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Author Topic:   is the advancement of macro evolution without hick up?
Wounded King
Member (Idle past 2381 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 31 of 41 (548771)
03-01-2010 4:46 PM
Reply to: Message 29 by Dr Adequate
03-01-2010 4:22 PM


Re: We Are All Mutants
Some of those transcripts might be doing something else besides serving as mRNA in the strict sense, but if they are, it's going to be something astonishingly subtle

Of course in some cases we do know what some non protein coding transcripts do, such as the snoRNAs, tRNAs and microRNAs. But most of these show patterns of conservation consistent with those in other biologically important genetic sequences. In contrast ENCODE only found around 5% of the transcribed regions to have any signs of conservation between different species, of course if you don't believe in common descent exactly what that sort of conservation means is highly debatable.

TTFN,

WK


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ZenMonkey
Member (Idle past 2797 days)
Posts: 428
From: Portland, OR USA
Joined: 09-25-2009


Message 32 of 41 (548772)
03-01-2010 4:47 PM
Reply to: Message 30 by Dr Adequate
03-01-2010 4:29 PM


Re: We Are All Mutants
Dr Adequate writes:

Consider that the more these hypothetical mutations accumulated in a genome, the more likely it would become that the next mutation will be slightly beneficial. Even chance alone would establish an equilibrium.

This may already have been answered a dozen times over, but isn't it the case that apparently neutral mutations that have been carried along in the genome for whatever reason can then capitalize on additional mutations that have beneficial effects but that might otherwise not have been possible? Actually, isn't that what you're already saying here?


I have no time for lies and fantasy, and neither should you. Enjoy or die.
-John Lydon

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Dr Adequate
Member
Posts: 16107
Joined: 07-20-2006
Member Rating: 8.0


Message 33 of 41 (548780)
03-01-2010 7:03 PM
Reply to: Message 32 by ZenMonkey
03-01-2010 4:47 PM


Re: We Are All Mutants
This may already have been answered a dozen times over, but isn't it the case that apparently neutral mutations that have been carried along in the genome for whatever reason can then capitalize on additional mutations that have beneficial effects but that might otherwise not have been possible? Actually, isn't that what you're already saying here?

No, I'm thinking of back mutations and other compensatory mutations. The more errors there are, the more likely it becomes that a random change will fix one of them. This leads to a stable equilibrium.

I'd make a computer model if there were any remotely evidenced figures known, but there aren't: the creationist fandango around this subject requires that the effect of the mutations they're talking about should by definition of these mutations be so small that no-one can even tell that any effect exists, and it is of course impossible to measure the frequency of such events or to distinguish them from neutral mutations --- i.e. to find out if they actually exist.

(This reminds me of certain other branches of Christian apologetics.)

Edited by Dr Adequate, : No reason given.


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RAZD
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Posts: 20156
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.1


Message 34 of 41 (548789)
03-01-2010 8:43 PM
Reply to: Message 28 by subbie
03-01-2010 3:40 PM


"junk DNA" now called "non-coding DNA"
Hi subbie, thanks for the link,

This letter to Nature describes an experiment involving the deletion of over 2,300 non-coding intervals from mice DNA with no apparent effect on the mice.

I can use that on another thread.

I note that somewhere around 2006 (iirc) then name "junk DNA" was officially (did you get the memo?) changed to "non-coding DNA" - meaning that it does not code for producing proteins or other usable functions within living cells, but may have other (not yet known) uses.

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


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subbie
Member (Idle past 30 days)
Posts: 3509
Joined: 02-26-2006


Message 35 of 41 (548804)
03-01-2010 10:18 PM
Reply to: Message 34 by RAZD
03-01-2010 8:43 PM


Re: "junk DNA" now called "non-coding DNA"
Glad I could help, RAZD. Found it in a Wikipedia article.

Personally, I think I'll stick with "junk DNA." I'm not a professional in the field, so I'm not particularly concerned about what the officials have to say (plus it feeds my maverick instincts), and I like the sound of it. But I will probably continue to put scare quotes around it, acknowledging that it's nonstandard.


Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson

For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama

We see monsters where science shows us windmills. -- Phat


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Dr Adequate
Member
Posts: 16107
Joined: 07-20-2006
Member Rating: 8.0


Message 36 of 41 (548805)
03-01-2010 10:39 PM
Reply to: Message 35 by subbie
03-01-2010 10:18 PM


Re: "junk DNA" now called "non-coding DNA"
Personally, I think I'll stick with "junk DNA."

It introduces an ambiguity invented by creationists. First they pretend that "junk DNA" means all non-coding DNA, then they'll point out that some non-coding DNA is functional, which was of course discovered by evolutionists, then they'll explain that it's evolutionist dogma that all non-coding DNA is "junk", an hence non-functional ... well, you know how it goes. Creationists, eh?

It's best to distinguish between non-coding DNA and non-functional DNA, and leave the creation of ambiguity by the use of the word "junk" to the people who really need ambiguity.


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Dr Adequate
Member
Posts: 16107
Joined: 07-20-2006
Member Rating: 8.0


Message 37 of 41 (548806)
03-01-2010 10:40 PM
Reply to: Message 35 by subbie
03-01-2010 10:18 PM


Re: "junk DNA" now called "non-coding DNA"
dp

Edited by Dr Adequate, : No reason given.


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AnswersInGenitals
Member
Posts: 518
Joined: 07-20-2006


Message 38 of 41 (548839)
03-02-2010 12:58 AM
Reply to: Message 27 by slevesque
03-01-2010 3:16 PM


Re: We Are All Mutants
A few quick comments on this whole deleterious versus beneficial versus neutral mutation argument:

Mutations can be non-neutral, i. e., have biological effect, and be neither beneficial or deleterious or can be both beneficial and deleterious. For example, suppose a sub-population acquires a mutation that slightly reduces the expression of growth hormone, while another sub-population acquires a different mutation that augments the expression of that hormone.

There are now three populations that are on average short, "standard" height (the unmutated wild population), and tall. Which is the most advantaged height (for species survival)? The short population will have lesser food needs and the taller population may have greater food foraging capability. Usually, each sub-population will tend to adapt to areas that best fit their capabilities. For survival of the species the best strategy is to display a range for each trait to allow maximum use of resources and to be pre-adapted to changes in the environment. And this is what we generally see.

So, mutations in opposite directions can all be beneficial, particularly at the species level.

There was a thread a while back that got into this rate of mutation question that had several references. I recall a sort of consensus that each cell duplication in mammals incurred from a couple of dozen to a few hundred mutations with a lot a variability. Also, lets not forget about the homologous recombination that occurs during meiosis in which homologous chromosomes are literally reshuffled together and that often induces genetic changes.

Finally, while writing this, I produced a few billion new skin cells, I'm sure some of those had mutations in the insulin gene and/or its control region. But since that gene is silenced in skin cells, weren't those neutral mutations in junk DNA? I understand that we are really talking about mutations in germ line cells and not in somatic cells, but those germ line cells have pseudo-genes, endogenous retroviral (ERV) genes and a lot of other unexpressed DNA fragments. I would think that these DNA segments would qualify as junk.

Finally, finally, has everyone noticed that, after throwing his ignorant little stink bomb into the classroom, SHEKINAH seems to have left the building. But this has become an interesting thread that is much better off without him/her, so lets keep it going.


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subbie
Member (Idle past 30 days)
Posts: 3509
Joined: 02-26-2006


Message 39 of 41 (548844)
03-02-2010 1:09 AM
Reply to: Message 36 by Dr Adequate
03-01-2010 10:39 PM


Re: "junk DNA" now called "non-coding DNA"
It's best to distinguish between non-coding DNA and non-functional DNA, and leave the creation of ambiguity by the use of the word "junk" to the people who really need ambiguity.

You sure know how to harsh a guy's mellow, dude.


Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson

For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama

We see monsters where science shows us windmills. -- Phat


This message is a reply to:
 Message 36 by Dr Adequate, posted 03-01-2010 10:39 PM Dr Adequate has not yet responded

  
Peepul
Member (Idle past 3304 days)
Posts: 206
Joined: 03-13-2009


Message 40 of 41 (548866)
03-02-2010 6:43 AM
Reply to: Message 11 by Dr Jack
02-27-2010 4:10 PM


Re: We Are All Mutants
quote:
The tRNAs needed to translate GGA to glycine or GGU to glycine exist in differing quantities; altering the code can alter the expression rate of proteins.

This is correct - and there is evidence from sequence studies that certain codons are selected over others that code for the same amino acid. So these changes are not invisible to selection.


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Peepul
Member (Idle past 3304 days)
Posts: 206
Joined: 03-13-2009


Message 41 of 41 (548867)
03-02-2010 6:48 AM
Reply to: Message 33 by Dr Adequate
03-01-2010 7:03 PM


Re: We Are All Mutants
quote:
This may already have been answered a dozen times over, but isn't it the case that apparently neutral mutations that have been carried along in the genome for whatever reason can then capitalize on additional mutations that have beneficial effects but that might otherwise not have been possible? Actually, isn't that what you're already saying here?

I think this is what Lenski's experiments with E coli demonstrate. I'm ready to be corrected on this though!


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