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In a message dated 96-10-08 18:35:42 EDT, email@example.com (Jonathan R.
> Both of these theories violate Occam's Razor. They require the
> assumption of things for which we have no proof and no direct modern analog.
> And yes, I am aware of intermediate metabolisms, but I have not heard any
> which tidily reconcile all of the available evidence.
What's so sacred about Occam's Razor? The minimal hypothesis is seldom if
ever the one that ultimately proves best. This is also the Great Flaw in
cladistic analysis. Your next sentence says it quite well:
> This is science, we don't look for quick fixes, we don't seek to
> tidily reconcile everything all the time, we look for evidence and
> hypotheses and theories, and sometimes data just don't fit.
The data, such as they are, fit BCF far better than they do BADD. And as far
as quick fixes go, here's one: jam all your characters into a matrix, plug
and chug it through a cladogram-generating program, and bingo! The quick-fix
cladogram. Evolution is a random walk through a multimultidimensional
morphospace; it almost never goes from point A to point B in a straight line.
That's just an approximation we make when we have no handle on the
intermediate steps, an approximation that, as I noted previously, seldom
> Sometimes, we do find some way to explain most of the conflicting
> evidence, but neither of the theories I have mentioned above do
> this. Voodoo evolution just isn't going to cut it. So, we come
> back to... dinosaurs could have needed insulation.
Whose voodoo evolution? BCF or BADD? When we can't make an argument, let's go
for _ad hominem_...
Yes, dinosaurs could have needed insulation. I don't question this, because
it is merely a possibility; they may also >not< have needed insulation. The
question is >not< whether they >needed< insulation, but why--IF THEY NEEDED
INSULATION--did they SPECIFICALLY acquire FEATHERS for insulation rather than
hair, fat, asbestos linings, fiberglass, etc. Nobody has explained why
feathers are BETTER insulators than hair, for example, or what it even means
to be a better insulator, or how one would go about measuring heat flow in
organisms extinct for 200 million years to show that feathers were better
insulators than hair. (Has anyone done this for living birds and mammals?
Seems like a basic question that could be resolved by a few roomfuls of fancy
electronic metabolism-measuring gear and a small grant from some worthy
foundation or other.) Why a rachis, why barbs and barbules, why all that
architecture, even in the contour feathers, if we're going for insulation?
All these features appear in fossil feathers 150 million years old. Where did
they come from?