[asa] Falsification of Darwinian mechanisms

-----Original Message-----
From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu] On
Behalf Of Dave Wallace
Sent: Tuesday, October 21, 2008 3:47 PM
To: Iain Strachan
Cc: ASA
Subject: Fwd: [asa] Rejoinder 6D From Timaeus - for Iain Strachan, Jon Tandy
and Others

With regard to cotton thread and UEM, well said Iain, although I would point
out that in one of his books Karl Popper regarded Darwinian evolution as a
UEM since it was difficult to postulate reasonable predictions that would
falsify it. To my mind especially the RM + NS mechanism is problematic in
this respect.

Dave W
----------------------------

I think this is an excellent topic, one which has probably been discussed in
various ways, but a good approach in light of recent discussions with
Timaeus.

If "Darwinian evolution" (meaning, the full scope of currently proposed
natural mechanisms for common descent) were able to be falsified, what would
be the means by which it could be falsified? I have heard many proposed
evidences for common descent and natural mechanisms, and many claims for
LACK of evidence of the proposed mechanisms, but lack of evidence does not
constitute anything like certain proof. I am specifically asking the
following questions of those knowledgeable in the biological sciences, for
honest evaluations of how the current hypotheses in biological evolution
could be falsified, or whether they ever could be.

What would falsify the random mutation/natural selection hypothesis, or is
it simply a Universal Explanatory Mechanism which can explain everything by
simply inferring from present knowledge that the large gaps in our knowledge
may someday be filled? I've got some suggestions.

1. If species were found deviating significantly from the predicted "tree of
life", meaning that descendents appeared to be disconnected from their
ancestors, would that falsify the evolutionary model? Or would the tree
simply be redrawn to include the new information? It has often been claimed
that the species fit perfectly into their predicted sequence, but is that
really true? Isn't it true that the "predicted sequence" has been a work in
progress over the years, requiring some adjustment as new data is
discovered? If so, how much could this be seen as retrofitting the
predicted model to the data as a UEM, as suggested above?

2. If the genetic/molecular evidence showed an entirely different hierarchy
of ancestor/descendent relationship and nearness to one another from the
phylogenies previously determined from other means, that might constitute
strong evidence against the standard model of common descent. As it is, the
confirmation from genetics does seem to be strong evidence for the standard
model, because it confirms the previously developed "tree of life" sequence.
But does it really? How much adjustment is there being made even now, as
genetic evidence is discovered and added to the present body of knowledge?
I'm not asking for the scientific model to be fixed and unmovable in order
for it to be valid, because that is unrealistic. But I am asking, what (if
any) changes are made to the so-called "standard model" as new evidence is
discovered? If the standard model is being corrected by reference to
genetic evidence, how can this be considered a "proof" of the previously
existing model? What kind of falsification of the standard model could be
anticipated as evidence against the hypothesis of common descent, if the
model is continually modified by new information? Could it potentially ever
be falsified?

3. Once specific evolutionary steps in the predicted model are identified
and well-defined, could the hypothesis of naturalistic evolution be
falsified by showing the improbability of making the transition(s) from
point A to point D? This seems to be the approach used by many in the IDM,
however I don't see that this method of falsification is likely to be very
effective. It always relies on gaps in our knowledge to disprove
naturalistic explanations, and it's very difficult to prove that the gaps
will never be filled. However, could evolution of various specific
structures from primitive to complex forms be potentially falsified at some
point, by showing that the complex forms could not possibly have been
derived from simpler forms? What sort of evidence would be necessary to
demonstrate beyond reasonable doubt that such transitions could never have
occurred naturally? We have seen statistical approaches which rely solely
on the probabilities of random mutations to arrive by fiat from random
molecules to the final configuration, which isn't realistic because it
doesn't take into account transitional form and function of more primitive
structures. If that approach is invalid, are there means by which specific
evolutionary steps could be absolutely ruled out as impossible to occur
naturally, and therefore by inference constitute a failure of the
naturalistic evolutionary model? Or will scientists continue to fall back
on explanations such as Gould's punctuated equilibrium to justify the
speculation of dramatic but unexplainable jumps in complexity?

4. Could Mike Behe's approach, given much greater development of scientific
knowledge, someday provide sufficient falsification of naturalistic
evolutionary explanations? I.e., given much more knowledge of the
underlying biochemical and genetic structures, evolutionary history at both
macro and micro levels, and knowledge of form and function of primitive
forms that were probable precursors to the complex versions, would it be
possible at some point to prove that the intermediate structures and
functions for a given organ could never have survived numerous transitional
forms, because the organism would not have been able to survive, reproduce,
etc. in the interim? To my way of thinking, as in the previous paragraph, I
don't see our knowledge ever expanding to the point that we could absolutely
rule out unknown natural mechanisms, and thus we can never by this means
construct a suitably definitive falsification, except through the argument
from incredulity (we can't possibly imagine how it could have arisen
naturally, so therefore it must have been designed).

Are there any other means by which the hypothesis of common descent and its
mechanisms could truly be falsified? If there isn't any way it could
realistically be falsified, what does this say about its status as a
scientific theory? What does it say about the claims that other
explanations (such as ID) are not science, because they can't be falsified?

I am asking honest questions, while at the same time realizing that
biologists sincerely tell us that biological evolution (in general, and in
many specifics) does have power as a scientific theory, because it fits
known evidence, and it makes predictions that lead to useful experiments and
conclusions in the field.

Jon Tandy

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Received on Tue Nov 4 00:21:27 2008