> Species, Genera, Families, etc are HUMAN terms used to describe
> biological groups. They are fuzzy....
>
> The Basic Type is composed of members
> which have such similar developmental pathways that
> hybridisation linkages are feasible. It does not mean that A can
> interbreed with B,C,D,E, etc; but that A can interbreed with B, which
> in turn is linked to C, etc. The "Basic Type" can be researched, and
> to date, it looks as though a workable rule of thumb is that "Basic
> Types" are at or near the Family level in animals....
>
> In my view, "proofs" of "evolution" or of "macroevolution" that are
> within the Family category are totally missing the point. What is
> needed is a demonstration that the proposed limits on variability
> (ie within the Basic Type) can be breached.
I think you're right. Evolutionary links below the Family category are
mostly undisputed (albeit largely unproven). The real "macroevolution"
question is above the Family level. In many cases there are a small
number of "chimeric" fossils above the family level, but that does not
prove evolutionary links.
What we really need, IMO, is extensive genomic comparisons --- both below
and above the Family level. This will elucidate the types and extent of
genetic differences, and suggest _possible_ mutational pathways which can
be studied for viability. This kind of work is already starting with
parsimony reconstruction of a few putative "ancestral" genes for various
proteins. The really interesting work will be comparison of "control" and
developmental-program genes. I hope we'll get those sorts of answers in
the next 30-50 years, though it might take longer than that.
-----------
You're usually quite careful with your terminology, but I believe you
fumbled on the last sentence:
> Only evidence which
> shows variation crossing Family barriers (or higher level categories)
> constitutes as evidence for the "Blind Watchmaker" version of
> Darwinian evolution.
By that standard of "evidence" (i.e. something which distinguishes a
theory from its rivals), even variation crossing Family barriers (or
higher) will not be evidence for "Blind Watchmaker" evolution, because
evolutionary creationism also expects it.
I believe what you meant to say is, "Only evidence which shows variation
crossing Family barriers (or higher) will DISTINGUISH macroevolution
(theistic or naturalistic) from progressive creationism." (Or words to
that effect.)
You are quite correct that microevolution below the Family level is
expected by "Blind Watchmaker" evolution, progressive creationism,
evolutionary creationism, and most versions of YEC, so it cannot be used
to distinguish among them.
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In theory, there is no difference between | Loren Haarsma
theory and practice, but in practice | lhaarsma@opal.tufts.edu
there is a great deal of difference. |