From: John Marlow (johnmarlow@gmx.net)
Date: Sat Feb 03 2001 - 10:09:10 MST
**See below.
On 3 Feb 2001, at 8:32, Technotranscendence wrote:
> On Friday, February 02, 2001 7:47 PM John Marlow johnmarlow@gmx.net wrote:
> Marlow quoting Hogan:
> > Hmm. Difficult to know which to pick. Maybe the question of the
> > origin of the stupendous amount of information in a genome -- genetic
> > program coding not only structural organization & growth, but
> > instincts, behavior, responses to injury, stress, etc. etc.
>
> How is this being measured? I've cited the work of Brooks and Wiley in
> previous posts. They use a formalism to evaluate the information in living
> systems.
>
> However, the surprising thing should not be the amount of information, but
> the amount of noise in living systems. I'm sure we are all aware of DNA
> changes -- to stick with DNA; the focus should not be on DNA alone -- many
> random changes in DNA have no or little impact on anything else. Part of
> this is because DNA and proteins made from it -- indirectly, of course --
> have active sites and passive sites. Most of DNA and most of protein is
> passive -- just there for the ride and as long as it doesn't affect anything
> else, it doesn't make a difference. An analogy might prove helpful here. A
> protein's active site might be compared to the tires on a car or any other
> vital component. The license plate cover on a car, however, is more like a
> passive site. It has no or little effect on performance. It might on
> margin, but, for the most part, it does not.
>
> (Now, imagine if lots of random change accumulates in passive areas, then an
> active area changes or an area changes that makes formerly passive areas
> active. You might wind up with a huge shift in DNA or protein behavior.)
**I believe what he's saying is that all, or at least many, eventualities were coded
for at or near inception. That "useless excess" DNA is not in fact useless--but
waiting to be triggered into usefulness by changing conditions.
>
> > If
> > Darwinism were correct, such programs accumulated from nothing in
> > tiny increments. Hence every evolutionary step along the way, on
> > average, should add information to the growing genome. But _not one_
> > of the examples usually cited in textbooks etc. as "evolution in
> > action" has ever been found to add information, and so cannot count
> > as a meaningful evolutionary step. Bacterial resistance to
> > antibiotics, for example, (e.g. streptomycin) results from a
> > deterioration that loses the molecular specificity necessary to
> > accept the antibiotic's deactivating "key" -- i.e. a loss of genetic
> > information, not a gain. The much-touted pepper moth in England is a
> > simple instance of population dynamics, the dominant color changing
> > as the environment changes. But light and dark varieties were both
> > present to begin with. Nothing genetically new came into existence.
>
> I agree with the peppermoth example. In fact, Brooks and Wiley use it in
> their _Evolution as Entropy_ to highlight the difference between reversible
> and irreversible change. They believe the latter is more important to
> evolution. However, you seem to be overlooking the fact that variations can
> arise. We'd have to do further, deeper analysis to see why both varieties
> exist -- under the assumption that such variation is not primary.
>
> > Yet these are offered as among the best examples. Programs of this
> > complexity don't write themselves from random changes. In
> > fact, the reverse -- the more complex and precise a program becomes,
> > the more random changes are likely to disrupt it.
>
> Genomes, in general, are very resilient to some disruptions. Even though,
> e.g., humans get cancer, even most cancer victims live long enough to
> reproduce, raise their children, and so on. I would look at the problem the
> other way. Why is there so little information in any genome of any
> relevance to the organism?
**See above point. Little of relevance to the organism _in the
present environment._
>
> > It's important to distinguish between information and the medium
> > holding it. "Macbeth" remains the same play whether represented as
> > ink on paper, dots on a diskette, sound waves, laser pulses, etc.
> > Similarly with genetic information. I'd contend that saying genomes
> > are just an emergent property of DNA is like saying Macbeth is an
> > emergent property of ink and paper, missing the whole point that the
> > medium isn't the origin of the message. It just carries it.
>
> Such a distinction makes sense in an abstract symbol system like writing.
> The alphabet we use has no necessary relation to information coded in it.
> "Macbeth" would still be "Macbeth" even if it were coded in, say, Unifon --
> and we knew how to read Unifon. However, the relation between DNA and an
> organism is a lot different. The genome of any living thing is not an
> abstract symbol system. In fact, it's an active information system and
> makes proteins and regulates itself. There are triggers of when to do
> certain things and what to do in it. It requires no outside interpreter and
> it does have emergent properties.
>
> Of course, the analogy between "Macbeth" and biological information breaks
> down on these points. (But getting back to random mutations, imagine
> changing a period to a comma in "Macbeth." How much meaning would be lost?)
>
> As for not wanting to debate the issues, well, whatever.:)
>
> Cheers!
>
> Daniel Ust
> http://uweb.superlink.net/neptune/
> Film recommendation: "The Color of Paradise."
>
John Marlow
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