I don't think evolutionists look at it quite this way. Since evolutionary
theory takes common ancestry as a starting point, "macroevolution" is
usually considered to be the starting point of investigation. The
approach to finding support for macroevolution is quite different, then,
from finding examples of "microevolution." Where they coincide is in
the argument that the mechanisms of that we can observe in action now,
extended over geological time, have been responsible for common ancestry.
> In the first case, random mutations are unprovable. How can you prove
> that an event is random, versus the possibility that perhaps you just
> don't know enough about the system in question to factor in all
> causalities? A computer can feign randomness, but in the end, it is not
> random at all, it is algorithmic.
I don't think this is a sticking point for most theories of evolution.
That is, if mutations are non-random in some way, that is interesting,
but in order to make the case, you'd have to perform experiments
demonstrating the non-random nature of the mutations, and showing how
knowing they weren't random was an important explanatory device. For
example, if there were some effect which imitated Lamarckian-style
mutations that specifically reinforced somatic patterns, that would
be interesting, and observable.
> In the second case, scientists are fond of telling us that you can't PROVE
> macroevolution because it just takes too darn long. Okay, I reply, then
> quit assuming macroevolution to be true, and admit that macroevolution is
> merely a theory, not a "fact".
No, common ancestry is assumed to be true, not because someone was
videotaping it, but because of many different lines of physical evidence,
one of the most important of which is the nested heirarchical patterns
found in the DNA of living things. Paleontological discoveries of the
time frames in which the various species existed, transitional fossils, and
so on are all supporting lines of evidence for this conclusion. (This
is nowadays, of course; Darwin reached the conclusion on much slimmer
grounds, but sufficient for he and his contemporaries to realize common
ancestry. In those days, it was considered impossible to notice the
"microevolution" of species, because it was thought to be too slow
a process.)
The worry about 'fact' and 'theory' is usually a misnomer: any scientific
idea is 'theoretical' in the sense that further observations can overturn
or modify it. Some are so well grounded, though, that they serve further
investigations in the role of 'facts.'
-Greg