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Author Topic:   Genetic Redundancy and Natural Selection
Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 14 of 37 (564757)
06-12-2010 10:15 AM
Reply to: Message 1 by BobTHJ
06-11-2010 2:00 PM


Non-synonymous point mutations in these genes are often lethal because they code proteins that don't "turn-off" leading to cancerous cell division.
Although I am not a professional biologist, I seem to remember reading in some popular science book that there's a difference between the concepts "often" and "always". No, wait, that was a dictionary.
SRC proteins are not identical (sharing only 60-80% of their sequences), so since these genes are highly selective against mutation it is highly unlikely that they arose as a result of gene duplication - they would have to have evolved separately.
Since SRC proteins are so variable, it seems that there is not a strong selection pressure against the variations which actually exist in SRC proteins, just against some of the ones that don't.
Fortunately, the theory of evolution is only required to account for things that do exist and not for things that don't.

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Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 20 of 37 (565237)
06-15-2010 4:27 PM
Reply to: Message 18 by BobTHJ
06-15-2010 2:36 PM


Funny you should mention that - because that is exactly what we see at the cellular level.
No. Try reading through what Percy wrote again. (Or, possibly, for the very first time.)
On the cellular level, we do not see:
(a) Massive complexes of laboratories to design organisms on a world-wide scale about 6000 years ago.
(b) Significant infrastructure for world travel about 6000 years ago.
(c) A major genetic bottleneck affecting all species about 6000 years ago.
---
You mean, other than the irreducible complexity I eluded to above? Nope that's it.
(1) You were asked for positive evidence of design, not just an argument of the form "evolution couldn't do that, therefore it was designed". But this false dichotomy is exactly what creationists' blunders over irreducible complexity amount to.
(2) You said in your OP:
While mutation often results in a lethal phenotype knockout experiments on SRC genes show that mice can survive without some SRC genes.
Hence, the system is not irreducibly complex.
(3) If it was, then since we know that IC can evolve, it would not constitute evidence against evolution, let alone evidence for design.
Edited by Dr Adequate, : No reason given.

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Replies to this message:
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Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 27 of 37 (565302)
06-15-2010 10:27 PM
Reply to: Message 18 by BobTHJ
06-15-2010 2:36 PM


Borger gives this quote:
Which says that it would be difficult for evolution to remove the redundancy, not to create it.

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Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 28 of 37 (565303)
06-15-2010 10:29 PM
Reply to: Message 24 by BobTHJ
06-15-2010 9:59 PM


If the YEC model is correct we should see more degeneration of the genome (ie a higher rate of disease, cancer, loss of function, declining lifespans etc.) as time progresses.
At last, a testable prediction!
We see no such thing. Bye-bye YEC model, it was nice knowing you. Oh, wait, it wasn't.
Edited by Adminnemooseus, : See the Suspension message triggered by this message

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Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 34 of 37 (565460)
06-16-2010 11:33 PM
Reply to: Message 30 by BobTHJ
06-16-2010 3:49 PM


Try reading what I wrote again. Note the words "...at the cellular level."
I did note them. This is why I quoted them, when I wrote:
On the cellular level, we do not see:
(a) Massive complexes of laboratories to design organisms on a world-wide scale about 6000 years ago.
(b) Significant infrastructure for world travel about 6000 years ago.
(c) A major genetic bottleneck affecting all species about 6000 years ago.
Your logic is flawed. I could see you arguing this line of reasoning if you could demonstrate piece by piece the reversal of a process without the destruction of the functionary (still not sure I'd agree - but at least you'd have a logical argument). However, you are suggesting that since a single piece of a system can be removed and the system will still function then it must not be irreducibly complex - this argument has no merit.
This argument is true by definition of "irreducible complexity".
According to Michael Behe, who coined the phrase, an irreducibly complex system is:
A single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. --- Michael Behe, Darwins Black Box
I'm not sure whether the SRC genes fit the first clause of that definition, but according to your own post they do not fit the second clause, since it is possible to knock out entire SRC genes and still be left with a functioning system.

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Dr Adequate
Member (Idle past 284 days)
Posts: 16113
Joined: 07-20-2006


Message 35 of 37 (565467)
06-17-2010 12:47 AM
Reply to: Message 33 by BobTHJ
06-16-2010 4:38 PM


And no - I don't have evidence - but I'm sure somewhere someone is keeping statistics on this stuff.
People are indeed keeping records --- they're called "scientists". They can watch organisms becoming better adapted to their environments. If they are bacteria, we can even directly compare their fitness against that of their ancestors by putting them into direct competition, since it is possible to freeze samples of the ancestral generations.
What we do not see is the sort of genetic degeneration that is the stuff of creationist fantasy.
This is a prediction for the baranome hypothesis - and it can likely be proven true or false to some degree of accuracy within the next 50 years or so (though environmental agents such as carcinogens as well as medical efforts to prevent disease do rather complicate the recordkeeping).
Perhaps instead of looking at one of the few species (humans) for which you have an excuse for increased or stable phenotypic fitness, you should be looking at species for which you have no such excuse, such as bacteria.
You could, for example, look up the Lenski experiment.
So consider your hypothesis falsified.

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