One of the persisting problems with ID theorists's claims that
macroevolution is impossible is that they do not go through the cycle of
events that NET (naturalistic evolutionary theory) claims occurs and show
at what point it breaks down.
Indeed, they *agree* with what seem to be the *only* requirements for
full-fledged naturalistic evolution to occur:
1. That mutations and other variations in genetic material can and do occur.
2. That such variations, once they occur, *can* be at least tolerated by
the organism, and may even be beneficial to it.
3. That such variations, once they occur and are allowed to be perpetuated,
may be combined with *later-occurring* variations, so that the effects of
both variations are present in the resulting organism.
4.That facts of biological viability, reproductive capability, and ability
to cope with the environment (all of which may be categorized under
"fitness" or "unfitness") are differentially selective in determining which
organisms survive and reproduce and which die out without reproducing.
But, at least by implication, they assert that the accumulation
microevolutionary steps of 3 above cannot be continued indefinitely to the
point of producing what they would be willing to call macroevolution (and,
if it was too obvious that it *did* occur, of course, they would *redefine*
macroevolution so that, once again, "macroevolution" would, by virtue of
the new definition, no longer occur).
The question is, at what point in the progression of a series of
microevolutionary steps does something prevent further steps of
microevolution in order to keep it from producing results that would be
called macroevolution? And, just what *is* it that intervenes and prevents
further microevolutionary steps? How does it work? What triggers it into
action? *WHY* does it intervene? What is the evidence that such a "barrier"
to macroevolution exists?
The best I've seen from ID folks in this regard is vague remarks about
pleiotropism and the requirement that several genes change for certain
morphological changes to be biologically successful. Since Nature is quite
capable of suppressing pleiotropism when such suppression is needed, and of
performing many small changes on a number of features over time (so that,
for example, the heart becomes stronger to support the higher pumping
requirements of the giraffe's longer neck), these facts hardly seem to be
anything except "speed limits," not actual uncrossable barriers or boundaries.
So the questions of the paragraph before the just-previous one remain.
There is one final question: Can any member of this list provide real and
verifiable answers to these questions that do in fact support the
ID-theorist thesis in this regard?
My guess is that there aren't, but is it possible that I'm wrong?
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