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Re: going offlist on Protista, bacteria



Sorry for responding so late, I didn't have time this week...

----- Original Message -----
From: "philidor11" <philidor11@snet.net>
To: "Tim Williams" <twilliams_alpha@hotmail.com>; <dinosaur@usc.edu>
Sent: Monday, March 05, 2001 4:06 AM
Subject: Re: going offlist on Protista, bacteria


> You wrote:
> Birds are not superior to dinosaurs, so why give them a "Class" of their
> own.
> I responded:
> Easy:  because they are obviously different.
> Your rejoinder:
> Deja vu all over again.
> No, they are not.  Birds are no [more ( I assume)] different from
> dromaeosaurids than bats are from monkeys.
>
> Fair enough.  There has been a decision that the similarities between bats
> and monkeys (and other mammals) are more important than the differences.
> There has also been a decision that the resemblances between dinosaurs
> (excluding dromaeosaurids) and dromaeosaurids are greater than the
> resemblances between dromaeosaurids and birds (even considered as a subset
> of dinosaurs).

There has been an _opinion_. Nobody can _decide_ such things with the same
power as an ICZN/ICBN "opinion". BTW, count the similarities between
dromaeosaurids and birds, and the similarities between dromaeosaurids and
either *Eoraptor* or *Triceratops*... the former are greater in number at
least.

> Therefore, dromaeosaurids are dinosaurs.

True anyway.

> The discussion in the last paragraph concerns the question of the proper
> placement of dromaeosaurids.
> Another issue is whether the great majority of the entire 900 (or whatever
> it is now) species of dinosaurs all have enough differences from birds on
> the one side and lizards, snakes, crocs, etc. on the other to be
considered
> a separate group.
> Intuitively, most people would say, 'Yes.'

Most people that don't know the feathered dinosaurs from Liáoníng would
intuitively say 'yes'...

> Contradicting this intuition is a different logic which looks more closely
> at the small differences at the initial stages of evolution than at the
> substantial differences which accumulated later.

Every single clade will accumulate lots of apomorphies if it just has the
time and ecological "space" to do so.

> Without changing your view of which is correct, I hope you can agree that
> these are alternate logics based on reasonable premises, and that the more
> intuitive is not just the inappropriate application of a concept like
> superiority.
> I commented because you observed:
> <Birds are not superior to dinosaurs, so why give them a "Class" of their
> own.  Go way back to the base
> of the Aves, and the differences between birds and dinosaurs resolves into
> one or two evolutionary innovations.>
> Please recognize that arguing birds are in a different group from
dinosaurs
> is not just attitudinizing; it can involve a reasonable but different way
of
> looking at the same evidence.  The difference is emphasis, not fact.

That's it! This, to emphasize its distinctness, is the reason why the clade
Aves (whatever its definition) has a name*! We don't need to take it out of
Dinosauria for that, IM and lots of other people's HO.

*Theoretically. Practice, of course, is derived from history _in this case_.