -- 7/2/2009 11:12:55 AM >
_____________________________
"The success of Darwinism was accompanied by a decline in scientific integrity. ...To establish the continuity required by the theory, historical arguments are invoked even though historical evidence is lacking." -W. R. Thompson, PhD
|
|
|
|
|
RE: DNA Damage repair - 7/1/2009 2:54:42 PM
|
|
|
SamSpick
Posts: 31
Joined: 12/13/2005
From: England
Status: offline
|
quote:
Because that6's what it is.
Um, I see... I'll leave it there I think.
_____________________________
Of all your limitations, the greatest are the ones you don't even know about.
We cannot be judged guilty for our deviation from the alien moral code of our conqueror.
|
|
|
|
|
RE: DNA Damage repair - 7/3/2009 10:05:29 AM
|
|
|
GHitch
Posts: 998
Joined: 7/6/2008
Status: offline
|
quote:
ORIGINAL: SamSpick
quote:
Because that's what it is.
Um, I see... I'll leave it there I think.
Yes I think you should, at least until you look it up in the bio journals - as though I just made this up!
_____________________________
"The success of Darwinism was accompanied by a decline in scientific integrity. ...To establish the continuity required by the theory, historical arguments are invoked even though historical evidence is lacking." -W. R. Thompson, PhD
|
|
|
|
 New Messages |
 No New Messages |
 Hot Topic w/ New Messages |
 Hot Topic w/o New Messages |
 Locked w/ New Messages |
 Locked w/o New Messages |
|
 Post New Thread
Reply to Message
Post New Poll
Submit Vote
Delete My Own Post
Delete My Own Thread
Rate Posts |
|
|
|
|
|
|
|
|
|
|
|
Forum Tools
Printable Version
