RE: Increasing Complexity was [RE: What 'naturalists' really

Arthur V. Chadwick (chadwicka@swau.edu)
Thu, 03 Sep 1998 08:55:59 -0700

At 11:11 PM 9/2/98 -0400, Tim wrote:
>> I would like to interject a suggestion. Complexity is probably the
>> wrong word to use, since randomness is the most complex state possible
>> requiring the greatest volume of descriptors). I prefer the term
>> information, identified in biological systems by the addition of
>> specific new functionality.
>
>I don't think that will move us a whole lot closer to a solution.
>I think all these terms are necessarily vague when it comes to
>describing biological systems. We really don't have a good handle
>on these sorts of questions. For example, if a protease's specificity
>changes so that it now hydrolyzes a different substrate, is that
>considered a new function or simply a modification of a previously
>existing one? If a mutation permits a "new" sugar to be harvested
>by a cell for metabolism, is this a new function?

Clearly not. as Spetner points out a generalization of an existing
function is a loss of information, not an increase (his example is
instructive...it takes more information to tell you how to get to my house
than it does to tell you how to get to my town, or state, etc., so a loss
of specificity is nothing more than a loss of information.)

>
>Also, going back the the HbS question... It seems to me that producing
>RBCs which reduce the severity of malaria by sickling is a completely
>unexpected, new function for a molecule of hemoglobin.

He does deal with these kinds of cases.

>
>> In this context, Lee Spetner (Not by Chance!) has made a (in my
>> opinion) compelling case for the absence for any evidence for the
>> addition of new information in the whole history of the study of
>> biological organisms.
>
>Interesting. What is his method and metric for quantifying "information"
>in this context? For example, I would have thought that the capture
>of bacteria as mitochondria and plastids in eukaryotes would result
>in the addition of new "information" to the merged organisms (Well,
>perhaps that's one of the more dramatic, "one-shot" examples).

He limits his consideration to what has been demonstrated or claimed from
research, and does not give consideration to what people may have
speculated to have happened, so he has nothing to say about that.
>
>> Thus, those who believe that an increase in information can
>> result from evolution are in the same boat as those who do not.
>
>I've seen functions arise in bacteria that weren't originally in the
>bugs -- Even "irreducibly complex" functions. Chemostats and other
>continuous culturing methods are wonderful for this sort of work
>in metabolism. Well... provided you can get >1E10 of your organisms
>into the growth chamber.*

True, these claims have been made many times, but I think he carefully
covers every known claim, and I think rather compellingly demonstrates them
not to represent de novo generation of new information. At least I was
impressed with his approach.
Art
http://biology.swau.edu