Re: Is evolution really the central theory for all of biology?

Cornelius,

Are you engaged in this debate with Terry and David for the sake of
critically evaluating epistemology as it relates to evolutionary biology,
or do you in fact think that evolution did not take place? I'm just
wondering.

I think you need to realize that once a theory has been established as fact
(I use "fact" in the lowercase, understanding that all scientific knowledge
is provisional on some level), every application and new investigations
involving that theory are not really constructed for the purpose of testing
the theory, per se. For example, applications of general relativity to
understanding differences in space-time at different elevations on the
earth's surface or to charting the positions of stars are not specifically
constructed as tests of the hypothesis "The theory of general relativity is
true/false". However, when those applications of the theory "work" well,
those occurrences do rightly become additional "evidences" for the theory.

In the same way, all these data that Terry, David and others have been
describing are evidences in favor of evolution even though they may appear
circular in the sense that they were obtained and analyzed assuming
evolution in the first place. It is valid and right that evolution
textbooks should list and describe all these kinds of data as evidences for
evolution even thought they were not obtained by strict Popperian
constructions of the scientific method for testing evolution, per se.

I've said this before (and I'm sure it is not original with me), but
Darwin's theory of evolution required a specific form of inheritance to
work, and this requirement constituted a bold prediction that amounts to a
Popperian test of evolution. No one had ever conceived of inheritance in
the manner predicted by Darwin, yet we later found (thanks to Mendel and
the Neo-Darwinian Synthesis of the 1930s) that inheritance works in
precisely the manner that allows for evolution to work. I think if one
thought about it, many such historical examples could be described.

Douglas

                                                                                                                                        
                      "Cornelius
                      Hunter" To: <asa@calvin.edu>
                      <ghunter2099@sbcg cc:
                      lobal.net> Subject: [BULK] - Re: Is evolution really the central theory for all of biology?
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                      asa-owner@lists.c
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                      09/21/05 07:33 AM
                                                                                                                                        
                                                                                                                                        

Terry:

In addition to the fossil evidence, you mentioned the nested hierarchy
evidence from comparative anatomy. Let's have a look at this one, according
to the criteria:

====================
A. The evidence should not include problems for the theory (obviously).

B. The evidence should be the fulfillment of a somewhat narrow prediction
of the theory. That is, if the evidence as well as several other outcomes
are all accommodated by the theory, then the evidence is not compelling.

C. The evidence severely damages all alternative theories (need to be
careful not to misrepresent or ignore the alternative theories, of course).
====================

The nested hierarchy data suggest or reveal:

1. The designs of the species seem to be clustered, and the clusters seem
to cluster in larger groups, and so on, in what is called a nested
hierarchical pattern.
2. There are a great many exceptions that violate the pattern, at all
levels, such that, for example, a paper out of Doolittle's lab has called
for a "relaxation of tree thinking."
3. There is massive convergence, meaning similar designs show up in distant
clusters.
It seems obvious that 3 fails on A, but I realize you may disagree. Setting
that aside then, obviously 2 fails on A and 1-3 all fail on B. Also, none
succeed on C. So as with the fossil evidence, I don't see how this can be
compelling evidence for evolution.

--Cornelius

 ----- Original Message -----
 From: Terry M. Gray
 To: asa@calvin.edu
 Sent: Tuesday, September 20, 2005 12:51 PM
 Subject: Re: Is evolution really the central theory for all of biology?

 Cornelius,

             If we "assume" that evolution is true, it's because there is
             significant warrant for doing so.

       Yes, evolution is supposed to be a fact. What we need are compelling
       evidences though. How about this: start by supplying *one*
       compelling evidence.

 Back to where we've been before. I and most biologist, palentologists,
 think that the "textbook" examples are compelling especially taken
 together. So there's a bunch of them there: fossil record, homologies of
 all sorts (nested hierarchies), biogeography. It seems what's compelling
 to me is not compelling to you. (By the way, I also like some forms of
 punk rock and there's no better music in all the world than
 progressive/classical rock!)

 I'll even leave out the small-scale evidence that you're fond of
 criticizing, because I agree that it doesn't address directly
 "macroevolutionary" questions. However, it does show us that the genetic
 variations that are observed in the large-scale tree of life are for the
 most part "more of the same" as what is observed in virus, bacteria, fruit
 flies, zebrafish, mouse, pigeon, dog, cows, pigs, horses, and humans. Are
 you going to tell me that all of the instances of hemophilia or
 sickle-cell anemia or cystic fibrosis or whatever mutation you want to
 track arose independently? Maybe some did, but who cares? The vast
 majority are examples of descent with modification of single base pair.
 That's how a good chunk of modern molecular genetics actually works.
 Traditional pedigrees based instances of disease identify "families".
 Detailed genome analysis of these families identifies regions of the
 chromosome where the modified gene exists. Further analysis usually
 locates a single base pair modification.

 BTW, I still owe you a response to something from Saturday night. Hope to
 get to it soon.

 TG

 ________________
 Terry M. Gray, Ph.D.
 Computer Support Scientist
 Chemistry Department
 Colorado State University
 Fort Collins, CO 80523
 (o) 970-491-7003 (f) 970-491-1801
Received on Wed Sep 21 09:56:40 2005