I wrote:
>> I think we should take the time to consider the possibility that
>> at least some irreducibly complex systems may evolve (via indirect
>> means, as John points out).
>>
>> Otherwise, we're going to have to start looking for the nano-sized
>> engineers which installed new and irreducibly complex functions in
>> some of the bacteria I once cultured.
[...]
You said...
>I am interested in those bacteria.
I used to be; they provided a nice data point on a graph I made a
couple years back. Salmonella typhimurium- Strains SK2979 or SK3041
were the parentals. A common lab strain, the original LT-2 isolate,
would probably give similar results.
> Did they seem to develop some novel functions?
Yes. The ability to utilize aspartate as the sole nitrogen and carbon
source. I wrote a quick post about it in talk.origins. See the
following: http://www.dejanews.com/getdoc.xp?AN=375867501
This story is not going to make anyone say, "Gosh darn it, evolution
explains it all!" It is intended to illustrate a method of how an
"IC" system could arise through indirect steps (such as functional
recruitment).
> If so, do you have thoughts on the source of the variability?
Mutation. The first was possibly a point mutation. The second
step very likely involved the duplication of a segment of the
bacterial chromosome.
> Was it something like the iteration of viruses or of the immune
> system?
I'm sorry but I don't understand the question. As far as I know
the mutations were random.
> Evolved or not seems retrospective which seems speculative
> unless confirmed by a reproducible experiment.
Interestingly, it is sometimes possible to repeat such experiments.
And this one did repeat. I don't know if the mutations were exactly
the same the second time but the phenotypes of the resultant strains
were pretty similar.
> How do you see it?
Check out the article listed above.
To forestall the possible counter that these sorts of mutations were
already in the bacteria before the experiments were run, see an old
post of mine: http://www.dejanews.com/getdoc.xp?AN=180274123
Toward the bottom of the letter I describe some classic experiments
by Luria, Delbruck and the Lederbergs to show how we can know the
composition of our cultures before we run the experiments.
Regards,
Tim Ikeda (tikeda@sprintmail.com)