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Re: flying Archie
Well, my original point apparently stands; it is at least OK to use terms like
"inferior" and "superior" relative to quantifiable traits/processes. I mention
this only so that everybody, including me, is reminded that the topic has
changed somewhat. Might even delete the foregoing before sending (or not).
The points about what constitutes evolutionary success/superiority are very
interesting and well taken. I would like to pose questions based on the
following assumptions: 1). the ancestral croc gave rise to a number of
long-lived species. 2). the ancestral (modern) bird gave rise to a larger
number of species of shorter "lifespan".
The genome of the ancestral bird, _as it exists today_, outranks the croc's by
measures such as morphological/behavioral complexity/diversity, and (I posit)
the potential for the generation of new forms to exploit both new and old
environments. Ignoring the fact that the final croc and the final bird are
likely to die at the same time (geologically speaking), is the croc more
successful that the bird? And if the timespan between the "first" and "final"
croc is larger than between "first" and "final" bird, does that mean the crocs
have won?
Or, within birds, is the ancestral osprey (old species) more successful than
it's "clutchmate", that eventually gave rise to the cardinal (young species),
among many, many others?
Couple more comments below.
Don
----- Original Message ----
From: Michael Habib <mhabib5@jhmi.edu>
To: DINOSAUR@usc.edu
Sent: Sunday, September 24, 2006 3:16:45 PM
Subject: Re: flying Archie
> 2. Maybe not morally superior. Relative to speciation, passerines are
> definitely superior to ratites or penguins or birds of prey.
>
> Don
True, though I would suggest that 'superior' is a poor term in
reference to speciation. There is a tendency to think of clade size as
a measure of "success" in lineages. It is not a bad measure of such
things (though trying to measure success in the first place is pretty
subjective),
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Absolutely. Fun, though. And sometimes necessary.
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but it is not the only one. And, in fact, I do not think
it is the best. The main reason that there are 5,000+ species of
passerines is because they isolate easily. While that is interesting
and important biologically, I (personally) don't see isolation tendency
as a measure of "success" (others may disagree, of course).
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Heh. That is guaranteed, especially in this cyber-world.
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Geographic range size is probably more important if speaking of resistance to
extinction, and population size better indicates the ability to replace
losses or decrease mortality. At the broadest scales, species
durations seem just as good a measure of "success" as clade size.
Measuring the tendency to form isolates strikes me as very important,
but not a measure of adaptive "superiority", at least by the way I tend
to view adaptive traits.
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Point taken, but see above.
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Cheers,
--Mike Habib