Chris
This, at best, would eliminate one small type of falsification. Since
Neo-Darwinism *does* make predictions of directly approaching a certain
state under certain conditions, this hardly protects it from falsification
in any general way. Further, Neo-Darwinism will also predict that an
organism under certain *other* conditions will *not* arrive at such a result
by a straightforward step-by-step process. Evolution follows environmental
conditions in whatever way is handiest and effective. If those conditions
change first one way and then another way and then yet another way the
number of cases of results at the end of the final period of adaptation that
are sideways or indirect paths will be higher than if the environment
changes very smoothly, because the environmentally allowed paths are more
direct. For example, if camels are forced, slowly, over eons, to adapt to
cold and wet climates, and then later forced to adapt to mountainous
terrain, it's conceivable that some aspect of adapting to the cold and wet
climate may then be included in adapting to mountainous terrain. But, if
camels are simply gradually moved to progressively more mountainous terrain
over the same *total* time, their adaptations will more likely be directly
aimed at living in mountainous terrain, or at least will more likely have a
direct path from heat-and-dryness adaptation to mountainous-terrain
adaptation (without the cold-and-wet adaptations, unless the mountains are
also cold and wet).
SJ
> If Neo-Darwinism was false, how would a Neo-Darwinist known it?
Chris
See above. We might, in fact, use so-called "irreducible complexity" as a
clue to search out paths of indirect or circuitous evolution. We could
predict that, where there is "irreducible complexity," we should more often
find *other* evidence of circuitous evolution as well.
Of course, falsifiability is no problem at all with ID theory, I suppose.
SJ
> Or, to put it another way, if an Intelligent Designer did in fact create
> histone-4 in one jump, how would a Neo-Darwinist ever know it?
Chris
We'd find species that were just like the creatures that have histone-4 and
slightly earlier, very similar, creatures that did not have it, perhaps. Or,
we'd find that even an exhaustive computer simulation could not find a
plausible path, perhaps. Or, we'd find laboratory organisms that started out
without any precursors of histone-4 that *suddenly* started having
histone-4, thus indicating that some outside force was at work.
Of course, even this would not show that Neo-Darwinism was wrong so much as
incomplete. Stuart Kauffman, in "The Origins of Order," argues that there
are strong self-organizational forces at work in living organisms, forces
that derive from the *basic* facts of atom-to-atom binding and the various
features of the relevant elements. He regards the building of DNA as akin to
a process of crystalization, in which there is a natural selective mechanism
*at the chemical level*, that ensures that such molecules tend to bet built
in some ways but not in others, somewhat as snowflake crystals tend to get
built in a six-sided way and not in a four-sided way -- but not, apparently,
because of any activities of any designer, intelligent or otherwise.
SJ
> The postulation of hypothetical circuitous routes is always possible to
save
> Neo-Darwinism. But as Mike Behe notes. such explanations become less
> plausible as the number of unexplained irreducibly complex biological
> systems increases:
>
Behe
> "Even if a system is irreducibly complex (and thus cannot have been
> produced directly), however, one can not definitively rule out the
> possibility of an indirect, circuitous route. As the complexity of an
> interacting system increases, though, the likelihood of such an indirect
> route drops precipitously.
Chris
I wonder what Behe's reasoning is here? Since complex structures are often
more flexible functionally than simpler ones, it might be the case that
circuitousness would be quite common. If it is "easier," in genetic terms,
to make a small adjustment in a complex structure to enable it to handle new
environmental factors than to generate a suitable alternative from something
simpler, such a change would seem to be *more* likely, not less. Further,
the a priori probability of the genes for a complex structure suffering from
variations is higher than that for an othewise-equal but simpler structure
(assuming a corresponding simplicity in the genetic encoding for the simpler
structure).
SJ
> And as the number of unexplained irreducibly
> complex biological systems increases, our confidence that Darwin's
> criterion of failure has been met skyrockets toward the maximum that
> science allows." (Behe M.J., "Darwin's Black Box", 1996, p40).
Chris
Again, I'm not sure what Behe's reasoning is, but the conclusion does not
seem to follow from any visible premises. In fact, because evolution picks
up speed as the environment and the genetic mechanisms available for
producing variations increases, and because, the *environment* changes
faster as evolution picks up speed, it would appear that the number of
"irreducibly complex" structures might increase, as more and more *existing*
complex structures were impressed into more functions that they had not had
to have before. Further, in *many* cases when this happens, the structures
will pick up *further* complexities, but not always. Having made the change
in function, there will may be a period of genetic adjustment, in which the
structure becomes simpler. Whether this occurs for the population as a whole
will depend on the relative values of the original change vs. later
"adjustment" variations, and so on. Also, if the environment changes *again*
before this period of adjustment has a chance to occur, we may get yet
*more* "irreducible complexity."
Then, once the new structure becomes widespread, Hoyle and Behe, a couple of
billion years later, may say, "Why, that structure is irreducibly complex.
Therefore, naturalistic evolution is false."
SJ
> One can continue to rescue Neo-Darwinism by such ad hoc auxiliary
> hypotheses, but Neo-Darwinism, like Ptolemaic astronomy, has then
> lost its original simplicity in a maze of ad hoc `epicycles':
Chris
Not really, though I can see why you might say that. This is because, first
of all, *many* modern living organisms *are* complex. It makes no sense at
all to suppose that they all got that way by some simple-minded
straightforward bottom-up process. The actual details of evolution (the
process, not the theory) are inherently complex for any large ecology (i.e.,
the Earth) over a long period of time in which significant environmental
changes occur.
This does not mean that the *theory* will necessarily grow more complex,
though it might, as new observations or chemical or genetic discoveries are
made.
Denton
> "The concept of the epicycle was one of the characteristic features of the
> Ptolemaic system. In the centuries following its formulation, the gradual
> accumulation of astronomical data by medieval Christian and Moslem
> astronomers revealed further irregularities in the movements of the
planets
> which required further adjustments to the traditional geocentric system.
To
> account for these irregularities, more and more epicycles were proposed
> and as time went on the theory underwent successive modifications and
> amendments. By the early sixteenth century the whole Ptolemaic system
> had become, in the words of a contemporary astronomer, "a monstrosity",
> a fantastically involved system entailing a vast and evergrowing
complexity
> of epicycles. The state of astronomy is described in Kuhn's The Structure
> of Scientific Revolutions:
Chris
Notice here that it's the *theory* that is growing more and more complex, as
new observations demand changes. In the case of evolutionary theory, the
theory essentially remains the same, with occasional changes (such as
allowing for irregularity in the *rate* of evolution as required by
environmental changes and by gradual introduction of new methods of
evolution (such as sexual reproduction), etc.). The *principle* of evolution
*never* required gradualism, for example. It only required that each truly
individual change be reasonably small.
Kuhn
> `By the thirteenth century Alfonso X could proclaim that if God had
> consulted him when creating the universe, he would have received good
> advice. In the sixteenth century, Copernicus' co-worker, Domenico da
> Novara, held that no system so cumbersome and inaccurate as the
> Ptolemaic had become could possibly be true nature. And Copernicus
> himself wrote in the Preface to the De Revolutionibus that the
astronomical
> tradition he inherited had finally created a monster.'
>
> However, so ingrained was the idea that the Earth was the centre of the
> universe that hardly anyone, even those astronomers who were well aware
> of the growing unreality of the whole system, ever bothered to consider an
> alternative theory."
>
> (Denton M.J., "Evolution: A Theory in Crisis", 1985, p349)
Chris
Again, since evolutionary *theory* has increased in complexity only slightly
since Darwin's day (due largely to the advent of genetics, etc., this entire
criticism does not really apply.
Further, I think even Stephen, Mike Behe, and Denton would agree that life
on Earth is *radically* more complex than the nice orbits of a few planets.
The planets only have, for the most part, nine other objects to contend
with, and the influence of most of them on each other is very slight. When
you see a theory of such complexity growing to deal with such a simple
situation, it's time to rethink things. But, life on Earth is peraps a few
*billion* times as complex, so having a theory that has some complexity in
it to account for that complexity in the facts makes sense.
Finally, right now, we don't *have* any alternatives that can even
*approximate* naturalistic evolutionary theory's effectiveness. Designer
theory doesn't do it (even if we *assume* a designer!) because it has no
causal *principle* that, for example, implies that genetically complex
organisms must arise only after genetically simpler ones (if we postulate a
designer, we cannot use that fact to imply that genetically complex
organisms will follow genetically simpler ones, because there is no causal
*principle* involved, but *only* the postulated cause, whose nature and
principles of behavior we don't know). It does no good whatever to suggest
that the designer might use naturalistic evolution to achieve its goals,
because that would just make the designer superfluous, since evolutionists
*already* claim that naturalistic evolution is at work. It does no good to
introduce some additional causal principle, because, if that principle is
true, what do we need the designer for? Not much, *unless* (fat chance):
1. the principle passes empirical testing
*and*
2. it is such that it could not be true *without* the
designer
*and*
3. it does not face significant competition from an
implicationally-equivalent but purely naturalistic principle.
The Ptolemaic theory did not go away until an alternative was found that
actually *worked*. Where is such a replacement for naturalistic evolutionary
theory?
Finally, positing a designer does *not* make for a simpler theory, because
the alleged *designer* would himself/itself/themselves have to be *much*
more complex than evolutionary theory, no matter how complex it might get.
Simply *positing* a designer is not sufficient. You must also determine how
he works, what rules he follows, if any, etc.; these are *necessary* parts
of such a theory, thus almost certainly making vastly more complex than
evolutionary theory.
This is why (among other reasons) the proper replacement for the Ptolemaic
theory was *not* a designer theory of the orbits of the planets. If another
theory is to be found it will have to be *simpler* than evolutionary theory,
not introduce a hyper-complex and largely unknown designer. Doing that would
be the equivalent of introducing millions or even billions *more* epicycles
to the Ptolemaic theory, since then we'd have to have a fairly detailed and
empirically *predictive* knowledge of the designer(s)' mind(s). Plus, in the
version that Stephen wants us to accept, the designer is *supernatural* as
well as being unknown, which adds another massive burden of proof.
To get an idea of the relative complexity of the two theories, consider that
the principle of evolution can be stated in a paragraph or two, including a
little elaboration, but the relevant attributes of the alleged designer's
mind and methods and so on would require *much* more than that, because
you'd have to include significant facts about his/their knowledge, about
their ability to manipulate matter, about their long-term motives and how
those motives relate to their genetic manipulations (or whatever it is they
are alleged to do). Without this, there is no basis for predicting new
observations or even reconciling theory with old observations (except, of
course, the old scientifically useless standby: "That's just the way the
designer did it").
So, Stephen, when are you going to unveil the central causal principle(s) of
your new theory, complete with at least *some* empirically testable
implications?
Us naturalistic evolutionists have been waiting for you to get on the stick
in this respect for at least a few months now.