Not Random. [UPDATED]

UPDATE:  Scott Adams at The Dilbert Blog has become convinced of Intelligent Design!  The piece of evidence that tipped him might just be your last straw, too. (H/T:  True Ancestor)

Beneficial mutations that advance an organism's fitness are, as we know, rare.  Most spontaneous mutations are deleterious.  Now, in a finding reported in the journal Heredity that has evolutionary biologists going "WTF??", it appears that the identical mutation is more likely to prove beneficial in less fit organisms than in their fitter cousins, improving the weaklings' chances not to die out.  Huh??  Look:

Breed almost any organism under conditions where it is forced to accumulate random mutations, its fitness will invariably decay. The reason is that very few mutations improve an organism's ability to survive or reproduce; the majority are harmful. But a recent study suggests that the size of this majority depends, to a surprising extent, on the [context] in which the mutations occur. The same mutation occurring in a poorly adapted individual, Silander et al. (2007) argue, is more likely to be beneficial than if it occurred in a well-adapted individual.

These results are noteworthy because they suggest that the effects of mutations are dynamic rather than fixed. Such a view is consistent with some models of evolution and not with others. For example, it suggests that very small populations, which tend to accumulate harmful mutations, will be protected from the endless accumulation of more and more harmful mutations by an increasing rate of beneficial mutation. This 'compensatory mutation' view contrasts with the 'mutational meltdown' view, which instead suggests that such populations will suffer a build-up of harmful mutations until they become extinct. [...]

To investigate this, Silander et al. (2007) applied techniques first used decades ago to study the fitness effects of mutations in Drosophila (Mukai, 1964), but instead used a virus system, a DNA bacteriophage known as X174. With the addition of sophisticated statistical tools and computer simulations, they were able to estimate the proportion of beneficial mutations in virus lines with both high and low fitness. For all three high-fitness lines measured, they were unable to detect any beneficial mutations. But for two out of three low-fitness lines, beneficial mutations were clearly evident. In fact, the fraction of mutations inferred to be beneficial was substantial—16%. [...]

One possibility is that low-fitness populations, which suffer from more deleterious mutations, could simply be experiencing a high rate of back mutation—that is, the fitness decline might halt simply because the harmful mutations are changing back to the more benign versions of themselves. Silander et al. (2007) approached this problem by using a mutagen to ensure that nearly all of the mutations in their study were in one direction (from a cytosine nucleotide to a thymine). Another possibility is that selection is working overtime in low-fitness populations, helping them to maintain their fitness: a mutation might well be more harmful in an already sick virus than it is in a healthy individual. Since the worst mutations are quickly eliminated—dead viruses do not replicate—selection would, in this case, more effectively curtail further fitness decline in low-fitness populations. But, as Silander et al. (2007) show, selection is acting only slightly more strongly in low-fitness populations, and the difference is not large enough to explain their results. [...]

[T]he results from this study are consistent with what has been found in some studies of more complex organisms (Estes and Lynch, 2003). Furthermore, the use of viruses for this kind of work opens up exciting future possibilities. Viral genomes are small and easily manipulated, and viral fitness is straightforward to measure. Thus, the main result of Silander et al. (2007), that particular mutations have different effects in high- versus low-fitness virus lines, could potentially be tested directly.

It's as if a species or population, like an individual, is spurred to a desperate creativity by a threat to its existence.   A sort of molecular necessity-is-the-mother-of-invention.  But wait a minute.  We're talking about creativity and invention at the level of DNA molecules. 

Kinda makes you go WTF??

Comments

[realpc]

If ID is not a theory, Cedric, then what? Some people call ID a theory, others do not. The fact that I have called ID theory does not prove I am stupid or unscientific. In case that was where your argument was heading.

If I say now that ID is not a theory -- although I was not stupid or unscientific for having called it that -- what would be the next step in your argument? Do you have an argument?

ID IS NOT A THEORY. What happens then? I already said I don't want ID taught in school. I have no idea where you are taking this, and you probably have no idea either.

[Cedric Katesby]

RealPC said...
"The fact that I have called ID theory does not prove I am stupid or unscientific."

This isn't about you.
It's about ID.

Maybe you're stupid. Maybe not.
I have no idea. Let's keep personalities out of this.

I am claiming that ID is not a theory.
That's it.

A while back, you asked me to define what I meant by the word "theory".
I gave you a definition.

You never bothered to acknowledge it or use it in an argument.
You just decided to fuzz the meaning of the word "theory" for your own purposes.

I have been consistant in the use of the word "theory".
I have provided multiple sources to banish any possible ambiguity on what the word "theory" means to the scientific world.

You claim that ID is science.
You claim that ID is a theory.
As in a "scientific theory".
This is a claim.
A testable, verifiable claim.

I am asking for a simple, baffle-gab free answer.

Do you still claim that ID is a theory?
Yes or no?

This question is an opening salvo in a scientific argument on Intelligent Design.

If you answer with a simple "Yes" then I will ask you to defend your claim in your next post.
Scientifically.
You will be obliged to back up your words.
Scientists love to do this.
They display their hard work with pride, to their peers in peer-reviewed journals and to the public in general.

RealPC said...
"If I say now that ID is not a theory'...'what would be the next step in your argument? Do you have an argument?"

Why not find out for yourself?
Ready?

******(Dramatic Pause)********

Do you still claim that ID is a theory?
Yes or no?

[realpc]

[You claim that ID is science.
You claim that ID is a theory.
As in a "scientific theory".]

No I didn't. You want simple answers but there aren't any. People define ID in various ways. I can't give you simple answers so I guess we won't find out what your simple argument was going to be. Something you learned at JREF probably -- 5 simple steps for arguing with ID advocates.

[Cedric Katesby]

Previously on this thread...

RealPC said...
"There is nothing unscientific about the ID hypotheses."

RealPC said...
"The science of ID is questioning Darwinism..."

RealPC said...
"...now that ID makes testable predictions."

RealPC said...
"...about the actual scientific controversy."

Cedric said...
"So, according to you, ID is not actually a scientific theory.
Right?"

RealPC replied...
"Absolutely wrong."
..................................

RealPc said...
"No I didn't."

Coward. Liar.

RealPC evades...
"People define ID in various ways."

Yes, but YOU define it as a theory.
Or sometimes as a hypothesis...

You repeatedly refer to Intelligent Design as a theory.
"...Intelligent Design theory..."
"...ID theory does not..."
"...strengthen the ID theory."
"...ID theorists acknowledge..."
"...the ID theory of evolution is despised..."
"...Intelligent Design is a theory..."
"...nothing about the ID theory..."

Do you still claim that ID is a theory?
Yes or no?

They're your words.
Make sure you don't choke on them.